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OrganochlorinepesticideinwaterandbottomsedimentfromAibaReservoir(SouthwesternNigeria)

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Organochlorine pesticide in water andbottom sediment from Aiba Reservoir(Southwestern Nigeria)Godwin Oladele Olutonaa, Solomon Ayanwuyi Ayanoa & OludayoObayomi-Daviesa

a Department of Chemistry and Industrial Chemistry, BowenUniversity, Iwo, NigeriaPublished online: 12 Feb 2014.

To cite this article: Godwin Oladele Olutona, Solomon Ayanwuyi Ayano & Oludayo Obayomi-Davies(2014) Organochlorine pesticide in water and bottom sediment from Aiba Reservoir (SouthwesternNigeria), Chemistry and Ecology, 30:6, 513-531, DOI: 10.1080/02757540.2013.877002

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Chemistry and Ecology, 2014Vol. 30, No. 6, 513–531, http://dx.doi.org/10.1080/02757540.2013.877002

Organochlorine pesticide in water and bottom sediment fromAiba Reservoir (Southwestern Nigeria)

Godwin Oladele Olutona∗, Solomon Ayanwuyi Ayano and Oludayo Obayomi-Davies

Department of Chemistry and Industrial Chemistry, Bowen University, Iwo, Nigeria

(Received 7 August 2013; final version received 16 December 2013)

Levels of organochlorine pesticides (OCPs) in water and sediment from Aiba reservoir (SouthwesternNigeria) have been assessed. The aim of the study was to investigate the pollution status of the reservoirwater and the bottom sediment. Analytical measurements were carried out for 20 OCPs using standardliterature methods. The results showed higher levels of OCPs in the bottom sediment than the water.Significant positive correlations at p < 0.05 level were observed for OCPs compounds in water exceptγ -BHC and endosulfan III, whereas in sediments α-chlordane, dieldrin, endosulfan II, pp-DDT, endrinketone and methoxychlor did not show any correlation, and aldrin was negatively correlated with pp-DDD.The mean levels of OCPs in both water and sediments were higher, in most cases, than recommendedlevels for drinking water. Owing to possible toxicity and bioaccumulation tendency of OCPs by the aquatichabitats, the levels of OCPs detected in water and sediment samples could be a source of future healthproblems. Environmental monitoring of the reservoir is highly recommended.

Keywords: organochlorine pesticides; persistent organic pollutant; tropical reservoir; Iwo

1. Introduction

The increasing needs of the food production have resulted in overuse of fertilisers and pesticides,which enter aquatic systems, following aerial application or runoff inputs and reduce quality ofwater.[1] As pesticides runoff constitute a significant contribution to aquatic pollution, their usein agriculture is under constant screening to ensure non-target animals’ welfare, leading to theban and restriction of a large number of products.[2]

In water bodies, many of the persistent organic pollutants such as organochlorine pesticides(OCPs) and trace metals have been predominantly transported in association with suspendedparticulate matter. The suspended particles and the semi-bound pollutants accumulate in theregion of low turbulence, such as groyne fields, harbours and river reservoir.[3] This has resultedin pollution of bottom sediment.

Within the sediments, usually with anoxic conditions, many contaminants are strongly bound tothe solid phase. Therefore, pore water concentrations, mobility and bioavailability except throughparticle ingestion of most pollutants are rather low.[3] However, the possible erosion duringflood events leads to the transfer of contaminated sediments to the oxidised water column, whichgenerally enhances bioavailability and toxicity of pollutants.[4,5]

∗Corresponding author. Email: delog2@gmail.com

© 2014 Taylor & Francis

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Residues of OCPs in sediments and aquatic biota have been an environmental concern sincethe 1960s.[6] Owing to their toxicity, persistence, tendency to accumulate in biota, and adverseimpacts on wildlife, the majority of OCP were banned in the US during the 1970s.[7] Yet morethan 20 years later, residue of DDT and other OCP continue to be detected in water sedimentsand aquatic biota throughout the world.[8] The mechanism underlying the toxicity of organochlo-rine involves the induction of enzyme activity through free radicals, ultimately affecting theimmune response, the reproductive and neurological systems, lipid metabolism, and the transportof vitamins and glucose. In addition, some of these compounds are mutagenic, teratogenic and car-cinogenic not only in humans, but also in biotic communities with different levels of sensitivity.[9]The persistent nature of OCPs in the environment may pose the problem of toxicity to animalsand human through air, water and food intake.[10] Furthermore, because of their chemical stabil-ity, long-range atmospheric, lipophilicity and persistence, these chemicals tend to bioaccumulateand biomagnify in the food chains and persist in the environment for many years, representinga definite health hazard for both wildlife and human.[11,12] Owing to the hydrophobic natureof OCPs, these persistent organic pollutant (POP) present in aquatic system have high affinity tobind to suspended particles and tendency of long-term vertical transport of organic contaminantfrom surface waters to the deep sea floor.[13,14] OCPs have the potential to affect development,reproduction and behaviour of fish and wildlife.[15]

Long-term chronic exposure to OCPs and poly chlorinated biphenyls (PCBs) has been corre-lated with severe injury to the nervous, endocrine, reproductive and immune systems in birds, fishand mammals.[16] Ecological effects of OCPs include interference with reproductive success oforganisms high on food chain especially fish eating birds such as osprey, pelicans, falcons andeagles.[17] DDT has been reported to have esterogenic and enzymes inducing properties.[17]The adverse effects of DDT demonstrated in experimental animals include infertility,[18] adecrease in the number of planted ova,[19] intrauterine growth retardation,[20] neurologicaldevelopmental disorders [21] and mortality.[22] Isomers of DDT (ortho and para) compete withestradiol for binding to oestrogen receptors in uterine cytostol therefore causing changes in steroidmetabolism and thereby alter the ability of birds to mobilise calcium to produce strong eggshell.[23]

Generally, the greatest source of human exposure to OCP is daily intake via foodconsumption,[24] in particular, the consumption of sea food from contaminated areas.[25] More-over, several studies have recently demonstrated a clear correlation between the frequency of fishconsumption and the levels of organochlorine in human tissues, serum and milk.[26,27] Over90% of the body burden of DDT in the general population is derived from food, particularly fishand other fatty foods of animal origin.[28] In Nigeria, it has been reported that 116 students ofa school in Doma, Gombe state fell ill and were hospitalised after eating cowpea contaminatedby pesticide.[29] Shaibu [30] reported that two children and 112 people were hospitalised aftereating cowpea treated with pesticide in Cross River state, Nigeria. In 2010, it was reported that20 fast food outlets were closed in Nigeria because of fatalities traced to pesticide residue in theirproducts.[31]

Aiba reservoir, the second oldest impoundment of Osun River Basin came into full operationin 1957 and was created primarily for the provision of portable water with fisheries develop-ment as an ancillary benefit to Iwo town and the surrounding communities.[32,33] Recently,there has been a sharp rise in the development of Iwo as evidenced by the establishment of aprivate University and Polytechnic, proliferation of banking industry as well as establishment oftelecommunication industry. This has led to an increase in the population of Iwo. Construction ofresidential houses is encroaching into the north-eastern part of the reservoir. Anthropogenic prac-tices in and around the reservoir include intense fishing activity, agricultural practices, washingof domestic wares and automobiles, bathing and fetching of water for construction and domesticpurposes.[34]

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Organochlorine pesticide levels in water, sediment and soil have been studied by various authors.In Iwo however, no published work has been reported in this regard. Hence, the objective of thispaper is to give a pilot screening of OCP levels in water and sediment of Aiba reservoir and toprovide a preliminary insight into the accumulation pattern based on the matrices considered inthis study.

