By Leila Waid.
As a research project for a university course, I conducted a literature review and systematic analysis of the health effects of PFAS in drinking water. This blog post contains a highlight and broad overview of the health effects discovered.
The systematic analysis included 44 observational epidemiological studies focused on PFAS-contaminated water as the exposure and adverse health effects as the outcome of interest. (For inquiries, references to individual studies, or any other information about the information about the systematic review study, email info@chej.org).
The results:
PFAS in drinking water is associated with a variety of different health effects. However, it is important to note that the results included here do not prove causation. In other words, the studies cannot prove that PFAS caused these health issues, only that an increase in PFAS exposure is associated with these health effects.
- Cardiovascular health: increase in “bad” cholesterol, triglyceride lipids, blood pressure, hypertensive pregnancy disorder.
- Hormonal health (endocrine system): impaired thyroid function, disruption in the growth hormone IGF-1 in children, lower levels of estradiol and testosterone, increase in Poly-Cystic Ovary Syndrome, fibroids, and testicular cancer.
- Immune health: increase in adverse health effects from COVID-19, disruption in inflammation production, lower immune cell count and production, increase in ulcerative colitis (stomach ulcers).
- Urinary system health: kidney function impairment, kidney cancer, bladder cancer
- Digestive system: esophageal cancer.
- Neonatal (infant) health: lower birthweight and small for gestational age.
- PFAS has also been found to cause epigenetic changes, which is a process through which our environment impacts how our genes are expressed. In other words, it does not change the actual DNA structure, but how the body reads the DNA sequence. Specifically, PFAS is associated with DNA methylation (a process through which chemicals attach to a DNA chain and turn a specific gene on or off. This process affects how the gene is read).
- Mortality: exposure to PFAS associated with all-cause mortality, as well as mortalities from liver cancer, cerebrovascular disease, diabetes, myocardial infarction, kidney cancer, breast cancer, and Alzheimer’s disease.
- Neurological system: developmental language disorder.
- Skeletal system: increase in bone fractures (hip, proximal humeral, and distal forearm fractures).
- Non-regional specific: mesothelioma cancer (affects tissues around organs), increase in multi-morbidity (multiple chronic morbidities occurring at the same time).
- Mental health: increased anxiety, financial stress around health issues, emotional distress due to worrying about living in PFAS-contaminated region. Also, PFAS was associated with an increase in behavioral problems among children.
It is important to note that all the adverse health effects discussed above were found from observational studies on human health, not animal or in vitro (cell) studies. Although the findings cannot prove causation, they still paint an alarming picture for human health. The results showcase that urgent and robust policy action is needed at the federal and state levels to protect our waterways from PFAS contamination. This situation is critical because almost half (45%) of all tap water systems in the U.S. have PFAS contamination. And one study found that an estimated 97% of all Americans have PFAS in their blood streams.