Threat of Arsenic Occurrence in the Vietnamese Mekong Delta

砷的發生對越南湄公三角洲之威脅

10.6234/JGR.2015.63.06

Vo Le Phu；Rizlan Bernier；Pham C. Hoai Vu；Ho T. Ngoc Ha；Nguyen T. Bao Tu

砷 ； 地下水 ； 湄公三角洲 ； Arsenic ； groundwater ； Mekong Delta

地理研究

63期（2015 / 11 / 01）

129 - 142

英文

高溶解砷在地層孔隙水中移動已被世界廣泛報導，地下水中高濃度的砷對人類健康及地下水利用造成威脅。全球已有許多文獻針對含砷的地下水進行研究，但近年來，越南紅河及湄公河三角洲砷的發生才引起科學家的注意。本文主要目的在於回顧亞洲孟加拉及越南沖積扇平原砷的汙染，接著經由在越南湄公三角洲安江省安富縣的近期調查，於2014年乾濕季時收集36個地下水樣本及2個沉積物核心，說明湄公三角洲砷發生的證據。調查結果顯示，研究區域內砷的濃度介於208 到1,523μg/L之間，遠高於世界衛生組織（WHO）及越南飲用水的標準（10μg/L）。此外，乾季時地下水砷的濃度比濕季時更高，且砷的濃度隨著沉積物深度增加而增加，在25公尺深時高達201ppm。

The occurrence of high dissolved Arsenic (As) levels mobilized from geogene sources in pore water has been reported worldwide. High elevations of Arsenic concentration in groundwater have posed threats to human's health and implication for groundwater use. Previous studies on As-rich groundwater around the world have been in the literature. Particularly, Arsenic occurrence in the Red River and Mekong River deltas of Vietnam has recently drawn much attention from scientists. The purpose of this paper is to review Arsenic contamination in alluvial plains of Asian deltas of Bangladesh and Vietnam. Further, an additional evidence of Arsenic occurrence in the Mekong Delta region will be reported through our recent survey in An Phu district, An Giang province of the Vietnamese Mekong Delta. Thirty six (36) groundwater samples and two (02) cores of sediment were collected in the rainy and dry seasons of 2014. The investigated results show that Arsenic concentration in groundwater resources in the study area is much higher than the WHO and Vietnam drinking water standard (10μg/L), ranging from 208 to 1,523μg/L. In addition, the arsenic concentration in groundwater in the dry season tends to be higher than in the rainy season. Arsenic concentration in sediment cores increases with depths, reaching to 210 ppm at 25m depth.