2. Materials and methods

2.1. Description of the study area

The Aiba reservoir is a small tropical man-made lake located in Iwo city in the southwestern Nige-ria. The reservoir lies between longitude 4◦11′ to 413′ East and latitude 7◦38′ to 7◦39′ North. Theaverage monthly rainfall ranges from about 254 mm in July to 25.4 mm in December-January.[35]The reservoir has a catchment area of 54.39 km2 and a surface area of about 0.32 km2 (32 ha).The dam is 11.58 m high and 455.2 m long, and the reservoir has a capacity of approximately1.91 billion m3 with a mean depth of 0.75 m and a maximum depth of 7.5 m.[36] The mean Secchidisc transparency ranges from 0.90 m during the dry season to 0.97 m during the wet season.[32]The reservoir is regarded as being eutrophic.[36]

2.2. Apparatus and reagent used

All glassware and bottles used for trace organics were thoroughly washed with hot liquid detergentsolution, rinsed with acetone (99.5%) and n-hexane (99.0%) mixture (1:1 v/v) and then heatedin an oven at a temperature of 120◦C for 12 h prior to use.[37] The entire reagent used, viz.dichloromethane and n-hexane (GFS chemicals, Inc Colombus); acetone (Park Scientific Ltd.Northamptom, United Kingdom); Silical gel (silica gel 60, particle size 0.0630–0.200 mm, 7–230 mesh from Lab Tech Chemicals); and Sodium sulfate (BDH, England). Standard mixturecontaining 22 OCPs (22 compounds specified in EPA method 8081B) was purchased from SigmaAldrich, South Africa.

2.3. Purification of solvents and chemicals

The solvents (dichloromethane and n-hexane) for trace organics were triply distilled to obtainpure solvent that precluded all trace organic contaminants. Other materials such as glass wool,anhydrous sodium sulfate and silica gel were all heated in a muffle furnace model ECF 3 at 450◦Cfor 4 h. The Whatman filter papers were oven dried to constant weights at 105◦C and cooled in adesiccator.

2.4. Collection of bottom sediment and surface water

Four sampling locations in the reservoir were selected for this study (Figure 1). Location 1 was theentry point which receives water from Osun stream in the middle region of the reservoir. This areais also an agricultural area. Location 2 is located at the upper region, the source of the reservoir. Thisarea is also close to the agricultural area and cattle rearing are predominant in this area. Location3 is the agricultural area and receives agro-allied chemicals from the surrounding farm land. Thislocation is the north- eastern region, close to the main road characterised with mechanic workshopsand also receive domestic sewage from the encroaching residential buildings. Location 4 is the

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Figure 1. Map of Aiba reservoir showing sampling locations.

spillway area, the lower reaches of the reservoir. In this area, spiritual bath, domestic washing aswell as washing of motor cycle by cyclists are very common features of this area.

Sampling took place in November and December 2012. Samples of bottom sediment for eachfour locations were collected in triplicates with grab sampler at a depth of 0 to 10 cm. The samplescollected were stored in clean aluminium foils and preserved in a refrigerator at about 4◦C prioranalysis. The samples were air-dried at ambient temperature in an inert surface in a ventilatedcupboard to minimise cross contamination of samples with the atmospheric particulate. Sedimentsamples from each location were made into composite representative samples sieved through astainless steel 2 mm pore size to get rid of pebbles and large particles.

The water sample was collected in a sterilised 2.5 L Winchester bottles for each of the fourlocations. Water collected from each spot was used to rinse the bottles three times before samplingwas done. Alteration of the organics due to microbial activities was prevented by acidification ofthe samples to pH 2 by adding concentrated HNO3 immediately after collection.

2.5. Extraction procedure

Liquid-liquid extraction was used to extract OCP from the water samples. About 500 mL ofthe water sample was measured and poured into a 1 L separatory funnel then extracted with10 mL (three portions) of dichloromethane by shaking vigorously for 30 min for each of thetriplicate extraction. The extracts were then combined, dried with anhydrous sodium sulfate andconcentrated to about 2 mL under a stream of nitrogen gas of 99.99% purity.

The sediment samples were extracted by soxhlet extraction method (USEPA method 3540).A dried, sieved sediment sample (20 g) was weighed into extraction thimble and placed in asoxhlet extractor. Extraction was done for about 10 h using triply distilled dichloromethane ata temperature of about 40◦C. The extract was concentrated by distilling off part of the solvent.The concentrated extract was cooled to room temperature and then concentrated further to about2 mL under a stream of nitrogen gas of 99.99% purity. The reduced extract was preserved forchromatographic clean-up prior to GC-ECD analysis.

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2.6. Clean-up experiment

Clean-up method (USEPA Method 3630C) was used in this research work. A column of about15 cm × 1 cm (internal diameter) was packed with about 5 g activated silica gel prepared in aslurry form in n-hexane. About 0.5 cm3 of anhydrous sodium sulfate was placed at the top of thecolumn to absorb any water in the sample or the solvent. The column was pre-eluted with 15 mLof n-hexane without the exposure of sodium sulfate layer to air. The reduced extract was placed inthe column and allowed to sink below the sodium sulfate layer. Elution was done with 2 × 10 mLportion of the extracting solvent. The eluate was collected, dried with anhydrous sodium sulfateand then evaporated to dryness under a stream of analytical grade nitrogen gas.

2.7. GC-ECD analysis

Gas chromatography from Institute of Oceanography, Victoria Island Lagos was used in deter-mining the presence and levels of organochlorine in both the surface water and bottom sedimentof Aiba reservoir. The dried eluate above was reconstituted with 1 mL n-hexane and 0.5 mL of20 ppm of the internal standard. Qualitative and quantitative analysis of the OCPs were carriedout with the aid of HP GC 5890 series 11 coupled with detector (ECD). The levels of OCP werecalculated from the relationship given by Harris (1999) as:

Ax

[x] = F

(As

[s])

where Ax = area of analytical signal; As = area of internal standard signal; F = response factor;[x] = concentration of analyte and [s] = concentration of internal standard. The GC was underthe following conditions: injector temperature of 250◦C; detector temperature, 300◦C; (held for5 min); capillary column, Zebron ZB-1701. 30 m × 0.25 mmi.d × 0.25 μm film thickness; oventemperature programme, 280◦C starting from 50◦C for 1 min and continued at 20◦C/150◦C andat 5◦C/min to 280◦C held for 4 min; injected sample volume 1 μL; splitless mode; carrier gas N2

at 30 mL/min; and splitless flow rate, 19.6 mL/min. identification of OCP was by comparison ofretention times of the peaks with those of standard OCP compounds.

2.8. Quality control measure

Since no standard pesticide reference materials were available to us during the course of this study,recovery analysis was performed in order to ascertain the efficiency of the analytical proceduresusing standard methods. 500 mL aliquot of ultra-pure water was measured into 1000 mL separatoryfunnel and acidified with concentrated HNO3 to pH 2. This was spiked with 10 mL of 1000 ppmstandard mixture consisting 20 different organochlorine pesticides. The mixture was extractedand clean-up following the procedure outlined above.

Two 20 g portions each of dried sediment samples were pulverised. One portion was spiked with10 mL of 1000 mg/L standard mixture consisting 20 different organochlorine pesticides, whereasthe other that served as control was left unspiked. The two portions were extracted separately andtaken through the same procedure earlier outlined. Moreover, 10 mL of the standard 1000 mg/Lmixture of the organochlorine in spectra grade n-hexane was put into a clean oven dried samplebottle and dried at ambient temperature followed by purging with high purity nitrogen gas, whereasthe residue was redissolved in 1 mL n-hexane. To both the spiked and the control standard mixture,1 μL was separately injected into the column of the GC-ECD and analysed sequentially. Therecoveries of the OCPs were determined by comparing the peak areas of the OCPs after spiking

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with those obtained from the evaporated standard residue. Calculation of the % recoveries wasperformed as follows:

% R = Peak area of A − Peak area of A′

Peak area of OCP in standard× 100

Where A = OCP in spiked sediment sample; andA′ = OCP in unspiked sediment sample

2.9. Evaluation of response factor

The response factor of the standard was estimated by analysing 1.0 μL of 1000 ppm stock solutionof the standard mixture containing the internal standard on the GC-ECD.[22] The response factorswere obtained using the expression below:

RF = Peak area of OCPs

Peak area of internal standard

2.10. Evaluation of limit of detection

The limit of detection was evaluated based on the mathematical relationship described by Millerand Miller [38] as expressed below:

yc = yn + 3sB

where yc = analyte signal equivalent to detection limit; yn = blank signal; and SB standard devi-ation of the blank. From the values yc, the analyte concentration corresponding to the detectionlimit was evaluated.

