This is the third blog in a series focused on important tools that people can use to quantify the societal benefits of reducing lead exposure. To find the series, click on “Societal Benefits” in the Categories menu to the right.
What Happened
In support of its October 2024 rulemakings1 that tightened standards for lead in drinking water and lead in interior dust, EPA finalized its formula to quantify the number of avoided cardiovascular disease (CVD) premature deaths. For purposes of estimating the societal benefits, value of each avoided death—called the “value of a statistical life” (VSL)—is $12,980,000 in 2022 dollars.
As an example, a 10% reduction in the adult median blood lead level would reduce CVD premature deaths between 6,213 and 16,344 nationally for societal benefits of $80 billion to $212 billion per year. For context, the estimated CVD-related societal benefits for EPA’s Lead and Copper Rule Improvements were $9.5 billion to $25 billion per year and its Dust Lead Standard and $614 million to $6.9 billion per year.
Unleaded Kids has developed an Excel Spreadsheet to help those wanting to make their own calculations. See end of blog for details.
Why it Matters
Reducing adult lead exposure is critical to protect public health. CVD is the leading cause of death in the United States, so even a small reduction in the risk can yield significant benefits for society.
At its December meeting, CDC’s Lead Exposure and Prevention Advisory Committee (LEPAC) adopted a Protecting Lead Exposure in Adults Draft Report that found that lead exposure is a cardiovascular risk factor on par with high cholesterol, smoking, and high blood pressure and that risk “has received relatively sparse attention in health professional education and outreach to the lay public.”2 See our blog on the LEPAC’s approval of the report.
LEPAC’s comparison to other CVD risk factors is helpful. However, quantifying societal benefits in a rigorous, defensible manner enables people to better evaluate options in setting priorities and policies. While EPA quantified the societal benefits from increasing IQs in children a quarter century ago, only last year was scientific evidence from researchers by Aoki et al in 2016 and Lanphear et al. in 2018, and others sufficiently vetted to do the same for premature CVD deaths. This research, is summarized in a 2023 report by EPA’s consultant, Abt Global, and published in Environmental Health Perspectives (Brown et al, 2020).
Our Take
Thanks to EPA’s efforts to quantify the relationship between premature CVD deaths and blood lead levels, we have a valuable tool to make more informed decisions about reducing adult exposure to lead. These informed decisions will help more people live longer lives by reducing what is clearly an underappreciated risk factor.
Fortunately, researchers such as Lanphear, Aoki, and many others have invested much of their careers in gathering data, developing those statistical tools, and refining the analysis based on feedback and peer review. After the researchers published the studies in the peer review literature, EPA rigorously:
- Reviewed all available studies that could be used to develop quantitative relationships between changes in lead exposure and/or changes in blood lead levels and changes in health endpoints.
- Evaluated the studies for quality and potential biases.
- Developed a separate report for each health endpoint. In addition to the study quality review findings, each report provides quantitative estimates, based on health impact functions derived from the identified relationships between blood lead and adverse health effects which allow researchers to quantify the potential changes in the health endpoint due to an intervention.
- Had the reports for quantified health endpoints reviewed by EPA experts and external peers.
- Successfully completed inter-agency review through White House’s Office of Management and Budget.
Only then are we able to sufficiently quantify the societal benefits of reducing lead exposure for use in federal rulemaking. And even then, EPA recognizes the uncertainty and provides a range of estimates.
What is a VSL?
The VSL is an estimate of the public’s willingness to pay for small reductions in mortality risks. The estimate is based on the aggregate dollar amount that a large group of people would be willing to pay for a reduction in their individual risks of dying in a year.
EPA provides an example in its economic benefits analysis for the Lead and Copper Rule Improvements.
“Suppose each person in a sample of 100,000 people were asked how much they would be willing to pay for a reduction in their individual risk of dying of 1 in 100,000, or 0.001 percent, over the next year. Since this reduction in risk would mean that the EPA would expect one fewer death among the sample of 100,000 people over the next year on average, this is sometimes described as ‘one statistical life saved.’ Now suppose that the average response to this hypothetical question was $100. Then the total dollar amount that the group would be willing to pay to save one statistical life in a year would be $100 per person × 100,000 people, or $10 million. This is what is meant by the “value of a statistical life.” Importantly, this is not an estimate of how much money any single individual or group would be willing to pay to prevent the certain death of any particular person.”
Details on Estimating the Calculating the Number of Avoided Premature CVD-related Deaths
Unleaded Kids reviewed Section 5.5.7 and 5.5.8 of EPA’s Economic Analysis for its Lead and Copper Rule Improvements and developed an Excel Spreadsheet to help those wanting to make their own calculations. The instructions are in the spreadsheet. Click here for a PDF of the worksheet. Click here for the key pages from EPA’s economic analysis explaining the formula.
To estimate the change in premature CVD deaths for a given change in blood lead levels, EPA used the following equations 14, 15, and 16.
For the high-end, EPA used the central beta (β) estimate from Lanphear et al., 2018. For the low end, it used Aoki et al., 2016. Exhibit 5-31 provides these values.
To calculate the baseline hazard rate for CVD premature mortality, EPA used Exhibit from the 2023 Report by Abt Associates.
- Lead and Copper Rule Improvements and Dust-Lead Hazard Standards. ↩︎
- Note that CDC updated the webpage for the December 14 LEPAC meeting. The revised webpage describes the draft report, but the link has been removed. The Link is https://www.cdc.gov/lead-prevention/media/pdfs/2024/12/Draft-Copy-PLEA-Workgroup-Report-to-LEPAC-25NOV2024.pdf. ↩︎