Antibody response to COVID-19 vaccines among workers with a wide range of exposure to per- and polyfluoroalkyl substances.

Per- and polyfluoroalkyl substances (PFAS) are a broad class of synthetic chemicals; some are present in most humans in developed countries. Several studies have shown associations between certain PFAS, such as perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS), and reduced antibody concentration after vaccination against diseases such as Tetanus. Recent studies have reported associations between COVID-19 occurrence and exposure to certain types of PFAS. However, studies of antibody concentration after COVID-19 vaccination in relation to PFAS serum concentrations have not been reported. We examined COVID-19 antibody responses to vaccines and PFAS serum concentrations among employees and retirees from two 3M facilities, one of which historically manufactured PFOS, PFOA, and perfluorohexane sulfonic acid (PFHxS). Participants completed enrollment and follow-up study visits in the Spring of 2021, when vaccines were widely available. In total 415 participants with 757 observations were included in repeated measures analyses. Log-transformed concentrations of anti-spike IgG and neutralizing antibodies were modeled in relation to concentration of PFAS at enrollment after adjusting for antigenic stimulus group (9 groups determined by COVID-19 history and number and type of vaccination) and other variables. The fully adjusted IgG concentration was 3.45 percent lower (95% CI -7.03, 0.26) per 14.5 ng/mL (interquartile range) increase in PFOS; results for neutralizing antibody and PFOS were similar. For PFOA, PFHxS, and perfluorononanoic acid (PFNA), the results were comparable to those for PFOS, though of smaller magnitude. In our study data, the fully adjusted coefficients relating concentration of vaccine-induced antibodies to COVID-19 and interquartile range difference in serum concentration of PFOS, PFOA, PFHxS, and PFNA were inverse but small with confidence intervals that included zero. Our analysis showed that the coefficient for the four PFAS examined in detail was considerably affected by adjustment for antigenic stimulus group.

Perfluoroalkyl and polyfluoroalkyl substances, bisphenol and paraben compounds in dust collected from residential homes in Klang Valley, Malaysia

Endocrine disrupting chemicals (EDCs) are a growing global concern due to their widespread use and potential harm to human and animal health. Several EDCs have been linked to cancer, obesity, and diabetes in children and adults. EDCs come from manufacturers or everyday products like cookware, textile, cosmetic, furniture, and plastic. Some EDCs are volatile and may be inhaled by the inhabitants where indoor exposure to EDCs is considered worse than outdoor exposure due to the limited and confined area allowing dermal contact and ingestion of EDCs. During the COVID-19 pandemic in 2020–2021, all Malaysians were confined to their homes, prompting the goal of this study to investigate EDCs in household dust collected from Klang Valley homes. A total of 57 dust samples were collected, filtered, and extracted using methanol. EDCs including perfluoroalkyl and polyfluoroalkyl substances (PFAS), bisphenol and parabens were identified and quantified in dust samples by liquid chromatography mass tandem spectrometry (LCMS/MS). The presence of perfluorooctanoic acid (PFOA), perfluorooctane sulfonic acid (PFOS), butylparaben (BuP), methylparaben (MeP), ethylparaben (EtP), and propylparaben (PrP) was detected in 50–100% of dust samples, with range of concentration of 0.31–3693.96 ng/g, indicating that these compounds are common in indoor dust. Methylparaben was the most prevalent EDC in collected dust samples with mean concentration at 148. 18 ng/g, accounting for 54% of the concentration distribution, followed by BuP and PFOA. There were regional differences in EDC profiles, with higher PFAS and paraben levels in urban areas such as Putrajaya, Kuala Lumpur, and Petaling. The estimated daily intake (EDI) of EDCs from indoor dust ingestion varied by age, with infants having a significantly higher EDI (p <.01) than children and adults. Despite safe for consumption (Hazard Quotient, HQ < 1), these findings provide a baseline for assessing PFAS, bisphenol, and paraben in indoor dust from Malaysian homes. © 2022 Taylor & Francis Group, LLC.

A Participatory Science Approach to Evaluating Factors Associated with the Occurrence of Metals and PFAS in Guatemala City Tap Water

Limited information is available regarding chemical water quality at the tap in Guatemala City, preventing individuals, water utilities, and public health authorities from making data-driven decisions related to water quality. To address this need, 113 participants among households served by a range of water providers across the Guatemala City metropolitan area were recruited as participatory scientists to collect first-draw and flushed tap water samples at their residence. Samples were transported to the U.S. and analyzed for 20 metals and 25 per- and polyfluoroalkyl substances (PFAS). At least one metal exceeded the Guatemalan Maximum Permissible Limit (MPL) for drinking water in 63% of households (n = 71). Arsenic and lead exceeded the MPL in 33.6% (n = 38) and 8.9% (n = 10) of samples, respectively. Arsenic was strongly associated with groundwater while lead occurrence was not associated with location, water source, or provider. One or more PFAS were detected in 19% of samples (n = 21, range 2.1–64.2 ppt). PFAS were significantly associated with the use of plastic water storage tanks but not with location, water source, or provider. Overall, the high prevalence of arsenic above the MPL in Guatemala City tap water represents a potential health risk that current water treatment processes are not optimized to remove. Furthermore, potential contaminants from premise plumbing and storage, including lead and PFAS, represent additional risks requiring further investigation and public engagement.

Influence of Perfluoroalkyl Substances on Occurrence of Coronavirus Disease 2019.