2.11. Statistical analyses

The mean standard deviation for the organochlorine pesticide congeners from duplicate mea-surements was determined using the Statistical Package for the Social Science (SPSS) software,15.0 for window evaluation version. Duncan’s multiple range test [39] was used to determinesignificant differences between means. The linear correlation coefficient of the OCP congenerswas determined using the Pearson correlation coefficient.

3. Results

The reliability and reproducibility of the analytical procedures used based on the recoverieswork of the individual OCP congeners obtained during the spiking experiment gave the valuesof 82.54 to 98.35% in water samples and 87.65 to 110.78% in sediment samples with relativestandard deviation of less than 10%. Hence, these values are adjudged reliable and efficient.The retention time (min) ranges from 6.908 in α-BHC to 11.046 in water and 6.965 in α-BHCto 10.687 in sediment, whereas the range of response factors of 0.657 to 1.885 indicated theseparation efficiency of the programmed method for GC-ECD identification and the quantificationof the OCPs was efficient. The LOD values for the OCPs ranged from 0.055 to 2.105 μg/L(Table 1).

The results of the levels of OCPs studied in all the matrices fell into three cate-gories: dichlorodiphenylethanes (pp-DDD, pp-DDE and pp-DDT), cyclodiens (heptachlor,

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Table 1. Response factor, retention time, limit of detection and % recovery for OCPs.

Retention Time % RecoveryResponse Limit of

OCP factor Water Sediment Water Sediment Detection (ppb)

α-BHC 1.77 ± 0.01 6.91 ± 0.25 6.97 ± 0.33 84.56 ± 4.58 88.91 ± 8.25 1.086β-BHC 0.68 ± 0.01 7.27 ± 0.12 8.18 ± 0.24 88.75 ± 6.84 95.21 ± 7.70 0.101γ – BHC 1.16 ± 0.02 7.73 ± 0.42 8.52 ± 0.45 95.06 ± 4.68 89.54 ± 5.44 0.095δ - BHC 1.46 ± 0.02 7.89 ± 0.26 8.92 ± 0.21 90.34 ± 5.75 92.38 ± 4.32 0.067Heptachlor 1.29 ± 0.15 8.23 ± 0.34 9.04 ± 0.28 90.23 ± 5.44 89.78 ± 8.77 1.090Aldrin 1.34 ± 0.02 8.67 ± 0.39 9.24 ± 0.18 88.52 ± 5.62 91.67 ± 4.88 2.105Heptachlor-epoxide 1.45 ± 0.01 8.95 ± 0.45 9.49 ± 0.41 91.99 ± 1.45 89.43 ± 7.89 0.041γ - Chlordane 0.55 ± 0.02 9.02 ± 0.15 9.65 ± 0.26 90.22 ± 4.78 93.55 ± 6.88 0.479Endosulfan I 0.56 ± 0.02 9.27 ± 0.37 9.81 ± 0.29 84.23 ± 4.88 88.89 ± 3.49 0.076α - Chlordane 0.60 ± 0.01 9.52 ± 0.22 9.94 ± 0.43 92.23 ± 3.75 94.15 ± 5.48 0.481Dieldrin 0.95 ± 0.05 9.68 ± 0.17 10.06 ± 0.22 83.88 ± 4.27 89.45 ± 2.38 0.894pp- DDE 0.89 ± 0.01 9.85 ± 0.48 10.33 ± 0.35 93.55 ± 3.34 98.11 ± 4.65 0.182Endrin 1.08 ± 0.02 9.91 ± 0.52 10.41 ± 0.49 82.69 ± 5.25 92.34 ± 6.21 0.305Endosulfan II 0.66 ± 0.06 10.06 ± 0.44 10.59 ± 0.45 81.22 ± 3.77 86.78 ± 3.99 0.065pp- DDD 1.88 ± 0.03 10.29 ± 0.25 10.62 ± 0.52 95.82 ± 5.66 89.78 ± 2.22 2.001Endrin- CHO 1.58 ± 0.01 10.40 ± 0.37 10.63 ± 0.55 92.31 ± 5.80 88.89 ± 4.08 0.051Endosulfan III 0.89 ± 0.03 10.74 ± 0.51 11.09 ± 0.44 86.78 ± 4.03 89.74 ± 5.12 0.044pp- DDT 0.95 ± 0.02 11.05 ± 0.45 11.23 ± 0.57 90.32 ± 6.01 92.78 ± 4.44 0.055Endrin CO 1.25 ± 0.02 11.33 ± 0.49 11.37 ± 0.55 84.76 ± 4.67 88.65 ± 3.66 0.055Methoxychlor 1.67 ± 0.03 11.57 ± 0.53 11.48 ± 0.48 85.79 ± 5.08 90.55 ± 5.64 0.046

heptachlor-epoxy, aldrin, α- chlordane, γ -chlordane, dieldrin, endrin, endrin aldehyde, endrinketone, endosulfan I, endosulfan II, endosulfan III, and methoxychlor); and chlorinatedbenzenes/cyclohexane (α-BHC, β-BHC, γ -BHC and δ-BHC). The distribution of OCPs (mg/L)in water samples for all the four locations are presented in Tables 2 and 3. The presence of all thethree categories of OCPs (chlorinated benzene/cyclohexane, dichlorodiphenylethane and cyclo-dienes) was evident in all the locations. Analyses shows the presence endosulfan I, endosulfanIII, and methoxychlor in 62.5% of the samples; β- BHC, heptachlor and endrin ketone in 50%of the samples; α-BHC, δ- BHC, pp-DDT, aldrin, endosulfan II, dieldrin and endrin aldehyde in37.5% of the samples; and pp-DDE, pp-DDD, heptachlor-epox, endrin and γ -Chlordane in 25%of the samples. γ -BHC was not detected in all the locations.

Tables 4 and 5 present the distribution of OCPs in bottom sediment for all the four locations.Despite the evidence of presence of all the three categories of OCPs in all the locations, endosulfanIII was not detected in all locations. Analyses show the presence of α-BHC, β-BHC, γ -BHC,δ-BHC and heptachlor in 100% of the samples; γ -Chlordane in 87.5% of the samples; endrinketone in 75% of the samples; pp-DDD, endosulfan I and endrin in 62.5% of the samples; pp-DDE,pp-DDT, heptachlor-epox and aldrin in 50% of the samples; α-Chlodane, dieldrin, endosulfan IIand methoxychlor in 25% of the samples; and endrin aldehyde in 12.5% of the samples.

The levels (mean ± sd, mg/L) of OCPs in water samples (Tables 6 and 7) in all thethree categories of OCPs were as follows: α-BHC (0.09 ± 0.14), β-BHC (0.09 ± 0.11), γ -BHC (ND), δ-BHC (0.09 ± 0.12); pp-DDD (0.03 ± 0.06), pp-DDE (0.04 ± 0.07), pp-DDT(0.05 ± 0.08), heptachlor (0.09 ± 0.11), aldrin (0.06 ± 0.08), heptachlor-epox (0.05 ± 0.09),α-Chlordane (0.03 ± 0.06), γ -Chlordane (0.04 ± 0.07), endosulfan I (0.19 ± 0.19), endosulfan II(0.05 ± 0.06), endosulfan III (0.23 ± 0.28), dieldrin (0.06 ± 0.08), endrin (0.04 ± 0.06), endrinaldehyde (0.09 ± 0.14), endrin ketone (0.09 ± 0.09) and methoxychlor (0.11 ± 0.10).

The levels (mean ± sd, μg/g) of OCPs in sediment samples (Tables 6 and 7) were as follows:α-BHC (0.36 ± 0.63), β-BHC (0.19 ± 0.21),γ -BHC (0.02 ± 0.05), δ-BHC (0.12 ± 0.12), pp-DDE (0.38 ± 0.51), pp-DDD (2.69 ± 3.02), pp-DDT (0.54 ± 1.17), heptachlor (0.17 ± 0.16),

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Table 2. Levels (mg/L) of organochlorine pesticide in surface water of Aiba reservoir.

