Drinking Water Quality, the Health of Older Americans, and Inequality

Clean drinking water is crucial to human health and longevity. Despite enormous improvements in water treatment over the early 20th century, drinking water pollution remains a critical threat to US public health, particularly for older people and individuals with chronic conditions. In an effort to protect public health, federal regulations set drinking water quality standards and regulate the public water purification systems and pipes that carry treated water to households for human consumption. An estimated $473 billion in current national construction funding is needed to achieve compliance with drinking water standards, even as much remains unknown about how polluted drinking water affects health, especially among older Americans. Policy debates about drinking water regulations highlight the need for an improved understanding of the benefits and costs of drinking water regulations, including determining whether drinking water investments should be increased and ensuring that safe drinking water remains accessible and affordable to vulnerable communities. This project seeks to add substantially to the existing stock of knowledge about the health effects of drinking water pollution by studying the effects of large federal loans intended to upgrade drinking water treatment plants that service residential communities. By harnessing quasi-experimental variation in loan receipt, the project will examine how these loans affect drinking water pollution and how they shape short- and long-run mortality and disease burdens among older Americans. Because some loans target specific pollutants, like arsenic or pathogens, the analysis will examine the extent to which these loans specifically affect the pollutants they target and the health conditions associated with those pollutants. To enable this research, the project will compile the most complete set of records on drinking water systems linked to pollution measures based on Freedom of Information Act requests made to each of the 50 states. These data will be posted online to catalyze broader research on drinking water pollution and health. This project will combine these drinking water records with the most comprehensive individual-level health dataset—Medicare administrative data for 100% of beneficiaries—allowing for rigor, accuracy, and generalizability of findings. Beneficiary identifiers will allow us to follow individuals over time regardless of whether and where they relocate, with minimal attrition. The Medicare data provide the 9-digit zip code of residence, allowing the analysis to pinpoint the location of individuals more precisely than prior research. In addition, the analysis will examine the extent to which low-income communities and communities of color benefit equally from drinking water improvement policies, both in spending and health terms, and it will summarize the distribution of drinking water quality by household race, income, and other important demographics.