Getting the Lead Out: The Public Health Benefits of Infrastructure Upgrades

In November 2023, the US Environmental Protection Agency (EPA) issued a proposed rule that would require water systems to replace all lead service lines over a 10-year period, along with other steps that would reduce the amount of lead in drinking water, thereby decreasing lead exposures among the population. Lead pipes have been banned from being installed since the 1980s, but not all older pipes have been removed, so millions of Americans continue to receive drinking water through pipes that are known to contribute to lead exposure and associated health risks. The remaining lead service lines are disproportionately found in older housing, which is also more likely to have lead paint, and there are racial/ethnic exposure disparities as a result. For example, in New York City, communities with higher proportions of Hispanic/Latino residents and greater vulnerability to lead exposure from other sources had higher proportions of lead service lines.¹

The proposed EPA rule is a prototypical example of how investment in infrastructure upgrades can yield public health benefits while often also addressing health inequities. There are many similar examples currently in the United States. For example, while modern sewer systems separate wastewater and stormwater, there are older combined sewer systems (largely in Northeastern and Midwestern states) that result in combined sewer overflows during storms with impacts on gastrointestinal health² and beach closures. Many older cities have aging gas pipeline infrastructure that can contribute to methane leaks and accident risks. There are numerous additional examples, such as power plants, transmission lines, roadways, and buildings, where infrastructure upgrades could produce multiple downstream health benefits.

However, infrastructure upgrades often come with substantial costs and logistical challenges. In deciding when and how to invest in health-promoting infrastructure, we face a few basic but important questions. Are the health and safety benefits large enough to justify the cost of the infrastructure upgrades? Who receives the benefits and who pays the costs, and how do we address any discrepancies or disparities? If aging infrastructure needs to be addressed in the near term, are we better off repairing the existing infrastructure, replacing it with something comparable but newer, or moving to something completely different? And is the cost of inaction high, such that we pay a price for delaying action?

The proposed lead service line replacement offers answers to these questions and a potential pathway for making decisions about many types of infrastructure upgrades. The analyses conducted by the EPA showed that the monetized health benefits of lead service line replacement would greatly exceed the costs. For example, using a 3% discount rate, the annual incremental costs of lead service line replacement were $2.1 – $2.9 billion, versus $17 – $35 billion in benefits. The benefits were driven by reductions in adult premature mortality due to cardiovascular disease, given strong evidence of a causal linkage between lead and cardiovascular outcomes³, as well as increases in IQ given the well-established association between lead and neurocognitive outcomes with no discernable threshold.⁴ The EPA analysis illustrated the importance of a comprehensive assessment of health benefits when conducting a benefit-cost analysis, substantiated by a recent independent publication that showed large health benefits of lead service line replacement in relation to costs when numerous health endpoints causally associated with lead exposures were included.⁵ This same independent analysis also argued for a holistic consideration of costs, as the authors showed that materials benefits related to reduced corrosion damage outweigh the costs of lead service line replacement without even considering health benefits.

The question of who receives the benefits of lead service line replacement versus who pays the costs is a complex one. An environmental justice analysis conducted as part of the EPA benefit-cost analyses concluded that there was evidence of inequitable distribution of lead service lines across seven case study cities, though with significant differences in patterns across individual water systems. In addition, while any household receiving a lead service line replacement would derive some benefit, the health benefits would be greater among households with younger children and individuals with cardiovascular disease. There would be multiple challenges if the costs were borne by homeowners, given differential ability to pay as well as the fact that health benefits are more difficult to discern on an individual basis than costs. The cost in this case would be partly defrayed by funds from the Bipartisan Infrastructure Law, but the balance may be covered by a combination of water utilities (a portion of which may be passed through to consumers) and homeowners. In situations like this when the societal health benefits greatly exceed the societal costs and the investment addresses existing exposure or health inequities, it is important to develop policy mechanisms that provide centralized resources or utilize other strategies to ensure that the costs are shared.

Turning to the final two questions, in the case of lead service lines, the replacement of corroded lead service lines with newer lead service lines is illegal, so replacement with a different technology is clearly required. Regarding the cost of inaction, there are two key dimensions. The first is that aging infrastructure is likely to engender more problems over time. For example, according to the EPA analysis, 82% of all cast iron water mains and 27% of all cement mains in the United States are over 50 years old, when the average service life is expected to be 40 years. This means that the risk of leaks is increasing and water main replacement will need to increase in the coming years. This will provide the opportunity to concurrently replace lead connectors in a more efficient manner than if action on lead were delayed. The second is that inaction would convey a lack of urgency in addressing an issue at the forefront of many communities’ minds since the Flint water crisis. This would further erode public trust with multiple negative downstream consequences.

The proposed lead service line replacement provides a roadmap for other potential health-promoting infrastructure upgrades. First, many aspects of infrastructure influence health and well-being but are invisible to us either literally (e.g., underground pipes) or figuratively (by vanishing into the background when they have been part of our landscape for many years). Further, because inadequate infrastructure is not randomly distributed and is more likely found in low-income communities and communities of color, infrastructure upgrades can be a valuable strategy to address longstanding health disparities. It is therefore important to explain the connections between infrastructure and both health and health disparities. This can be strengthened by formally examining the health benefits in relation to costs, including environmental justice analyses. When data, resources, or time are limited, comprehensive quantification may be impractical, but qualitative information would remain extremely helpful. Broadly, the “health in all policies” mantra embedded within health impact assessment⁶ and similar tools reinforces that many investments outside of the health sector are beneficial for health, and that we should formally evaluate those benefits when policy decisions are made.

We are entering an era when substantial infrastructure investments are anticipated, whether from the Bipartisan Infrastructure Law, from state or local investments in climate mitigation and adaptation, or from other long-delayed and much-needed projects. These investments will influence public health through multiple pathways, and policymakers should explain those connections to the public and support analyses that articulate the health and equity benefits in relation to the costs of such investments.

References

1. Nigra AE, Liberman-Cribbin W, Bostick BC, Chillrud SN, Carrion D. Geospatial assessment of racial/ethnic composition, social vulnerability, and lead water service lines in New York City. Environmental Health Perspectives, 2023; 131(8):87015.
2. Miller AG, Ebelt S, Levy K. Combined sewer overflows and gastrointestinal illness in Atlanta, 2002-2013: Evaluating the impact of infrastructure improvements. Environmental Health Perspectives, 2022; 130(5):57009.
3. Brown L, Lynch M, Belova A, Klein R, Chiger A. Developing a health impact model for adult lead exposure and cardiovascular disease mortality. Environmental Health Perspectives, 2020; 128(9):097005.
4. Lanphear BP, Hornung R, Khoury J, Yolton K, Baghurst P, Bellinger DC, Canfield RL, Dietrich KN, Bornschein R, Greene T, Rothenberg SJ, Needleman NL, Schnaas L, Wasserman G, Graziano J, Roberts R. Low-level environmental lead exposure and children’s intellectual function: An international pooled analysis. Environmental Health Perspectives, 2005; 113(7):894-899.
5. Levin R, Schwartz J. A better cost:benefit analysis yields better and fairer results: EPA’s lead and copper rule revision. Environmental Research, 2023; 229:115738.
6. National Research Council of the National Academies. Improving Health in the United States: The Role of Health Impact Assessment. National Academics Press: Washington, DC, 2011.

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