That’s the surprising conclusion from a study conducted to measure the long-range effects of lead exposure in the womb. The finding is surprising because University of Houston’s Donald Fox, a professor of vision and other life sciences, led the study, which was devised to study the effect prenatal exposure to lead has on the retina.

During the study, conducted on mice, pregnant mice were given controlled amounts of lead during gestation. The mice consumed drinking water laced with various levels of lead and conditions were monitored throughout the pregnancy and the life of the offspring. A control group of mice received no lead during pregnancy.

During their first year of life, all baby mice developed in the same expected way but when the mice that were exposed to lead reached the one-year mark, startling changes developed. The male mice became slower and less coordinated. They also got fatter, gaining about 25% more weight than their control counterparts.

A 1-year-old mouse is equivalent to a human 30 to 40 years old.

Only male mice experienced obesity as a side effect of the prenatal lead exposure. Female mice did not gain excess weight. Researchers are continuing to study the phenomenon in order to determine if the male sex hormones are affected by the prenatal lead exposure.

Changes occurred in the group of mice receiving 10 micrograms of lead per deciliter of blood, a rate the US Centers for Disease Control and Prevention (CDC) considers acceptable for people at this time, down from the accepted rate in 1972 of 80 micrograms. Many scientists suggest a safer level would be in the 2 to 5 microgram range.

Lead accumulates in the body over a lifetime instead of being used or expelled by it. Most human exposure to it comes via the air, dust, soil, and water but paint and many toys contain the heavy metal also.

The results of this study are expected to be in the March issue of Environmental Health Perspectives.

Source: University of Houston