Location α-BHC β-BHC γ -BHC δ-BHC ppDDE ppDDD ppDDT Heptachlor Heptaclor Epox α-Chlordane

A 0.10 ± 0.14a 0.10 ± 0.15a ND 0.07 ± 0.10a ND ND 0.07 ± 0.09a 0.14 ± 0.20a ND NDB ND 0.05 ± 0.08a ND ND ND ND ND 0.08 ± 0.12a ND NDC 0.06 ± 0.08a 0.08 ± 0.11a ND 0.14 ± 0.20a 0.08 ± 0.11a 0.07 ± 0.10a 0.07 ± 0.09a 0.06 ± 0.09a 0.10 ± 0.15a 0.07 ± 0.10a

D 0.20 ± 0.28a 0.14 ± 0.20a ND 0.13 ± 0.19a 0.06 ± 0.09a 0.06 ± 0.09a 0.08 ± 0.12a 0.06 ± 0.08a 0.08 ± 0.12a 0.07 ± 0.09a

Mean with different letter of the alphabet for each column are significantly different (p < 0.05) from each other.

Table 3. Levels (mg/L) of organochlorine pesticides in surface water of Aiba reservoir.

Location γ -Chlordane Endosulfan I Endosulfan II Endosulfan III Aldrin Endrin Endrin Aldehyde Endrin Ketone Dieldrin Methoxychlor

A ND 0.46 ± 0.05b 0.06 ± 0.09a 0.50 ± 0.38a 0.17 ± 0.02b ND 0.18 ± 0.26a 0.10 ± 0.14a 0.09 ± 0.12a 0.18 ± 0.05a

B ND 0.13 ± 0.19ab ND 0.27 ± 0.39a ND ND ND 0.09 ± 1.28a ND 0.12 ± 0.17a

C 0.08 ± 0.11a 0.08 ± 0.11a 0.06 ± 0.09a 0.07 ± 0.09a 0.08 ± 0.11ab 0.07 ± 0.10a 0.69 ± 0.09a 0.08 ± 0.12a 0.09 ± 0.12a 0.07 ± 0.09a

D 0.07 ± 0.10a 0.08 ± 0.11a 0.05 ± 0.08a 0.08 ± 0.11a ND 0.07 ± 0.09a 0.12 ± 0.17a 0.08 ± 0.11a 0.05 ± 0.07a 0.06 ± 0.08a

Mean with different letter of the alphabet for each column are significantly different (p < 0.05) from each other.

Table 4. Levels (μg/g) of organochlorine pesticides in sediment of Aiba reservoir.

Location α-BHC β-BHC γ -BHC δ-BHC ppDDE ppDDD ppDDT Heptachlor Heptaclor Epox α-Chlordane

A 0.04 ± 0.00a 0.02 ± 0.00a ND 0.02 ± 0.00a ND ND 0.46 ± 0.02a 0.03 ± 0.00a 0.06 ± 0.01a NDB 0.99 ± 1.24a 0.12 ± 0.02a 0.07 ± 0.11a 0.15 ± 0.10ab 0.40 ± 0.32a 2.04 ± 2.88ab 1.69 ± 2.39a 0.26 ± 0.16ab 0.47 ± 0.51a 0.19 ± 0.03a

C 0.35 ± 0.01a 0.52 ± 0.03b ND 0.28 ± 0.02b 1.14 ± 0.06b 6.67 ± 0.14b ND 0.36 ± 0.02b ND NDD 0.06 ± 0.07a 0.09 ± 0.11a 0.01 ± 0.01a 0.03 ± 0.01a ND 2.05 ± 2.80ab ND 0.05 ± 0.05a ND 0.38 ± 0.54a

Mean with different letter of the alphabet for each column are significantly different (p < 0.05) from each other.

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Table 5. Levels (μg/g) of organochlorine pesticides in sediments of Aiba reservoir.

Location γ -Chlordane Endosulfan I Endosulfan II Endosulfan III Aldrin Endrin Endrin Aldehyde Endrin Ketone Dieldrin Methoxychlor

A 0.02 ± 0.00a 0.05 ± 0.01a 1.07 ± 0.01b ND 0.09 ± 0.00a ND ND ND ND NDB 0.19 ± 0.00a 0.17 ± 0.01a ND ND 0.01 ± 0.01a 0.21 ± 0.04b ND 0.43 ± 0.16a 0.09 ± 0.12a 0.32 ± 0.46a

C 1.35 ± 0.02b ND ND ND ND 0.19 ± 0.01b ND 2.78 ± 0.14b ND NDD 0.15 ± 0.22a 0.55 ± 0.77a ND ND 0.06 ± 0.09a 0.08 ± 0.11ab 0.03 ± 0.04a 0.46 ± 0.63a 0.38 ± 0.54a 0.51 ± 0.73a

Mean with different letter of the alphabet for each column are significantly different (p < 0.05) from each other.

Table 6. Mean ± SD of organochlorine pesticides in water and sediments of Aiba Reservoir.

Medium α-BHC β-BHC γ -BHC δ-BHC ppDDE ppDDD ppDDT Heptachlor Heptaclor Epox α-Chlordane

Water 0.09 ± 0.14 0.09 ± 0.11 Nd 0.09 ± 0.12 0.04 ± 0.07 0.03 ± 0.06 0.05 ± 0.08 0.09 ± 0.11 0.05 ± 0.09 0.03 ± 0.06Sediment 0.36 ± 0.63 0.19 ± 0.21 0.02 ± 0.05 0.12 ± 0.12 0.38 ± 0.51 2.69 ± 3.02 0.54 ± 1.17 0.17 ± 0.16 0.13 ± 0.29 0.05 ± 0.08

Table 7. Mean ± SD of organochlorine pesticides in water and sediments of Aiba reservoir.

Medium γ -Chlordane Endosulfan I Endosulfan II Endosulfan III Aldrin Endrin Endrin Aldehyde Endrin Ketone Dieldrin Methoxychlor

Water 0.04 ± 0.07 0.19 ± 0.19 0.05 ± 0.06 0.23 ± 0.28 0.06 ± 0.08 0.04 ± 0.06 0.09 ± 0.14 0.09 ± 0.09 0.06 ± 0.08 0.11 ± 0.09Sediment 0.43 ± 0.58 0.19 ± 0.37 0.27 ± 0.49 ND 0.04 ± 0.05 0.12 ± 0.10 0.01 ± 0.02 0.92 ± 1.19 0.12 ± 0.27 0.21 ± 0.40

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522 G.O. Olutona et al.

heptachlor-epox (0.13 ± 0.29), aldrin (0.04 ± 0.05), α-Chlordane (0.05 ± 0.08), γ -Chlordane(0.43 ± 0.58), endosulfan I (0.19 ± 0.37), endosulfan II (0.27 ± 0.49), endosulfan III (ND),dieldrin (0.12 ± 0.27), endrin (0.12 ± 0.10), endrin aldehyde (0.01 ± 0.02), endrin ketone(0.92 ± 1.19), and methoxychlor (0.21 ± 0.40).

WHO [40] recommended the following values (mg/L) for various OCPs compounds in drinkingwater 0.02 (lindane), 0.0002(chlordane), 0.006 (endrin), 0.00003(aldrin and dieldrin), 0.001(DDTand metabolites), and 0.02 (methoxychlor). The values obtained for various OCPs compoundsboth in water and sediment in this study were above the stipulated guideline values to chemicalsfrom agricultural activities to the area of health significance in drinking water by WHO. Nostipulated value for endosulfan and heptachlor by WHO.

4. Discussion

It was noted that the distribution pattern for the two matrices was not exactly predictable. However,the mean levels of OCPs in water were generally lower than that of the sediment where similarfindings were reported by Okoya et al.,[41] In water, endosulfan I, II and III, endrin ketone andendrin aldehyde as well as α, β and δ-BHC, heptachlor and methoxychlor were found in significantconcentrations in almost all the sites, indicating their wide use.

The composition of OCPs and its metabolites is a useful tool for better understanding of the ori-gin and transport pathways of these contaminants in the environment.[42] DDT is degraded underaerobic conditions by micro-organisms to DDE and under anaerobic condition to DDD. DDEis more stable end-product; resistant to further degradation. DDD is an intermediate metabo-lite in conversion of DDT to DDE.[42] The result of this study was in agreement of Pandeyet al.,[42] where the percentage distribution of DDD is higher than DDE suggesting fresh inputof DDT rather than historical usage. The concentration of heptachlor both in water and sedimentwas higher compared to heptachlor-epoxide. Heptachlor gets mobilised to heptachlor-epoxide inthe aquatic environment.[42] Heptachlor epoxides adsorbed strongly to the soil and very resis-tant to degradation.[43] The dominance of heptachlor in sediment may be attributed to its slowdegradation due to the low temperature of the bottom sediment.

