vol 3-Cont J. Env. Sci

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Continental J. Environmental Sciences 3: 1- 6, 2009 ©Wilolud Online Journals, 2009.

COLLAPSE OF BUILDINGS IN NIGERIA – ROLES OF REINFORCEMENT

Ayodele, Elijah Olusegun Department of Quantity Surveying, Rufus Giwa Polytechnic, Owo, Nigeria.

ABSTRACT This study examined the roles of reinforcement in the Collapse of buildings in Nigeria. The study was carried out by means of interview administered to steel benders and observation of steel work on construction sites of private building owners in Ondo State of Nigeria. Information from the forty-eight building projects ranging from one storey to two storeys formed the data, on which the study is based. The study showed that: in columns, 60.4% of building projects utilized (less than or equals to 11.5mm diameter) inadequate size of reinforcement rods; in beams/lintels 75% of projects utilized (less than or equals to 11.5mm) inadequate size of reinforcement rods; in upper floor slab 64.6% of projects utilized (less than or equals to 11.5mm) adequate size of reinforcement rods. The result also showed that: in columns 64.6% of the projects used (3 No reinforcement rods instead of 4) inadequate number of reinforcement rods, in beams/lintel 75% of projects utilized (3 No reinforcement rods instead of 4) inadequate number reinforcement rods. In upper floor slab 75% of projects studied utilized (100mm-150mm centres to centres) adequate centre to centre arrangement. At the openings (doors windows) 50% of projects studied utilized (less than 300mm as projection on both sides) inadequate projection at both sides of opening. It is recommended that clients especially prospective private building owners employ structural Engineers to take care of the structural aspects of their building projects. KEYWORDS: Reinforcement rods, Columns, beams/lintel, Structural Engineers, building projects, Nigeria

INTRODUCTION According to Seeley (1995) concrete is strong in compression but weak in tension, and where tension occurs it is usual to introduce steel bars to provide the tensile strength which the concrete lacks. For example with a concrete beam or lintel, compression occurs at the top and tension at the bottom, so the reinforcement is placed about 25mm up from the bottom of the beam and the ends are often hooked to provide a grip. The 25mm cover prevents rusting of the reinforcement. According to Barry (1999) the steel reinforcing bars are cast into underside of the floor with 20mm concrete cover below them to prevent the steel rusting and to give it one hour protection in case of fire. The thicker the concrete cover to reinforcement the greater the resistance of the floor to fire. Seeley (1995) recommends the steel must be free from loose mill scale, loose rust, grease, oil, paint, mud and other deleterious substances which impair the bond between the steel and concrete. Seeley (1995) also observes that the most common form of reinforcement is mild steel bar to BS4449 or BS4482. Medium and high tensile bars are also available and deformed bars which are twisted and/or ribbed provide a better bond and greater frictional resistance than round bars and obviate the need for hooked ends. According to Barry (1999) when the engineer designs a reinforced concrete floor he usually calculates the amount of steel reinforcement required for an imaginary 300mm wide spanning between walls as though the floor were made of 300mm wide concrete beams placed side by side. The engineer will first calculate the combined super imposed and dead load that the floor has to support. The super imposed load is determined just as it is for timber floors and the dead load will include the actual weight of the concrete, the floor finish and the plaster of the soffit from the loads and the span the required thickness of concrete will be determined and then the cross sectional area of steel reinforcement for every 300mm width of floor calculated.

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Ayodele, Elijah Olusegun: Continental J. Environmental Sciences 3: 1- 6, 2009 According to Barry (1999) a rough method of determining the thickness of concrete required for floors of houses and flat is to allow 15mm thickness of concrete for every 300mm of span. The main reinforcement consists usually of 12mm diameter mild steel rods spaced from 150mm – 225mm apart and these span across the floor between walls supporting the floor. The 6mm diameter mild steel rods wired across the main reinforcement are spaced 450mm – 900mm apart and are called distribution rods or bars. These rods are Table 1: Size of Reinforcement Rods (mm Ø)

S/No 1 2 3 4 5 6 7 8 9 10 11 12 Columns 10 12 11.5 11.5 12 11.5 10 10 10 12 11.5 11.5 Beams/lintel 10 10 10 12 11.5 12 10 10 12 10 10 10 Upper floor slab

12 16 12 16 14 14 14 12 11.5 11.5 10 10

S/No 13 14 15 16 17 18 19 20 21 22 23 24 Columns 12 11.5 11.5 11.5 14 11.5 10 10 12 11.5 10 11.5 Beams/lintel 12 11.5 11.5 12 11.5 10 10 10 10 10 12 12 Upper floor slab

12 16 12 16 14 14 14 12 11.5 11.5 10 10

S/No 25 26 27 28 29 30 31 32 33 34 35 36 Columns 11.5 11.5 14 10 11.5 12 11.5 10 12 11.5 10 11.5 Beams/lintel 11.5 12 11.5 10 12 10 10 12 11.5 14 10 16 Upper floor slab

11.5 10 10 11.5 11.5 12 11.5 14 16 10 11.5 11.5

S/No 37 38 39 40 41 42 43 44 45 46 47 48 Columns 10 11.5 12 11.5 14 10 11.5 10 11.5 10 10 11.5 Beams/lintel 11.5 11.5 10 10 11.5 11.5 11.5 11.5 10 10 10 10 Upper floor slab

11.5 10 11.5 16 14 11.5 11.5 12 12 11.5

11.5

11.5

Table 2: Number of Reinforcement Rods (No)

S/No 1 2 3 4 5 6 7 8 9 10 11 12 Columns 3 4 3 4 3 4 3 4 3 3 3 3 Beams/lintel 4 3 3 3 3 4 4 3 4 3 3 3




tied to the main reinforcement with wire and keep the main reinforcing rods come with spaced whilst the concrete is being placed and their main purpose is to assist in distributing point loads on the floor uniformly over the mass of the concrete. In raft foundation, according to Seeley (1995) reinforcement may take the form of steel fabric to BS4483 and this consists of a grid of small diameter bars, closely spaced and welded at the joints.

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Ayodele, Elijah Olusegun: Continental J. Environmental Sciences 3: 1- 6, 2009 Background to the Problem It was reported by Punch Newspaper (27th March 2008) that a building collapsed in Western Norweiglan Coastal town of Alesund in Norway on Wednesday 25th March, 2008 where 5 people died. A report from Nigerian Tribune Newspaper (19th February, 2008) indicated that a 3-storey structure collapsed at No 10 Oke Popo Street Lagos Island in Lagos State Nigeria, where 12 people died, it also affected 2 other adjoing buildings that are to be pulled down. Reported by Nigerian Tribune Newspaper (July 30th 2008) was the collapse of a-storey shopping plaza, situated at Utako district of Abuja on 29th July 2008. Table 3: Centre to Centre Placement of Reinforcement Rods (mm)

S/No 1 2 3 4 5 6 7 8 9 10 11 12

Upper floor slab 300 100 100 300 150 300 100 100 100 100 100 100

S/No 13 14 15 16 17 18 19 20 21 22 23 24

Upper floor slab 100 100 100 350 75 100 75 100 100 100 100 150

S/No 25 26 27 28 29 30 31 32 33 34 35 36

Upper floor slab 100 300 100 100 300 100 100 300 125 400 125 125

S/No 37 38 39 40 41 42 43 44 45 46 47 48

Upper floor slab 100 300 125 300 125 400 100 300 125 100 100 100

Table 4: Length of Projection of Reinforcement Rods at the Openings (mm)

S/No 1 2 3 4 5 6 7 8 9 10 11 12

Openings 150 400 150 150 450 150 300 300 150 150 450 150

S/No 13 14 15 16 17 18 19 20 21 22 23 24

Openings 400 150 400 150 150 150 100 400 150 450 300 300

S/No 25 26 27 28 29 30 31 32 33 34 35 36

Openings 100 150 300 150 300 150 300 150 300 300 300 300

S/No 37 38 39 40 41 42 43 44 45 46 47 48

Openings 400 150 450 150 450 150 150 450 300 300 150 150

Collapsed also, was a four-storey building at Idi Araba, Lagos State as reported by Nigeria Tribune Newspaper (March 27th 2009. It was reported also in The Nations Newspaper (May 7th 2009) that a yet to be completed 3-storey church building collapsed at Ochi Street, Achara Layout in Enugu, in Nigeria.

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Ayodele, Elijah Olusegun: Continental J. Environmental Sciences 3: 1- 6, 2009 Fadamiro (2002) reported some incidences of building collapse which were as a result of failure of structural members: uncompleted 2-storey building at the premises of St. Thomas Anglican Church, Isikan Akure on September 30th 1988 where 2 persons were reported dead and many others injured; school building at Diobu Port Harcourt in April 1990 where over 50 people were reported dead; residential building at Idusagbe lane, Idumota Lagos on September 14th 1987, where 4 people died and 15 injured; 2-storey building under construction at Agege, Lagos on May 9th 1987 where 17 people died and 12 injured; Mosque building at Osogbo in May 1986, no death was reported; uncompleted 4-storey building at Iponri Lagos on May 20th 1985 where 13 people died; 3 Findings Table 5: Summary of Findings

QUALITY REINFORCEMENT Adequate (%) Inadequate (%) Size (mm Ø) in columns

in Beams/lintel in Upper floor slab

39.6 (11) 25 (12 64.6 (21)

60.4 (29) 75 (36) 35.4 (17)

Number (No)

in Columns in Beams/lintel

35.4 (17) 25 (12)

64.6 (31) 75 (36)

Centres to centres in Upper floor slab 75 (36 25 (12) Projection at Openings 50 (24) 50 (24)

residential buildings at Barnawa Housing Estate Kaduna in July 1980 where 6 people died; and a multi storey building at Mokola Ibadan in October 1974 where 27 people were reported dead. This study is therefore set out to determine the roles of reinforcement in structural failures in building projects and proffer solutions to them. This will curb the incidences of losses of lives and properties. The objectives of the study are to:

- Determine the sizes in mm diameter of reinforcement rods in columns, beam/lintel and upper floor slab on construction sites.

- Determine the number of reinforcement rods placed in columns and beam/lintel on construction sites.

- Determine the centre to centre placement of reinforcement rods in upper floor slab on construction sites.

- Determine the mm projection reinforcement rods at both sides of openings. METHODOLOGY The study was carried out by means of interview of steel benders and observation of steel work on construction sites. Because of the constraints of time and fund the study is limited to Ondo State of Nigeria. Information from 48 building projects by private building owners formed the data used in the study. The interview and observation the means of eliciting information will help to determine the size of reinforcement rods that where utilized in columns, beams/lintel and upper floor slab; number of reinforcement rods placed in columns and beams; centre to centre placement of reinforcement rods in upper floor slab and length of projection of reinforcement rods at both sides of the openings. The data will be analyzed by percentages. From Table 1 In Columns: less than or equals to 11.5mm Ø reinforcement rods were utilized on 60.4% (29) of building projects studied (inadequate size) while 12mm Ø or greater than were utilized on 39.6% (11) of projects (adequate size). In beams/lintel: less than or equals to 11.5mm Ø reinforcement rods were utilized on 75% (36) of building projects studied (inadequate size) while 25% (12) of projects utilized 12mm or greater than reinforcement rods (adequate size). In the upper floor slab: less than or equals to 11.5mm Ø

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Ayodele, Elijah Olusegun: Continental J. Environmental Sciences 3: 1- 6, 2009 reinforcement rods were utilized on 35.4% (17) of projects studied (inadequate size) while 64.6% (21) of the projects used greater than or equals to 12mm Ø reinforcement rods (adequate size). From Table 2: In Columns: 64.6% (31) of the projects utilized 3 No reinforcement rods instead of 4 (inadequate number) while 35.4% (17) utilized 4 No reinforcement rods (adequate number) In beam/lintel: 75% (36) of the projects utilized 3 No reinforcement rods instead of 4 (inadequate number) while 25% (12) projects utilized the normal 4 No reinforcement rods (adequate number)

From Table 3 In the upper floor slab: 75% (36) of the projects utilized 100mm-150mm centre to centre (adequate) while 25% (12) utilized above 150mm centre to centre (inadequate). From Table 4 At Openings (doors windows): 50% (24) of projects utilized less than 300mm as projection at both ends (inadequate projection) while 50% (24) utilized 300mm and above as projection at both ends of openings (adequate projection). DISCUSSION The findings from the study which showed inadequacies in the size of reinforcement rods utilized in Columns and beams/lintel; inadequacies in the number of rods utilized in columns and beams/lintel; and also inadequacies in the projection of rods at openings. They are all in agreement with Sebotie (1996) who discovered in Lagos State that inadequate reinforcement in numbers such as slabs, columns, beams etc. are one of the reasons of building collapse. The findings are also in conformity with the allegation of Makinde (1996) that sub-standard building materials such as reinforcement rods have flooded the market. They are also in consonance with the qualitative assertion of Odunlami (2002) that various reinforcing rods come to site with varying diameters and strength. RECOMMENDATION It is hereby recommended that prospective private developers employ the services of Structural Engineers who will supervise the structural works in the building project and ensure that the steel benders utilize appropriate size, number and length of reinforcement rods on building projects in Nigeria. REFERENCES Barry P (1999) The Construction of Building. Sixth edition. New-Delhi. Affihated East-West Press Put Ltd. Fadamiro J.A. (2002) An assessment of Building regulations and standards and the implications for building collapse in Nigeria, in ed. Ogunsemi D.R. Building Collapse: Causes, Prevention and Remedies. Workshop Nigerian Institute of Building, Akure Makinde A. (1996) Collapsed building: whose responsibility, Engineers, Townplaners, Architects or Government proceedings of Seminar on Collapsed buildings. Nigerian Society of Engineers Nigerian Tribune (February 19th 2008) Collapsed Building. Page 19 Nigerian Tribune (July 30th 2008) 100 trapped in Building Collapsed. Page 9 Nigerian Tribune (March 27th 2008) four Storey Building Collapsed. Page 9 Odunlami A.A (2002) Building materials, specification and enforcement on site, in ed. Ogunsemi D.R. Building Collapse: Causes, Prevention and Remedies. Workshop Nigerian Institute of Building, Akure

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Ayodele, Elijah Olusegun: Continental J. Environmental Sciences 3: 1- 6, 2009 Punch Newspaper (March 27th 2008) Building Collapsed in Norway. Page 46 Seeley I.H. (1995) Building Technology Fifth edition. New York Palagrave Sobotie I. (1996) Economic and Social Implications of Collapsed Buildings – proceedings of Seminar on Collapsed Building Nigerian Society of Engineers, Lagos The Nation Newspaper (May 7th 2009) Three Storey Building Collapses in Enugu. Vol. 3 No.1021 Page 9

Received for Publication: 17/05/2009

Accepted for Publication: 13/06/2009

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Continental J. Environmental Sciences 3: 7 - 12, 2009 ©Wilolud Online Journals, 2009.