Epidemiologic evidence indicates exposure to polyfluoroalkyl substances (PFAS) influences immunosuppression, with diminished vaccination response. The relationship between PFAS blood levels and coronavirus disease 2019 (COVID-19) occurrence by age warrants further examination. This assessment identified blood PFAS exposure levels in discrete populations. Recent PFAS population studies summarizing age and gender results were identified and included. Geographically corresponding COVID-19 incidence data were determined for selected counties in North Carolina (NC) and Ohio (OH), and the state of New Jersey (NJ). Centers for Disease Control and Prevention COVID-19 databases were accessed for national incidence data by age groupings. We assessed associations between blood PFAS concentrations, COVID-19 incidence rates, and key demographic characteristics, within subpopulations. COVID-19 incidence counts and blood PFAS concentration were obtained for each age group, along with estimated U.S. Census total population. A general trend observed is higher PFAS levels in older age groups. Younger age groups contained fewer COVID-19 cases. Global COVID-19 mortality is highest in elderly populations with hospitalization and death greatly increasing from age 50. PFAS exposures occurring early in life may cause deleterious health effects later in life, including decreased antibody response and reduced disease resistance. Highest levels of both PFAS exposure and COVID-19 were found in the oldest populations. While this does not determine causality, such associations should help promote further study.

Per- and Polyfluoroalkyl Substances (PFAS) in Facemasks: Potential Source of Human Exposure to PFAS with Implications for Disposal to Landfills

Facemasks are important tools for fighting against disease spread, including Covid-19 and its variants, and some may be treated with per- and polyfluoroalkyl substances (PFAS). Nine facemasks over a range of prices were analyzed for total fluorine and PFAS. The PFAS compositions of the masks were then used to estimate exposure and the mass of PFAS discharged to landfill leachate. Fluorine from PFAS accounted only for a small fraction of total fluorine. Homologous series of linear perfluoroalkyl carboxylates and the 6:2 fluorotelomer alcohol indicated a fluorotelomer origin. Inhalation was estimated to be the dominant exposure route (40%-50%), followed by incidental ingestion (15%-40%) and dermal (11%-20%). Exposure and risk estimates were higher for children than adults, and high physical activity substantially increased inhalation exposure. These preliminary findings indicate that wearing masks treated with high levels of PFAS for extended periods of time can be a notable source of exposure and have the potential to pose a health risk. Despite modeled annual disposal of 29-91 billion masks, and an assuming 100% leaching of individual PFAS into landfill leachate, mask disposal would contribute only an additional 6% of annual PFAS mass loads and less than 11 kg of PFAS discharged to U.S. wastewater. © 2022 American Chemical Society.

Identifying environmental factors that influence immune response to SARS-CoV-2: Systematic evidence map protocol.

BACKGROUND: Widespread environmental contamination can directly interact with human immune system functions. Environmental effects on the immune system may influence human susceptibility to respiratory infections as well as the severity of infectious diseases, such as the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Furthermore, the efficacy of vaccines to respiratory diseases may be impacted by environmental exposures through immune perturbations. Given the quick pace of research about COVID-19 and associated risk factors, it is critical to identify and curate the streams of evidence quickly and effectively. OBJECTIVE: We developed this systematic evidence map protocol to identify and organize existing human and animal literature on high-priority environmental chemical classes (Per- and polyfluoroalkyl substances, pesticides, phthalates, quaternary ammonium compounds, and air pollutants) and their potential to influence three key outcomes: (1) susceptibility to respiratory infection, including SARS-CoV-2 (2) severity of the resultant disease progression, and (3) impact on vaccine efficacy. The result of this project will be an online, interactive database which will show what evidence is currently available between involuntary exposures to select environmental chemicals and immune health effects, data gaps that require further research, and data rich areas that may support further analysis. SEARCH AND STUDY ELIGIBILITY: We will search PubMed for epidemiological or toxicological literature on select toxicants from each of the chemical classes and each of the three outcomes listed above. STUDY APPRAISAL AND SYNTHESIS OF METHODS: For each study, two independent reviewers will conduct title and abstract screening as well as full text review for data extraction of study characteristics. Study quality will not be evaluated in this evidence mapping. The main findings from the systematic evidence map will be visualized using a publicly available and interactive database hosted on Tableau Public.

How to investigate human health effects related to exposure to mixtures of per- and polyfluoroalkyl substances: A systematic review of statistical methods.

BACKGROUND: Humans are exposed to several per- and polyfluoroalkyl substances (PFAS) daily; however, most previous studies have focused on individual PFAS. Although attention to effects of exposure to mixtures of PFAS has grown in recent years, there is no consensus on the appropriate statistical methods that can be used to assess their combined effect on human health. OBJECTIVES: We aim to perform a comprehensive review of the statistical methods used in the existing studies which evaluate the association between exposure to mixtures of PFAS and any adverse human health effect. METHODS: The online databases PubMed, Embase and Scopus were searched for eligible studies, published during the last ten years (last search performed on April 08, 2021). Covidence software was used by two different reviewers to perform a title/abstract screening, followed by a full text revision of the selected papers. RESULTS: A total of 3640 papers were identified, and after the screening process, 53 papers were included in the current review. Most of the studies were published between 2019 and 2021 and were conducted mainly in North America and Europe; more than half of the studies (28 out of 53) were conducted on mother and child pairs. WQS (Weighted Quantile Sum) Regression and BKMR (Bayesian Kernel Machine Regression) were used in 36 out of 53 papers to model mixtures' effects. Health outcomes included in the studies are immunotoxicity (n = 8), fetal development (n = 7), neurodevelopment (n = 9), reproductive hormones (n = 6), thyroid hormones (n = 7), outcomes related to metabolic pathways (n = 16). CONCLUSION: Studies on human exposure to PFAS as complex mixtures and health consequences have substantially increased in the last few years. Based on our findings, we propose that addressing risk from PFAS mixtures will likely require combinations of approaches and implementation of constantly evolving statistical methods. Specific guidelines and tools for quality assessment and publication of mixture observational studies are warranted.