Residues of BHC isomers in both water and the sediments in significant concentrationsmay be attributed to the heavy use of this pesticide both for agricultural and fishing activitieswithin and around the reservoir. The concentration of the four isomers of BHC reveals a het-erogenic nature of distribution. Similarly, the composition of BHC isomers may be relative toisomerisation of BHC during the process of transport and transformation.[42] It is evident toassume that vector control programmes are very poor especially in rural area compared to urbanenvironment.

Agunloye [44] and Tongo [45] studied the occurrence and levels (μg/L) of chlorinated hydro-carbons in rivers and lakes in Southern Nigeria and reported the occurrence of lindane (ND - 167),aldrin (Nd - 190), endosulfan (ND - 750), HCB (ND - 9.2) and heptachlor (ND - 96). Ogunlowo[46] in his own studies reported the levels of OCPs in nine rivers in Ondo state and obtained arange of ND - 2150 ng/L for lidane, heptachlor, endrin, aldrin and dieldrin. Nwankwoala andOsibanjo [47] reported the occurrence of OCPs in surface water in Ibadan the values (ng/L) ofα and β-BHC (1–302), lindane (7–297), aldrin (Nd - 19), heptachlor (4–202) and total DDT(Nd-1266). Ogunfowokan et al.,[48] in their studies of OCPs levels in pond water and fish of anagricultural fish pond in Oke-sun, Osogbo Nigeria reported monthly mean levels (μg/L) rangefrom chlordane (2.65 ± 2.50) in May to pp-DDE (85.12 ± 26.35) in June, the wet season had arange values between chlordane (12.42 ± 12.75) and o,p′-DDD (39.60 ± 36.61); for dry season,the mean levels ranges between β-BHC (0.27 ± 0.90) and dieldrin (17.24 ± 8.71).

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523Table 8. Concentrations of organochlorine pesticide residue in water and sediment of some African rivers.

Location/Water Type pp-DDE pp-DDD pp-DDT DDD Total α-BHC β-BHC γ -BHC δ-BHC Reference

Water (ng/L)Lagos Lagoon 3(Nd-15) 83(Nd-344) Nd 2500 (Nd-4000) – – – – Tongo [45]Ero Reservoir Nd Nd Nd Nd – – 2.0 – Ogunlowo [46]Ero River Nd Nd Nd Nd 2.0Osse River Nd Nd Nd Nd 2.0Owesse River Nd Nd Nd Nd 6.4Apomu River Nd Nd Nd Nd 4.8Ibadan stream – – – – 150(1–302) – 100(7–297) – Nwankwoala and Osibanjo [47]River Ogun – – – – – – 13.3(1.441.9) – Agunloye [44]River Imo 0.2(Nd-0.6) Tongo [45]Cross River 0.3(Nd-1.1)Awba Dam 61(9–167)Kainji Lake – – – – – – 0.12(Nd-0.24) – Adeniji et al. [50]HartbeepoortReservoir 100 100 100 300 Greichus et al. [51]Voelvlei Reservoir, SA < 100 < 100 < 100 – – – – – Greichus et al. [51]Mcllwaine Lake 100 < 100 < 100 – – – – – Greichus et al. [52]Akure – – – – Nd Nd 0.037 Nd Idowu et al. [53]*Ifedore Nd Nd Nd NdIdanre Nd Nd Nd Nd

Sediment (ng/g)Ogunpa, Ibadan 13(Nd-32) Nd 0.1(Nd-5.3) – 0.7(Nd-2) 0.5(Nd-1.2) – Sunday [54]Ona River 7(Nd-14) Nd 1(Nd-2) – 0.5(Nd-0.9) NdOniyere 9(Nd-50) Nd Nd – 0.1(Nd-0.4) 0.9(Nd-2.0)Lekki, Lagoon 263(11-555) Nd 88(Nd-438) – 18.6(Nd-116) 1.1(0.1–4.9) 0.4(Nd-3.3) – Ojo [55]Ebrie Lagoon,CoteD’Ivorie 7.4(0.1–149) 28.1(0.2–803) 15.7(0.2–354) 17.1(1.1–997) – – – – Marchand and Martins [56]Mallwaine, Zimbabwe – – – 76(32–146) 16(2–42) – – – Mhlanga and Madziva [57]Hartbeespoort Dam, SA 10 18 13 45 – – – – Grechus et al. [51]Voelvlei Dam, SA 5 2 6 13Lake Nakuru, Kenya 10 10 < 10 – – – – – Greechus et al. [52]Numbaya Mungu,Tanzania 1(Nd-1) 1(Nd-3) 3(2–7) – – – – – Paasivita et al. [58]Pond, Osogbo – – – – 24.59w 23.01w 22.11w – Oyekunle et al. [49]

40.06d 57.94d 46.31d

Akure – – – – Nd Nd Nd Idowu et al. [53]*Ifedore Nd 4.86–5.64 1.2–3.73 Nd-1.93Idanre Nd Nd Nd Nd

Author with asterisk reported their result in mg/L and ug/g, w, wet, d, dry.

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Table 9. Concentrations of organochlorne pesticide residue in water and sediment of some African rivers.

Location/Water Type HCB Heptachlor Aldrin Heptaclor epoxide α Endosulfan β Endosulfan Dieldrin Reference

Water (ng/L)Ibadan stream 17(Nd-92) 72(4–202) 20(Nd-40) – 98(Nd-430) 250(17.8–652) Nwankwoala and Osibanjo [47]River Ogun – 0.28(Nd-0.8) 40(5.1–49) – 116(Nd-260) – – Agunloye [44], Tongo [45]River Imo 4(Nd-11.4) 13(Nd-40) 1.3(Nd-41)Cross River 1.0(Nd-5) 2(Nd-8.6) 36(Nd-143) 20(Nd-80)Awba Dam 0.8(Nd-2.5) – 18(12–29) 20(Nd-30)Kainji Lake – 0.47(Nd-3.48) 0.55(Nd-3.05) – – – – Adeniji et al. [50]Ero Dam – 3.3 3.1 – Nd – 560 Ogunlowo [46]Ero River Nd Nd Nd 740Osse River 5.0 Nd Nd 2150Owesse River 1.6 Nd Nd 1120Apomu River 4.6 3.5 nd 1380Akure – Nd Nd Nd 1.91–3.12 0.005 Nd Idowu et al. [53]*Ifedore Nd Nd Nd 0.38–6.49 0.030 0.002Idanre Nd Nd Nd 3.42–6.05 0.026–0.034 Nd

Sediment (ng/g)Ogunpa – Nd Nd – Nd – 0.9(Nd-1.8) Sunday [54]Ona River – Nd Nd Nd 0.3(Nd-0.5)Oniyere – Nd Nd Nd 2.0(Nd-6)Lekki Lagoon 64(Nd-1845) 56(Nd-3471) – 30(7–1155) – 4560(190–8460) Ojo [55]Mellwaine – – 1.0(Nd-12) – – – 5.0(Nd-16) Mhlanga and Madziva [57]Pond, Osogbo – 28.30w 28.30w – 23.73w Nd 30.63w Oyekunle et al. [49]

44.69d 63.32d 64.99d 69.17d

Akure – Nd Nd 0.19–1.76 0.06–0.68 Nd Idowu et al. [53]*Ifedore Nd Nd Nd-5.93 86.40–127.14 0..1–0.05 Nd-0.11Idanre Nd Nd-0.02 Nd 0.39–8.29 0.06–0.99 Nd

Author with asterisk reported their result in mg/L and ug/g; w, wet season, d, dry season.

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Table 10. Correlation coefficient in water samples for individual OCPs from Aiba Reservoir.