CHEMICAL QUALITY OF GROUNDWATER FROM HAND-DUG WELLS IN JOS METROPOLIS AND ENVIRONS, NORTHCENTRAL NIGERIA.

N. C. Beka,1, T. Aga,2* and A. C. Eziashi,3

1National Environmental Standards and Regional Enforcement Agency, Jos, Nigeria.2Department of Geology and Mining, University of Jos, Nigeria.3Department of Geography and Planning, University of

Jos, Nigeria ABSTRACT Water samples were obtained from 30 hand-dug wells, distributed in the different rock types within Jos and its environs, Nigeria were analyzed for chemical parameters. The Nitrate elevated values where noticed to be predominant within the most built up areas resulting from sewage, pit latrines and refuse dumps. The results in this study could be used to structure a public health programme that would take into cognizance this threat to human health in health care programme planning. Also, selection and siting of wells for the purposes of monitoring groundwater quality based on the places where some of these parameters measured above the WHO standard are therefore suggested. KEYWORDS: Chemical, groundwater, wells, nitrate, Jos

INTRODUCTION In Nigeria ground water occurs practically every where in the country, it supplies potable water to a very large percent of the population, in situ, through boreholes, hand dug-wells and springs. Ground water provides the immediate panacea for the provision of potable water to the majority of Nigerians despite the varied climatic environments (Offodile 2000). The study area is located within the Jos metropolis and is bounded by latitudes 10º 00′ and 9º 50′ and longitudes 9º 00′ and 8º 55′ (Figures 1& 2). This study area covers parts of four local government areas namely Jos north, Jos south and Jos east and Bassa local government areas of Plateau State, Nigeria. The study area covers an area of about 340 km2, extending for about 18 km from north to south, and 18.5 km from east to west. The area is accessible through a major road passing from Toro and Zaria road in the north; it passes through Jos metropolis and heads towards Buruku at the southern end. As Jos continues to grow in population and size, activities would also increase. This is bound to certainly impact on the quality of the groundwater. This engenders issues like groundwater protection, groundwater quality monitoring and emphasizes the need for planning development along side with groundwater resources. Unfortunately, there is no visage of this kind of planning in our developmental efforts presently in Jos metropolis. It is hoped that the results presented in this work may improve on our present and potential uses of our groundwater. Specifically, it is hoped that the results and findings would have practical implications in the groundwater resources planning.

Figure 1: Plateau State Showing the Study Area

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N. C. Beka et al: Continental J. Environmental Sciences 3: 7 - 12, 2009

Figure 2: Geological map of the study area showing sample locations

METHODOLOGY Water samples were obtained from 30 hand-dug wells, distributed within the different rock types within the study area and analyzed for chemical parameters. GPS positions were taken for each well point using a Garmin model 72 GPS. At each well, water samples were collected using a 75cl plastic bottle. The bottles were rinsed with ionized water before samples were collected; a cooler with ice packs was used to store the samples in the field before taken to the laboratory. Table 1: Values of Chemical Parameters in the Study Areas Samples pH

T.D.S mg/l

Total Hardness mg/l

Ca2+

mg/l Mg2+

mg/l Cu2+

mg/l Fe(T) mg/l

Mn2+

mg/l NO-3

mg/l SO4

2-

mg/l Cl-

mg/l

S1 7.15 105.50 97.90 36.16 14.34 0.09 0.09 0.00 7.92 0.00 4.00 S2 7.30 95.00 70.40 28.16 10.31 0.17 0.10 0.10 17.60 4.00 7.00 S3 7.60 64.50 62.20 24.88 9.113 0.13 0.01 0.40 0.44 7.00 6.50 S4 7.25 105.00 74.70 29.88 10.94 0.01 0.01 0.00 0.44 1.00 7.00 S5 5.84 2.50 3.90 1.56 0.571 0.17 0.05 0.01 1.32 3.00 1.50 S6 7.16 61.50 34.60 13.84 5.069 0.21 0.08 0.30 11.88 5.00 6.00 S7 7.48 29.50 6.45 2.58 0.945 0.26 0.27 0.05 11.00 8.00 16.00 S8 5.33 111.00 32.20 12.88 4.717 0.15 0.05 0.02 68.20 8.00 16.00 S9 6.39 364.5 198.70 79.48 29.11 0.23 0.01 0.30 181.30 0.00 103.2 S10 6.77 61.00 22.60 9.04 3.311 0.19 0.02 0.10 7.92 0.00 12.20 S11 6.77 61.00 22.60 9.04 3.311 0.19 0.02 0.01 7.92 0.00 12.20 S12 6.08 390.00 96.50 38.60 14.14 0.25 0.00 0.30 97.24 9.00 112.60 S13 6.17 5.00 7.15 2.86 1.047 0.16 0.01 0.00 8.80 0.00 1.60 S14 5.91 19.00 6.80 2.72 0.996 0.16 0.04 0.01 19.36 0.00 3.03 S15 5.92 50.50 22.00 8.80 3.223 0.17 0.06 0.00 37.84 1.00 19.20 S16 6.01 11.50 9.60 3.84 1.406 0.15 1.17 0.30 19.36 2.00 1.70 S17 5.73 6.00 7.83 3.14 1.15 0.14 0.01 0.00 3.96 0.00 0.80 S18 6.26 2.50 6.00 2.40 0.879 0.17 0.02 0.01 2.20 1.00 0.75 S19 6.39 13.60 11.80 4.72 1.729 0.24 0.04 0.00 14.52 0.00 2.55 S20 6.65 14.00 14.60 5.84 2.139 0.35 0.16 0.60 9.68 8.00 0.90 S21 6.55 16.00 10.30 4.12 1.509 0.23 0.10 0.30 6.16 4.00 0.90 S22 6.20 62.00 37.10 14.84 5.435 0.17 0.00 0.20 21.56 17.00 6.70 S23 5.33 274.5 81.30 32.52 11.91 0.25 0.00 0.20 109.6 11.00 7.99 S24 6.60 168.5 95.20 38.08 13.94 0.17 0.01 0.20 32.12 25.00 23.30 S25 6.98 73.50 56.50 22.60 8.277 0.01 0.01 0.20 6.60 2.00 1.45 S26 7.19 88.50 64.00 25.60 9.37 0.00 0.02 0.00 21.12 1.00 8.40 S27 6.96 73.50 67.20 26.88 9.85 0.00 0.04 0.00 6.60 0.00 1.20 S28 7.14 74.00 54.10 21.64 7.93 0.20 0.03 0.10 91.96 0.00 4.45 S29 7.05 73.00 77.80 31.12 11.39 0.50 0.25 0.60 24.64 17.00 1.30 S30 5.87 179.50 74.20 29.68 10.87 0.26 0.00 0.10 105.60 2.00 45.30

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N. C. Beka et al: Continental J. Environmental Sciences 3: 7 - 12, 2009 Analytical procedures for chemical parameters are generally in accordance with the specifications and standard methods of USEPA (United States Environmental Protection Agency) standard. pH was estimated using the HANNA pH meter, model HI 98129, TDS was measured using the TDS/conductivity meter (HACH) model 44600.00. Total hardness, Ca2+,Mg2+, Cl-, using the digital titrator (HACH) model 16-99-01, NO3

-,Fe2+,Cu2+,SO42-,Mn2+ were measured using the

spectrophotometer. RESULTS AND DISCUSSION Anomalous Concentrations. The constituents of most interest here are the nitrate and pH. These constituents registered values well beyond the acceptable WHO (2004) guideline levels. Nitrate levels Nitrate leaches into the water-table throughout the year, although the rate of leaching depends on factors such as geology, soil type, rainfall pattern, and crop utilization rate of nitrogen, the microbial conversion rate of nitrate and fertilizer application pattern. From Madison and Brunett’s interpretation of nitrate levels about 90% of the values of nitrate in this work seem to suggest human influence as they seem to exceed the threshold of 3.0 mg/l. Moreover in certain wells nitrate values exceeded the WHO health standards of 45mg/l, about twenty percent (20%) of the samples gave these levels (Fig. 3). The nitrate elevated values where noticed to be predominant on the Jos Biotite granite rock type which happens to be the largest rock type with the most built up areas. This leads to the deduction that the high nitrate values could result from sewage, pit latrines and refuse dumps High nitrate concentrations in drinking water are associated with the development of methaemoglobinaemia in infants. This is a situation where nitrate is reduced to nitrite as nitrate itself does not cause this disorder. The nitrite combines with haemoglobin in red blood cells to form methaemoglobin, which is unable to carry oxygen and so reduces oxygen uptake in the lungs. Normal methaemoglobin level in blood is between 0.5 and 2.0%. As methaemoglobin does not carry oxygen, excess levels lead to tissue anoxia (i.e. oxygen deprivation). It is only when the methaemoglobin concentration in the blood exceeds 10% that the skin takes on a blue tinge in infants, the disorder known as methaemoglobinaemia or blue-baby syndrome. The progressive symptoms resulting from oxygen deprivation are stupor, coma and eventual death. Death ensues when 45-65% of the haemoglobin has been converted. However the disorder can be readily treated using an intravenous injection of methylene blue, which results in rapid recovery (WHO, 2004). Although methaemoglobinaemia is well recognized and is unlikely to be a problem in areas with adequate medical facilities, it may be more important in the developing areas where such facilities are lacking. All the health considerations relating to nitrate are related to its conversion to nitrite. In the gastrointestinal tract, nitrite reacts with certain compounds in food under acidic conditions to produce N-nitroso compounds with amines and amides. Many of these compounds are known carcinogens. Although there is no epidemiological evidence to link nitrate directly with cancer in humans, increased concentrations of nitrite and N-nitroso compounds have been detected in people who secrete inadequate amounts of gastric acid, a group known to be particularly at risk from gastric cancer. (Gray, 1994, Forman et al., 1985)

0

20

40

60

80

100

120

140

160

180

200

Con

c. M

g/l

S1 S3 S5 S7 S9 S11 S13 S15 S17 S19 S21 S23 S25 S27 S29

Nitrates Indicating Contamination by Human Influence =3.0mg/l WHO Standard for Nitrate = 45mg/l Figure 3: Concentration of Nitrates

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N. C. Beka et al: Continental J. Environmental Sciences 3: 7 - 12, 2009 pH The pH of an aqueous system is a measure of the acid-base equilibrium achieved by various dissolved compounds and, in most natural waters, is controlled by the carbon dioxide-bicarbonate- carbonate equilibrium system. The pH of most raw water sources lies within the range of 6.5-8.5. pH can be rightly referred to as the backbone of water quality parameters since almost every other water quality parameter is related to pH. Hence if pH characteristic in the study area was not anomalous,

Allowable minimum for pH = 6.5 Figure 4: Concentration of pH in the study area. From figure 4, low pH values (below the allowable minimum standard) in samples S,13,14,15, 16 17 18 19, 23, 8 may be responsible for the spatial behaviour of chloride. Average Concentrations Manganese The quality for Concentrations of manganese in the samples where on the average, being widely found in rocks and like iron turns up in groundwater due to reducing conditions in soils and rocks bringing it into soluble form. Once it is exposed to air by aeration, manganese is oxidized into its insoluble form. Manganese like iron causes problems of taste, discoloration and staining. Gray, (1994) notes that staining is far more severe with manganese than iron and it imparts an unacceptable taste to the water. For this reason much stricter limits have been imposed on the concentration at which laundry and sanitary ware become discoloured to grey/black; MAC (PCV) limits it at 0.05 mg/l., while the EC guide level is just 0.02 mg/l,. The World Health Organization has a health-related guide of 0.5 mg/l, but since staining occurs at much lower concentrations, a guide value of 0.1 mg/l has been set to prevent consumer complaints. The concentration of manganese in the study area is averagely acceptable for health purposes as toxicity is not a factor with manganese, consumers would reject at concentrations long before any danger threshold is reached. However this is not true for laundry purposes as illustrated in the figure 5.

