Lead exposure may be causing ten times more deaths in the United States than previously thought, a new study says.
Researchers found that over 400,000 deaths each year in the United States can be blamed on lead contamination, CNN reports. This is a figure much higher that was previously reported by the Institute for Health Metrics and Evaluation at the University of Washington in Seattle.
The study monitored over 14,000 adults over a period of around 20 years, and found that individuals with an initial blood lead concentration at the 90th percentile saw a 37% increase in deaths and a 70% jump in cardiovascular disease mortality, compared to people with a blood lead concentration at the 10th percentile.
A link between lead exposure and high blood pressure has been established for decades now, but this is the first time the magnitude of such an effect on cardiovascular mortality has been established, according to Bruce Lanphear, a professor of health sciences at Simon Fraser University and lead author of the study.
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.
The team of scientists looked at a nationally representative sample of 14,289 adults over the age of 20, who participated in the Third National Health and Nutrition Examination Survey between 1988 and 1994. This is given by the US Centers for Disease Control and Prevention annually.
Of the respondents, 4,422 had died by 2011. Around 18% of these deaths could have been prevented by taking steps to reduce blood lead concentrations, according to the researchers.
“There’s no safe threshold,” Lanphear said. “Once we found that there was a risk across the entire range of exposures, we could estimate the number of attributable deaths. And instead of it being 40,000 deaths, which is what had previously been estimated, we found that it was about 10 times that.”
The study was published in The Lancet Public Health.