α-BHC β-BHC γ -BHC δ-BHC Hepta-chlor Aldrin Heptachlo Epox γ -Chlordane Endo-sulfan I α-Chlodane

α-BHC 1β-BHC 0.87 1γ -BHC 0 0 1δ-BHC 0.82∗ 0.54 0 1Heptachlor 0.02 0.76∗ 0 0.05 1Aldrin 0.05 0.23 0 0.31 0.47 1Heptachlor-Epox 0.64 0.64 0 0.91∗∗ 0.18 0.18 1γ -Chlordane 0.71∗ 0.69 0 0.92∗ 0.18 0.12 0.99∗∗ 1Endo-sulfan I 0.22 0.28 0 0.16 0.51 0.75∗ 0.09 0.10 1α-Chlodane 0.69 0.68 0 0.92∗∗ 0.18 0.13 0.99∗∗ 1.00∗∗ −0.10 1Dieldrin 0.26 0.79∗ 0 0.52 0.74∗ 0.65 0.65 0.62 0.30 0.03ppDDE 0.65 0.65 0 0.92∗∗ 0.18 0.17 1.00∗∗ 0.99∗∗ −0.09 0.99∗∗Endrin 0.68 0.67 0 0.92∗∗ 0.18 0.14 0.99∗∗ 0.99∗∗ −0.10 1.00∗∗Endo-sulfan II 0.79∗ 0.33 0 0.93∗∗ 0.08 0.44 0.71∗ 0.71 0.38 0.71∗ppDDD 0.67 0.66 0 0.92∗ 0.18 0.16 0.99∗∗ 0.99∗∗ 0.09 0.99∗∗Endrin Aldehyde 0.81∗ 0.18 0 0.73∗ 0.19 0.37 0.39 0.42 0.52 0.41Endo-sulfanIII 0.14 0.49 0 −0.19 0.89∗∗ 0.49 0.19 0.19 0.74∗ 0.19ppDDT 0.91∗∗ 0.46 0 0.95∗∗ −0.04 0.31 0.76∗ 0.78∗ 0.31 0.77∗Endrin Ketone 0.61 0.33 0 0.68 0.12 0.21 0.49 0.49 0.50 0.49Methoxychlor 0.29 0.29 0 0.33 0.52 0.49 0.15 0.15 0.8∗∗ 0.14

(Continued)

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Table 10. Continued

Dieldrin ppDDE Endrin Endo-sulfan II ppDDD Endrin Aldehyde Endo-sulfan III ppDDT Endrin Ketone Methoxychlor

α-BHCβ-BHCγ -BHCδ-BHCHeptachlorAldrinHeptachlor-Epoxγ -ChlordaneEndo-sulfan Iα-ChlodaneDieldrin 1ppDDE 0.64 1Endrin 0.63 0. 99** 1Endo-sulfan II 0.35 0.71∗ 0.71∗ 1ppDDD 0.64 1.00∗∗ 1.00∗∗ 0.71∗ 1Endrin Aldehyde 0.08 0.39 0.41 0.91∗∗ 0.40 1Endo-sulfanIII 0.44 −0.19 −0.19 −0.16 −0.19 −0.11 1ppDDT 0.36 0.76∗ 0.77∗ 0.97∗∗ 0.77∗ 0.89∗∗ −0.17 1Endrin Ketone 0.10 0.49 0.49 0.75∗ 0.49 0.71∗ 0.16 0.73∗ 1Methoxychlor 0.34 0.15 0.14 0.45 0.15 0.48 0.68 0.40 0.82∗ 1

∗∗Correlation is significant at the 0.01 level (2-tailed).∗Correlation is significant at the 0.05 level (2-tailed).

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Table 11. Correlation coefficient in sediment samples for individual OCPs from Aiba Reservoir.

α-BHC β-BHC γ -BHC δ-BHC Hepta-chlor Aldrin Hepta-Chloro Epox γ -Chlodane Endo-sulfan I α-Chlorodane

α-BHC 1β-BHC 0.12 1γ -BHC −0.18 −0.19 1δ-BHC 0.53 0.8∗∗ −0.15 1Hepta-chlor 0.67 0.79∗ −0.09 0.9∗∗ 1Aldrin −0.46 −0.67 −0.14 −0.66 −0.77∗ 1Hepta chlorEpox 0.9∗∗ −0.17 −0.04 0.28 0.45 −0.29 1γ -Chlodane 0.06 0.9∗∗ −0.19 0.8∗∗ 0.76∗ −0.62 −0.23 1Endo-sulfan I −0.12 −0.41 0.05 −0.28 −0.37 0.64 −0.04 −0.39 1α-Chlodane 0.71∗ −0.19 0.54 0.19 0.37 −0.39 0.82∗ −0.25 −0.31 1Dieldrin −0.19 −0.07 0.07 −0.37 −0.25 −0.35 −0.19 −0.12 0.22 0.09ppDDE 0.39 0.9∗∗ −0.19 0.9∗∗ 0.9∗∗ −0.64 0.13 0.9∗∗ −0.34 0.05Endrin 0.60 0.63 0.23 0.74∗ 0.8∗∗ 0.9∗∗ 0.45 0.57 −0.42 −0.56Endo sulfan II −0.32 −0.49 0.24 0.52 0.56 0.59 −0.17 −0.44 −0.24 −0.33ppDDD 0.38 0.9∗∗ 0.39 0.8∗∗ 0.8∗∗ −0.77∗ 0.09 0.8∗∗ −0.42 −0.09Endrin Aldehyde −0.23 −0.33 −0.06 −0.27 −0.39 0.66 −0.19 −0.30 0.9∗∗ −0.22Endo sulfanIII 0 0 0 0 0 0 0 0 0 0ppDDT 0.22 0.26 0.9∗∗ −0.23 0.17 −0.09 0.06 −0.25 0.08 0.50Endrin Ketone 0.02 0.9∗∗ −0.15 0.82∗ 0.73∗ 0.65 −0.27 0.9∗∗ −0.40 −0.26Methoxychlor −0.30 −0.39 0.51 −0.32 −0.39 0.49 −0.18 −0.37 0.8∗∗ 0.12

(Continued)

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Table 11. Continued

Dieldrin ppDDE Endrin Endo sulfan II ppDDD Endrin Aldehyde Endo sulfanIII ppDDT Endrin Ketone Methoxychlor

α-BHCβ-BHCγ -BHCδ-BHCHepta-chlorAldrinHepta chlorEpoxγ -ChlodaneEndo-sulfan Iα-ChlodaneDieldrin 1ppDDE −0.34 1Endrin −0.19 0.68 1Endo sulfan II −0.27 −0.46 −0.73∗ 1ppDDD 0.09 0.88∗∗ 0.73∗ −0.55 1Endrin Aldehyde −0.18 −0.30 −0.48 −0.22 −0.35 1Endo sulfanIII 0 0 0 0 0 0 1ppDDT 0.03 0.25 0.13 0.39 0.47 0.19 0 1Endrin Ketone 0.03 0.89∗∗ 0.59 0.47 0.88∗∗ −0.31 0 −0.22 1Methoxychlor 0.11 −0.37 0.28 −0.32 0.52 0.82∗ 0 0.39 0.35 1

∗∗Correlation is significant at the 0.01 level (2-tailed).∗Correlation is significant at the 0.05 level (2-tailed).

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Oyekunle et al. [49] studied the levels of organochlorine in pond sediments from a farm settle-ment in Osogbo Nigeria and reported mean range (μg/kg) of 15.45 heptachlor to 45.93 p.p′-DDTin rainy season and 31.88 chlordane to 102.23 p,p′-DDE in dry season. Pandey et al.,[26] in theirstudy of surface sediments of River Yamuna (Delhi, India) reported that total OCPs level rangedfrom 157.71 to 307.66 ng/g in June, 195.86–577.74 ng/g in August and 306.9–844.45 ng/g inOctober. Okoya et al.,[25] in their study of OCPs residue in sediments and waters from cocoaproducing area of Ondo state, south-western Nigeria reported mean range of OCPS (μg/g)forsediment as cis-chlordane 0.03–6.99; α-endosulfan 0.03–6.99; pp-DDE 0.08–19.04 and dieldrin0.01–7.62.

