Overview of Environmental Contamination in Lao PDR
Dr. Kesiny Phomkeona
Department of Chemistry
Faculty of Science
National University of Laos
Department of Chemistry (DOC) was found
along with the establishment of National
University (05-11-1996).
DOC is a department member of Faculty of
Science (FOS).
Chemistry DepartmentEstablishment
Mrs. Sysavad LUANGSISUPHANHead of Chemistry Department
Analytical Chemistry
Environmental
Chemistry
General Chemistry
Inorganic Chemistry
Organic Chemistry
Physical Chemistry
Pesticide Residue and
water Quality
Researches
Chemistry DepartmentAcademic Distribution
Theoretical and practical works are distributed to not only chemistry students but also to other students from other institutes.
Chemistry DepartmentMain Research Facilities
HPLC/UV-Vis or RID and IC/CD
UV-Vis Spectrophotometers
AAS/Hydride Generation for As and Cold for Hg
TOC Analyzer
CO2 Analyzer
DI water production system and electric Balance GC-MS
Research Activities in Chemistry Department, NUOL
• Pesticide Residues Analysis: Research is focused on contamination of organochlorine pesticides in foods and environmental samples (2005-2012).
• Water Qualities Analysis: Conduct research in water contaminations and water quality test for fresh and wastewater, and drinking water.
General Information• Land area:
236,800 km2
• Stocked forest land >40%
• Population: 6.5 million people (2012)
• Approx. 83% of population live in rural area.
Current Environment Issue in Lao PDR
The environment and natural resources of Lao PDR are being threatened by a number of factors associated with the mining sector, including hazardous chemicals, including heavy metals such as mercury, lead, cadmium, arsenic, chromium, copper, and zinc as well as persistent organic pollutants (POPs) such as dioxins and furans, PCBs, and various pesticides and herbicides.
Current and Future Interested Researches
•Water Quality.
•Pesticide Residue.
•Chemical Contaminants in Food and water.
•Renewable Energy-Biodiesel.
•Air pollution.
Previous Study on Pesticide Residue
• Department of Chemistry have had assistance from International Program in Chemical Science (IPICS)/ISP, Sweden, to set up capacity on pesticide residue analysis including laboratory and methods to be used since 2005.
• The primary focus of the project was qualitative analysis of organochlorine pesticides in samples, including evaluation of extraction methods by recovery tests, to get an idea of which pesticides can be found in the environment.
2008 (Department of Chemistry, NUOL)• The following organochlorine pesticides were found in sediments, water and
aquatic animals samples collected from Vientiane capital.
PesticidesAmount found, ng/g. Lowest-Highest
Dry season Rainy season
α-HCH 0.023 - 19.630 0.023 - 32.194
β-HCH 0.115 - 19.721 0.526 - 146.200
γ-HCH 1.865 - 424.87 10.362 - 274.611
Aldrin 0.584 - 52.164 2.589 - 89.9
Heptachlor-endo-epoxide 6.485 - 104.686 3.458 - 7.349
α-Endosulfan 0.387 - 76.997 4.842 - 75.329
β-Endosulfan 501.319 15.831-203.166
Dieldrin 60 ND
4,4’-DDE 0.218 - 245.441 0.051 - 132.385
4,4’-DDD 7.352 - 201.203 5.347 - 16.042
4,4’-DDT 0.134 - 91.133 1.691 - 128.078
2009 (Department of Chemistry, NUOL)• The following organochlorine pesticides were found in fruits and
vegetable samples collected from local markets in Vientiane capital.
Pesticides Highest amount found, μg/g.
α-HCH 5.99
β-HCH 0.721
γ-HCH 0.04
Aldrin 1.487
Dieldrin 6.107
4,4’-DDE 0.131
2,4’-DDT 14.876
4,4’-DDT 0.417
2012 (Department of Chemistry, NUOL)
Samples 2,4’ DDT (μg.kg-1) 2,4’ DDE (μg.kg-1) 2,4’ DDD (μg.kg-1)
Orange ND ND < LOQ
Mango ND ND < LOQ
Apple ND < LOQ < LOQ
Chinese pear ND ND < LOQ
Morning glory ND < LOQ < LOQ
Chinese cabbage ND < LOQ < LOQ
Chinese lettuce ND < LOQ < LOQ
Yard long bean < LOQ ND < LOQ
Fish(1) ND 0.48 < LOQ
Fish(2) ND < LOQ < LOQ
Fish(3) ND 0.49 0.47
Fish(4) ND < LOQ < LOQ
Previous Studies on Water Contamination by Heavy Metals
• Water Quality Unit of Chemistry Department has conducted researches on water contamination of heavy metals. The studies were done by staff members and together with supporting undergraduate students to undergo their final projects.
Analysis of heavy metals in samples were performed by Atomic Absorption Spectrophotometer (AAS) with suitable technique for each element.
• Hg : AAS with cold vapor generation• As : AAS with hydride generation• Zn, Cd, Fe, and others: AAS with flame
Hg Contamination in Aquatic Samples(2012)
1 2 3 4 MPL0
0.2
0.4
0.6
0.8
1
1.2
1.4
0.035 0.0420.121
1.18
0.001
Sample
Hg
conc
entr
atio
n, p
pm
MPL = Maximum Permissible Level
1 2 3 4 5 MPL0
0.02
0.04
0.06
0.08
0.1
0.12
0.030.02
0.08
0.1
0.03
0.002
Sample
Hg,
con
cent
rati
on, p
pm
Hg Contamination in Water Samples
MPL = Maximum Permissible Level
d1 d2 d3 d4 d50
0.005
0.01
0.015
0.02
0.025
0.01
0.007
0.011
0.02
0.005
Sample
Hg
conc
entr
atio
n, p
pm
Hg Contamination in Sediment Samples
MPL = Maximum Permissible Level
Arsenic Contamination in Ground Water(UNESCO 2011)
• River mouth & along Mekong River
B.Nam
San
B.Bua
khai
B.Dan
Nua
B.Dan
Taii
B.Paks
e(SV)
Paks
e(KM
)
B.Bun
g San
tha
Don
e Khe
o Nua
Don
e Khe
o Taii
0
20
40
60
80
100
120
10
25
100
50 50
100
10
25
100
As, ppb
As
STD = 10 ppb
Arsenic Contamination in Ground Water(ISP 2012)
s1 s2 s3 MPL0
2
4
6
8
10
12
8.025
6.5637.474
10
Sample
As
con
cen
trat
ion
, pp
b
MPL = Maximum Permissible Level
• Environmental samples in Laos are nowadays contaminated by toxic heavy metals (As and Hg) which exceed maximum permissable limit.
• Organophosphorus and Pyrethroid are nowadays widely used in Laos.
• Studies on Organophosphorus and Pyrethroid are not able to do. Due to the limitation of chemicals and equipments and human resourse.
Conclusion
Acknowledgement
Ms. S. Louangsysouphan
Ms. V. Chounlamany
Dr. P. Inthapanya
Mr. V. Phouthavong
Assoc. Prof. Dr. Peter Sundin Mr. Lars Lundmark
IPIC/ISP
Mr. S. Bouta
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