A cross-sectional study of the association between perfluorinated chemical exposure and cancers related to deregulation of estrogen receptors

Exposure to Per- and Polyfluoroalkyl Substances and the Risk of Prostate and Ovarian Cancer: An Epidemiologic Meta-Analysis

BACKGROUND

Per- and polyfluoroalkyl substances (PFAS) are persistent environmental contaminants. Previous research has linked PFAS exposure to prostate and ovarian cancer risk, however, the conclusions have been inconsistent. This research purpose was to determine the relationship between PFAS exposure and prostate and ovarian cancer at the population level.

METHODS

We systematically reviewed three databases-PubMed, Web of Science, and Embase-for research from when these databases were established to April 15, 2024. The quality of the retrieved research was evaluated using the Newcastle-Ottawa Scale (NOS) quality measurement tool. Meta-analysis of the extracted data was conducted using Stata 18. We also conducted sensitivity and subgroup analyses, as well as Begg's and Egger's tests.

RESULTS

Twelve publications were involved in the analysis for prostate cancer, and six were included for ovary cancer. The outcomes indicated that PFOS exposure was positively related to prostate cancer (OR: 1.13, 95% CI: 1.00-1.28), while mixed PFAS exposure was positively related to ovarian cancer (OR: 1.63, 95% CI: 1.49-1.78). The source of heterogeneity identified in the subgroup analysis was primarily attributable to variations in study design. No significant study bias was detected in the analysis.

CONCLUSION

The study demonstrated an association between PFAS exposure and both prostate and ovarian cancers. Further investigation is required to clarify the underlying mechanisms and potential associations.

Per- and polyfluoroalkyl substances in environment and potential health impacts: Sources, remediation treatment and management, policy guidelines, destructive technologies, and techno-economic analysis

Per- and polyfluoroalkyl Substances (PFAS), also known as forever chemicals and ubiquitous persistence, pose significant public health challenges due to their potential toxicity, particularly in drinking water and soil contamination. However, PFAS occurrence and their concentrations in different environmental matrices vary globally, but factors influencing trends, transport, fate, toxicity, and interactions with co-contaminants remain largely unexplored. Therefore, this review critically examines the state-of-the-art worldwide PFAS sources, distribution, and pathways, and evaluates how PFASs are processed in wastewater treatment, generally, which causes severe problems with the quality and safety of drinking water. Importantly, the review also underscores health issues due to PFAS consumption and recent research trends on developing effective treatment strategies to manage PFAS contamination. Potential effects of PFAS were linked to urban land use and the proportion of wastewater effluent in streamflow. Besides, major emphasis was provided on challenges for conventional treatment, destructive technologies, environmental accumulation, precursor transformation, and cost-investment related to PFAS removal technologies. To combat PFAS contamination, this review proposes a framework that promotes the comprehensive identification of prevalent compounds, with a focus on their eradication through knowledge-based and targeted analysis. Additionally, it explores the ongoing debate surrounding PFAS laws and legal frameworks, offering ideas for enhancing contamination management. Lastly, this review provides a strategic plan for improving response and preparedness, serving as a foundation for addressing future environmental challenges and informing health risk assessments.

Per- and Polyfluoroalkyl Substances and Female Health Concern: Gender-based Accumulation Differences, Adverse Outcomes, and Mechanisms

The deleterious health implications of perfluoroalkyl and polyfluoroalkyl substances (PFAS) are widely recognized. Females, in contrast to males, exhibit unique pathways for PFAS exposure and excretion, leading to complex health outcomes. The health status of females is largely influenced by hormone-related processes. PFAS have been reported to be associated with various aspects of female health, including reproductive system disorders and pregnancy-related diseases. In this article, we provide insights into the correlations between PFAS and female-prevalent diseases. Current epidemiological and toxicological evidence has demonstrated that the adverse effects of PFAS on the health of the female reproductive system are primarily attributed to the disruption of the hypothalamic-pituitary-gonadal (HPG) axis and hormonal homeostasis. However, these findings do not sufficiently elucidate the intricate associations between PFAS and specific diseases. Furthermore, autoimmune disorders, another category that is more prevalent in women compared to men, require additional investigation. Immune biomarkers pertinent to autoimmune disorders have been observed to be influenced by PFAS exposure, although epidemiological evidence is insufficient to substantiate these relations. Further thorough exploration encompassing epidemiological and toxicological studies is essential to elucidating the inherent influence of PFAS on human pathologies. Additionally, comprehensive investigations into female health issues beyond their reproductive functions is essential.

Interference Mechanisms of Endocrine System and Other Systems of Endocrine-Disrupting Chemicals in Cosmetics-In Vitro Studies

Endocrine-disrupting chemicals (EDCs), found in various cosmetic products, interfere with the normal functioning of the endocrine system, impacting hormone regulation and posing risks to human health. Common cosmetic EDCs, such as ultraviolet (UV) filters, parabens, and triclosan, can enter the human body through different routes, including skin absorption. Their presence has been linked to adverse effects on reproduction, immune function, and development. High-throughput in vitro assays, using various human cell lines, were employed to assess the effects of common cosmetic EDCs such as ethylhexyl methoxycinnamate (EHMC), benzophenone-3 (BP-3), homosalate, and parabens. Despite ongoing regulatory efforts, gaps persist in understanding their long-term impacts, particularly when they are present as mixtures or degradation products in the environment. This study focuses on recent in vitro research to investigate the mechanisms through which cosmetic-related EDCs disrupt the endocrine system and other physiological systems. The in vitro findings highlight the broader systemic impact of these chemicals, extending beyond the endocrine system to include immune, reproductive, and cardiovascular effects. This research underscores the importance of developing safer cosmetic formulations and enhancing public health protection, emphasizing the need for stricter regulations.

