They’re in the air. They’re in the water. They’re in the food we consume. And now, they’re in our blood. They are perfluoroalkyl and polyfluoroalkyl substances (PFAS) or “forever” chemicals — substances that make up plastic and never degrade. They’ve been linked to numerous health conditions: they contaminate the delicate balance of gut microbiomes, cause asthma and other lung diseases, and now they’re in our bloodstream where they’re difficult to remove.

A landmark trial has now found that donating blood regularly can cleanse the bloodstream of PFAS — a finding that marks the first time we’ve figured out how to rid the body of forever chemicals that have entered seemingly, well, forever.

The research, published in JAMA Network Open, included 285 firefighters from Australia who donated blood and plasma over 12 months. Firefighters are more exposed to PFAS than the average person, making them a perfect case study for the research.

The firefighters were divided into three groups: one would donate plasma every six weeks; one would donate blood every 12 weeks; and one would simply be under observation. “They say ‘we don’t want these chemicals in our body, we don’t want to be guinea pigs to see what’s going to happen to us in 10, 20, 30 years. Let’s get them out,'” study co-author Mark Taylor said, of the firefighters’ response.

“Plasma donation was the most effective intervention, reducing mean serum perfluorooctane sulfonate levels by 2.9 ng/mL compared with a 1.1-ng/mL reduction with blood donation, a significant difference; similar changes were seen with other PFASs,” the paper stated. In other words, donating plasma was found to be more effective than donating blood; though both were effective in reducing the overall amount of chemicals in the bloodstream. This is significant: thus far, no other intervention has worked in reducing PFAS in the blood.

Related on The Swaddle:

What You Need to Know About the Chemicals We’re Exposed to Every Day and Ingest Without Realizing

PFAS are ubiquitous: they’re used in a variety of non-stick utensils, water-resistant materials, and others due to their heat and water resistance. There are thousands of chemicals in the PFAS family; with very little regulation monitoring their use. The costs of utility, however, are steep: apart from being identified as potentially carcinogenic, PFAS are associated with “low fetal weight, impaired immune response, thyroid function abnormalities, obesity, increased lipid levels, liver function alterations, and, potentially, an increased risk of some malignant neoplasms.”

The petrochemical industry is largely responsible for PFAS everywhere we look, touch, and breathe. Concerned about growing regulation, industries are now moving to more “permissive regimes” such as India, Brazil, and China, The Guardian reported. There is now no place on Earth uncontaminated by PFAS — but some populations stand to be at risk from contamination more than others.

The logic in removing them is simple: PFAS work by binding to serum proteins in the blood; removing some of this blood, therefore, would lead to the reduction of forever chemicals in the bloodstream. As to the question of what happens to recipients of this blood: “Perfluoroalkyl and polyfluoroalkyl substances are ubiquitous, and no threshold has been identified that poses an increased risk to recipients of donated blood components.”

While more research is needed to test if simply removing blood or plasma at regular intervals can be an effective long-term solution, the research nevertheless highlights the alarming rate of contamination at the behest of these chemicals. And while interventions to remove them from the blood are crucial, regulations to ensure they don’t enter it in the first place are also key.