Prenatal Arsenic Exposure Detected in Newborns

Leona Samson, Ph.D. and Rebecca Fry, Ph.D.
Massachusetts Institute of Technology
NIEHS Grants R01ES011399 ∧ P30ES002109

MIT researchers have found that the children of mothers whose water supplies were contaminated with arsenic during their pregnancies harbored gene expression changes that may lead to cancer and other diseases later in life. In addition to establishing the potentially harmful effects of these prenatal exposures, the new study also provides a possible method for screening populations to detect signs of arsenic contamination.

The evidence comes from a genetic epidemiologic study including 32 mothers and their children in a province of Thailand with heavy arsenic water contamination caused by tin mining. The mean arsenic level in the water was 503.5 micrograms/liter or about 50 times higher than current U.S. standards. Similar water levels of arsenic are also found in many other regions, including the U.S. Southwest.

The scientists identified 11 gene transcripts that predicted with about 80% accuracy whether the infant had been exposed to arsenic. Eight of the 11 genes were involved in inflammatory processes. This is the first time evidence of such genome-wide changes resulting from prenatal exposure has ever been documented from any environmental contaminant. It suggests that even when water supplies are cleaned up and the children never experience any direct exposure to the pollutant, they may suffer lasting damage.

Citation: Fry RC, Navasumrit P, Valiathan C, Svensson JP, Hogan BJ, Luo M, Bhattacharya S, Kandjanapa K, Soontararuks S, Nookabkaew S, Mahidol C, Ruchirawat M, Samson LD. Activation of Inflammation/NF-kappaB Signaling in Infants Born to Arsenic-Exposed Mothers. PLoS Genet. 2007 Nov 23;3(11).