FRIDAY, Jan. 30, 2015 (HealthDay News) -- Hormones may explain why lead exposure is less likely to cause brain damage in girls than in boys, researchers report.
Specifically, the female hormones estrogen and estradiol may help protect against lead's harmful effects on the frontal areas of the brain, according to the findings published recently in the Journal of Environmental Health.
"The study supports existing research suggesting that estrogen and estradiol in females may act as neuroprotectants against the negative impacts of neurotoxins," study author Maya Khanna, a psychology professor at Creighton University, said in a university news release.
The study included 40 children. They were between the ages of 3 and 6, and all lived in an area of Omaha considered the largest residential lead clean-up site in the United States. The area has high levels of lead contamination in the soil due to emissions from a lead refinery that operated there for 125 years.
Also, many homes in the area are old and still have lead-based paint.
The researchers found that 23 of the children had elevated blood lead levels. Boys with elevated lead levels scored low on tests of memory, attention and other thinking abilities. Girls with elevated lead levels did not do as poorly on the tests, according to the study.
The researchers also found that elevated lead levels had a much stronger negative impact on thinking abilities than on reading readiness.
This is the first study to show that very young children already experience harm from lead exposure, and that lead has a greater impact on thinking abilities in boys than in girls, according to Khanna.
The U.S. Centers for Disease Control and Prevention has more about lead.