The geologists at Banaras Hindu University (BHU) have said rainwater harvesting is the best remedy against arsenic contamination of groundwater in the city. Arsenic is highly toxic and a known carcinogenic.
“People affected with arsenic contamination are advised to maintain a nutritious diet, which is often not possible because most of them are neither health conscious nor can afford the suggested line of treatment because of extreme poverty,” said Prof RP Singh of the department of Geology, BHU. Rainwater harvesting involves collecting water from rooftops to cement tanks for drinking, or channeling the rain into shallow bodies or even wells dug for household use. But this will have to be combined with good sanitation practices, he said.
According to his research paper titled ‘Human Risk Assessment of Arsenic Contaminated Groundwater in India’, arsenic contamination in water is a major human health concern worldwide. The greatest threat to human health arises from arsenic in drinking water because millions of people are at the risk of drinking the water contaminated with the metalloid.
In India there is more water ingestion and its rural population is more vulnerable to the adverse affects of arsenic due to undernourishment.
Singh said sustained exposure to arsenic may lead to skin lesions, arsenicosis, melonosis, keratosis, jaundice and even cancer. Chemical precipitation was identified as being the most effective means of treatment.
Singh said that the highest arsenic concentrations in the world appear to be in the Bengal- deltaic alluvial aquifers, generally at the depth of 20-50m. Due to increased population and their need to meet their food requirements, three or more crops are harvested each year. As a result, excessive groundwater is used. Arsenic and arsenical compounds are found in effluents from metallurgical, ceramic, tanning, dyeing, pesticide, herbicide, insecticide, petroleum refining, inorganic and organic chemical industries, wood and hide preservative, copper smelting and coal combustion, specially low grade brown coal.
“We need to take up necessary measures for optimal utilization of the available water resources. The artificial recharge may be defined as augmenting the natural movement of surface water into underground formations,” said Singh.