A new study suggests that deaths from lead poisoning in the US may be 10 times as common as was previously believed. The new research indicates that 412,000 deaths each year in the US can be linked to lead contamination in the blood, 10 times higher than the last figure suggested by research from the Institute for Health Metrics and Evaluation in Seattle, according to CNN.
The new research was published Monday in The Lancet Public Health, based on data from 14,000 individuals over 20 years. Adults with initial blood concentration levels in the 90th percentile faced a 37 percent increased risk of mortality from all causes, a 70 percent higher risk of death from cardiovascular disease than those in the 10th percentile.
The link between cardiovascular disease and even low levels of lead contamination were stronger than expected, despite the already established link between lead exposure and high blood pressure.
According to the study’s lead author, Simon Fraser University health science professor Dr. Bruce Lanphear:
“Nobody had even tried to estimate the number of deaths caused by lead exposure using a nationally representative sample of adults. But if we’re underestimating the impact of lead exposure on cardiovascular disease mortality and other important outcomes beyond IQ, then it might have a big impact on the way we make investments in preventing lead poisoning exposure.”
To be in the 10th percentile meant levels of lead concentration in the blood 1.0 micrograms per deciliter. Those in the 90th percentile had 6.7 micrograms per deciliter. According to the Centers for Disease Control and Prevention, action is needed when concentrations exceed 5 micrograms per deciliter. Over time, the CDC has lowered this threshold, from 40 micrograms per deciliter in the early 70s, to 10 in the 1990s, and finally down to the current threshold, only several years ago.
“When you start looking at the risk across the entire range of people exposed, all of a sudden the number of affected people balloons. Mostly it’s a numbers thing — there are so many people in the low- to moderate-risk groups that, as long as there are some risks with low-level exposure, many more people are going to die or develop heart disease.”
Lead based paint was banned for use in residential buildings in 1978, and new guidelines were established for gasoline. However, 90 percent of Americans are still exposed to some degree of lead contamination. Exposure is most pronounced in those who work in a field like construction, live in areas with contaminated runoff, or near a regional airport, where single piston jet engines still rely on gas with lead.