HealthDay News — Among U.S. adults who were alive in 2015, more than 53 percent are estimated to have had blood lead levels (BLLs) greater than 5 μg/dL in early life, according to a study published online March 7 in the Proceedings of the National Academy of Sciences.
Michael J. McFarland, Ph.D., from Florida State University in Tallahassee, and colleagues produced overall and cohort-specific estimates of early-life lead exposure for the U.S. population in 2015. The number and proportion of people exposed to various lead levels as young children were estimated based on those falling into seven BLL categories.
The researchers estimated that in 2015, more than 170 million people (>53 percent), more than 54 million people (>17 percent), and more than 4.5 million (>1 percent) had BLLs greater than 5, greater than 15, and greater than 30 μg/dL, respectively, in early life. Among those born from 1951 to 1980, BLLs greater than 5 μg/dL in early life were almost universal (>90 percent), while among those born since 2001, BLLs in early life were considerably lower than 5 μg/dL. As of 2015, the average lead-linked loss in cognitive ability was estimated to be 2.6 IQ points per person, resulting in a total loss of 824,097,690 IQ points. Those born between 1951 and 1980 were disproportionately affected.
“The scope of such widespread exposure, particularly from the late 1950s to the early 1980s, suggests the legacy of lead continues to shape the health and well-being of the country in ways we do not yet fully understand,” the authors write.