1. GSO [General Statistics Office] (2011): Statistical Yearbook of Vietnam 2010. Hanoi: Statistical Publishing House
2. GSO [General Statistics Office] (2012): Statistical Yearbook of Vietnam 2011. Hanoi: Statistical Publishing House
3. Berg, M.,Stengel, C.,Trang, P.T.K.,Viet, P.H.,Sampson, M.L.,Leng, M.,Samreth, S.,Fredericks, D.(2007).Magnitude of arsenic pollution in the Mekong and Red River deltas-Cambodia and Vietnam.Sci. Total Environ.,372,413-425.
4. Buschmann, J.,Berg, M.,Stengel, C.,Sampson, M. L.(2007).Arsenic and manganese contamination of drinking water resources in Cambodia: coincidence of risk areas with low relief topography.Environ. Sci. Technol.,41(7),2146-2152.
5. Chowdhury, U.K.,Biswas, B.K.,Chowdhury, T.R.,Samanta, G.,Mandal, B.KI.,Basu, G.C.,Chanda, C.R.,Lodh, D.,Saha, K.C.,Mukherjee, S.K.,Roy, S.,Kabir, S.,Quamruzzaman, Q.,Chakraborti, D.(2000).Groundwater arsenic contamination in Bangladesh and West Bengal, India.Environ. Health Perspect.,108(5),393-397.
6. DONRE [Department of Natural Resources,Environment] An Giang(2010).Synthesis of groundwater status.Long Xuyen City:DONRE An Giang.
7. Erban, L.E.,Gorelick, S.M.,Zebker, H.A.,Fendorf, S.(2013).Release of arsenic to deep groundwater in the Mekong Delta, Vietnam, linked to pumping-induced land subsidence.PNAS,110(34),13751-13756.
8. Halim, M.A.,Majumder, R. K.,Nessa, S. A.,Hiroshiro, Y.,Uddin, M. J.,Shimada, J.,Jinno, K.(2009).Hydrogeochemistry and arsenic contamination of groundwater in the Ganges Delta Plain, Bangladesh.Journal of Hazardous Materials,164,1335-1345.
9. Hoang, T.H.,Bang, S.,Kim, K.-W.,Nguyen, M.H.,Dang, D.M.(2010).Arsenic in groundwater and sediment in the Mekong River Delta, Vietnam.Environmental Pollution,158,2648-2658.
10. Hossain, M.F.(2006).Arsenic contamination in Bangladesh - An overview.Agriculture Ecosystems & Environment,113,1-16.
11. IARC(1987).Overall evaluations of carcinogenicity: an updating of IARC Monographs volumes 1 to 42.IARC Monogr. Eval. Carcinog. Risks Hum. Suppl.,7,1-440.
12. Kocar, B.D.,Polizzotto, M.L.,Benner, S.G.,Ying, S.C.,Ung, M.,Ouch, K.,Samreth, S.,Suy, B.,Phan, K.,Sampson, M.,Fendorf, S.(2008).Integrated biogeochemical and hydrologic processes driving arsenic release from shallow sediments to groundwaters of the Mekong Delta.Appl. Geochem.,23,3059-3071.
13. Meharg, A.A.(2005).Venomous Earth: How Arsenic Caused the World's Worst Mass Chemical Poisoning.London:Macmillan.
14. Mekong River Commission=MRC(2010).State of the Basin Report 2010.Vientiane:Mekong River Commission.
15. Nguyen, V.A.,Bang, S.,Pham, H.V.,Kim, K-W.(2009).Contamination of groundwater and risk assessment for arsenic exposure in Ha Nam province, Vietnam.Environ. Int.,35,466-472.
16. Nickson, R.T.,McArthur, J.M.,Ravenscoft, P.,Burgess, W.G.,Ahmed, K.M.(2000).Mechanism of arsenic release to groundwater, Bangladesh and West Bengal.Applied Geochemistry,15,403-413.
17. Pham, T.K.T.,Berg, M.,Pham, H.V.,Nguyen, V.M.,Meer, J.R.(2005).Bacterial bioassay for rapid and accurate analysis of arsenic in highly variable groundwater samples.Environ. Sci. Technol.,39,7625-7630.
18. Ravenscroft, P.,Brammer, H.,Richards, K.(2009).Arsenic Polution: A Global Synthesis.Chichester:Wiley-Blackwell.
19. Renaud, F.G.(ed.),Kuenzer, C.(ed.)(2012).The Mekong Delta System: Interdisciplinary Analyses of a River Delta.Dordrecht:Springer.
20. Shinkai, Y.,Duong, V. T.,Sumi, D.,Doan, C.,Kumagai, Y.(2007).Arsenic and other metal contamination of groundwater in the Mekong River Delta, Vietnam.Journal of Health Science,53(3),344-346.
21. Smedley, P. L.,Kinniburgh, D. G.(2002).A review of the source, behaviour and distribution of arsenic in natural waters.Applied Geochemistry,17,517-568.
22. Smith, A.H.,Lingas, E.O.,Rahman, M.(2000).Contamination of drinking water by arsenic in Bangladesh: a public health emergency.Bulletin of the World Health Organization,78(9),1093-1103.
23. Stanger, G.,Truong, T.V.,Ngoc, L.T. M.,Luyen, T.V.,Tran, T.(2005).Arsenic in groundwaters of the Lower Mekong.Environmental Geochemistry and Health,27(4),341-357.
24. Ta, T. K .O.,Nguyen, V. L.,Tateishi, M.,Kobayashi, I.,Tanabe, S.,Saito, Y.(2002).Holocene delta evolution and sediment discharge of the Mekong River, Southern Vietnam.Quaternary Science Reviews,21,1807-1819.
25. Tran, A.T.,Tran, K.T.,và Vo, Q.M.(2011).Arsenic Contamination of Groundwater in An Phu district, An Giang province.Tạp chí Khoa học - Đại học Cần Thơ,17a,118-123.
26. Tran, Dang An,Tsujimura, Maki,Vo, Le Phu,Kawachi, Atsushi,Doan, Thu Ha(2014).Chemical Characteristics of Surface Water and Groundwater in Coastal Watershed, Mekong Delta, Vietnam.Procedia Environmental Sciences,20,712-721.
27. Tran, T.B.(ed.),Bach, T.S.(ed.),Miller, F.(ed.)(2007).Challenges to Sustainable Development in the Mekong Delta: Regional and National Policy Issues and Research Needs.Bangkok:The Sustainable Mekong Research Network.
28. Tran, T.B.(ed.),Bach, T.S.(ed.),Miller, Fiona(ed.)(2007).Challenges to Sustainable Development in the Mekong Delta: Regional and National Policy Issues and Research Needs.Bangkok:The Sustainable Mekong Research Network.
29. Tran, T.B.(ed.)Bach, T.S.(ed.),Miller, F.(ed.)(2007).Challenges to Sustainable Development in the Mekong Delta: Regional and National Policy Issues and Research Needs.Bangkok:The Sustainable Mekong Research Network.
30. Winkel, L.H.E.,Pham, T.K.T.,Vi, M.L.,Stengel, C.,Amini, M.,Nguyen, T.H.,Pham, H.V.,Berg, M.(2011).Arsenic pollution of groundwater in Vietnam exacerbated by deep aquifer exploitation for more than a century.PNAS,108,1246-1251.