BETHESDA, Md., Aug. 26 (UPI) -- Female mice whose mothers were exposed to low doses of arsenic early in pregnancy started puberty early and became obese as adults in lab tests, according to a new study.
The study was done to find what, if any, are the results of mothers drinking tap water that contains arsenic. Currently, the EPA allows arsenic to be present in drinking water up to 10 parts per billion -- which researchers considered to be low dose in the experiments with mice.
"We unexpectedly found that exposure to arsenic before birth had a profound effect on onset of puberty and incidence of obesity later in life," said Dr. Humphrey Yao, a reproductive biologist at the National Institute of Environmental Health Sciences, in a press release. "Although these mice were exposed to arsenic only during fetal life, the impacts lingered through adulthood."
Researchers tested three groups of mice to measure the effect of arsenic: one received drinking water with 10 parts per billion arsenic; one received 42.5 parts per million, which is known to have health effects on mice; and a control group that had no arsenic in its water.
The water was given to the mother mice gestational day 10, the equivalent of halfway through the first trimester of human development, until the baby mice were born.
The mice whose mothers drank water with any arsenic entered puberty early, with the group that received a significantly higher concentration also experiencing fertility problems. Both groups that received arsenic also had higher body weight gain and glucose intolerance.
Dr. Linda Birnbaum, director of NIEHS, said more research is needed on the full effects of arsenic on biological processes, and that research especially needs to be done on both high and low doses of the compound.
"Although the health effects from low doses were not as great as with the extremely high doses, the low-dose effects may have been missed if only high doses were studied," Birnbaum said.
The study is published in Environmental Health Perspectives.