New Study Says Lead – Even at Low Levels – is Associated with Risk of Premature Death

Dr. Ananya Roy is Health Scientist and Tom Neltner, J.D. is Chemicals Policy Director

This week, a team of researchers led by Dr. Bruce Lanphear published an important new study on the deadly impact of lead exposure for adults. The researchers examined data on more than 14,000 adults and found that an increase of 1 to 6.7 micrograms of lead per deciliter of blood (µg/dL) was significantly associated with an increase in mortality of 37% for all-causes, 70% for cardiovascular, and 108% for ischemic heart disease. The findings remained significant even after they considered and accounted for other factors that could have explained this effect.

This research fills a gap identified by the National Toxicology Program in 2011 in our understanding of the risk of lead exposure at low levels in adults. And it goes further by providing a quantitative relationship crucial to better evaluating the potential economic benefits of various policy options.

The study also had startling estimates about how many people are hurt by lead exposure. The authors estimated that over 400,000 Americans every year die from lead related illnesses – ten times higher than previous assessments. That’s on par with deaths from smoking cigarettes.

Dr. Lanphear has a track record of shaking conventional wisdom. He was the lead author on a groundbreaking article in 2005 showing that blood lead levels (BLLs) less than 10 µg/dL were associated with a drop in children’s IQ levels AND, for a given change in BLL, the IQ loss was significantly greater at lower levels than at higher levels. In other words, lead did more harm to a child’s IQ at low levels than at higher levels. This study resulted in a fundamental reassessment of how policymakers approach lead, putting a priority on preventing even low-level exposures that were discounted earlier.

While the numbers are surprising, the idea that lead is associated with cardiovascular disease is not. Experimental studies have explained the biological mechanism. What is new is the national estimates of the impact and the quantitative relationship of harm with increasing levels of lead. Regulatory agencies like the Environmental Protection Agency (EPA), Food and Drug Administration, and Occupational Safety and Health Administration need that information in order to estimate the societal benefits from various policy alternatives.

Before this study, they could only describe the benefits in qualitative terms. Now, they can quantify those benefits and greater benefits can justify more aggressive policy changes. Incorporating these new estimates in economic analyses of regulations may significantly increase the economic benefits associated with preventing lead exposure.

Federal regulatory agencies have a rigorous process of vetting significant studies like this one through peer review panels, science advisory boards, agency experts, and the Office of Management and Budget before it can be the basis of an economic analysis to support rulemaking. The agencies have a legal and ethical obligation to give serious consideration to this study and take it through the review process. The next opportunity is the EPA’s long-awaited revisions to the Lead and Copper Rule that limits lead in drinking water.

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One Comment

  1. Beth Butler
    Posted March 15, 2018 at 10:05 pm | Permalink

    The targets are the census tracts with the greatest disparity in mortality rates. In New Orleans, those tracts are near or have a freeway thru them, the older neighborhoods. Where did they place freeways in cities? African-American and minority communities.