Certain highly pervasive environmental pollutants may have a variety of negative effects on kidney health, according to an analysis of all relevant studies published on this topic to date.
In the Clinical Journal of the American Society of Nephrology analysis, researchers assessed studies on per- and polyfluoroalkyl substances (PFAS), which are a large group of manufactured non-biodegradable compounds used to provide stain and grease repelling properties to consumer products including textiles, papers, and food packaging. PFASs are also used in aqueous fire-fighting foams. Recently, they have been detected on military bases, as well as in public water supplies from industrial contamination and in agricultural and crop products.
Because PFASs have been detected in soil, air, and water from all regions of the world, with bioaccumulation across entire ecological food chains, the compounds are now recognized as globally ubiquitous pollutants.
“The kidneys are very sensitive organs, particularly when it comes to environmental toxins that can get in our bloodstream,” said John Stanifer, MD, a nephrologist and clinical researcher at Duke University. “Because so many people are now exposed to these PFAS chemicals, and to the newer, increasingly produced alternative PFAS agents such as GenX, it is critical to understand if and how these chemicals may be contributing to kidney disease.”
Dr. Stanifer and his colleagues systematically searched PubMed, EMBASE, EBSCO Global Health, World Health Organization Global Index, and Web of Science for studies from 1990 to 2018 on the epidemiology, pharmacokinetics, or toxicity of PFAS exposure and kidney-related health.
In the 74 studies identified (21 epidemiologic, 13 pharmacokinetic, and 40 toxicological studies), there were many adverse outcomes linked to PFAS exposure, including worse kidney function and dysregulated pathways linked to kidney disease. Those dysregulated pathways include oxidative stress pathways, peroxisome proliferators-activated receptor pathways, and NF-E2-related factor pathways.
Toxicology studies showed tubular histological and cellular changes from PFAS exposure, and pharmacokinetic studies demonstrated that the kidneys are the major routes of elimination.
“By searching all the known studies published on the topic, we concluded that there are several potential ways in which these chemicals can cause kidney damage,” said Dr. Stanifer. “Further, we discovered that there have already been multiple reports suggesting that these chemicals are associated with worse kidney outcomes.”
Fan Fan Hou, MD, PhD, a researcher at Southern Medical University, in Guangzhou, China, noted that the findings add to previous studies on PFAS compounds.
“The increase in environmental pollution, a result of accelerated industrialization and urbanization worldwide, has become a global health challenge. Although there is evidence for the association between exposure to PFAS and kidney cancer, the impacts of PFAS exposure on non-cancer kidney outcomes are inconclusive,” said Dr. Hou, who was not involved with this research. “Large prospective cohort studies with accurate exposure measurement and long follow-up period are required to better understand the renal adverse effect of PFAS.”