What is PFAS & how can it be removed from drinking water supplies
What is PFAS?
PFAS, or perfluoroalkyl substances, are a group of more than 4,000 man-made chemicals, with strong carbon-fluorine bonds, that have been used to make cookware packaging, stain repellents, food packaging and other consumer products for nearly a century. Airports, factories and military bases have all heavily used PFAS in the past.
Not only were PFAS included in certain products and packaging, but they were also released as a production byproduct in factories. This resulted in a buildup of PFAS in the environment, including the air, soil, and in natural water sources. PFAS are known as “forever chemicals” because they can persist in the environment for a long time, which gives a high likelihood of public exposure.
RELATED: PFAS Removal Technologies
How Do Forever Chemicals Affect People’s Health?
PFAS exposure can cause several health effects, many of them long-term. Human bodies are unable to expel these chemicals, so they can accumulate gradually until they reach harmful levels.
Some of the potential health-damaging effects of PFAS exposure include:
In a range of studies, PFAS have been found to have strong links with several types of cancer, including kidney, testicular, ovarian, prostate and thyroid cancer, as well as childhood leukemia. PFAS have been labeled as possible human carcinogens by the International Agency for Research on Cancer.
Low Infant Birth Rate
In a study of prenatal exposure to PFAS, these forever chemicals were linked to preterm birth and small-for-gestational-age. The study found that when one or both parents had elevated blood PFAS levels, the child’s growth rate was affected for the first two years of life.
Immune System Effects
Studies have found that eating food or drinking water containing PFAS may reduce our resistance to infectious disease. There is even evidence to suggest that PFAS exposure may affect the immune system’s antibody response to vaccines.
According to a CDC report, one of the harmful health outcomes of PFAS is high cholesterol, although more evidence is needed to confirm how this health effect may present itself in the long term.
Thyroid Hormone Disruption
PFAS have the ability to disrupt endocrine function and impair thyroid function, according to new data. Studies have found that PFAS exposure in children may harmfully affect the thyroid cells and can cause “accumulation, cytotoxicity, genotoxicity, interference with TH synthesis, TPO function, and iodine uptake”. This may affect brain development, cognitive functions and behavior.
How Do PFAS Get Into Water?
Even if you avoid using products that contain PFAS, you may still be exposed to these chemicals in your drinking water. Localized PFAS water contamination is uncommon but still possible.
Communities near factories that produce PFAS or use this chemical in the manufacturing process are more likely to drink PFAS in their water. PFAS may be dumped or released into the atmosphere, where it can settle on the ground and leach into groundwater sources.
Firefighting foam, which contains PFAS, can also contaminate water. Communities living near airfields or military bases may be at a higher risk of PFAS in their drinking water.
Research has found that water supplies for at least 6 million people in the US contain elevated PFAS levels that exceed the Environmental Protection Agency’s public health recommendations.
What Are the Regulations Around PFAS in Tap Water?
The EPA’s public health advisory for PFOS and PFOA, the two most prevalent types of PFAS, says that these chemicals should not exceed 70 ppt (parts per trillion) in public drinking water supplies.
The Environmental Working Group (EWG) believes that the EPA’s standards are too lenient, and has set its own much more stringent advisory level for PFAS in water. According to this activist group, a public water sample with more than 1 part per trillion of PFAS may have harmful health effects.
Some states and government bodies in the US have set their own lower limits to regulate PFAS in local water supplies. You can find out your area’s Maximum Contaminant Level for PFAS by visiting your state’s Department of Health website.
How Are PFAS Removed From Drinking Water Supplies?
PFAS are some of the more difficult-to-remove drinking water contaminants, but there are still ways to remove them, both on a large scale and in at-home applications.
Some of the most effective means of removing PFAS from drinking water are as follows:
Reverse osmosis systems consist of several filter stages, including a carbon filter, a pre- and post- filter, and a reverse osmosis membrane. These systems are effective enough to remove more than 99.99% of nearly all contaminants from drinking water, including PFAS.
A reverse osmosis system works by forcing water through a sem-permeable membrane, which is made up of tiny pores that allow only water particles to pass through. Contaminants that are larger than water particles rebound off the membrane and are eventually flushed out of the system down a drain. Because of the water waste involved in the RO process, it is not typically used as a large-scale water treatment solution.
A more affordable, efficient alternative to reverse osmosis is carbon filtration. Carbon filters use the adsorption process to trap contaminants in their media, preventing them from passing through with water. Both granular activated carbon and powder activated carbon can be used to reduce or remove PFAS.
Carbon filtration isn’t as effective as reverse osmosis, as water flows through a single filtration stage, rather than several.
Ion Exchange Resins
Finally, ion exchange resins consist of hydrocarbon resins that attract contaminants like magnets. PFAS stick to the resin beads and are removed when the system flushes or regenerates.
While ion exchange is an effective option for PFAS removal, not all ion exchange resins will remove these chemicals. For instance, water softeners that use ion exchange to remove calcium and magnesium are incapable of removing PFAS.
Many small-scale filtration methods are now available for reducing PFAS and other common drinking water contaminants at home. Filters that have an NSF 53 certification have been tested by an accredited third party and deemed effective at removing impurities that have potential health effects, including PFAS.