Sir — This refers to the article, “Heavy metal toxicity and water contamination” (September 7) by Kota Sriraj. Coal combustion, synthetic fertilisers, pesticides, paints, detergents, metal works, smelting, refining have all been contributing to arsenic poisoning in the Gangetic delta ie parts of West Bengal and Bangladesh. Dyeing, bleaching and leather industries, especially in Uttar Pradesh and Tamil Nadu are sources of chromium, cadmium pollution that have ruined rivers.
Recently, Hindustan Uniliver limited reached an out-of-court settlement with the workers of it’s thermometer factory in Kodaikanal which not only posed an health hazard for the workers but was causing mercury pollution in the sensitive watershed areas of Pampadum Shola National Park, where it was dumping the wastes.
last year, there was the problem of lead contamination of drinking water in the city of Flint, Michigan, when ageing water pipes, made of lead, corroded and leached lead, causing the water to turn dirty brown with odd smell and taste. Outrage was expressed at the excuse of funds scarcity in failing to replace the pipes. Natural and low cost solutions like the powder of water Hyacinth can remove arsenic from waste water. Bioremediation through activated effective microorganisms is another eco-friendly way to clean lakes and sewers.