New York, Oct 4 (IANS): Mothers with high levels of lead in their blood not only affect the foetal cells of their unborn children, but also their grandchildren, says a study.

If a pregnant woman is exposed to lead, the lead passes through the placenta into the baby's developing bones and other organs.

Pregnant women with a past exposure to lead can also affect the unborn child's brain, causing developmental problems later in life.

Previous research studies have suggested that exposure to heavy metal toxicants can influence a person's global DNA methylation profile.

In the recent research it was found that lead exposure can cause specific changes in DNA methylation, which can be detected in dried blood spots beyond one generation.

"Our results suggest lead exposure during pregnancy affects the DNA methylation status of the foetal germ cells, which leads to altered DNA methylation in grandchildren's neonatal dried blood spots," said lead researcher Douglas Ruden from Wayne State University.

The research team stated that this novel, two-generational study design might be able to identify the genes that may serve as possible candidate biomarkers for future transgenerational risk assessment studies.

"However, the altered DNA methylation profiles of the grandchildren's blood are apparently normalised during postnatal development," he added.

The study was published online in the journal Scientific Reports.