Sealing off tubewells and using water purifiers may not be enough to prevent arsenic poisoning, according to Times of India. The harmful chemical was still affecting thousands through contaminated poultry products and meat, according to a study by researchers at the West Bengal University of Fisheries and Animal Sciences (WBUFAS). Chicken, mutton and egg samples collected from affected areas on the northern fringes of the city were found to contain more than five times the permissible limit of arsenic.

The alarming finding has left green activists and environmentalists shocked. "This is indeed shocking, for there is no screening of food items. If this is true, then all efforts to try and minimise the impact of arsenic contamination will be negated. But this should act as an eye-opener for the authorities," said Sudipta Bhattacharya of the Saviours and Friends of Environment (SAFE), a green NGO.

The study was centred around the Kolsur village in Deganga and covered seven more villages in the vicinity. Arsenic content in the water has touched 0.01 ppm in the affected area whereas the permissible limit was 0.05. According to the study, egg, goat meat, eggs and fish produced in the poultry and other farms of eight arsenic-prone villages in the Deganga block of North 24-Parganas had much higher levels of arsenic than the human system could tolerate. While the chemical cannot affect the animals for it takes time to attack the system, those consuming the affected chicken and mutton were turning arsenic victims. A substantial amount of poultry products, fish and meat from the area are sold in Kolkata.

"We found that broiler chicken produced in the poultry farms had an arsenic content of 0.77 ppm while country chicken was slightly better at 0.83 ppm. Both are much higher than the permissible limit. Goat meat was found to be even more contaminated with an arsenic content of 0.1 ppm while the fish had an average of 0.42 ppm. Apart from those in the area who are consuming these, the affected products are also being sent to Kolkata. Consumers in the city are falling prey without even suspecting that the fish, egg or chicken they are having might contain arsenic," said Barun Roy, senior researcher at the WBUFAS who took part in the study. Eggs had an average arsenic content of 0.38 ppm.

Arsenic interferes with cellular longevity by inhibiting an essential metabolic enzyme pyruvate dehydrogenase (PDH) complex. With the enzyme inhibited, the energy system of the cell is disrupted resulting in a cellular apoptosis episode. Biochemically, arsenic prevents use of thiamine resulting in a clinical picture resembling thia. Poisoning with arsenic can raise lactate levels and lead to lactic acidosis. It could reduce potassium levels in the blood and lead to a life-threatening heart rhythm problem. More than 2,000 villages across eight districts of the state are arsenic affected. Nearly 10 million of the state's population is believed to be at risk.

"Kolkata gets 60 per cent of its chicken and egg supply from the affected areas of North 24-Parganas. So, it is a cause for concern for both consumers and the poultry. We must have a stricter set of safety and hygienic norms for poultry," said Abhijit Kanjilal of Shanti Hatcheries that operates in six districts of the state.

According to Times of India, scientists at WBUFAS called for a reference laboratory for a stricter vigil on poultry and animal products in arsenic affected areas. "A lot of damage has already been done. Unfortunately, arsenic victims are no longer restricted to the affected areas which makes it difficult to address the problem. Unless, the authorities crack down on the poultry farms and fishery units immediately," said Dr Roy.