A recent comprehensive study reveals that almost everyone tested has dangerous “forever chemicals” in their blood, intensifying worries about how deeply these man-made substances have infiltrated modern life. Scientists examined over 10,500 blood samples and discovered that 98.8% contained at least one type of PFAS, a group of chemicals commonly called “forever chemicals” because they degrade very slowly, lingering in the environment and human bodies for years.
Published in the Journal of Occupational and Environmental Hygiene, this marks one of the largest investigations into PFAS levels in human blood. The findings also show that most individuals don’t just carry a single PFAS compound but multiple at once—about 98.5% of tested individuals had several types in their bodies.
PFAS, which stands for per- and polyfluoroalkyl substances, have been widely used since the 1940s due to their resistance to heat, oil, water, and stains. They’ve been incorporated into thousands of everyday products. Today, PFAS are found in nonstick cookware, waterproof clothing, food packaging, stain-resistant carpets, firefighting foam, cosmetics, electronics, and some medical supplies. Over time, these chemicals can seep into water sources, soil, food, and indoor dust.
Scientists are increasingly worried because PFAS don’t break down easily once released into the environment. Instead, they gradually accumulate in animals, ecosystems, and humans over many years. While more research is needed to fully understand the health impacts of all PFAS variants—there are about 10,000 different types—studies have linked some to serious health issues. These include cancers, infertility, hormone disruption, liver problems, weakened immune systems, high cholesterol, thyroid disease, and developmental issues in children.
One chemical frequently detected in this study was perfluorohexane sulfonic acid, known for its potential to harm the liver, thyroid, and immune system. Researchers analyzed 10,566 blood serum and plasma samples collected by NMS Labs, a leading independent testing laboratory. Most samples were checked for 13 PFAS chemicals, while a smaller subset tested for 18.
Results indicate that exposure to PFAS rarely involves just one chemical. Instead, people are typically exposed to complex mixtures of several types simultaneously. Researchers identified dozens of different combinations, with the most common—including five PFAS chemicals—appearing in more than 25% of samples. These combinations often contain older PFAS compounds like PFOS and PFOA and newer replacement chemicals used in consumer products.
This complexity is crucial because safety assessments traditionally examine one chemical at a time. However, people are exposed to many PFAS chemicals together, which may have combined effects that are more harmful than individual exposures. Dr. Laura Labay, the study’s lead author and a toxicologist at NMS Labs, explained that these findings offer a “real-world snapshot” of widespread PFAS exposure and can help scientists better understand potential health risks while guiding public health policies.
It’s also worth noting that some PFAS chemicals might not have been included in the testing panels, meaning actual exposure levels could be even higher. Public concern about PFAS has surged recently, especially as communities across the U.S. and beyond discover contamination in drinking water near military bases, airports, factories, and sites where firefighting foam has been used extensively.
Efforts to curb exposure are underway, with some countries already banning or restricting certain PFAS. Yet, many of these substances remain in widespread use because they are highly valued in manufacturing, thanks to their resistance to heat and water. Developing safer alternatives has proved challenging for many industries.
Individuals can take small steps to reduce their exposure, such as avoiding products labeled as stain- or water-resistant, using water filters certified to remove PFAS, and limiting consumption of heavily packaged fast foods. Nevertheless, given how pervasive PFAS are today, total avoidance remains nearly impossible.
This study emphasizes how embedded these chemicals are in modern life and highlights the importance of ongoing research into their long-term health effects. It also suggests that future studies should focus more on the combined impacts of multiple PFAS chemicals rather than treating each one separately.
While the research doesn’t directly link these chemicals to specific illnesses, it supports mounting concerns about widespread exposure. Larger, more detailed studies are needed to understand how these chemical mixtures influence health over decades.