0

1

2

3

4

5

6

7

8

pH


Samples

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N. C. Beka et al: Continental J. Environmental Sciences 3: 7 - 12, 2009

0

0.1

0.2

0.3

0.4

0.5

0.6

Con

c. (

Mg/

l)


Samples ( Manganese) WHO Standard of Manganese (health related) = 0.5 Guide level for Staining (laundry) = 0.1 Figure 5: Various Concentrations of Manganese Acceptable Concentrations Hardness Hardness or softness of water varies from place to place and reflects the nature of the geology of the area with which the water has been in contact. The principal metal cations causing hardness are Ca2+, Mg2+, Sr2+, Fe2+, Mn2+,and the major anions associated with them are HCO3

-, SO42-, Cl-, NO3

-, SiO32-.

The figure 5 shows the classification in terms of hardness from the work of Gray 1994 (see Table 2). Table 2: Classification use for water Hardness

Degree of Hardness

Conc. (Mg/l)

Soft 0-50 Moderately Soft 50-100 Slightly Hard 100-150 Moderately Hard 150-250 Hard 250-350 Excessively Hard 350+

Source: Gray, 1994

0

2

4

6

8

10

12

14

16

No

of S

ampl

es

Soft Moderately Soft Slightly Hard ModeratelyHard

Hard ExcessivelyHard

Degree of Hardness

Figure 5: Classification of the water quality in terms of hardness The water in the study area is generally soft which is associated with impermeable rocks such as granite (Gray, 1994). Also parameters like Iron, Copper, Sulphate, Chloride, Magnesium, Calcium and TDS measure within the acceptable concentration range of the WHO acceptable limits. CONCLUSION Nitrate have been identified with values well beyond the WHO standard and is therefore a risk to public health particularly infants. These results in this study could be used to structure a public health programme that would take into cognizance this threat to human health in health care programme planning. Another area in which the

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N. C. Beka et al: Continental J. Environmental Sciences 3: 7 - 12, 2009 results of this study will find usefulness is the selection and siting of wells for the purposes of monitoring groundwater quality base on the places where some of these parameters measured above the WHO standard. It is our contention that out of these monitoring programmes; zoning of aquifers and protection of certain areas that have shown from continuous records that are vulnerable to pollution from certain contaminants. Therefore areas like the Jos Township which is the most populated area in the study area with high nitrate values ought to haves its sewage and refuse disposal system reassessed. ACKNOWLEDGEMENT The authors wish to dedicate this paper in memory of the late Dr. A. I. Idornigie of the Department of Geology and Mining, University of Jos, Nigeria whose constructive criticism before his demise improved the quality of this research. REFERENCES Forman, D., Al-Dabbagh, S. and Doll, R. (1985). Nitrates, Nitrites and Gastric Cancer in Great Britain.Pp 313, 620. Gray N. F., (1994). Drinking Water Quality Problems and Solutions.John Wiley and Sons, England. Pp 43-63. Offodile, M. E. (2000). The Development and Management of Ground Water for Water Supply in Nigeria, Paper Presented at the 2nd Fellow’s Workshop of NMGS on Monday 6th March. World Health Organization (2004). Guidelines for Drinking-water Quality, Vol. 1: Third Edition Recommendations. World Health Organization, Geneva. Received for Publication: 07/11/2008 Accepted for Publication: 24/03/2009 Corresponding Author: email address: [email protected]

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CHROMIUM IN SOILS: A REVIEW OF ITS DISTRIBUTION AND IMPACTS

Yahaya Ahmed Iyaka Department of Chemistry, Federal University of Technology, P.M.B. 65, Minna.

ABSTRACT Generally, the parent material determines the levels of chromium in soils, and typical soil chromium concentrations vary widely with elevated contents been associated with anthropogenic contamination. The less toxic, less mobile and naturally abundant trivalent chromium is mainly found bound to organic matter in soils, but chromium compounds in the hexavalent state are toxic, rare and usually associated with industrial pollution. Soil-plant barrier system limits the chromium impact on the food chain, due to the immobility of the soil-chromium, however, at the elevated levels chromium in soils may influence chromium uptake by plants, as well as ingestion by children through touching and eating contaminated soil. KEY WORDS: Chromium, trace metal, soil, environmental impact.

INTRODUCTION Chromium was discovered by the French Chemist Louis Nicolas Vanquelin in 1797, who prepared the metal from the Siberian red lead ore (crocoite; PbCrO4)in 1798(Berloux,1999). It is the tenth most abundant metal in the earth’s crust (Bartlett and James, 1996), and belongs to the first five in commercial importance. The natural or major sources of chromium in the earth’s crust are in the trivalent state, but naturally occurring chromium compounds in the hexavalent state are rare and mostly man-made products (WHO, 1988).Chromium (III) is less toxic, less mobile and is mainly found bound to organic matter in soils (Becquer et al., 2003), while Chromium (VI) is the most toxic form of chromium, that usually occurs in association with oxygen as chromate or dichromate. Table 1 shows the occupational sources associated with chromium exposure. Physical and Chemical properties Chromium is brittle, hard, lustrous and silver-gray metal. It is more difficult to shape than most other metals. It has a melting point 1907oC, boiling point 2672oC and density of 7.19gcm-3 at 20 oC. Chromium is a transition metal of atomic number 24 with relative atomic mass 51.996 belonging to Group VI of the Periodic Table. Chromium may theoretically occur in any oxidation state from -2 to +6; however, it is most often common in 0, +2, +3, and +6. Elemental chromium (0) is inert in biological materials and not naturally present in the earth’s crust. Divalent chromium (Cr+2) is not also available in the biological system, but gets readily oxidized when in contact with air, hence, a strong reductant. Trivalent chromium (Cr+3) is the most stable oxidation state in which chromium is found in biological materials. Chromium (III) is soluble in acidic solutions, forming hexahedral complexes with ligands such as oxalate and sulphate ions. The second most stable oxidation state is the hexavalent chromium ((Cr+6), with strong oxidizing potential, particularly in acidic media (Garrett, 1982; EVM, 2002; Pechova and Pavlata, 2007). Applications Chromium is most useful in combination with other metals, either as an ingredient in alloys or as an electroplated coating. It is highly valued due to its ability to impart corrosion resistance, heat resistance and increased strength to other metals (Garrett, 1982). Major applications of chromium that impact significantly in the environment are in stainless steel, industrial liquors and urban sewage; electroplating baths as waste chromates, tanning processes as trade effluents and heat exchange systems as corrosion inhibitors(Cabrera- Vique et al., 1997), as well as leather manufacturing wastes. Chromium is also used widely as a catalyst and in giving glass an emerald green colour. Chromium contents, inputs and distribution in soils The common chromium mineral is chromite, and the chromium content of acid igneous and sedimentary rocks ranges from 5-120ppm (Kabata-Pendias and Pendias, 1992). Generally, the parent material determines the levels of chromium in soil, and typical soil chromium contents range from 20-65ppm (Kabata-Pendias and Pendias, 1984). However, Langard (1980), has identified the elevated levels of chromium with anthropogenic contamination mainly through industrial processes. Alloway and Ayres(1997) have reported an average concentration of 100ppm for chromium in earth’s crust, and natural chromium content in surface soils has been

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Yahaya Ahmed Iyaka: Continental J. Environmental Sciences 3: 13 - 18, 2009 estimated to range from 5-1100ppm, with a mean value of 60ppm(Ward,1995). Furthermore, Kabata-Pendias and Pendias (1992) have reported the mean chromium content for world sandy soils to be 47ppm. Table 2 shows various chromium concentrations in soils from different sources. Table 1 Occupational sources associated with chromium exposure (with chemical forms of interest given in bracket)

Sources

Stainless steel welding [chromium (VI)] Chromate production [chromium (VI)] Chrome plating [chromium (VI)] Ferrochrome industry [chromium (III) and chromium (VI)] Chrome pigments [chromium (III) and chromium (VI)] Leather tanning [mostly chromium (III)] Battery makers [chromium (VI)] Candle makers [chromium (III) and chromium (VI)] Cement makers [chromium (III) and chromium (VI)] Dye makers [chromium (III)] Painters [chromium (III) and chromium (VI)] Printers [chromium (III) and chromium (VI)] Rubber makers [chromium (III) and chromium (VI)] Workers involved in the handling of copying machines [chromium (VI)]

Source: Public Health Statement for Chromium (2008).

Table 2 Chromium contents in soils from different sources Source Content ppm

Natural soils 5-1000 5-1500 5-3000 30-300 World soils 100-300 (mean 200) 10-150 (mean 40) Canadian soils 100-5000 (mean 43) Japanese soils 87 (mean) U. S. soils 25-85 (mean 37) 57 (mean) Swedish soils 74 (mean)

Adapted from Shanker et al., 2005; Discarded manufactured products and coal ashes constitute the major sources of anthropogenic chromium inputs into soils, and the total worldwide inputs of chromium into soils is estimated to be 898 x 103 tonnes per year(Nriagu,1990). Values representing the maximum allowable limits (MAL) of chromium contents in soils for many countries have also been documented by Kabata-Pendias (1995); Great Britain (50ppm), Canada (75ppm), Austria and Poland (100ppm), as well as 200ppm for Germany. Chromium of environmental concern is the waste chromium, which has the characteristic spinel structure, FeO.Cr2O3; whose trivalent chromium can be converted to hexavalent chromium after an alkaline roasting process (Bartlett and James, 1996), leaving them as residuals that become waste forms of chromium in soil-water system.

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Yahaya Ahmed Iyaka: Continental J. Environmental Sciences 3: 13 - 18, 2009 Generally, very little chromium is leached from soil due its presence as an insoluble Cr2O3

. xH2O (Fishbein, 1981). However, mobility and toxicity of chromium depend on its oxidation state; trivalent chromium is relatively immobile, often bound to both organic and inorganic ligands in soils, more stable and extremely less toxic than hexavalent chromium (Ross et al., 1981), which is a peculiar industrial pollutant. Furthermore, the biological reduction of toxic and more mobile hexavalent chromium to trivalent chromium by organic matter occurs in soils (Barlett and Kimble, 1976), and this is responsible for the low chromium availability to plants. The major processes by which the trivalent chromium is transported from soil include aerial and surface water transport through aerosol formation and runoff respectively (U.S.EPA, 1984) Transmission through the food chain Soil-plant barrier helps in protecting the food chain, because of the immobility of the soil-chromium. However, in animals, chromium introduction into feeds could lead to its bioaccumulation in meat by-products such as skin, bone and meat meals, and consequently into soils and crops fertilized with animal manure (Gallo and Serpe, 1997), and finally into humans through the food chain. Chromium in Plants Generally, chromium is not considered as an essential element for plant growth and development, however, Bonet et al.,(1991) have reported that low concentrations of chromium stimulates plant growth. Chromium is toxic for agronomic plants at a content range of about 5.0 to 100ppm of available chromium in soil (Hossner et al., 1998), but Davies et al., (2002) reported that chromium is toxic to higher plants at 100µM kg-1. Moreover, hexavalent chromium compounds due to their high solubility (James, 1996), easy permeability through biological membranes and subsequent interaction with protein components and nucleic acids inside the cell (Basu et al., 1997) are comparatively more toxic than trivalent chromium. Chromium distribution in crops has a stable character that is independent of the soil properties and content of the element; usually the major concentration of the contaminant element is always found in roots with minimum levels present in the vegetative and reproductive organs (Golovatyj et al., 1999). The high chromium accumulation in the roots could be due to immobilization of chromium in the vacuoles of the root cells, thereby rendering it less toxic, probably because of the natural toxicity response of the plant (Shanker et al., 2004a).However, effects of chromium toxicity on plant growth and development include reduction in seed germination (Rout et al., 2000; Peralta et al., 2001), decrease in root growth (Samantaray et al., 1999; Chen et al., 2001; Prasad et al., 2001),and reduction in plant height and shoot growth due to adverse effects of chromium has also been reported by various researchers(Sharma and Sharma,1993; Joseph et al.,1995; Barton et al.,2000). Furthermore, various authors have reported different adverse effects of chromium on leaves depending on the concentration of the applied chromium and plant type (Karunyal et al., 1994; Jain et al., 2000; Singh, 2001), hence, Tripathi et al.,(1999) observed that leaf growth traits could serve in the choice of suitable bioindicators and resistant species. Chromium in animals and humans The primary sources of chromium exposure are by breathing air, drinking water, eating food containing chromium or through skin contact with chromium or chromium compounds. For the general population, the most likely route of exposure to trivalent chromium is by eating foods that contain chromium, and trivalent chromium is identified as a natural essential nutrient for humans in many fresh vegetables, fruits, grain, meat and yeast (Public Health Statement for Chromium, 2008). 50-200µg/d has been identified as an estimated safe and adequate daily dietary intake (ESADDI) for chromium (NRC, 1989), which corresponds to 0.71-2.9µg/kg/day for a 70-kg adult. Reference Daily Intake for chromium of 120 µg/d has also been selected by FDA (DHHS, 1995). However, hexavalent chromium is more easily absorbed by the body than trivalent chromium, but once inside the body system, hexavalent chromium is changed to trivalent chromium (DeFlora et al., 1987; Debetto and Luciani, 1988), that is essential for animals and humans (EPA, 1998), because it facilitates interaction of insulin with its receptor site, influencing metabolism of glucose, lipid and protein in its biologically active form. Chromium deficiency has been associated with atherosclerorsis, cataract, growth failure, hyperglycaemia, and neuropathy (Saner et al., 1980) as well as with diabetes in human body due its vital role in metabolism of carbohydrates (Jamal et al.,1986). Furthermore, effects such as acute tubular necrosis, kidney failure, and metabolic acidosis and in some cases death have been identified with accidental poisoning through hexavalent chromium compounds such as chromic acid and potassium tetrachromate (Saryan and Reedy, 1988).

