A recent study involving more than 10,500 blood samples revealed a widespread presence of "persistent chemicals," or PFAS, within the bodies of the US population.
It turned out that the vast majority of participants carried more than one type of these compounds.
The results, published in the Journal of Occupational and Environmental Health, indicate that approximately 98.5% of the samples contained multiple types of PFAS, reflecting a near-universal prevalence of these substances in the human body, making this study one of the largest to date to measure blood levels of these compounds.
PFAS are a large group of approximately 10,000 chemicals that have been used for decades in numerous industries and everyday products, such as clothing, non-stick cookware, electronics, and medical equipment. These chemicals are characterized by their ability to persist for extended periods without degrading, leading to their accumulation in the environment and the human body, including water, food, and homes.
Although the health effects of all these compounds are not yet fully understood, previous studies have linked some types to serious health problems, such as cancer, infertility, high cholesterol, and a weakened immune system.
The study showed that perfluorooxanesulfonic acid (PFOA) was the most prevalent compound in the samples, appearing in approximately 97.9% of them. This compound is among the most researched substances, having been linked to potential adverse effects on the liver, immune system, and thyroid gland, leading many countries to impose restrictions on its use.
Regarding the methodology of the study, the researchers analyzed serum and plasma samples, examining dozens of different PFAS compounds to detect their presence and interactions within the body. The results showed 58 different chemical structures when examining 13 compounds, and another 16 structures when examining 18 compounds.
The results also showed that 98.8% of the samples contained at least one of these compounds, while a very small percentage (0.18%) contained only one compound at the lower limit of its measurement.
The researchers noted that the most common combination consisted of five PFAS compounds, including PFOS and PFOA, along with other chemical substitutes used in consumer products such as non-stick cookware, stain-resistant fabrics, and fire extinguishing foam. This combination appeared in more than 2,700 samples, representing nearly a quarter of the participants.
Dr. Laura LaBaye, a researcher involved in the study, explains that the results confirm that exposure to these substances does not occur individually, but rather as a mixture of several compounds within the body. She points out that this pattern of exposure may be more important than studying each substance separately, given the interaction of these compounds with different body systems.
The researchers conclude their study by noting that one of the main limitations is the possibility that not all PFAS compounds actually present in the samples were included, meaning that the true levels of exposure may be higher than what was observed.
