"Lead Exposure on the Rise Despite Decline in Poisoning Cases"

"BOSTON -- Exposure to lead—so toxic—is a problem of the past, right? Wrong. Since the U.S. took lead out of gasoline in 1976 and banned lead paint in 1978, most health scientists, regulators and the public have considered the problem largely solved. But ongoing testing shows that even though the average concentration of lead in the American bloodstream has dropped by a factor of 10 since the late 1970s, the levels are still two orders of magnitude higher than natural human levels, which have been determined by studying skeletal remains of native Americans dating to before the industrial revolution."

"Equally problematic, recent health studies have shown that exposure levels previously thought to be “safe” were too high. Scientists from various disciplines are advising the Environmental Protection Agency and health departments to lower the concentration deemed acceptable in the bloodstream, which today averages 1.3 micrograms per deciliter but can be much higher for many individuals. The change is warranted because the latest set of long-term tests done over decades has revealed that many of the health complications from lead arise even at low exposures. Higher levels are not necessary to instigate damage to the body or brain, Joel Schwartz of the Harvard School of Public Health told a somewhat surprised crowd on Feb. 16 here at the annual American Association for the Advancement of Science (AAAS) meeting. Excessive lead exposure correlates with a host of ills, including impaired cognition, attention deficit disorder and lower academic test scores for children, psychiatric disorders, and increased blood pressure, hypertension and arrhythmia."

Mark Fischetti reports for Scientific American February 17, 2013.

Source: Scientific American, 02/18/2013