About 6 million U.S. residents – and possibly many more – get their drinking water from supplies that are contaminated by industrial chemicals linked to cancers, a new study has found.
Researchers from Harvard University say a class of chemical compounds known as polyfluoroalkyl and perfluoralkyl substances, or PFASs, exceed recommended limits in 194 of 4,864 public water supplies.
The health effects of PFASs aren’t well understood, according to the Agency for Toxic Substances and Disease Registry, but tests on animals have shown that exposure to high levels of PFASs can affect hormone levels and changes in the function of the liver, thyroid and pancreas.
In humans, the toxins accumulate in the body and the amount reduces very slowly over time, the agency said. According to the toxic substance registry, studies involving people have shown a potential association between some PFASs and:
- Developmental delays in the unborn and children, possibly affecting growth, learning and behavior
- Decreased fertility
- Increased cholesterol
- Changes to the immune system
- Increased uric acid levels
- Changes in liver enzymes
- Prostate, kidney and testicular cancer
Where the problems are
PFASs are widely used in making non-stick coatings and heat- stain- and water-resistant products. Such industrial uses have led to contamination of soil and water, especially in areas near industrial sites, fire training areas, wastewater treatment plants and airports.
The researchers said drinking water in 13 states accounted for three-quarters of the unsafe water samples. The 13 states with the most findings of excessive levels of PFASs are, in order:
- California
- New Jersey
- North Carolina
- Alabama
- Florida
- Pennsylvania
- Ohio
- New York
- Georgia
- Minnesota
- Arizona
- Massachusetts
- Illinois
“For many years, chemicals with unknown toxicities, such as PFASs, were allowed to be used and released to the environment, and we now have to face the severe consequences,” said lead author Xindi Hu, a Harvard doctoral student. “In addition, the actual number of people exposed may be even higher than our study found, because government data for levels of these compounds in drinking water is lacking for almost a third of the U.S. population — about 100 million people.”
About 44.5 million U.S. residents get their water from private wells and another 52 million rely on smaller public supplies, according to the study.
Research findings and health effects of PFASs
You can download the study from the Harvard T.H. Chan School of Public Health site, on the page titled “Unsafe levels of toxic chemicals found in drinking water for six million Americans.”
You can learn about PFASs -- including a description of how they enter the environment, how humans are exposed to them and how they can affect your health -- at the website for the Agency for Toxic Substances & Disease Registry.
Talk to your provider about how you can limit your exposure to harmful chemicals. You can find a Providence provider in our multistate directory.