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Yahaya Ahmed Iyaka: Continental J. Environmental Sciences 3: 13 - 18, 2009 Municipal waste water which may contain <0.7mgl-1 chromium in hexavalent chromium form, mainly represents the major route of chromium toxic intake by marine species, algae and microorganisms. Moreover, Alloway and Ayres (1997) observed that in the presence of organic matter reduction of chromate (VI) to chromite (III) which appears to be more toxic to fish, especially salmon, often occurs, and the toxic contents for several species of fish ranged from 0.2 – 5.0 mgl-1. The bioconcentration factor (BCF) has been estimated to be <1.0 for hexavalent chromium in fish, but values of as high as 125 and 192 have been reported for oyster and blue mussel respectively (U.S.EPA, 1980). CONCLUSION The natural and abundant trivalent chromium is less toxic, less mobile and is mainly found bound to organic matter in soils, but chromium compounds in the hexavalent state are toxic, rare and usually associated with industrial pollution. Soil-plant barrier system limits the chromium impact on the food chain, because of the immobility of the soil-chromium, however, elevated levels of chromium in soils through anthropogenic contamination may influence chromium uptake by plants, as well as ingestion by children through touching and eating contaminated soil. Furthermore, chromium deficiency has also been identified to have adverse effects on the growth and development of animals and humans, particularly in children. Hence, to predict a comprehensive impact of chromium in soil and its consequence on the environment through the food chain, the model requires knowledge of soil chromium, reaction and mobility of chromium in soil as well as levels of atmospheric chromium especially in industrial areas, since soil is an ultimate sink for heavy metal deposition. REFERENCES Alloway,B. J. and D.C. Ayres. 1997. Chemical Principles of Environmental Pollution. Blackie Academic and Professional, London. Bartlett, R. J. and J. M. Kimble. 1976. Behviour of chromium in soils II. Hexavalent forms. J. Environ. Qual. 5: 383-386. Barton, L. L., G.V. Johnson, A.G. O’Nan, and B.M. Wagener. 2000.Inhibition of ferric chelate reductase in alfalfa roots by cobalt, nickel, chromium and copper. J. Plant Nutr. 23: 1833-1845. Basu, M., S. Bhattacharya and A. K. Paul. 1997. Isolation and characterization of chromium- resistant bacteria from tannery effluents. Bulletin of Environmental Contamination and Toxicology. 58(4): 535-542 Batlett, R. J. and B.R. James. 1996. Chromium. Pp 683-701. In: J.M. Bigham (ed). Methods of Soil Analysis. Part 3. Chemical Methods. Soil Sc. Society of America Inc ., USA Becquer, T., C.Quatin, M. Sicot and J. P. Boudot. 2003. Chromium availability in ultramafic Soils from New Caledonia. Sci. Total Environ. 301: 251-261. Berceloux, D. G. 1999. Chromium. Clinical Toxicology, 37: 173-194. Bonet, A., C. Poschenrieder, J. Barcelo. 1991. Chromium III- iron interaction in Fe- deficient and Fe- sufficient bean plants. I. Growth and nutrient content. J. plant Nutr. 14: 403- 414. Cabrera- Vique, C., P. Teissedre, M. Cabanis and J. Cabanis. 1997. Determination and levels of Chromium French wine and Grapes by Graphite Furnace Atomic Absorption Spectrometry. J. Agric. Food Chem. 45: 1808-1811 Chen, N. C., S. Kanazawa, T. Horiguchi and N.C. Chen. 2001. Effects of chromium on some enzyme activities in the wheat rhizosphere. Soil Microorg. 55: 3-10 Davies, F. T., J. D. Puryear, R.J. Newton, J.N. Egila and J. A. S. Grossi. 2002. Mycorrhizal fungi increase chromium uptake by sun flower plants: Influence on tissue mineral concentration, growth, and gas exchange. J. Plant Nutr. 25: 2389-2407. Debetto, P. and S. Luciani. 1988. Toxic effect of chromium on cellular metabolism. Sci. Total Environ. 71:365-377.

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Yahaya Ahmed Iyaka: Continental J. Environmental Sciences 3: 13 - 18, 2009 DeFlora, S., G. S. Badolati, D. Serra, et al. 1987. Circadian reduction of chromium in the gastric environment. Mutat Res. 192: 169-174 Department of Health and Human Services (DHHS). 1995. Food and Drug Administration. Food Labelling: Reference Daily Intakes, Final Rule.21 CFR Part 101. Federal Register. 60(249):67164-67175 U.S. Environmental Protection Agency (EPA). 1998.Toxicological Review of Hexavalent Chromium. In Support of Summary Information on the Integrated Risk Information System (IRIS). Washington, D.C. EVM. 2002. Expert Group on Vitamins and Minerals. Review of Chromium. Fishbein, L. 1981. Source, transport and alterations of metal compounds: An Overview. In: Arsenic, Beryllium, Cadmium, Chromium and Nickel. Environ. Health Perspect. 40: 43-64. Garrett, A. B. 1982. Zinc. Pp116-117. In : W.D. Halsey, and E. Friedman(Eds). Merit Students’ Encyclopedia. Macmillan Educational Company, New York. Golovatyj, S. E., E.N. Bogatyreva, S.E. Golovatyi. 1999. Effects of levels of chromium content in a soil on its distribution in organs of corn plants. Soil Res. Fert. 197-204 Hossner, L. R., R.H. Loeppert, R. J. Newton, P.J. Szaniszlo and Jr., Moses Attrep. 1998. Literature review: Phytoaccumulation of chromium, uranium, and plutonium in plant systems. Amarillo National Resource Center for Plutonium. Report ANRCP Jain, R., S. Srivastava, V.K. Madan and R. Jain. 2000. Influence of chromium on growth and cell division of sugarcane. Indian J. Plant physiol. 5:228-231. Jamal, H., H. Raza, K. M. Janua and M.K. Bhatty. 1986. Effect of minor minerals containing chromium on human health. Pak. J. Sci. Ind. Res. 29:45-47 James, B. R. 1996. The challenge of remediating chromium- contaminated soil. Environ. Sci. 30(6): 248-251 Joseph, G.W., R.A. Merrilee and E. Raymond. 1995. Comparative toxicities of six heavy metals using root elongation and shoot growth in three plant species. The symposium on environmental toxicology and risk assessment, Atlanta, G.A, U.S.A. pp26-29 Kabata-Pendias, A. 1995. Agricultural Problems related to excessive Trace Metal Contents of Soil. Pp3-18. In: W. Salomons, U. Forstner, and P. Mader(Ed). Heavy Metals (Problems and Solutions). Springer Verlag, London. Kabata-Pendias, A. and H. Pendias. 1984. Trace Elements in Soils and Plants. CRC Press Inc., Boca Raton, Florida. Kabata-Pendias, A. and H. Pendias. 1992. Trace Elements in Soils and Plants. CRC Press, London. Karunyal,S., G. Renuga and K. Paliwal. 1994. Effects of tannery effluent on seed germination, leaf area, biomass and mineral content of some plants. Bioresour Technol. 47: 215-218. Langard, S. 1980. Chromium. Pp 111-132. In: Waldron(Ed). Metals in the Environment. Academy Press Inc., New York. National Research Council (NRC). 1989. Recommended dietary allowances. 10th Ed. Washington, D.C. National Academy of Sciences. pp241-243 Nriagu, J.O. 1990. Global Metal Pollution poisoning the Biosphere? Environment. 32: 7-32. Pechova, A. and L. Pavlata. 2007. Chromium as an essential nutrient: A Review. Veterinarni Medicina. 52(1): 1-18

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Yahaya Ahmed Iyaka: Continental J. Environmental Sciences 3: 13 - 18, 2009 Peralta, J. R., J.L. Gardea Torresdey, K.J. Tiemann, E. Gomez, S. Arteaga, Rascon, E., et al. 2001. Uptake and effects of five heavy metals on seed germination and plant growth in alfalfa (Medicago sativa)L.B. Environ. Contam. Toxicol. 66(6): 727-734. Prasad, M.N.V., M. Greger and T. Landberg. 2001. Acacia nilotica L. bark removes toxic elements from solution: Corroboration from toxicity bioassay using Salix viminalis L. in hydroponic system. Int. J. Phytoremed 3: 289-300 Public Health Statement for Chromium. 2008. In: S. Draggan(Ed). Agency for Toxic Substances and Disease Registry and National Center for Environmental Health. Ross, D. S., R. E. Sjogren, and R. J. Bartlett. 1981. Behavior of chromium in soils IV. Toxicity to microorganisms. J. Environ. Qual. 10: 145-148. Rout, G.R., S. Sanghamitra and P. Das. 2000. Effects of chromium and nickel on germination and growth in tolerant and non-tolerant populations of Echinochloa colona L. Chemosphere. 40:855-859. Samantaray,S., G.R. Rout, and P. Das. 1999. Studies on differential tolerance of mungbean cultivars to metalliferous minewastes. Agribiol. Res. 52: 193-201 Saner, G., T. Yuksel and C. T. Gurson. 1980. Effect of chromium on insulin secretion and glucose removal rate in the new born. Am. J. Clin. Nutr. 33: 232-235 Saryan,L.A. and M. Reedy. 1988. Chromium determinations in a case of chromic acid ingestion. J. Anal. Toxicol. 12: 162-164 Shanker,A.K., M.Djanaguiraman, R.Sudhagar, C.N.Chandrashekar and G. Pathmanabhan. 2004a. Differential antioxidative response of ascorbate glutathione pathway enzymes and metabolites to chromium speciation stress in green gram ( vigna radiata L. R. Wilczek,cv CO 4) roots. Plant Sci. 166: 1035-1043. Shanker, A. K., C. Cervantes, H. Loza-Tavera and S. Avudainayagam. 2005. Chromium toxicity in plants. Environment International. 31:739-753. Sharma, D. C, and C.P. Sharma.1993. Chromium uptake and its effects on growth biological yield of wheat. Cereal Res. Commun. 21: 317-321. Singh,A. K. 2001.Effect of trivalent and hexavalent chromium on spinach(Spinacea oleracea L.). Environ. Ecol. 19: 807-810 Tripathi, A.K., S. Tripathi, and S. Tripathi. 1999. Changes in some physiological and biochemical characters in Albizia lebbek as bioindicators of heavy metal toxicity. J. Environ. Biol. 20: 93-98. U.S.EPA, 1984 Ward, N.I. 1995. Trace Elements. Pp321-351. In : Fifield, F. W. and H. R. J. Blackie(Ed). Environmental Analytical Chemistry. Academic and Professional,Glasgow. WHO. 1988. International Programme on Chemical Safety, Environmental Health Criteria 61. World Health Organisation, Geneva. Received for Publication: 07/11/2008 Accepted for Publication: 24/03/2009 Corresponding Author: Email: [email protected]

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ZOOPLANKTON COMMUNITY OF LAKE GBEDIKERE, BASSA, KOGI STATE, NIGERIA. Adeyemi, S.O1, Bankole, N.O2, Adikwu, I.A1, Akombu, P.M1., Okpanachi, M.A1 And Yusuf, M2.

1Department of Biological Sciences, Benue State University, Makurdi. 2Department of Biological Sciences, Kogi State University, Anyigba

ABSTRACT. A qualitative study of zooplankton fauna was carried out monthly for ten months from three stations marked A, B and C on Gbedikere Lake with a standard Clarke – Bumped plankton sampler between February and November 2008. Twelve (12) species of zooplankton were identified. The major groups found were Rotifers, Cladocera and Copepoda, their percentage are as follows: 45%, 27% and 25% respectively. The species composition of zooplankton comprised of Rotifers (6), Cladocera (3) and Copepoda (3). The zooplankton community showed evident seasonal pattern and some of the physico-chemical factors that may be responsible for these were found in all three stations. Zooplanktons are also used as natural fish food for fish larvae in fish breeding for aquacultural development. KEYWORDS: Species composition, seasonal variation, fish breeding.

