Arsenic Pollution: Global Distribution – Evaluation and Monitoring

Arsenic Pollution: Global Distribution – Evaluation and Monitoring

Bibudhendra Sarkar, of The Hospital for Sick Children and the Department of Biochemistry, University of Toronto, Toronto, Canada, (bibudhendra.sarkar@sickkids.ca) reviewed the global picture of arsenic pollution and the methods of monitoring it.

Arsenic pollution has been recognized as a global problem only since 1990. It is now evident that arsenic in groundwater is a problem around the world (Figures 8.1, 8.2, 8.3, 8.4). Dr. Sarkar cautioned that the last two columns of Figures 8.2, 8.3, 8.4 should be viewed with caution because of varied technology. Dr. Sarkar also noted that arsenic pollution can result from coal burning, especially indoors.

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Dr. Sarkar’s studies have focused on Bangladesh and the West Bengal region of India (Figure 8.5), two separate countries but geographically closely related.

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He first witnessed the effects of chronic arsenic poisoning in meeting an eight year old boy with skin disease. Following that encounter, Dr. Sarkar’s work in this field began. He subsequently found the enormous problem of arsenic pollution in Bangladesh. There was need for a multidisciplinary team to evaluate many sites and test for many metals (Figure 8.6), which also demanded the use of many techniques. Therefore collected samples were sent to many laboratories around the world.

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The distribution of arsenic pollution in Bangladesh is shown Figure 8.7. Neighboring Indian states also almost certainly have arsenic contamination.

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Contamination by other metals such as manganese (Figure 8.8) is also evident. In Figure 8.9 Dr. Sarkar shows that the levels of Arsenic (a known carcinogen) and Manganese (putative cause of Parkinson-like syndrome), are abnormally high in the waters of Bangladesh.

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A study of pregnancy outcome has been undertaken in Western Bangladesh (Figure 8.10). Preliminary findings suggest that stillbirths are 19% higher and abortions are 20% higher (in the arsenic affected group vs. the control group.

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Dr. Sarkar discussed the importance of using accurate, relatively inexpensive techniques to test water (Figure 8.11). He has developed and evaluated a arsenomolybdate technique (Figure 8.12) which is accurate and relatively inexpensive when compared to other methods (Figure 8.13). This technique was used to evaluate water samples in Western Bangladesh (Figures 8.14, 8.15, 8.16). It is now freely available and can be applied to the task of monitoring drinking water, an important method of preventing chronic arsenic poisoning.

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Dr. Sarkar’s conclusions are shown in Figure 8.17 and the laboratories and groups (all volunteers) involved in these studies are listed in Figure 8.18.

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