Exposure to “forever chemicals” interferes with several critical biological processes — including the metabolism of fats and amino acids — in children and young adults, a new study has found.
The disruption of these processes can increase susceptibility to a variety of illnesses, such as developmental disorders, cardiovascular disease, cancer and metabolic diseases like diabetes, according to the study, published on Wednesday in Environmental Health Perspectives.
Focusing on this age group was particularly important to the authors, as children and young adults go through key stages of development that may make them more vulnerable to toxic exposures.
This stage in life is also the period in which many serious diseases that manifest in adults begin to take root, the researchers noted.
The compounds in question, known as per- and polyfluoroalkyl substances (PFAS), are already linked to illnesses like thyroid disease, testicular cancer and kidney cancer.
Notorious for their ability to persist in the human body, water and soil, these synthetic compounds have become ubiquitous in both the environment and in everyday products.
“We found that exposure to a combination of PFAS not only disrupted lipid and amino acid metabolism but also altered thyroid hormone function,” lead author Jesse Goodrich, of the University of Southern California’s Keck School of Medicine, said in a statement.
Goodrich and his colleagues had set out to explore the impacts of a mix of PFAS — of which there are thousands — on biological processes in children and adolescents.
To do so, they used blood samples from 312 adolescents who had participated in a “Study of Latino Adolescents at Risk” and 137 children from the Southern California Children’s Health Study.
All the samples had a mixture of several common PFAS, including the chemicals PFOS, PFHxS, PFHpS, PFOA and PFNA, while more than 98 percent of participants also had PFDA in their blood, according to the study.
The researchers then developed a biostatistical method to measure thousands of naturally occurring chemicals in blood in order to identify how exposure to multiple types of PFAS would impact these compounds.
Their analysis showed that PFAS exposure changes the way the body metabolizes lipids and amino acids — the building blocks of fats and proteins, respectively — as well as the levels of thyroid hormones.
This last finding was particularly significant to Goodrich, who emphasized the essential role thyroid hormones play in growth and metabolism.
Changes in thyroid hormones can disrupt development during puberty and can raise the risk of developing conditions like diabetes, cardiovascular disease and cancer later in life, the authors warned.
“Our findings were surprising and have broad implications for policy makers trying to mitigate risk,” said Goodrich, who is an assistant professor of population and public health sciences at the Keck School.
An additional important finding flagged by the authors was the fact that exposure to a mixture of PFAS, rather than to a single type, fueled the disruption of these biological processes.
Almost all Americans, they warned, have detectable levels of several types of PFAS, which can be found in common household items like waterproof apparel and food packaging.
While some manufacturers have already begun to phase out individual types of PFAS, the researchers argued that it could be important to regulate these substances as a class.
“We are really only beginning to understand the range of effects that these chemicals have on human health,” co-author Leda Chatzi, a professor of population and public health sciences at the Keck School, said in a statement.
“While current interventions have focused on phasing out the use of individual PFAS, such as PFOS and PFOA, this research shows why the focus should be on reducing exposure to all PFAS chemicals,” Chatzi added.