Three years ago, a number of deaths in small villages near the Indian capital of New Delhi appeared to be linked but only recently has the cause been determined: mercury.

Reports from October identify drinking water as the cause of the dozens of deaths since 2011, and a 2012 report from a public interest group showed as much as 26 times the safe levels of mercury present, according to Bloomberg.

The New Delhi-based Centre for Science and Environment released a report in October 2012, which discovered that drinking water was polluted and fish from the same region had twice the safe limit for human consumption.

But this is not a new issue in India as reports dating back to the 1990s show similar unsafe mercury levels. United Nations data show India is second only to China in annual mercury emissions.

Coal and uranium mining are being blamed for the problem, as India pursues these industries to modernize the country at the cost of its residents' lives.

Shining a spotlight on the issue has drawn criticism that India is putting money ahead of the health of its people.

India does not consider the cost of the effects of pollution on human and ecosystem health when it performs cost-benefit analysis for industrial projects, a Colorado-based senior scientist at the U.S. Environmental Defense Fund told Bloomberg.  

And as the metals, including mercury, have been accumulating for years unwatched, the almost 1.1 million in the region are at risk. But no one knows for sure what the extent of illnesses and deaths are in the area, since no government agency has conducted any kind of study.

Amarendra Bahadur Singh, the current chief medical officer of the Sonbhadra district, told Bloomberg he planned to recommend such a study to his superiors.