INTRODUCTION In natural ecosystems, zooplanktons occupy a strategic position in the food chain of aquatic organism. Ecologically, they have been shown extert tremendous influence on phytoplankton succession by means of selective grazing (Porter, 1977). They are also an important source of natural food for carnivorous and omnivorous fishes and are prepared over artificial food such as beans and groundnut cakes under experimental conditions (Kirk and Howel, 1972; Kinne, 1977). There has been no previous comprehensive study of zooplankton population in Gbedikere Lake. However, Adeyemi et al., (2009) in their study of the food and feeding habits of Synodontis resupinatus in the lake, gave a check list of zooplanktons found in the stomach of this fish species. Okayi et al., (2001) in their studies the of seasonal pattern of zooplankton community of River Benue (Makurdi), reported that zooplankton consisted of Copepoda, (17.08%) Cladocera, (24.24%) and Rotifer, (12.5%) in the river. Adeniji, (1978) also reported the zooplankton composition of I.I.T.A reservoir in Ibadan to hold 29.32/62.66 organisms/litters of zooplankton and 100-20, 700 organisms of zoobenthos. Adeniji and Olowe, (1983) noted in their study of the vertical distribution of zooplankton in Jebba Lake that the zooplankton in the river was dominated by crustaceans. Ovie and Adeniji, (1994) identified a total of twenty six species of pelagic zooplankton in Shiroro lake (Sokoto). The community structure and ecological role of pelagic zooplankton in natural and man made lakes and rivers are of great concern to aquatic productivity and especially fish production. In view of their grazing activities and their role in nutrient recycling zooplankton potentially have both subtle and gross effects on phytoplankton populations which in turn have an effect on water quality (Mavuti, 1990). Zooplanktons are important food items for many larvae and same adults of many fish species which constitute an important component of human diet in development countries. The species composition of lake and river zooplankton is influenced by physical, chemical, biological and geographical factors among lakes. Environmental stress can operate in association with these factors to alter species composition. The aim of this study is to determine the composition and abundance of zooplanktons in Gbedikere Lake. MATERIALS AND METHODS The study was carried out monthly for the period of ten months between February and November 2008 in Gbedikere Lake. Lake Gbedikere is a natural lake located between Latitudes 3024N and Longitudes 5014E

and is about 10km to the East of Oguma the Headquarter of Bassa Local Government Area of Kogi State.

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Adeyemi, S.O et al: Continental J. Environmental Sciences 3: 19 - 23, 2009 Water enters the Lake from tributaries that run from River Benue during rainy or flood season. When the season is over, the Lake separates out. The Lake is about 450m north of Gbedikere village. The water body covers about 400 – 450m and a depth of 10 – 14m deep, depending on the season. The Lake is used for fishing and other domestic activities; consequently most of the settlers around the Lake are fishermen (Upper Benue River Basin Development Authority, 1985). The lake experience two seasonal periods; the rainy season starts in the month of May and last till October and is characterized by heavy down pour which sometimes have an extensive flood action. The dry season is from late October to April and is characterized by cold, dusty -dry wind followed by intense heat. The lake contains fish, other aquatic animals and some macrophytes such as wire grass (Cyperus articulatus) which are used for waving mats. ZOOPLANKTON SAMPLING Three sampling stations were selected on the lake for sampling marked A, B and C respectively. Results from ten (10) months sampling are reported. A standard plankton net (month diameter 2.5cm No. 10 silk straining net, mesh size 158 mm) was used to collect zooplankton. At each station five standard sweeps were made by oroggin the net along the water (Wually from profunda to litteral zone) for about two meters. Zooplankton-zoobenthos samples were always taken from the bottom to the surface using the plankton net. Plankton samples were concentrated into 20cm specimen bottles and immediately fixed and preserved with 5% formalin (APHA, 1985). ENUMERATION OF ZOOPLANKTON The study adopted a procedure by Teje and Fornado, (1986) for identification and estimation of zooplankton into various groups (Cladocera, Copepoda and Rotifer). Before enumeration each sample was centrifuged by 10ml aliquot and 1ml of the aliquot was withdrawn at a time and introduced into a country chamber using a vide-bore (3mm diameter) automatic pipet. Five sub-samples were taken from each concentrate. The second and subsequent sub-samples were taken after the previous sub-samples had been put back into the bottle. The mean number of the individual per ml was computed. Organisms’ concentration was calculated from the following relationship: No of organisms Per Liter of water = Organism per ml concentrate X 1000 Vol. Of water filtered The individual number of individual per-liter for each species per station was calculated, percentage abandon computed. Identification and enumeration was done using a vision light binocular microscope. PHYSICO-CHEMICAL PARAMETERS

Temperature was measured in the field using the ten way temperature meter (9091 model). Water samples for dissolved oxygen were taken in a 250ml sampling bottle as was determined using Winkler method (Wetzel and Westbland, 1979; America Public Health Association, 1980). Water transparency was measured using a 20cm secchi-disk (Wetzel and Westbland, 1979). The pH was determined in the field using potable electronic pH meter Probe Mettler Deita 320 model which had been standardized with dissolved water and butter solution shortly before used. The probe was inserted below the water surface until the readings stabilize. RESULTS Water temperature variation in the lake followed closely with a change in atmospheric temperature and season in Gbedikere. Variation in water temperature ranges between 25.30oC during the period of study (Table 1). There were no significant difference (P<0.05) in the pattern of distribution of temperature in all the three stations measured. The lake water was well oxygerated with dissolved oxygen values between 4.80ml/c and 5.21ml/c during the study period. No significant difference was found between the mean dissolve oxygen within the stations. Water transparency was generally low as a result of dilution caused by the inflow of water from inland effluent during the wet season. The pattern of seasonality in water transparency is similar at all stations with a range between 0.30m – 0.35m.

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Adeyemi, S.O et al: Continental J. Environmental Sciences 3: 19 - 23, 2009 The homogenous nature of the water with regards to pH is reflected from the stations in the pattern of seasonal variation (Table 1). The lake was generally slightly acidic (pH below the neutral value of 7.0) with few exceptionally acidic value of 6.02, 6.03 and 6.13 in the 2nd, 3rd and the 8th month and alkaline value of above 7 in the 1st and 7th month respectively.

Table 1: Variations in Physico-chemical Parameters of Gbedikere Lake. Month Temperature

(0c)

Dissolved o2 (mg/l)

pH Transparency (m)

FEB 29.3 4.80 7.00 0.331 MAR 29 4.84 6.02 0.34 APRI 29 5.21 6.02 0.34 MAY 27.3 4.86 7.21 0.35 JUNE 26.6 4.83 6.97 0.32 JULY 28 4.69 6.13 0.33 AUG 25.3 4.83 6.65 0.33 SEPT 25.6 4.80 6.03 0.31 OCT 28.3 5.02 6.42 0.33 NOV 28 5.12 6.94 0.30

Three major groups of zooplankton with varied numbers were identified at the end of the 10 months study in Gbedikere Lake. These include Rotifers 453 (48%), Cladocerans 247 (27%) and Copepods 237 (25%). Six species were identified under Rotifers, three for Cladocera and three for Copepoda. Table 2 shows the three classes of zooplankton and available species under each class and their abundance in Gbedikere Lake. It equally summarizes the total species and percentage for easy understanding of the three classes of zooplankton and the various species identified. Table 2: Total Percentage (%), Composition of Zooplanktons, Groups and their Species in Gbedikere

Lake. Zooplanktons

STA

A STA

B STA

C Total Percentage (%)

% Total

Composition

ROTIFERS Asplanchna 27 25 25 77 16.99% 8.21% Brachionus 20 28 20 68 15.01% 7.25% Keratella 33 32 24 89 19.64% 9.49% Rotatoria 28 27 25 80 17.66% 8.53% Synchaeta 22 22 22 66 14.56% 7.04% Proales 26 24 23 73 16.11% 7.79%

Total 156 158 139 453 100% 48%

CLADOCERA

Daphnia 25 28 27 80 32.38% 8.53% Ceriodaphnia 29 31 24 84 34.00% 8.96% Bosmina 29 29 25 83 33.60% 8.85% TOTAL 83 88 76 247 100% 27% COPEPODA Calanoid 24 24 16 64 27.005 6.83% Nauplius 25 24 15 64 27.00 6.83% Cyclopod 37 38 34 109 45.99% 11.63% Total 85 86 65 237 100% 25% Grand Total 937 100% STA = Station

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Adeyemi, S.O et al: Continental J. Environmental Sciences 3: 19 - 23, 2009 DISCUSSION The result obtained from the study shows variation and dynamism among various species of zooplankton, which calls for further monitoring. Twelve species of zooplankton were identified in the lake. Table 2 shows the group of zooplankton, their species availability and number identified in the lake, it equally shows the total number of species and the percentages of various groups of zooplanktons, the groups of zooplanktons identified are Rotifera, Copepoda and Cladocera. The highest percentage of Rotifera found could be because of its wide range in Nigeria and as it has the shortest life cycle with peak reproductive period, life span is 12 days at 20oC and 5 days at 25oC (Eya, 1999). The following were identified; Cladocera (Monia sp, Diaphoanosoma sp, Bosmina sp, Ceriodaphia sp). Rotifera (Filinia sp, Brachionus sp, Lecane sp, Polyarthra sp, Asplanchina sp, Tricocerca sp, Keratella sp). Copepoda (Copepodites sp, Thermocyclops sp, Tropodiaptomus sp, Mesocyclops sp) (Jeje and Fornado 1986). REFERENCES Adeniji, H.A. (1978) Diurnal vertical distribution of zooplanktons during stratification in Kainji Lake, Nigeria vern. Internet.verein limnol 20: 1677-1683. Adeniji, H.A and D.C. Olowe (1983). Fisheries Limnological study of the River Niger in the Proposed Jebba area, in the Pre-Impoundment studies of Jebba Lake, New Bussa, Kainji Lake Research Institute Annual Report pp. 41– 59. Adeyemi, S.O., Bankole, N.O. and Adikwu, I.A. (2009). Food and Feeding Habits of Synodontis resupinatus(Boulenger, 1904) in Gbedikere Lake, Bassa, Kogi State, Nigeria. Continental J. Applied Sciences 4:18 – 25. America Public Heath Association, (1985). America Public Heath Association, Washington D.C. p1268. America Public Heath Association, (1980). Standard method of examination of water and Waste Water 15th Edition. APHA AWWA-WPCF. Eya, J.C. (1999). Zooplankton Productivity/Water Quality Management. Winrock International, Farmer to Farmer Program. Jeje, C.Y. and Fornado, C.H. (1986). A Practical Guide to the Identification of Nigerian Zooplankton (Cladocera, Copepoda, Rotifera) pp 1-142. Kirk, R.G. and B.R. Howel (1972). Growth Rates and Food Conversion in Young (P. platessa) feed on Artificial and Natural Diets Agriculture pp. 29 – 34. Kinne, R. (1977). Marine Ecology Vol. 111 Cultivation, New York: John Wiley and Sons. Mavuti, K.M. (1990). Ecology and Role of Zooplankton in Fishing of Lake Naivasha, Hydrobiology.93:52 - 58 Okayi, R.G., Jeje, C.Y and Fagade, F.O. (2001). Seasonal Patterns in the Zooplankton Community of River Benue (Makurdi), Nigeria. African Journal of Environmental Studies (2) 1:9 – 19. Ovie S.I. and Adeniji, H.A. (1994). Zooplankton and Environment Characteristics of Shiroro Lake at the Extremes of its Hydrological Cycle Hydrobiological Kluwar Academic Publisher, 286: p.151–170. Porter, K.G. (1977). The Plant-Animal Interphase in Fresh Water System American Scientist 65:159 170. Upper Benue River Basin Development Authority (1985). Feasibility Study of Lake Geriyo by Upper Benue River Basin Development Authority. Authority Information Manual.

23

Adeyemi, S.O et al: Continental J. Environmental Sciences 3: 19 - 23, 2009 Wetzel, R.G. and Westbland, E. (1979). Some observations of the Dissolved Solids of Surface Waters and the Effects of Conductivity on the Growth of Algae. J. New England Wat. Wks. Ass.14:1-25. Received for Publication: 17/03/2009 Accepted for Publication: 13/05/2009 Corresponding Author (Present Address) Adeyemi, S.O Department of Biological Sciences, Kogi State University, Anyigba. Email: [email protected]

24

Continental J. Environmental Sciences 3: 24 - 32, 2009 ©Wilolud Online Journals, 2009. GEOELECTRICAL AND GEOCHEMICAL EVALUATION OF GROUNDWATER RESOURCES

IN SAPELE METROPOLIS, WESTERN NIGER DELTA.

