In children, even trace residues of lead can wreak harm. One recent study reported evidence of IQ deficits in children with blood concentrations of the metal below 5 micrograms per deciliter (g/dl) (SN: 4/26/03, p. 269: Available to subscribers at Traces of lead cause outsize harm), an amount found in 90 percent of U.S. kids. Now, epidemiologists have turned up evidence that similarly low lead concentrations delay puberty in girls.
Log in
Subscribers, enter your e-mail address for full access to the Science News archives and digital editions.