Superfund Research Program
Spatial Patterns of Metals and Metal Mixtures in Drinking Water
Project Summary (2020-2025)
In 2016, approximately 15 million people lived within one mile of Superfund a site, including approximately 5 percent of all children in the U.S. under five years of age. Arsenic (As) and cadmium (Cd) are among the top ten contaminants on the Agency for Toxic Substances and Disease Registry's 2017 Substances Priorities List for Superfund sites. These and other metals/metalloids can contaminate surface waters and groundwater systems, leading to elevated exposures through drinking water. Across the U.S., tens of millions of individuals consume drinking water with concentrations of heavy metals in excess of regulatory guidelines. Exposures to heavy metals have been associated with many negative impacts on public health, including impacts on neurodevelopment and cognitive aging. However, the contribution of different Superfund sites to this contamination problem remains poorly characterized on a national scale. This is important because regulations for drinking water contaminants and risk mitigation actions are often undertaken at the federal level, but most prior work has focused on site-specific studies. Proximity to Superfund sites may be associated with higher risk of contamination by heavy metal mixtures in tap water. This relationship is likely more prominent in private wells than in municipal drinking water supplies, where the finished water quality is influenced by water treatment technologies. Across different geographic areas, there are considerable differences in municipal water treatment technology and continuous development of innovative technologies, but little information is available on how this affects spatial patterns of metal concentrations in tap water. In Aim 1, the researchers are characterizing the role of Superfund sites across the country for heavy metals in private wells by developing novel hybrid mechanistic-empirical models for heavy metals across the U.S. using a large database of measurements in groundwater from the U.S. Geological Survey, locations of point sources such as Superfund sites, and hydrogeological features/predictors that affect the fate and transport of trace metals. For Aim 2, they are using new measurements and models to identify the spatial co-occurrence of different metal mixtures relevant to human exposures from drinking water. This analysis is being used to identify the composition of metal mixtures for in vitro toxicity tests on brain organoids in the EV miRs in Cognitive Function Decline Associated with Early-Life Metal Exposure project. This project provides a link between biomedical research in the Metals and Metal Mixtures: Cognitive Aging, Remediation, and Exposure Sources (MEMCARE) Superfund Research Center (SRC), human exposures, and potential benefits of remediation technology being developed in the Designing the Next Generation of Highly Selective Sorbent Materials for Remediation of Target Inorganic Contaminants in Aqueous Systems project.