Arsenic: The king of poisons, the poisons of kings, and the bane of investigators1. The IARC2 has classified arsenic as a group 1 human carcinogen. Chronic exposure to inorganic arsenic can cause cancerous2-5 and non-cancerous health hazards6,7 in humans. Arsenic can get entry into the human body via drinking water, eating food, inhaling dust, and/or ingesting soil.
In arsenic affected areas of West Bengal-India and Bangladesh huge quantity of arsenic is falling on agricultural land. A study in West Bengal-India reported that in a 201 km2 area of the Deganga block in the arsenic-affected district of North 24-Parganas, 6.4 tons of arsenic is falling on agricultural land in one year from 3200 contaminated tube wells for agricultural irrigation8. They expect tons of arsenic is coming with underground water in the arsenic affected areas of West Bengal-India and Bangladesh and falling on irrigated land. Thus, it is expected arsenic is entering the food chain.
Figure. Using tube well water for agricultural irrigation.
Rice and vegetable are the staple food for poor villagers of West Bengal, India and Bangladesh. This is true for the villagers in Kolsur gram-panchayet (G.P.) in Deganga block of North 24-Parganas district, West Bengal-India, where a group of researchers studied for arsenic in soil, rice, and vegetables from fields cultivated with arsenic contaminated water. From the results of total arsenic (drinking water + rice + vegetables + Pantavat + water added for food preparation) body burden to North Kolsur villagers [1185.0 µg for per adult per day and 653.2 µg for per child (around 10 years) per day], as the amount of arsenic coming from rice, vegetables, and water added for Pantavat and food preparation is 485 µg i.e., 41% of total for adult and 253.2 µg i.e., 38.8% for child and from rice and vegetable 285 µg i.e., 24% of total for adult and 153.2 µg i.e., 23.4% for child9-11. Their findings show most of the arsenic coming from food is inorganic in nature10. They reported that 95% and 5% of the arsenic are inorganic arsenic and methylated arsenic in rice, and 96% and 4% are inorganic arsenic and methylated arsenic in vegetables, respectively10.
According to WHO12 1.0 µg of inorganic arsenic per day may give rise to skin effects within a few years.
It has been estimated that based upon the current U.S. Environmental Protection Agency (EPA) standard of 50 µg/L, the lifetime risk of dying from cancer of the liver, lung, kidney, or bladder, from drinking 1 liter per day of water could be as high as 13 per 1000 persons13. Using the same methods, the risk estimate for 500 µgL of arsenic in drinking water would be 13 per 100 persons14. In its latest document on arsenic in drinking water, the U.S. National Research Council (NRC) concluded that exposure to 50 µg/L could easily result in a combined cancer risk15 of 1 in 100. Comparing to the WHO, EPA, and NRC document with arsenic burden to Kolsur villagers from water and food it appears that Kolsur villagers’ risk of suffering from arsenical skin effect and cancer is there. Compared to worldwide arsenic consumption from food, it appears Kolsur villagers are also consuming high amount of inorganic arsenic from food and vegetables. Kolsur village is an example of many such villages in West Bengal-India and Bangladesh.
Furthermore, products from arsenic irrigated water- soil system rich in arsenic are also coming to common marketplace far away from contaminated areas and even people who are not drinking arsenic contaminated water may get arsenic from food products produced from contaminated fields. In West Bengal-India and Bangladesh rice, vegetables, and other products are coming to cities (including Kolkata in West Bengal-India and Dhaka in Bangladesh) from villages and possibility that city people consuming arsenic contaminated products from contaminated areas cannot be ruled out.
- Aposhian, H.V., Avram, M.D., Tsaprailis, G., Chowdhury, U.K., 2006. Arsenic: The king of poisons, the poisons of kings, and the bane of investigators (Conference paper). Chem Res. Toxicol., Vol. 16, 1680-1680.
- IARC (International Agency for Research on Cancer). 1987. In IARC Monograph on the Evaluation of Carcinogenicity Risk to Humans. Overall Evaluation of Carcinogenicity: An Update of IARC Monographs 1-42 (Suppl. 7). Lyon, France: International Agency for Research on Cancer, pp. 100-106.
- NRC (National Research Council). 2001. Arsenic in Drinking Water. Update to the 1999 Arsenic in Drinking Water Report. Washington, DC: National Academy Press.
- Chen, C.J., Chen, C.W., Wu, M.M., Kuo, T.L. 1992. Cancer potential in liver, lung, bladder, and kidney due to ingested inorganic arsenic in drinking water. Br. J. Cancer 66, 888-892.
- Rossman, T.G., Uddin, A.N., Burns, F.J. 2004. Evidence that arsenite acts as a cocarcinogen in skin cancer. Toxicol. Appl. Pharmacol. 198, 394-404.
- Huang, Y.K., Tseng, C.H., Huang, Y.L., Yang, M.H., Chen, C.J., Hsueh, Y.M. 2007. Arsenic methylation capacity and hypertension risk in subjects living in arseniasis-hyperendemic areas in southwestern Taiwan, Toxicol. Appl. Pharmacol. 218, 135-182.
- Tseng, C.H. 2007. Metabolism of inorganic arsenic and non-cancerous health hazards associated with chronic exposure in humans. J. Environ. Biol. 28, 349-357.
- Mandal, B.K., 1998. Status of arsenic problem in two blocks out of sixty in eight groundwater arsenic affected districts of West Bengal - India (Ph.D. Thesis). Jadavpur University, Kolkata, India.
- Chowdhury, U.K., 2001. Groundwater arsenic contamination status at four geo-morphological areas in Bangladesh (Special reference to arsenic in biological samples and agricultural crops) (Ph.D. Thesis). Jadavpur University, Kolkata, India.
- Chowdhury, U.K., Rahman, M.M., Mandal, B.K., Paul, K., Lodh, D., Basu, G.K., Chanda, C.R., Saha, K.C., Mukherjee, S.C., Roy, S., Das, R., Kaies, I., Barua, A.K., Palit, S.K., Quamruzzaman, Q., and Chakraborti, D. Groundwater arsenic contamination and sufferings of people in West Bengal, India, and Bangladesh. Environmental Sciences, 2001, 8, 393-415.
- Chowdhury, U.K. (2021). Total arsenic, arsenic species, and trace elements in crop and vegetables grown in an area irrigated with arsenic contaminated water in West Bengal, India (submitted).
- WHO (World Health Organization), 1981. Arsenic: Environmental Health Criteria 18. Geneva, Switzerland: World Health Organization.
- Smith, A.H. et al., 1992. Cancer risks from arsenic in drinking water. Environmental Health Perspectives. 97: 259-267.
- Smith, A.H. et al., 1999. Cancer risks from arsenic in drinking water: Implications for drinking water standards. In: Proceedings of the Third International Conference on Arsenic Exposure and Health Effects, 12-15 July 1998, San Diego, Elsevier Science Ltd., Oxford, UK. pp 191-200.
- NRC (National Research Council), 1999. Arsenic in drinking water. Washington, DC, National Academy Press.