PFAS (per- and polyfluoroalkyl substances) are a group of manufactured chemicals that have been used since the 1940s in industrial and consumer products. It’s a term you have probably heard all over the news in recent years.
There are thousands of different PFAS, but Perfluorooctanoic Acid (PFOA) and Perfluorooctane Sulfonate (PFOS) are two of the most widely used and studied in the PFAS group of chemicals. They can be present in water, soil, air, food, and materials found in homes or workplaces (US EPA 2 and 3). They break down very slowly and can build up in people, animals, and the environment over time. The reason PFAS are causing so much concern is that they have been linked to cancer, weakened immune systems, fertility problems and more. Continued research is needed to determine how different exposure levels to PFAS effect people’s health (US EPA 2 and 3).
Surveys conducted by the U.S. Centers for Disease Control and Prevention (CDC) show that most people in the United States have been exposed to some PFAS. Most of these known exposures are of relatively low detection, but some people exposed to a concentrated source for a long time had higher detection. This is because PFAS have such widespread production and uses, and especially because these “forever chemicals,” as they are deemed, remain volatile for long periods of time.
People can be exposed to PFAS by:
- Working in occupations such as firefighting or chemicals manufacturing and processing.
- Drinking water contaminated with PFAS.
- Eating certain foods that may contain PFAS, including fish.
- Swallowing contaminated soil or dust.
- Breathing air containing PFAS.
- Using products made with PFAS or that are packaged in materials containing PFAS (U.S. EPA 2 and 3).
Last year, the U.S. Environmental Protection Agency (EPA) determined limits for PFOA and PFOS in drinking water at 4 parts per trillion (ppt). These PFAS have been found in drinking water sources in all 50 states. Currently, if a consumer wants to test their drinking water for PFAS, they must send the sample to an environmental contract laboratory. It could take several weeks to get results back and cost hundreds of dollars.
Due to the various ways people can be exposed to PFAS and its link to harmful health effects, chemists at Massachusetts Institute of Technology (MIT) developed new sensor technology that can detect PFAS levels as low as 200 ppt in a water sample. As technology is always evolving and improving, this device could become very beneficial for consumers to test their own drinking water and purchase a water filter for their home. And, industries that rely on PFAS in their manufacturing process can test their water to ensure it is safe to release into the environment (Trafton).
To make this technology affordable and quick, the MIT team designed the sensor based on lateral flow technology, the same technology used for rapid Covid-19 tests and pregnancy tests. Their device can only work for PFAS that are acidic, which includes PFOA, as low as 400 ppt, and perfluorobutanoic acid (PFBA), as low as 200 ppt. Quantitative results are sent to an external device, such as a smartphone (Trafton).
Since this device doesn’t reach EPA detection limits because it uses less than a milliliter of water, the researchers are now working on a larger-scale device that would filter more water, which they hope will increase the sensitivity enough to meet the EPA detection limits (Trafton).
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Sources:
- Trafton, Anne. “A new sensor detects harmful ‘forever chemicals’ in drinking water.” A new sensor detects harmful “forever chemicals” in drinking water | MIT News | Massachusetts Institute of Technology. Published March 11, 2024. Accessed April 29, 2024.
- United States Environmental Protection Agency. “PFAS Explained.” https://www.epa.gov/pfas/pfas-explained. Published October 25, 2023. Accessed April 29, 2024.
- United States Environmental Protection Agency. “Our Current Understanding of the Human Health and Environmental Risks of PFAS.” https://www.epa.gov/pfas/our-current-understanding-human-health-and-environmental-risks-pfas. Published June 7, 2023. Accessed April 29, 2024.