Aweto, K.E Geology Department, Delta State University, Abraka, Delta State, Nigeria

Email: [email protected]

ABSTRACT A combination of geoelectrical and geochemical investigation was carried out in Sapele metropolis to ascertain the aquifer characteristics and geochemical parameters of the groundwater of the area,Ten (10) water samples were collected from hand-dug wells into sterilized containers for geochemical analysis. The geochemical parameters showed average values of 6.20 pH; 156.60µs/cm EC; 7.60mg/l TH ; 4.50mg/l Ca2+; 4.20mg/L Mg2+; 0.95mg/l K+; 1.00mg/l Na+; 0.87mg/l ∑Fe; 0.03mg/l Cu

2+; 0.04mg/l Cr2+; 28.68mg/l Cl- ; 5.40mg/l HCO3- ;

2.41mg/l NO3- ;0.80mg/l SO4

2- and average sodium absorption ratio (SAR) of 1.36. The relative abundance of cations using these concentrations is in the order of Ca2+ > Mg2+ > Na+ > K+ > ∑Fe > Cr2+> Cu2+ while those of anions are in the order Cl- > HCO3

- > NO3- > SO42-. Fifteen (15) vertical electrical soundings were

carried out in the study area using Schlumberger electrode configuration. The result of the interpretation of the VES curves showed that the area is made up of four and five geoelectric layer and the average depth to the aquifer is 35.2m with resistivities ranging between 1229.4Ωm and 3816.3Ωm. All the concentration of the various parameters determined in the groundwater was relatively in accordance with WHO recommended standard for domestic uses except pH and ∑Fe. Cr2+ concentrations generally were below stipulated standard in most of Sapele metropolis, but the concentrations at Ugbeyiyi and Ugberikoko were above WHO maximum allowance limit of 0.05mg/l. KEYWORDS: Domestic water, relative abundance, geochemical parameters, WHO, Sapele

INTRODUCTION Domestic water supply in Sapele metropolis comes largely from groundwater found in large reservoirs called aquifers and it is accessed by wells (Price, 1985). Water is ubiquitous in the natural environment but still there are some areas in which groundwater cannot be obtained in sufficient quantities due to factors like the porosity and permeability of the reservoirs (aquifers). Groundwater, even if present in sufficient quantities may be contaminated by dissolved natural chemical constituents which depends on the geochemical environment and source of groundwater. Thus proper precautions should be taken in such areas to reduce the risk of spending large sums of money in sinking abortive wells. This paper discusses the results of a geoelectrical survey employing vertical electrical sounding (VES) and geochemical analysis of groundwater in Sapele metropolis. The interpretation of the acquired VES data reveals depth to water bearing formations (aquifers), their thicknesses, and resistivities. Also, the measured parameters from the geochemical analysis was compared with the WHO stipulated standard in order to assess their suitability for domestic and agricultural uses. LOCATION, GEOLOGY AND HYDROGEOLOGY Sapele lies on latitude 50 38′ E and 50 45′ E and longitude 50 30′ N and 50 37′ N (Fig.1) and covers an area of about 347 km2.The study area lies within the Tertiary Niger Delta, which is stratigraphically made up of three major formations: Akata, Agbada and Benin Formations.The three formations were laid down under marine, transitional and continental environments respectively (Short and Stauble, 1967).

25

Aweto, K.E: Continental J. Environmental Sciences 3: 24 - 31, 2009 The Akata Formation which is the lowermost unit is 4000ft thick and made up dark grey sandy, silty shale and thin sandstone lenses. The Agbada Formation is made up of alternating sequences of sandstone and shale. This formation is 1000ft thick. The Benin Formation (topmost unit) is made up of over 90% sandstone with shale intercalation. The thickness of this formation is variable but generally exceeds 6000ft. Unconsolidated coarse and gravelly sands constitute the aquiferous units that are unconfined, the basic groundwater recharge of the study area

Fig. 1: Map of Sapele metropolis showing sampling/sounding locations are from direct infiltration of rainfall into the ground and infiltration through rivers beds such as the Ethiope river and Mayuku creek (Offodile,1992). The map of Sapele metropolis indicating sampling and sounding locations is given in Figure 1. MATERIALS AND METHODS. Geoelectrical Investigation Fifteen schlumberger vertical electrical soundings (VES) were made in the study area using an ABEM tetrameter SAS 1000 with maximum current electrode spacing (AB/2) of 225m. The apparent resistivity obtained from the field was plotted on a log-log graph paper

26

Aweto, K.E: Continental J. Environmental Sciences 3: 24 - 32, 2009 The initial interpretation of the VES data was carried out using the conventional partial curve matching techniques with two-layer master curves in conjunction with auxiliary point diagrams (Zhandov and Keller, 1994). The estimates of resistivities and thicknesses obtained from the partial curve matching were used as initial input to a computer programme that is based on optimization technique. Fig.2 and 3 shows examples of some sounding curves and their interpretation.

Geochemical Investigation Groundwater samples were collected in sterilized polyethylene bottles from 10 locations (fig.1). Parameters such as pH, electrical conductivity, total hardness, total iron (∑Fe), cations such as Ca2+, Mg2+, Na+ and K+, Pb2+, Cr2+, Zn2+ and anions such as Cl-, SO4

-, HCO3

- and NO3- were determined in

the laboratory. pH was measured with standard pH meter while electrical conductivity was measured with HACN conductivity meter. The Atomic Absorption Spectrophotometer methods were used to determine the concentrations of Ca2+, Mg2+, K+, Na+, Pb2+, Cu2+, ∑Fe, Cr2+, Zn2+, S04

2-, HCO3- , NO3

- and Cl-. RESULTS AND DISCUSSION The VES results (Fig.2 and 3) showed slightly different depths to the aquifer. At Amukpe (VES I and VES 4) the depths to the aquifer were 32.8m and 35.2m respectively while at Okirighwre (VES 8), the depth to the aquifer was 40.7m. The aquifer (fourth layer) in this area as shown in Fig.4 is unconfined and made up of gravelly sands. At Ugberikoko (VES 10), the depth to the aquifer was 38.2m and at Gana (VES 12) the depth to the aquifer was 28.6m while the depth to aquifer at Ogorode (VES 15) was 35.7m. The aquifer (fourth layer) in these parts as shown in Fig.5 are also unconfined but are made up of coarse sands. The result from the geochemical analyses of groundwater samples are presented in Table 1. The pH values ranged between 5.4 and 6.7. This indicates that the groundwater is acidic and that values fall below the minimum limit of 6.5 recommended by WHO (1998b). On the basis of the above, most of the groundwater sources can be regarded as quite acidic; such acidity has usually been associated with acid rain resulting from crude oil station flares (Ekakitie et al. 2000). Total hardness ranged from 2.32mg/l to 20mg/l. According to Hem (1970), when the total hardness in water is less than 60mg/l (Table 2), it is classified as soft. Hence the groundwater in Sapele metropolis is acidic, soft and fresh. The measured electrical conductivities of the investigated groundwater varied between 75µs/cm and 300µs/cm. The measured values of electrical conductivity were below the 1400µs/cm maximum permissible level stipulated by WHO (1984a). For the major cations, Sodium (Na+) concentration ranged from 8.53 -11.22mg/l, Potassium (K+) 0.20 - 1.54mg/l, Calcium (Ca2+) 1.42 -18.50mg/l and Magnesium (Mg2+) 1.50 - 18.50mg/l. The concentrations of these cations in the investigated groundwater (Table 1) have been compared with the internationally recommended standard of WHO (1984a) and were found to be below these standard values. Heavy metals such as Lead (Pb2+) and Zinc (Zn2+) were not detected in the groundwater during the analytical work and hence, show conformity to WHO recommended standards (WHO desired level for Lead is 0.01mg/l and Zinc is 0.1mg/l). The concentration of copper (Cu2+) as well as the pH of water is regarded as toxic (Seim and Tischendorf, 1990). Copper (Cu2+) was not detected in the groundwater at most sample locations except at Okirighwre, Okpe road, Ajogodo and Ugbeyiyi (Table 1), with concentrations ranging between 0.01mg/l and 0.05mg/l. These values are below WHO specification of 1.0 mg/l. Except for sample from Ugbeyiyi which shows (∑Fe) concentration to be 0.25mg/l, concentrations of total iron (∑Fe) at other sample points are quite high ranging between 0.36 -1.82mg/l which are above WHO maximum allowance limit of 0.3mg/l. Concentrations of chromium (Cr2+) in groundwater sample varied between 0.01mg/l and 0.11mg/l and are generally below WHO maximum

27

Aweto, K.E: Continental J. Environmental Sciences 3: 24 - 32, 2009 allowance limit of 0.05mg/l except at Amukpe, Ugbeyiyi and Ugberikoko where the concentrations are above WHO standards. The source of iron and chromium in the groundwater has not been ascertained but it may be due to industrial activities, refuse dumps and metal scraps along the river courses which are also source of groundwater and those naturally induced (i.e from the geology of the area) as reported by FEPA (1991).

Fig 2: Typical VES Curves for Amukpe and Okirighwre

28

Aweto, K.E: Continental J. Environmental Sciences 3: 24 - 32, 2009 Fig 3: Typical VES Curve for Ogorode

Fig 4: Typical geoelectric section for Amukpe and Okirighwre

29

Aweto, K.E: Continental J. Environmental Sciences 3: 24 - 32, 2009

Fig 5: Typical geoelectric section for Ugberikoko, Gana and Ogorode

Coarse sand

30

Aweto, K.E: Continental J. Environmental Sciences 3: 24 - 32, 2009 Table 1: Generalized result of the geochemical parameters of groundwater from Sapele metropolis

Parameters/ locations Amukpe Okirigwre Okpe Rd Ajogodo Ugbeyiyi Chechester Rd Crudas Rd Gana Ugberikoko Ogorode.

pH 5.90 6.40 6.70 6.00 6.30 5.80 5.70 5.40 6.80 6.60 Electrical Conductivity (µs/cm) 300 210 108 190 75 90 150 130 165 148 Total Hardness (mg/l) 4.62 3.96 14.60 30.00 4.32 5.00 2.30 2.77 2.85 6.00 Calcium (Ca2+) (mg/l) 3.05 2.50 3.00 18.50 2.70 3.50 4.30 1.42 2.20 4.01 Magnesium (Mg2) (mg/l) 4.27 3.40 1.62 5.00 2.30 1.50 18.50 1.86 2.00 3.70 Potassium (K+) (mg/l) 1.54 0.20 0.48 1.52 0.92 0.64 0.84 1.25 1.05 1.06 Zinc (Zn2+) (mg/l) ND ND ND N ND ND ND ND ND ND Lead (Pb2+) (mg/l) ND ND ND ND ND ND ND ND ND ND Copper (Cu2+) (mg/l) ND 0.03 0.05 0.01 0.02 ND ND ND ND ND Chromium (Cr2+) (mg/l) 0.11 0.04 0.05 0.03 0.06 0.02 0.01 0.01 0.06 0.01 Sodium (Na+) (mg/l) 9.00 9.80 11.80 11.60 9.50 8.96 9.25 10.30 11.22 8.53 Total Iron (∑Fe) (mg/l) 0.62 1.60 0.88 1.8 0.25 0.80 0.55 0.72 0.36 1.10 Chloride (Cl-) (mg/l) 15.00 45.80 16.10 122.00 10.20 8.44 15.72 10.75 19.97 22.85 Bicarbonate (HCO3

-) (mg/l) 4.03 6.52 9.20 7.2 3.45 3.40 8.33 3.95 3.20 4.65 Nitrate (NO3

-) (mg/l) 1.96 2.88 2.24 2.72 1.28 2.24 1.86 3.01 2 .85 3.06 Sulphate (S04

2) (mg/l) 1.34 1.28 0.22 0.45 0.30 0.50 0.78 1.56 0.25 1.40 SAR 1.10 1.34 1.94 0.87 1.45 1.43 0.61 1.90 1.86 1.05

ND = No Detection

31

Aweto, K.E: Continental J. Environmental Sciences 3: 24 - 32, 2009 Table 2: Water class based on total hardness (After Hem, 1970).

Hardness mg/l water class

0-60 Soft 61-120 Moderately hard 121-180 Hard

>180 Very hard.

All the determined anions Cl-, N03

-, S042- and HCO3

- showed concentrations (Table 1) below those recommended by World Heath Organization’s guideline, for drinking water quality (WHO, 1984a). The suitability of groundwater in Sapele metropolis for irrigation purpose was determined using the Sodium Absorption Ratio (SAR). (Etu-Efeotor, 1981).

Na+

SAR = ½ ( [Ca2+

] + [Mg2+

] ) Where, Na+, Ca2+ and Mg2+ concentrations are in millimole/litre (mmol/l). The value of Sodium Absorption Ratio (SAR) ranging between 0.61 and 1.96 indicate that the groundwater in Sapele metropolis is excellent for irrigation purposes (Table 3). The SAR values also showed that the ground water will not pose any serious problem to the soil when used for irrigation purposes. When the SAR value rise above 12 to 15, serious physical soil problems arise and plants have difficulty absorbing water (Munshower, 1994).