The organochlorine pesticides residues, their metabolites or conversion from one form toanother are harmful to human and ecologically harmful to aquatic habitats. The toxicity of theseOCPs can result in the death of fish perhaps due to deliberate application or accidental release ofthese chemicals to aquatic environment. Contamination of water body and bottom sediment withthese chemicals usually results in bioaccumulation in aquatic habitats.

Comparison with other studies revealed that the concentrations of individual OCPs reportedin this study are consistent with other studies of OCPs reported at the national and internationallevels. The values of OCPs observed in this study are comparable to those reported by otherauthors. Tables 8 and 9 list different studies together with the individual OCP concentrationsobserved in different parts of Africa. Generally, various compartments of the aquatic environmentin Nigeria and other parts of Africa are greatly contaminated by several OCPs. However, thevalues recently reported by Okoya et al.,[25] and Idowu et al.,[53] of the cocoa producing area ofOndo state, Nigeria were exceedingly high compared to this study, which could be attributed tointensive use of organochlorine pesticides in this area.

Correlation was performed for both water and sediments using bivariate Pearson correlationcoefficient for all pairs of compounds to determine the relationships between individual com-pounds. Correlation of OCPs in the surface water in Table 10 shows that apart from γ -BHCand endosulfan III, which did not significantly correlate with any other compounds, other com-pounds showed significant positive correlation with at least two other OCPs to a maximum ofnine compounds in δ-BHC. Table 11 shows the correlation coefficient for bottom sediment whereα-chlordane, dieldrin, endosulfan II, pp-DDT, endrin ketone and methoxychlor did not show anycorrelation at all; aldrin was negatively correlated with pp-DDD, whereas others showed strongpositive correlation with one another ranging from one to six individuals. The several positive andsignificant correlations were an indication that all OCPs were all related derivatives which wasan indication that they were likely to have originated from the same source and similarly affectedby related factors within the same environmental matrix.[26,32]

5. Conclusion

The preliminary study on the levels of organochlorine pesticide in water and sediments of Aibareservoir has been assessed. Three classes of OCPs (chlorinated benzene/cyclohexanes, cyclo-dienes and dichlorodiphenylethane) were identified and quantified. The study obtained indicatedthat both the water and bottom sediments were contaminated with high levels of these chemicals.The study further indicated that the concentrations of OCPs in water was lower to that of sedi-ments, hence they were hydrophobic and tend to accumulate in the sediments which act as a sinkfor these persistent organic pollutants. The levels of OCPs obtained revealed gross anthropogenicinputs of these chemical species by the farmers, fisher men and domestic sewages. Extensiveresearch work covering the seasonal evaluation and public enlightenment by the State Govern-ment and other appropriate agencies on the adverse health hazards of the use of these chemicalsare highly recommended.

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Acknowledgement

The authors appreciate the two anonymous reviewers for their objective criticisms which helped to improve the qualityof the manuscript.

References

[1] Fernandes MN, Paulino MG, Sakuragui MM, Ramos CA, Pereira CDS, Sadauskas-Henrique H. Organochlorineand metals induce changes in the mitochondria-rich cells of fish gills: An integrative field study involving chemical,biochemical and morphological analyses. Aquat Toxicol. 2013;126:180–190.

[2] Da Cuna RH, Pandolfi M, Genovese G, Piazza Y, Ansaldo M, Lo Nostro FL. Endocrine disruptive potential ofendosulfan on the reproductive axis of Cichlasoma Dimerus (Perciformes, cichlidae). Aqua Toxicol. 2013;126:299–305.

[3] Haag I, Kern U, Westrich B. Erosion investigation and sediment quality measurements for a comprehensive riskassessment of contaminated aquatic sediments. Sci Total Env. 2001;266:249–257.

[4] Calmano W, Hong J, Forstner U. Binding and mobilization of heavy metals in contaminated sediments affected bypH and redox potential. Water Sci Technol. 1993;28:223–235.

[5] Simpson SL, Apte SC, Batley GE. Effect of short-term resuspension events on trace metal speciation in pollutedanoxic sediments. Environ Sci Technol. 1988;32:620–625.

[6] Nowell LH, Capel PD. Dileanis, pesticides in stream, sediment and aquatic biota: Distribution, trends and governingfactors. Boca Raton, FL: Lewis Publisher; 1999.

[7] Sapozhnikova Y, Bawardi O, Schlenk D. Pesticides and PCBs in sediments and fish from the Salton Sea, CalifoniaUSA. Chemosphere. 2004;55:797–809.

[8] Fox WM, Connor L, Copplestone D, Johnson MS, Leah RT. The organochlorine contamination History of the mercyestuary, UK, revealed by analysis of sediment cores from salt marshes. Mar Environ Res. 2001;51:213–237.

[9] Castilla-Pinedo Y, Alvis EL, Alvis-Guzman N. Estimating exposure to organochlorine compounds from consumingpasteurised milk in Cartegena, Colombia. Review Salud Publications (Bogota). 2010;12(1):41–48.

[10] Loganathan BG. Global contamination trends of persistent organic chemicals: An overview. In: Laganathan BG,Lam PKS, editor. Global contamination trends of persistent. Chemicals CRC Press; 2012. p. 593–628.

[11] Covaci A, Gheorghe A, Hulea O, Schepens P. Levels and distribution of Organochlorine Pesticides, PolychlorinatedBiphenyls and Polybrominated Diphenyl ethers in sediments and biota from the Danube Delta, Romania. EnvironPollut. 2006;140:136–149.

[12] Roche H, Vollaire Y, Persie A, Buet A, Oliveira-Ribeiro C, Coulet E, Banas D, Ramade F. Organochlorine in thevaccares lagoon trophic web (Biosphere Reserve of Camargue, France). Environ Pollut. 2009;157:2493–2506.

[13] Scheringer M, Stroebe M, Wania F, Wegmann F, Hngerb ¨̄uhler K. The effect of export to the deep sea on the long-rangetransport potential of persistent organic pollutants. Environ Sci Pollut Res Int. 2004;11:41–48.

[14] Bouluobassi I, Mejanelle I, Pete R, Fillaux J, Lorre A, Point V. PAH transport by sinking particles in the openMediteranean sea: A 1 year sediment trap study. Mar Pollut Bull. 2006;52:560–571.

[15] Mckim JM. Physiological and biochemical mechanism that regulate the accumulation and toxicity of environmentalchemicals in fish. In: Hamelink JL, Landrum PF, Bergman HL, Benson WH, editor. Bioavailability: Physical,chemical and biological interactions. Boca Raton, FL: Lewis Publisher; 1994. p. 197–201.

[16] Toft G, Edwards TM, Baatrup E, Guillette Jr. LJ. Distributed sexual characteristics in male mosquito fish (Gambusiahalbrooki) from a lake contaminated with endocrine disruptors. Environ Health Perspect. 2003;111:695–701.

[17] Ogunfowokan AO, Oyekunle JAO, Torto N, Akanni MS. A study of persistent organochlorine pesticide residue infish tissues and water from an agricultural fish pond. Emir J Food Agric. 2010;24(2):165–184.

[18] Johnson HT, Keil JE, Gaddy RG, Loadholt CB, Hennigar GR, Walker EM. Prolonged ingestion of commercialDDT and PCB, effects on progesterone levels and reproduction in the mature female rat. Arch Env Cont Toxicl.1976;3:470–490.

[19] Lundeberg C. Effects of DDT in cytochrome P-450 and oestrogen dependent functions in mice. Env Physiol Biochem.1974;4:200–204.

[20] Fabro S, McLachlan JA, Dames NM. Chemical exposure of embryos during the preimplantation stages ofpregnancy:mortality rate and intrauterine development. Am J Obestrics Gynecol. 1984;148:929–938.

[21] Muino MAF, Sancho MT, Gandara JS, Vidal JMC, Huidobro JF, Lozano JS. Organochlorine pesticides residues inGalician (NW Spain) honeys. Apidologie. 1995;26:33–38.

[22] Clement J, Okey A. Reproduction in female rats born to DDT –treated parents. Bull Env Contam Toxicol.1974;12:373–377.

[23] O’Shea TJ, Everette AL, Ellison LE. Cyclodiene, insecticide, DDE, DDT&lt; Arsenic and Mercury contamination ofbig brown bats (Eptesicus fucui), foraging at Colorado super fund site, Arch. Environ Contam Toxicol. 2001;40:112–120.

