Scientists Found ‘Forever Chemicals’ In Nearly Every Blood Sample Tested
Almost every person included in a major US study was found to carry so-called forever chemicals in their blood, highlighting how deeply these substances have spread through daily life and the environment.
Researchers at NMS Labs in Pennsylvania analyzed 10,566 blood serum and plasma samples submitted for toxicology testing. PFAS were detected in 98.8 percent of the samples, revealing just how widespread human exposure has become.
Perfluoroalkyl and polyfluoroalkyl substances, commonly known as PFAS, have been used for decades in products designed to resist water, heat, and oil. Their exceptionally strong chemical bonds make them extremely difficult to break down, allowing them to accumulate in soil, water, wildlife, and the human body over time.
The research team focused on 13 common PFAS compounds and found that almost none of the samples contained just a single chemical. Only 0.18 percent of samples showed one PFAS compound alone, while most contained complex mixtures involving five or more different substances.
Persistent Chemicals And Potential Health Risks
One of the most commonly detected compounds was perfluorohexane sulfonic acid, or PFHxS, which has historically been used in textiles, furniture, and some adhesives. It appeared in 97.9 percent of samples despite restrictions or bans in several countries.
Animal studies and observational research in humans have linked PFHxS and related PFAS compounds to possible effects on the liver, immune system, hormone regulation, and cholesterol levels. Some evidence has also connected PFAS exposure to reduced vaccine response and developmental effects in children.
Researchers caution that proving direct cause-and-effect relationships remains challenging. Much of the available evidence comes from laboratory studies, animal experiments, and population-level associations, where many other variables may influence health outcomes.
Nevertheless, regulators increasingly view PFAS as a major public health concern because of their persistence, their tendency to accumulate in blood and organs, and possible links to cancers, thyroid disorders, pregnancy complications, and metabolic problems.
Why Chemical Mixtures Matter
The new study did not measure the exact concentration of PFAS in each sample. Instead, researchers focused on whether the chemicals could be detected using mass spectrometry. Even so, the analysis revealed more than 70 distinct PFAS combinations across the two testing panels used in the study.
This finding concerns toxicologists because people are rarely exposed to a single chemical in isolation. Chemical mixtures may sometimes produce additive or even synergistic effects, potentially intensifying impacts on the immune system, metabolism, or hormone signaling pathways.
The researchers argue that identifying recurring PFAS combinations in blood samples could become important for future health-risk assessments. It may help scientists determine which clusters of chemicals are most strongly associated with specific diseases or biological effects.
Because the dataset did not specify whether multiple samples may have originated from the same individual, the study cannot establish exact prevalence across the general population. However, the large sample size still provides a valuable snapshot of real-world exposure patterns.
Regulation, Cleanup, And What Comes Next
PFAS are found in products ranging from nonstick cookware and food packaging to firefighting foams and stain-resistant fabrics. Their versatility and durability have made them difficult to replace, slowing efforts to fully phase them out despite growing environmental and health concerns.
In recent years, regulators in the United States and Europe have tightened drinking water standards, restricted certain PFAS compounds in consumer products, and proposed broader limits on entire chemical groups. However, cleaning up contaminated industrial sites and water systems remains technically difficult and extremely expensive.
Emerging technologies—including advanced filtration systems, high-temperature destruction methods, and new adsorbent materials—show promise for removing PFAS from water supplies and industrial waste streams. Scientists are also investigating safer alternative chemicals for household and industrial applications.
The authors of the new study say their findings may help guide policymakers and healthcare professionals as they develop updated recommendations for screening, exposure reduction, and long-term monitoring. They argue that focusing on chemical mixtures rather than individual compounds will likely be essential for protecting public health.
The research, published in the Journal of Occupational and Environmental Hygiene, adds to growing evidence that PFAS exposure is now nearly universal. Researchers say the challenge ahead will be reducing future contamination while dealing with the enormous legacy of chemicals already circulating in the environment.
