Pregnant women exposed to arsenic-contamined water during pregnancy give birth to children who may develop cancer and other disease, researchers at Massachusetts Institute of Technology and and Chulabhorn Research Institute Thailand say.

The study analyzed 32 mothers and their children in an area of Thailand who were exposed to heavy arsenic contamination from tin mining. Specialists say that is not the only place who is highly contamined with arsenic. The Southwest in the United States seem to have the same problem.

Researchers analyzed the blood from the umbilical cords at birth. The results were worrisome. They found about 450 genes that could become significantly more active (in most cases) or less active than the same genes in unexposed children.

They also isolated 11 of those genes which were the most active and associated with inflammation, which can lead to an increased risk of cancer later in life, revealed the findings.

"The function of those 11 genes is involved in cellular stress responses particularly inflammatory responses," said one of authors Leona D. Samson, who is also the director of MIT's Center for Environmental Health Sciences or CHES. Mathuros Richirawat from Chulabhorn and Rebecca C Fry of CHES were among the participants at the study.

"We know that chronic inflammation at least in adults can predispose them to cancer. We don't now that in the case of these babies obviously, but there is a possibility," she said.

Samson said it is unclear how the arsenic found its way to the babies. "Either it's a response of the mother transmitted to baby inutero or arsenic getting across the placenta. Clearly, something has changed in the babies," she said.

The findings were reported in the November 23 issue of the journal PLoS genetics published by the Public Library of Science in San Francisco