EPA has not established an RfC or an RfD for lead. However, the lowest blood lead levels at which this occurs has not been established. These effects may be seen from acute as well as chronic exposures. Prenatal exposure to lead produces toxic effects on the human fetus, including increased risk of preterm delivery, low birthweight, and impaired mental development. Human studies are inconclusive regarding the association between lead exposure and birth defects, while animal studies have shown a relationship between high lead exposure and birth defects.
Human studies are inconclusive regarding lead and an increased cancer risk.
In addition, exposure to other chemicals probably occurred. Animal studies have reported kidney cancer in rats and mice exposed to lead via the oral route. Physical Properties Lead is a naturally occurring, bluish-gray metal that is found in small quantities in the earth's crust. Lead is present in a variety of compounds such as lead acetate, lead chloride, lead chromate, lead nitrate, and lead oxide. The primary use of lead is in the manufacture of batteries.