Industrial processes have filled the environment with chemicals that threaten your health. Within that list of substances, scientists have identified a heavy metal that can add inches around your waist.

Lead, a metal that used to be added to gasoline, is a persistent pollutant that is found in paint chips, many soil samples, air and water while also often presenting a danger in food and consumer products.

Many studies have shown that childhood exposure to lead hurts brain health and may lower IQ. And now a lab study at the University of Michigan School of Public Health shows that lead exposure in the womb can make you or your children more liable to be obese.

“The data support the obesogen hypothesis that toxicant exposures in the womb contribute to the higher rate of obesity,” says researcher Dana Dolinoy. “There are certain chemicals that are considered the hallmarks of the obesity epidemic, and lead (until now) has not been not one of them.”

The scientists note that previous research has connected lead exposure to less fetal growth. But this current study shows that if a mother takes in lead, even before she is pregnant, her children can later be more likely to have a weight problem.

Researcher Christopher Faulk says that before taking part in this study, he did not fully understand the serious dangers of lead exposure that most of experience.

“To see that the level I and others have considered very low has such statistical significance in this study is alarming. There is no minimum safe level for lead. Our research really supports this,” he says.