NEW DELHI, Dec. 3  Toxic chemicals in the water in Punjab, India’s grain belt, could be causing genetic mutations in the population, a recent study suggests.

Preliminary results say a two-year study commissioned by the Punjab Pollution Control Board found mutated DNA in blood samples of 65 percent of the people tested. The study also found high levels of arsenic and mercury in the tap water.

Some villages in the landlocked state of Punjab are experiencing high rates of cancer and other diseases. Scientists and government officials are investigating links between those incidence levels and chemicals used in farming and industry.

The most recent study, conducted by the Post Graduate Institute of Medical Education and Research, a school in Punjab, looked at the chemical composition of five drains, the open sewers that handle much of India’s waste, as well as the chemical pollution of the groundwater in the area and the health of people living near those drains.