Public Health and Karst Groundwater Contamination: From Multidisciplinary Research to Exposure Prevention

Karst aquifers account for up to 20% of the world land area and are a source of drinking water for much of the world. Despite the critical value of these aquifers as a drinking water source, there are a growing number of incidences of karst aquifer contamination worldwide, including inadvertent spills, dumping, industrial discharges, or sewage seepage events. Given the porous nature of carbonate rocks, the hydrogeology of karstic aquifers is extremely complex, making it difficult to predict movement of contamination in these aquifers and to identify exposure risks. These contamination events-together with emerging issues such as climate change, exposures to infectious agents, as well as the increase in informal mining practices-indicate the need to explore linkages between karst groundwater, contamination, and health. Accordingly, the issue of karst groundwater contamination presents a unique global public health challenge requiring a multidisciplinary problem-solving approach. The National Institute of Environmental Health Sciences (NIEHS) Superfund Research Program's (SRP) multidisciplinary approach serves as a model for integrating expertise across health, engineering, geological, and community-based approaches to solve problems. Using examples relevant to karst contamination, NIEHS SRP grantees are engaged in research endeavors to address issues of drinking water safety-from remediation to well-testing best practices. It is recommended that continued research addresses karst contamination, with particular attention given to identifying people at risk of exposures and to developing proactive means to prevent further exposures. This is particularly important in the USA, where two-fifths of the population's drinking water comes from karst aquifers. Furthermore, over 40 million US citizens are on private well water for drinking, yet testing for contamination in these wells is often not required. Given the challenges predicting contaminant transport in karst and the lack of uniform private well water testing regulations, there is a need to promote awareness of risks for people living in karst areas among public health, hydrogeology, and government officials, and to use community-based approaches as models for intervention and exposure prevention.