Table 3: Water class based on SAR (After Etu-Efeotor, 1981)

SAR WATER CLASS

0-10 excellent 10-18 Good 18-26 fair >26 poor

CONCLUSION Investigations for locating high yielding aquifers were carried out in Sapele metropolis using geoelectrical method. The area has thick sediment cover consisting of mainly sandy layers serving as potential good aquifers which are basically unconfined. The average depth to the water bearing formation is 35.2m with resistivity values varying between 1229.4Ωm and 3816.3 Ωm. From the result of the geochemical analyses, almost all the water quality parameters analysed were present in concentrations which were within the WHO permissible limit for drinking water. Total iron ∑Fe and pH were the only parameter that was present in concentrations higher than WHO permissible limit for drinking water. Comparing the geochemical parameters of the various water sample

32

Aweto, K.E: Continental J. Environmental Sciences 3: 24 - 32, 2009 with WHO standards, the result showed that the groundwater in Sapele metropolis are chemically potable except for the location where the total iron ∑Fe and chromium (Cr2+) contents were found to be above the maximum permissible levels. Since pH of groundwater can be improved through adequate treatment, the water quality of the area can be described as generally good for domestic and irrigational purposes. REFERENCES Ekakite, A. O. Akpoborie, I.A. and Adaikpoh, E.O. (2000): The quality of groundwater from dug wells in parts of the western Niger Delta. Journal of National Association for the Advancement of Knowledge. 2: 72-77. Etu-Efeotor, J. O. (1981): Preliminary hydrogeochemical investigation of the sub-surface waters in parts of The Niger Delta. Journ. Min. and Geol. 18(1): 103 -105. Federal Environmental Protection Agency. (1991): National Guidelines and standards for industrial effluents, gaseous emission and hazardous waste management in Nigeria. pp. 178-179. Hem, J. D. (1970): Study and interpretation of chemical characteristics of natural waters. Water supply paper, US Geological Survey, Washington DC. pp. 254-255. Offodile, M. E. (1992): An Approach to Groundwater Supply and Development in Niger Delta, 1st edition, Necon services,Warri. pp. 242. Munshower, F. (1994): Practical Handbook of Disturbed Land Revegetation. Lewis Publishers, Boca Raton, FL. pp. 265. Price, M. (1985): Introducing groundwater. Allen and Unwin (Publishers) Limited London. pp. 195. Short, K. C. and Stauble, A. J. (1967): Outline Geology of Niger Delta, A.A.P.G., Bulletin. 51:145-172. Siem, R. and Tischedorf, G. (1990): Grundtagen der Geochemie VEB Dentscher Verlag fur Grundstoff industries,Leipzig, pp. 425-456. World Health Organization. (1984a): Guidelines for drinking water quality, Vol.1, Recommendations, Geneva.130pp. World Health Organization. (1998b): Guidelines for drinking water quality, health criteria and other Supporting information, 2nd edition, Vol., 2, Geneva. pp. 281-283. Zhandov, M.S. and Keller, G.V. (1994): The Geoelectrical Methods in Geochemistry Exploration Methods in Geochemistry and Geophysics. 3rd edition. Elsevier Publishers, New York. Received for Publication: 07/11/2008 Accepted for Publication: 24/03/2009

33


EFFECTS OF MINING ON WATER QUALITY AND THE ENVIRONMENT; A CASE STUDY OF PARTS OF THE JOS PLATEAU, NORTH CENTRAL NIGERIA

1GYANG, J.D and

2ASHANO, E.C 1Raw materials Research and Development Council, Plateau State Coordinating Office,

2Department of Geology and Mining, University of Jos, P.M.B 2084 Jos, Plateau State, Nigeria

ABSTRACT Tin mining flourished in the study area from the beginning of this century to the early 1980’s and left behind a post-mining environment scarred by numerous mine ponds and dams surrounded by heaps of mine spoils (dumps/overburden) and a devastated landscape. Twenty water samples from mine ponds, wells and boreholes were collected and analyzed to evaluate for possible pollution arising from Leachates. A manganese value of 0.9 mg/l which is higher than the WHO highest desirable level of 0.05 mg/l was recorded from a mine pond, while two other samples also collected from mine ponds showed chromium values of 0.1mg/l and 0.12mg/l respectively, which exceeds the maximum admissible concentration of 0.005 mg/l. On the whole, the water samples did not show any significant pollution of public health concern. This is possible due to the fact that the minerals mined (tin and columbite) are not easily soluble in water. The mine ponds are presently used as source of water for irrigation and other domestic and industrial purposes. However, the major problem of the area still remains the devastated and devegetated land and mine spoils depriving the inhabitants of fertile farmland. KEYWORDS: mine ponds, overburden, mine waste, tailings, leachates

INTRODUCTION Formal mining started on the Jos Plateau as far back as 1902 with tin and collumbite as the major targets (Federal Department of Museum and Monuments, 1979). Prior to this period, mining was limited to shallow excavations of Laterite for extraction of iron to be fashioned into farm implements (Ngyang, 2007). The occurrence of these minerals brought about intense mining activities in the state at the beginning of this century, and infact, the early growth and development of the Jos city are closely related to commercial tin mining activities on the Plateau (Schoeneick and Aku, 1998). Commercial tin mining activities commenced about 1914 through the Royal Niger Company, and by late 1920’s the industry had been established, expanded and linked to the outside world, creating new communities and flourishing mining companies. Mining is achieved through several activities from exploration through exploitation to processing and finally to the consumer (Ogezi, 1998). The open cast mining method was generally used in predominantly flat plains of the Plateau, as tin and columbite were concentrated in old stream beds (alluvial), having been washed down from the younger granite outcropping units (falconer 1921). The Tin Mining industry on the Jos Plateau has cause extensive man made environmental damage, with vast tracks of pastoral land systematically destroyed in the quest for cassiterite and columbite, with increased radio active waste as a result of dumping of mine tailings and several heaps of mine dumps (overburden) and also mine ponds scattered all over the area. These mine ponds have resulted in several deaths, with about 106 recorded from the years 1980 to 1993 (Adiuku – Brown, 1999).The objective of this study therefore is to examine the effects of mining on water quality and the environment of selected parts of jos plateau, North central of Nigeria where tin mining took place. STUDY AREA AND LOCATION The study area is located on latitude 90 30 N and 90 33’N. And longitude 80 53’E and 80 59E, on the topographical sheet Naraguta 168, on a scale of 1: 100,000, and covers a distance of about 70km2. The administrative map of Plateau State showing the location of the study area is given

34

GYANG, J.D and ASHANO, E.C: Continental J. Environmental Sciences 3: 33 - 42, 2009

in figure1.

Fig 1: Administrative map of plateau state showing the location of the study area. It is underlain in most parts by rocks of the basement complex, which are the oldest rocks of the area and are found as small and widely scattered outcrops (Macleod, 1956). It falls within the granite complexes of central Nigeria, which represents one of the classical areas of occurrence of ring complexes in the world (Buchanan and Macleod, 1971). It has three main geological units: basement rocks; younger granite complex, and regolith. The basement rocks occur as highly metamorphosed and folded masses in contrast to the surrounding younger granite complex. The younger granite formation consists of various types of rocks, ranging from biotite granite, quartz-fayalite porphyry, and hornblende- porphyry(Black,1971). Hydrogeological studies revealed three hydrological units; quaternary sedimentary deposits, weathered zone of crystalline rocks, and tectonically fractured zone of crystalline rocks. The fractured crystalline aquifer water relates to tectonically fractured zones, and can be from open wells, blasted wells and sometimes bore holes. The soft overburden aquifer consist predominantly of clayey materials of alluvial, elluvial and deluvial origin, as well as insitu chemically weathered crystalline rocks (schoeneick and Aku, 1998). The volcanic aquifer occurs only locally, and consists of volcanic ash or basalts interbeded with volcanic ash. Its thickness is normally small, and is mostly tapped jointly with the underlying soft overburden aquifer. To extract minerals for use by industries, the earths crust must be disturbed (Howard and Ramson, 1998). On this crust are living things, man, animals and plants, whose life pattern are disturbed when mining is undertaken, resulting in loss of biodiversity. Mines, both active and inactive are potential water contamination sources (Davis, 1966). The Mining excavations create direct connection between ground water and the land surface. Oxidation of exposed minerals can lead to acid mine drainage (Domenico and Schwartz, 1990). Leaching of heavy metals is a threat. Drainage of materials from abandoned mines can act as ground water contamination source for years after mining operations have stopped (Freeze and Cherry, 1979). On the Jos Plateau, exploration, exploitation and processing of tin ore known to be

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35

GYANG, J.D and ASHANO, E.C: Continental J. Environmental Sciences 3: 33 - 42, 2009 associated with the alluvial sediments has left behind numerous ponds, Lotto, and prospecting pits, as well as heaps of mine waste in the course of mining. Since the minerals exploited are commonly associated with a variety of others, which are not needed, they were simply thrown away or heaped within the tin shed as tailings. Among the waste are minerals like magnetite, zircon, ilmenite, monazite, silica sand, thorite, amethyst etc (Ngyang, 2007). The abundant mine ponds, heaps of overburden and mine tailings are believed to have negative impact on the environment in the sense that the mine ponds and Lotto pits are considered to be death traps (Adiuku- Brown 1999), while the once flat land have been defaced by heaps of over burden with gully erosion taken over in many places. The tailings could be a silent and unnoticeable time bomb, as they are replete with radioactive materials excessively enhanced through the mineral processing. The mine ponds left by these mining activities are today used for irrigation, domestic and industrial purposes. The quality of these waters, and indeed that of the underground water with which they may possibly interact are not known. Leachates from mine waste can pollute the water in the mine ponds, which in turn can infiltrate the ground and pollute the ground water if it gets at it (Lindslay, 1975), while the rains could also wash off heavy metals and radioactive materials in mine tailing, which as surface run off could pollute the water. The use of mine tailings for baking and frying as well as for plastering of houses could result in exposure to radiation from naturally occurring radioactive material as well as from technologically enhanced naturally occurring radioactive materials (Solomon, 2005). It is also possible that the exposed heaps of mine waste and rock formation as a result of mining activities will be subjected to weathering and leaching of some of its elements which can contaminate the surface water (mine ponds) and also ground water in wells and boreholes around the study area. The extent of landscape originally disturbed by the large scale commercial tin mining operations on the Jos Plateau is put at 325km2 (Aguigwo, 1997) and represents more than 17% of the Agricultural land within the 8,600km2 of the entire Jos Plateau region, the bulk of which is virtually covered by rock outcrops. MATERIALS AND METHODS The procedure used for this work was systematic sampling of mine pond water, water wells and boreholes in the study area. The water samples were collected in polyethylene 250ml screw cap bottles. The location of sample collection points is taken using etrex Garmin global positioning system (GPS), while the depth at which the ground water samples were collected was also recorded. All vessels used for the collection of water samples were previously soaked in dilute acid and rinsed several times with distilled water. The vessels used for cation analysis were soaked in 2% HNO3, while that for anion were soaked in 6% HCl (except for Cl analysis). Insitu test was made for conductivity, pH and temperature using Esticks EC500 conductivity meter and Jen way 3150-pH/temperature meter respectively. Total hardness was determined using titrimetric method, while turbidity was measured using Secchi’s Disk. Ground water from boreholes and pumped wells were purged before sample collection to eliminate stagnant water, as this will not be representative of the water. Immediately before sample collection, bottles are rinsed again several times with water to be sampled, while water from mine ponds were as much as possible taken from 30- 50cm below the surface directly into sample bottle. Anions were analyzed using gravimetric method. About 2cm3 of concentrated nitric acid was added to water sample collected, for cation analysis using a dropper to reduce the pH to 2.0 or 1.5, and then shaken. A litmus paper is then used to measure the pH, and thereafter sample is sealed and labeled accordingly. Samples for anion analysis were not acidified, and the analysis was done using the atomic absorption spectrophotometer. The sample collection points in the study area are given in table 1.

36

GYANG, J.D and ASHANO, E.C: Continental J. Environmental Sciences 3: 33 - 42, 2009 Table 1: Sample collection points and coordinates S/N Sample

Identity Water type Location Coordinates

1 GW 01 Borehole Highland Bottling Company B/Ladi

N 090 33.534’ E080 54’

2 MP 02 Mine pond Behind Highland Bottling Company B/Ladi

N090 33.713’ E080 54.439’

3 GW 03 Shallow well Barkin Ladi N090 32.861’ E080 53.00’

4 GW 04 Shallow well Zat, Barkin Ladi N090 32.451’ E080 53.219’

5 GW 05 Shallow well Gangare, B/Ladi N090 32.327’ E080 53.369’

6 GW 06 Shallow well Gangare, B/Ladi N090 32.542’ E080 54.305’

7 GW 07 Shallow well Dorowa N090 32.922’ E080 52.931’

8 GW 08 Shallow well Zim N090 31.678’ E080 52.475’

9 GW 09 Bore hole Dorowa N090 31.678’ E080 58.45’

10 MP 10 Mine pond Pwomol N090 32.688’ E080 53..475’

11 GW 11 Shallow well Rabok N090 32.823’ E080 53.596’

12 MP 12 Mine pond Gwol N090 32.855’ E080 53.610’


14 MP 14 Mine pond Rakun N090 3.441’ E080 53.154’

15 MP 15 Mine pond Barkin Ladi N090 32.854’ E080 5.447’

16 MP 16 Mine pond Kwa Kopp N090 33.088’ E080 53.717’


18 MP 18 Mine pond Bet N090 32847’ E080 53.447’

19 GW 19 Shallow well Barkin John N090 32.802’ E080 53.450’

20 MP 20 Mine pond Dan Mangu N090 32.902’ E080 53.517’

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GYANG, J.D and ASHANO, E.C: Continental J. Environmental Sciences 3: 33 - 42, 2009 RESULTS AND DISCUSSION Table 2: Summary of the geo-chemical composition of water of the study area.

