Blood tests for the presence of “forever chemicals” should be available to patients who have a history of likely elevated exposure to these substances, a panel of top environmental health experts declared on Wednesday.

Clinicians should offer tests to patients who have been exposed to these cancer-linked compounds by either working or living in contaminated settings, the experts argued in a 300-page report published by the National Academies of Sciences, Engineering and Medicine.

The report calls upon the Centers for Disease Control and Prevention (CDC) to update its clinical guidance regarding blood testing for per- and polyfluoroalkyl substances (PFAS). These so-called forever chemicals are linked to a variety of illnesses, such as thyroid cancer, testicular cancer and kidney disease.

If testing then reveals PFAS levels associated with an increased risk of adverse effects, patients should receive regular screenings and monitoring for these health impacts, according to the report.

“We are going to need robust and effective collaboration between local communities, states, and federal agencies in order to respond to the challenge of PFAS exposure,” Ned Calonge, associate professor of family medicine at the University of Colorado, Denver, said in a statement.

Calonge, who is also an associate professor of epidemiology at the Colorado School of Public Health, chaired the committee responsible for the report.

Patients eligible for blood testing, according to the authors, should include those with occupational exposure, those who have lived in communities with documented contamination and those who have lived in locations where contamination likely occurred.

Some potential places of concern are areas near commercial airports and military bases — which often house PFAS-laden firefighting foam — as well as wastewater treatment plants, farms that have used sewage sludge and landfills or incinerators that received waste containing PFAS, the report stated.

Stressing that testing for PFAS should be “an informed and shared decision between clinicians and patients,” the authors urged clinicians to be transparent about the benefits, harms and limitations of the process.

“Testing can help people feel empowered in managing their own health, for example, or relieve the stress of not knowing one’s exposure level,” they said in a press statement accompanying the report.

Drawbacks of testing include difficulties in interpreting results and decreased property values once contamination is discovered, according to the report.

The authors recommended that the CDC, its Agency for Toxic Substances and Disease Registry and public health departments support clinicians by producing educational materials about PFAS exposure and the potential health impacts.

Laboratories that conduct testing should report the results to their state public health authorities with the goal of improving PFAS exposure surveillance, according to the report.

“We need to continue to identify communities with elevated PFAS exposure, learn more about specific health impacts, make testing available to patients and give clinicians more strategies for counseling patients and providing preventive medical care,” Calonge said.

Calonge and his colleagues recommended that clinicians take specific actions if the sum of seven types of PFAS reach specific threshold concentrations in a patient’s serum or plasma.

The authors said that they focused only on these seven types of PFAS — even though there are thousands — because those are the ones currently being monitored by the CDC.

Patients whose PFAS blood levels are below 2 nanograms per milliliter are not expected to experience adverse health impacts, according to the report.

Blood levels between 2 and 20 nanograms per milliliter could indicate possible adverse effects, particularly for sensitive populations or pregnant individuals, the authors found.

In this scenario, they suggested that clinicians encourage patients to reduce exposure while prioritizing screening for abnormally high cholesterol, hypertension associated with pregnancy and breast cancer based on age and risk factors.

Patients whose blood levels of PFAS exceed 20 nanograms per milliliter may face a higher risk of adverse effects, according to the study.

In this case, the authors urged clinicians to take the same steps indicated in the previous category, while also assessing thyroid function and looking for signs of kidney cancer, testicular cancer and ulcerative colitis.

A decade ago, scientists demonstrated a “probable link” between PFAS and diagnosed high cholesterol, ulcerative colitis, thyroid disease, testicular cancer, kidney cancer and pregnancy-induced hypertension — the result of a settlement in West Virginia at the time.

Since then, however, researchers have been probing a plethora of possible links to other illnesses.  

Calonge and his colleagues acknowledged that research has yet to determine the relationship between PFAS exposure at a specific level and potential health impacts.

The authors maintained, however, that “there is sufficient evidence” of a link between PFAS and heightened risk of decreased antibody response in adults and children, high cholesterol in adults and children, decreased infant and fetal growth and kidney cancer in adults.

The researchers said they saw “limited or suggestive evidence” of an increased risk of breast cancer, testicular cancer, thyroid disease and ulcerative colitis in adults, pregnancy-induced hypertension and liver enzyme alternations in adults and children.

Inadequate or insufficient evidence is available to indicate such a link to many other health impacts, including cardiovascular conditions aside from high cholesterol and fetal development outcomes apart from lower birthweight, according to the study.

The authors also addressed the potential risks of PFAS exposure to babies via breast milk, noting that “research has consistently shown benefits of breastfeeding even while PFAS exposures have been occurring for many years.”

The substances, the researchers added, may also be present in water used to produce infant formula.

Stressing that it is yet unclear what types and levels of exposure to PFAS could be harmful to a nursing child, the scientists urged federal health agencies to conduct research related to such transfer of toxins.

“Regardless of current gaps in knowledge, clinicians counseling parents of infants on PFAS exposure should discuss steps to lower PFAS exposure through feeding,” the authors stated.

Going forward, the scientists called upon the CDC to “use a reader-centered approach in its revised guidance” and update that guidance every two years.

The Hill has reached out to the CDC for comment.