PFAS Exposure Associated with Higher Cataract Prevalence

PFAS exposure has indicated with population research to trigger oxidative stress and inflammation, which may be one possible pathomechanism contributing to cataract formation. Photo: Julie Tyler, OD. Click image to enlarge. A pervasive and harmful group of chemical compounds known as per- and polyfluoroalkyl substances (PFAS), found in daily life due to widespread manufacturing processes, can be exposed to humans by inhalation, dietary intake and via contact with household items. PFAS are used in everything from nonstick frying pans to stain-free carpet treatments to microwave popcorn bags to form protective barriers of various kinds. Given such frequent contact by humans, researchers wanted to see if the harmful agent was linked to cataract, which is known to be influenced by environmental exposures.To explore this association, the investigators included 2,119 US adults aged 40 or older from the National Health and Nutrition Examination Survey for analysis who displayed six serum PFAS concentrations. Results indicated that single exposure to perfluorohexane sulfonic acid (PFHS) and perfluorononanoic acid (PFNA) were markedly associated with cataract prevalence after adjusting for covariates, with odds ratios of 1.58 and 1.63, respectively. One type of analysis, called the weighted quantile sum (WQS) regression index, was significantly linked with cataract with an odds ratio of 1.44, and PFNA and PFHS were the most influential exposures in the PFAS mixture. A different regression model had PFNA and PFHS exhibit the highest group posterior inclusion probability, in line with the WQS results. What’s more, serum albumin and neutrophil counts were found to mediate the relationship of PFHS and cataract, accounting for 26.2% and 6.0% of the mediation effect, respectively.The authors elaborate in their paper for Translational Vision Science & Technology on the importance of looking at PFAS specifically in ocular conditions, citing that these substances have been linked already to chronic conditions including various cancer forms as well as demonstrating increased mortality rates, highlighting their potential for widespread and detrimental harm. Simultaneously, cataract prevalence has increased to reflect a major public health issue, prompting researchers and clinicians alike to draw attention to understanding its potential risk factors.Their paper also discusses how the impact of PFHS on cataract prevalence may be modulated via serum albumin and neutrophil count—suggesting protective roles of both. Research has already demonstrated that PFHS exposure is correlated with increased serum albumin levels and decreased neutrophil counts. Albumin is a primary transporter of many PFAS in plasma and exhibits enhanced binding affinity for longer chain lengths as well as playing a vital role in maintaining lens health and protecting against cataract. Conversely, suppressed neutrophil functions may occur because PFAS are immunotoxic. The authors elucidate that, “considering the association between elevated neutrophil count, increased neutrophil-lymphocyte ratios and the development of cataract, we found that the effects of PFHS on cataract prevalence could be regulated negatively by neutrophil count, indicating the protection effects of neutrophil count.”The researchers convey in their paper that “this study addresses a notable gap in the existing literature” and advocate for future research. “Given that humans are exposed to multiple environmental exposures simultaneously, further exploration of the effects of the mixture of chemicals on health effects is essential.” Click here for the journal source.  Liu Y, Yao J, Ren M, et al. Association of per- and polyfluoroalkyl substance exposure with cataract prevalence among U.S. adults: a NHANES analysis (2005-2008). Transl Vis Sci Technol. 2025;14(4):1.