Summary of the geochemical analysis results of the study area Parameter Ground water Surface water WHO Standard

Range Mean Range Mean Recommended level

Maximum permissible level

Temperature (oC) 24 - 27 25.04 21 – 25 23.20 Variable Variable

pH 6.5 – 7.18 6.2 6.63- 799 7.30 6.5 9.5 Conductivity(usm/cm) 23.7-126.3 67.1 12.3-110.2 64.45 400 1480 Total hardness(mg/l) 32 – 72 52-83 2.0 –104.0 61.25 100 500 Turbidity 1.0 –130 20.33 0.0 –3761.0 478.79 <5 Cl-( (ppm) 17.04-191.7 73.34 22.72-

102.24 77.623 250 600

NO3 (mg/l) 0.0 –10.0 1.7 0.6 –2.40 1.163 25 50 SO4 (mg/l) 0.00 –17.0 3.23 0.00-14.00 5.063 250 400 Fe 2+ (mg/l) 0.01-04 0.14 0.00-0.48 0.133 0.3 1.0 Cu 2+ (mg/l) ND – 0.05 0.05 ND – 0.05 0.05 1.0 1.5 Zn 2+ (ppm) 0.02 –0.03 0.025 0.05 –0.08 0.053 - 3.0 Mn (ppm) 0.0-0.1 0.10 0.0-0.9 0.65 0.01 0.2 Ni 0.0-0.70 0.182 0.10-0.94 00.294 Pb 2+ (ppm) Nil Nil Nil Nil Cr 6+ (mg/l) 0.0-0.01 0.01 0.0-0.12 0.0175 - - ND-Not detected A total of twenty water (20) samples were collected in the study area, twelve (12) of which are ground water samples while eight (8) are surface water samples (a stream) and (mine ponds). They were analyzed for various parameters as given in table 2. The chemical parameters used in characterizing the waters are pH, conductivity, total hardness, Cl-, S04

-, N03

-, Mn 2+ etc. The conductivity values observed ranged from 23.7 – 126.3 with a mean value of 67.1 us/cm for ground water samples, and 12.3 – 110 for surface waters, with a mean value of 64.45 us/cm. It can be seen here that the ground water seems to have higher values, and this can be as a result of its close contact to earth materials and minerals it comes in contact with(Hem,1998).It however falls within the recommended level by the WHO.

The chloride (Cl-) values ranged from 17.04 – 191.7, with a mean value of 73.34 for ground water, and 22.72 – 102.24, with a mean value of 77. 623 for surface water and both values fall within the limit of WHO’s highest desirable limit for drinking water. The somewhat high values observed in some few samples in both surface and ground water could be an indication of pollution from effluents, even though not significant enough to warrant concern.

The manganese (Mn 2+) values ranged from 0.0 – 0.1 for ground water, and 0.0 - 0.9, for surface water. The value of 0.9 as observed in the surface water is above the highest desirable, and also above the maximum permissible (WHO, 2006) of 0.5 mg/l.

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GYANG, J.D and ASHANO, E.C: Continental J. Environmental Sciences 3: 33 - 42, 2009 Iron values ranged from 0.01 – 0.4 in ground water, and 0.00 – 0.48 in surface water. The highest desirable value of 0.1 (WHO, 2006) is exceeded by seven samples; they however fall within the maximum permissible value of 1.0 mg/l. The value 0.48 was recorded from an active mining site indicating the possibility of acid mine drainage. Zinc was detected in only four samples, two each from ground water and surface water. For ground water, the value ranged from 0.02 –0.03, with a mean value of 0.025, while for surface water it ranged from 0.025 – 0.08, with a mean value of 0.053. These values fall within the WHO permissible value.

Copper (Cu) was detected in only one sample each from ground water and surface water, and they both show values of 0.05 mg/l. This value is within the recommended value by the WHO.

Lead (Pb 2+) was not detected in any of the samples analyzed. Nickel (Ni) value ranges from 0.0 – 0.70 in ground water to 0.10 – 0.94 in surface water. This falls below the 1.0 mg/l given as guideline for effluent limitations in the mining and metallurgical industries.

Chromium values range from 0.0 – 0.01 in ground water, and 0.0 – 0.12 in surface water. The values 0.1 and 0.12 as recorded in surface water, one of which is an active mine site, while the other an abandoned mine site exceeds the maximum admissible concentration of 0.025 . Sulphate (S04

-) - The sulphate values obtained ranged from 0.00 –17.0 for ground water, and 0.00 to 14.00 for surface water. This figures fall within the WHO’s desirable and permissible level as can be seen from Table 2.

Nitrate (N03-). The nitrate values obtained ranged from 0.0 – 10.0 for ground water, while that of surface

water ranges from 0.6 – 2.40. This falls within the recommended value of the WHO.

Temperature – The temperatures recorded was in the range of 24– 27c in ground water, with a mean value of 25c while the surface water value ranged from 21 O C – 25c, with a mean value of 23.20c. The surface water temperature could be influenced by the atmospheric temperature, as well as evaporation, while ground water will normally be warmer. pH readings recorded for ground water were in the range of 6.5 –7.18, with a mean value of 6.2, while the surface water reading, ranged from 6.63 –7.99, with a mean value of 7.3. From the above readings, it can be noted that the ground water are weakly acidic which maybe due to break down of organic matter. However, both the surface and ground water fall within the WHO recommended and maximum permissible levels (WHO, 2006).

Total Hardness – Total hardness Measured on the study area was within the range of 32- 72, with a mean value of 52.83 for ground water and 2.0 –104.0 and a mean value of 61.25 for surface water respectively. The values recorded fall within the WHO’s highest desirable value of 100 mg/l, except one sample, from a mine pond with a value of 104 mg/l. Excessive total hardness affects taste of water, and low hardness causes flat taste of water. High total hardness on the other hand increased soap consumption. Classification of the water of the study area is given in table 3.

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GYANG, J.D and ASHANO, E.C: Continental J. Environmental Sciences 3: 33 - 42, 2009 Table 3. Percentage hardness of ground and surface water of the study area. Hardness Water classification Percentage hardness (%)

Ground water Surface water 0 – 75 Soft 91.67 87.50 75 – 150 Moderately hard 8.33 12.50 150 – 300 Hard Nil Nil > 300 Very hard Nil Nil

GYANG, J.D and ASHANO, E.C: Continental J. Environmental Sciences 3: 33 - 42, 2009 From the Table 3, most of the waters From the (over 87%) study area can be classified as soft water; while over 8% can be classified as moderately hard.

Turbidity, which is an indication of the presence of suspended materials such as clay, silt, finely divided organic material, plankton, and other organic and inorganic materials as measured in the study area was within the range 1.0 – 130 units, with a mean value of 20.33 for ground water, and 0.0 – 3761.0, with a mean value of 478.79 units for surface water. The high turbidity as observed in the surface water (mine pond) can be associated with the pumping of the water for irrigation, and also its use by the people for laundry and other domestic purposes, and also its use for drinking by cattle, which sometimes walk right into the ponds to drink water. The values recorded for seven (7) samples are above the highest desirable for drinking water (WHO) of 5NTU, but this can be attributed to the time and season of sampling, as it was sampled towards the end of dry season when water is sought the most within the study area. Furthermore, sample with the highest reading of 3,761 was recorded from a pond on an active mine site, into which water used for beneficiation is recycled. Five of the samples with high turbidity values are from mine ponds, while the remaining two samples are from shallow wells. The heaps of mine spoils (overburden) on the study area are given in figure 2.

Fig 2: The Heaps of Mine Spoils (Overburden) on the study area

CONCLUSION It can be observed from the results of water analysis that the tin mining activities carried out on the project area did not significantly affect its quality. The small traces of manganese, iron and chromium observed in some samples can not be said to be significant enough to warrant panic, except for fear of bioaccumulation. The major problem however, as observed from this studies is the several abandoned mine ponds and heaps of mine spoils that abound on the project area and spoiling the scenic beauty as well as serving as death traps for both humans and animals (Adiuku – Brown, 1994). Some authors (Schoeneick et al, 1998) are of the opinion that the area was left in a confused state. The several abandoned mine ponds have however, found use in irrigation, fishing and other domestic and industrial purposes such as, laundry, bathing and block making. Finally, mineralization is a blessing wherever it occurs; however, sustainable mining should be carried out for the purpose of mineral exploitation, while the lands should be restored to their original state after mining. A situation where these fields are left unreclaimed all over the place renders the soil infertile thereby depriving the people of farmlands, while the ponds act as death traps. The dangers of such unreclaimed activities could be summarized as follows:

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- Mine ponds - Heaps of over burden - Loss of arable land - Loss of bio – diversity - High accumulation of mine tailings containing radioactive minerals.

RECOMMENDATION Environmental hazards posed by mining activities can be reduced by adapting best mining practice such as mine reclamation after mining(Alford and Tulay1974), while mine waste should be properly disposed. Furthermore current mines should be properly planned to minimize the amount of hazardous waste they produce(Sawyer and McCarthy,1967), while on historical mines where waste already exist, remedial action maybe required, such as suitable land use planning, so as to restrict the use of contaminated sites. Mining laws enacted by Government should be strictly enforced to ensure compliance and prevent future unwholesome practice. It is the view of this author that more detailed investigation be carried out on these mine ponds, with a view to reclaiming those not found to be useful, while others could be put to proper use such as irrigation, fishing, industrial and public water supply. The heaps of mine waste, which is mostly laterite, can be used as a source of raw material for compressed earth bricks after confirmation that they do not contain radioactive materials.

REFERENCES Adiuku – Brown,M.E (1999). The dangers posed by abandoned mine ponds and lotto mines on the Jos Plateau. Journal of Environmental Sciences, 3(2):258–265.

Adiuku- Brown, M.E (2004). Effect of cassiterite mining and associated by-products on the environment; A study of some trace elements in the Jos Plateau and Zurak mining districts, north central Nigeria. PhD Thesis, University Of Jos.

Aguigwo, E. N (1997). The characteristics and viability of informal mining on the Jos Plateau. PhD Thesis, University Of Jos.

Alford, M.T. & Tulay (1974). Land forms, soils, climate and vegetation on the Jos Plateau. Land resources development center (LRDC) Miscellaneous Report 153 (1).

Black R. (1971).The Ropp Complex: Geology of the Jos Plateau, Bulletin of Geological Survey of Nigeria 32: 107 – 119. Buchanan, M. S, Macleod, W.N, (1971). Geology of the Jos Plateau. Bulletin of the Geological Survey of Nigeria; 12:10 – 34. Davis, S.N (1966). Hydrogeology,John Willy and Sons Publishing Company, New York. pp511. Domenico, P. A and Schwartz W.F (1990). Physical and Chemical Hydrogeology. John Wilay and Sons Inc, New York.pp 324. Falconer J.D. (1921) Geology of the Plateau tin fields. Bulletin of Geological Survey of Nigeria: 1

Federal Department of museum and monuments,(1979). History of tin Mining in Nigeria, National antiquities; 1:1 – 150, Jos.

Freeze, R. ……A and Cherry, J.A (1979). Ground water. Prentice Hall,inc Englewood Cliff,New Jersey.pp605

Herm, J. D (1970). Study and interpretation of chemical characteristics of water; water supply.US geological survey, Washinton.pp254-255

Howard, A. D and Ramson, J (1998). Geology in environmental planning. Mc Craw Hill Company, New York pp 478.

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Imevbore, A.M.and Adegoke, O.S (1998). The Application of Environmental Impact Assessment Procedure to Nigerian Industries. In FEPA MONOGRAPH 2; Towards Pollution Abatement in Nigeria. Lindslay, R. K. (1975). Hydrogeology for Engineers. McGraw-Hill Series in water resources and environment engineering. P48 Ngyang, F.G (2007). Legacy of mining activities on the Jos Plateau; A paper presented at the Nigeria nuclear regulatory authority stake holder’s forum held In Jos.pp7 Ogezi, A. E. (1988). Impact of Mining on Nigeria Environment. In FEPA monograph2, towards Pollution Abatement in Nigeria. Sawyer, C.N and McCarthy, P.I (1967). Chemistry for Sanitary Engineers, 2nd edition, Mc Graw Hill, New York, pp 518. Schoeneick, K, and Aku I. M (1998). The study of degraded mine lands of Jos, Bukuru, Riyom, Barkin Ladi and Bokkos areas of Plateau State for Development Possibilities; III. Solomon .A.O (2005).A study of natural radiation levels and distribution of dose rates within the younger granite province of Nigeria. Ph.D Thesis University of Jos. McLeod, W.N (1956). The geology of the Jos – Bukuru younger granite complex with particular reference to the distribution of columbite. Rec. Geological Survey of Nigeria. Pp 17 – 34.

WHO (2006) guidelines for drinking-water quality; Incorporating first addendum.vol1, recommendations.3rd Ed. Received for Publication: 21/09/2009 Accepted for Publication: 13/11/2009 Corresponding Author GYANG, J.D Raw materials Research and Development Council, Plateau State Coordinating Office

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