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Clean drinking water is essential for healthy life, but billions of people worldwide rely on water of unreliable quality. The United States is not immune to this problem and safe drinking water remains a public health priority.

Introduction

filling a glass of water from a faucett

Drinking water in the U.S. comes from a variety of sources, including public systems, private wells, and bottles. Although mechanisms are in place to keep water safe, contamination can result from:

  • Agricultural pesticides and fertilizers.
  • Corroded pipes that leach lead, copper, or other harmful chemicals.
  • Hazardous waste sites and industrial discharges.
  • Naturally occurring hazardous chemicals, such as arsenic and radon.
  • Plastic containers.
  • Sewage and food processing waste.

Health Effects

Little girl drinking from a water fountain

Contaminated drinking water can produce a broad range of health effects. Many can be severe and long-lasting, depending on the chemical and the level of exposure. Contaminants of concern include:

What is NIEHS Doing?

collecting a water sample from a natural water source

NIEHS research examines potential health effects of contaminants in water and explores ways to protect the public from contact with unsafe water. Recent projects supported by NIEHS have:

  • Developed models that estimate wastewater discharges may expose more than 23 million Americans to drinking water with PFAS chemical levels that exceed regulatory thresholds.
  • Documented the presence of heavy metals, pharmaceuticals, disinfection by-products, and other contaminants in public water systems throughout the United States.
  • Found that highly absorbable nanoplastics may be found in bottled water in much higher concentrations than previously suspected.
  • Shown that events like hurricanes can contribute to elevated levels of pesticide contaminants in drinking water.
  • Studied groundwater contamination and public health impact of the 2023 train derailment and chemical spill in East Palestine, Ohio.

NIEHS Superfund Research Program (SRP) grants support study of health effects of potentially hazardous substances as well as clean-up of hazardous waste sites. SRP funds have supported numerous efforts to protect waterways and drinking water.

  • A partnership between the University of Kentucky and communities in the Appalachian region of the state seeks to reduce levels of disinfection by-products in drinking water.
  • Dartmouth College scientists examined the sources of arsenic in New Hampshire’s drinking water, spurring a state law that lowered allowed limits.
  • Researchers at the University of California, Berkeley created an interactive, web-based Drinking Water Tool that documents water quality in communities throughout California.
  • Scientists from Texas A&M University and the University of Connecticut have developed strategies to trap PFAS in soil to prevent its spread into water supplies.
  • The Superfund Research Center at the University of North Carolina at Chapel Hill successfully encouraged the state Real Estate Commission to include well water quality information on home sale disclosure forms. Researchers also are developing a filtration device to remove arsenic and other chemicals from well water, an innovation that promises to benefit up to 3 million state residents.
  • University of Iowa researchers have devised a method to clean harmful polychlorinated biphenyls (PCBs) from aquatic ecosystem, using biochar — a material made from bacteria and corn kernel ashes.

NIEHS also awards Small Business Innovation Research and Small Business Technology Transfer to support private industry advances that reduce the dangers of contaminated water. Successes of the program include:

  • ANDalyze sensors detect heavy metals like cadmium, copper, and uranium in water supplies.
  • Cyclopure test kits and filtration systems help identify and remove PFAS chemicals from drinking water.
  • NanoAffix detectors support real-time, on-site detection of lead in tap water with a hand-held format.

Further Reading

Stories from the Environmental Factor (NIEHS Newsletter)

Printable Fact Sheets

Fact Sheets

Arsenic and your Health Cover
4 pages
(1MB)

Arsenic and Your Health

Drinking Water and Your Health Cover
2 pages
(1MB)

Drinking Water and Your Health

Endocrine Disruptors and Your Health Cover
4 pages
(902KB)

Endocrine Disruptors and Your Health

Press Releases

Podcasts

  • Reducing Exposure to Disinfection Byproducts in Drinking Water (2023) – Before drinking water reaches a home, it is treated with chlorine to kill bacteria, viruses, and germs that can cause disease. Although this disinfection step keeps people safe from waterborne illnesses, it also has the potential to create byproducts that can harm health. These compounds – called disinfection byproducts – are formed when chlorine combines with organic matter naturally present in water. NIEHS-funded researchers work with residents in eastern Kentucky who are concerned about high levels of disinfection byproducts detected in their drinking water.

Additional Resources

  • Water, Sanitation, and Hygiene (WASH) Collection – In the U.S., safe piped water is responsible for improving public health. Yet billions of people globally—including some residents of high-income countries—lack access to safely managed drinking water services. This collection of research papers published in Environmental Health Perspectives is related to WASH topics.
  • Medline Plus: Drinking Water – Consumer information from Medline Plus, a service of the National Library of Medicine.
  • CDC: Drinking Water – Public health information from the Centers for Disease Control and Prevention.
  • Ground Water and Drinking Water – Information from the U.S. Environmental Protection Agency.
  • Reducing PFAS in Drinking Water (1MB) – In the Cincinnati area, NIEHS-funded researchers discovered high levels of a specific PFAS chemical, called perfluorooctanoate (PFOA), in young girls. This research translation story shows how they worked with local water departments to implement water filtering techniques that resulted in a 40-60% reduction in PFOA levels in the girls and other residents.
  • Report on Carcinogens – This congressionally mandated, science-based, public health document is prepared by NTP for the HHS Secretary. The current report lists 248 agents, substances, mixtures, and exposure circumstances that are known or reasonably anticipated to cause cancer in humans.

Related Health Topics