[24] Wang H-S, Chen Z-J, Wa W, Man T-B, Giesy JP, Du J, Zhang G, Wong CH-C, Wong M-H. Concentrations oforganochlorine pesticides (OCPs) in human blood plasma from Hong-Kong: markers of exposure and sources fromfish. Environ Int. 2013;54:18–25.

[25] Alcock RE, Behnisch PA, Jones KC, Hagenmeaier H. Dioxin-like PCBs in the environment-human exposure andthe significance of sources. Chemosphere. 1998;37:1457–1472.

Dow

nloa

ded

by [

Cap

e Pe

nins

ula

Uni

vers

ity o

f T

echn

olog

y], [

God

win

Ola

dele

Olu

tona

] at

21:

25 2

4 Ju

ne 2

014

Chemistry and Ecology 531

[26] Kiviranta H, Vartianem T, Tuomisto J. Polychlorinated dibenzo-p-dioxins dibenzo furans, and biphenyls in fishermenin Finland. Environ Health Perspect. 2002;110:355–361.

[27] Fitzgerald EF, Hwang SA, Langguth K, Cayo M, Yang BZ, Bush B, Worswick P, Lauzon T. Fish consumption andother environmental exposures and their associations with serum PCB concentrations among Mohawk women atAkwesasne. Environ Res. 2004;94:160–170.

[28] Wang HS, Sthiannopka S, Du J, Chen ZJ, Kim KW, MohammedYasim MS. Daily intake and human risk assessmentof organochlorine pesticides (OCPs) based on cambodiam market basket data. J Hazard Mater. 2011;192:1441–1449.

[29] Adegbola JA, Anugwon HD, Awagu F, Adu EA. The concept of withholding period and pesticide residues in grainstorage. Asian J Agric Rur Dev. 2012;2(4):598–603.

[30] Shaibu I. National Agency for Food and Drug Administration and Control (NAFDAC) bans 30 agricultural products,Vanguard, May, 14, 2008, www.allafrica.com

[31] Chikwe A. National Agency for Food and Drug Administration and Control (NAFDAC) axes 20 fast food outlets.Task operators on good hygiene practices, Tuesday, July 6, 2010, www.nigeriabetforum.com

[32] Ayodele HA, Adeniyi IF. The zooplankton of six impoundments of river Osun, Southwest Nigeria. The Zoologist.2006;1(4):49–67.

[33] Atobatele OE, Ugwumba OA. Distribution, abundance and diversity of macrozoobenthos in Aiba reservoir, Iwo,Nigeria. Afri J of Aqua Sci. 2010;35(3):291–297.

[34] Olutona GO, Dawodu MO,Ajaelu JC. Trace metal levels and speciation pattern in the surface water ofAiba reservoir,after sorption on Amberlite XAD-16 resin. Biorem Biodiv Bioavail. 2013;7(1):85–90.

[35] Alamu WAO. The tree has blossomed. Nigeria: Ola Ayediran Prints; 1992.[36] Atobatele OE, Ugwumba OA. Seasonal variation in the physiochemistry of a small tropical reservoir (Aiba reservoir,

Iwo, Osun, Nigeria). Afri J Biotech. 2008;7:1962–1971.[37] Ogunfowokan AO, Asubiojo OI, Fatoki OS. Isolation and determination of polycyclic aromatic hydrocarbons in

surface runoff and sediment. Water, Air, and Soil Pollut. 2003;147:245–261.[38] Miller JN, Miller JC. Statistics and chemometrics for analytical chemistry, 4th ed. Edinburgh, UK: Pearson

Educational Limited; 2000. p. 271.[39] Duncan DB. Multiple range and multiple F-test. Biometrics. 1955;11:1–42.[40] WHO. Guidelines for drinking water quality, 3rd ed. Geneva: WHO Press; 2008. p. 230.[41] Okoya AA, Ogunfowokan AO, Asubiojo OI, Torto N. Organochlorine pesticides residues in sediments and waters

from cocoa producing areas of Ondo state southwestern Nigeria, Hindawi Publishing Corporation. ISRN Soil Sci.2013;2013:12.

[42] Pandey P, Khillare PS, Kumar K. Assessment of organochlorine pesticides residues in the surface sediments of riverYamuna in Delhi, India. J Env Pro. 2011;2:511–524.

[43] Keith LH. Environmental endocrine disrupters: A handbook of property data. New York: Wiley; 1997. p. 621.[44] Agunloye TO. A survey of chlorinated hydrocarbons in rivers of southern Nigeria. M. Sc Thesis. Department of

Chemistry, University of Ibadan, Nigeria; 1984.[45] Tongo AA. Baseline study of levels of organochlorine pesticides in Nigeria rivers and their sediments. M. Sc Thesis,

department of Chemistry, University of Ibadan, Nigeria; 1985.[46] Ogunlowo SO. Priority chemical pollutants in some rivers along the cocoa growing area of Ondo state. M.Sc Thesis,

Department of Chemistry, University of Ibadan, Nigeria; 1991.[47] Nwankwoala AU, Osibanjo O. Baseline levels of selected organochlorine pesticides in surface waters in Ibadan

(Nigeria) by electron capture gas chromatography. Sci Total Env. 1992;119:179–190.[48] Ogunfowokan AO, Oyekunle JAO, Torto N, Akanni MS. A study on persistent organochlorine pesticide residues in

fish tissues and water from an agricultural fish pond. Emir J Food Agric. 2012;24(2):165–184.[49] Oyekunle JAO, OgunfowokanAO,Akanni MS, Torto N. Levels of organochlorine pesticides residues in the pond sed-

iments from Oke-Osun farm settlement, Osogbo, Nigeria. Proceedings of the 33rd Annual International Conferenceof Chemical Society of Nigeria, 20–24 September; 2010, Abeokuta. p. 418–427.

[50] Adeniji HA, Mbagwu IG, Ibikunle F. A review of studies on the assessment of water quality in Nigerian inlandwaters: In proceedings of the first national symposium on water quality monitoring and status in Nigeria, 6–18October, 1991, Kaduna, Nigeria. Lagos Federal Environmental Protection Agency.

[51] Greichus YA, Greichus A, Ammam BD, Hopcraft J. Insecticides, polychlorinated biphenyls and metals in Africanlake ecosystems. Hartbeespoort Dam, Transvaal and Voelvlei Dam, Cape Province, South Africa. Arch EnvironContam Toxicol. 1977;6:371–383.

[52] Greichus YA, Greichus A, Ammam BD, Hopcraft J. Insecticides, polychlorinated biphenyls and metals in Africanlake ecosystems. Lake Mcllwaine, Rhodesia. Bull Environ Contam Toxicol. 1978;19:444–453.

[53] Idowu GA, Aiyesanmi AF, Owolabi BJ. Organochlorine pesticide residue levels in river and sediment from cocoaproducing areas of Ondo State central district, Nigeria. J Environ Chem Ecotoxicol. 2013;5(9):242–249.

[54] Sunday M. Determination of chlorinated pesticide residue and metals in sediments from rivers and streams in Ibadan,Nigeria. M. Sc. Thesis. Department of Chemistry, University of Ibadan, Nigeria; 1990.

[55] Ojo OO. Bottom sediments as indicators of chemical pollution in Lekki Lagoon. M. Sc. Thesis. Department ofChemistry, University of Ibadan, Nigeria; 1991.

[56] Marchand M, Martins JL. determination de la pollution chimique chydrocarbures, organochlores, metaux dans lalagune d’Abidjan (cote d’Ivoire) par l’etudes sediments. Oceanogr Trop. 1985;20(1):25–29.

[57] Mhlanga AT, Madziva JT. Pesticides residues in Lake Mcllwaine. J Human Environ. 1990;19(8):368–372.[58] Paasivita J, Palm H, Paukku P. Chlorinated insecticide residues in Tanzanian environment Tanzadrin. Chemosphere.

1988;17(100):2055–2062.

Dow

nloa

ded

by [

Cap

e Pe

nins

ula

Uni

vers

ity o

f T

echn

olog

y], [

God

win

Ola

dele

Olu

tona

] at

21:

25 2

4 Ju

ne 2

014