Exposure to even a moderately high level of lead may cause boys to reach puberty later, according to a new study.US researchers followed the progress of nearly 500 Russian boys over three years and found that those who had high levels of lead in their blo
Exposure to even a moderately high level of lead may cause boys to reach puberty later, according to a new study.
US researchers followed the progress of nearly 500 Russian boys over three years and found that those who had high levels of lead in their blood reached puberty later than boys who had lower levels.
Those who had more than 5 mcg/dL (micrograms per decilitre) began puberty between six and months later on average than those with levels below this amount.
More than a quarter (28%) of the boys had levels higher than 5 mcg/dL.
Lead levels vary between countries but have been declining in recent years thanks to bans on lead-based paint and other lead products.
While the study did not prove that lead exposure causes boys to reach puberty later the link held even after other variables such as parents’ income and education levels and the boys’ diet were taken into account.
Lead is known to have damaging effects on children’s growth, both mentally and physically, even at low doses.
However, the boys’ height and weight did not explain the link between lead levels and later puberty.
The researchers pointed to research on rodents that showed lead can lower levels of testosterone and other hormones.