Perfluoroalkyl and polyfluoroalkyl substances and Cancer risk: results from a dose-response Meta-analysis

Background

Perfluoroalkyl and polyfluoroalkyl substances (PFASs) are persistent organic pollutants in the environment. While some studies suggest that PFASs may contribute to cancer development, the link between PFAS exposure and cancer risk remains debated.

Methods

This dose-response meta-analysis explores the relationship between PFASs and cancer. It employs odds ratio (OR) and standardized mean difference (SMD), along with their 95% confidence interval (CI), to assess the effects of PFASs on cancer risk. Relevant studies were sourced from Web of Science, PubMed, Embase, Medline, and CNKI databases. The dose-response relationship was assessed by the fixed-effects model and least-squares regression.

Results

Forty studies, involving a total of 748,188 participants, were included in this meta-analysis. Out of these, 13 studies were specifically analyzed for the dose-response relationship. Findings revealed that exposure to PFASs, especially PFDA, significantly raises the risk of genitourinary cancers, and PFDA exposure shows a dose-dependent increase in overall and breast cancer risk. Additionally, PFOS exposure is associated with an increased cancer risk, and elevated PFOA levels were significantly observed in breast cancer patients.

Conclusions

The findings suggest that PFAS exposure is a potential cancer risk factor, with the carcinogenic potential of PFDA being dose-dependent.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40201-024-00899-w.

Examining the relationship between per-and polyfluoroalkyl substances and breast, colorectal, prostate, and ovarian cancers: a meta-analysis

Per- and polyfluoroalkyl substances (PFAS) are synthetic chemicals used widely in industrial and commercial applications. Concerns exist about their potential link to cancer risk as possible endocrine-disrupting chemicals. We conducted a meta-analysis to evaluate the dose-response relationship between PFAS, perfluorooctane sulfonate (PFOS), perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA), perfluorohexanesulfonic acid (PFHxS) exposure and risk of breast, prostate, colorectal, and ovarian cancers. We systematically searched major databases through May 2022 and identified 13 observational studies for inclusion. Using random-effects models, we calculated summary odds ratios (ORs) and 95% confidence intervals (CIs) comparing the highest versus lowest PFAS exposure categories. Additionally, we analyzed the dose-response correlation between PFAS and cancer risk in a subset of studies. The study revealed no substantial correlation between exposure to PFASs and the incidence of breast cancer (BC) (ORPFOS = 1.15, 95% CI = 0.91-1.46, ORPFOA = 1.01, 95% CI = 0.68-1.50, ORPFNA = 0.88, 95% CI = 0.64-1.21, ORPFHxS = 1.22, 95% CI = 0.40-3.77, and ORPFDA = 1.29, 95% CI = 0.41-4.10), ovarian cancer (ORPFOA = 1.43, 95% CI = 0.84-2.42), prostate cancer (ORPFOA = 1.05, 95% CI = 0.88-1.26), and colorectal cancer (ORPFOA = 0.77, 95% CI = 0.53-1.12) in the highest versus lowest exposure analysis. However, dose-response analysis showed that for every 1 ng/ml increase in PFNA and 2 ng/ml increase in PFOA, the relative risk for BC decreased significantly (RR 0.67, 95% CI 0.45-0.99 and RR 0.94, 95% CI 0.89-0.98, respectively). Non-linear dose-response analysis found no significant changes in BC risk with increasing PFAS levels. In conclusion, while the highest versus lowest analysis does not support associations between PFAS exposure and the risk of these cancers, linear dose-response analysis suggests potential inverse relationships between PFNA/PFOA levels and BC risk. Further research is warranted on these potential protective effects.

Organic food and internal exposure to pollutants among Flemish adolescents

Contrary to the initial hypothesis, Flemish adolescents who reported consuming organic food at least 7.5 times per week did not exhibit reduced internal exposure to the tested recently used pesticides. After adjustment for gender, age, country of origin, socioeconomic status, body mass index, consumption of high-fat foods and foods linked to organic food consumption, and concerning organochlorine derivatives and lead, additional adjustment for the duration of breastfeeding expressed in weeks, they displayed slightly elevated internal exposure to organochlorine derivatives, lead, methyl arsenate, and toxic relevant arsenic. A comparison was also made between the correlation of internal exposure to pollutants with the frequency of organic food consumption on one hand and the total consumption of equivalent products from all sources on the other. Regarding potatoes, vegetables, and fruits, no clear trends were observed. Regarding eggs, there was a trend towards higher internal exposures with organic food consumption, significant for trans-nonachlor, PCB118, and 2,4-dichlorophenoxyacetic acid, and marginally significant for glyphosate. For dairy, there was a trend towards higher internal exposures with organic food consumption, significant for perfluorononanoic acid and marginally significant for PCB153. Regarding nuts and seeds, the higher internal exposure to dichlorophenoxyacetic acid and the lower exposure to 3-phenoxybenzoic acid were marginally significant, while there was also a trend towards higher internal exposure to other pollutants with organic food consumption, significant for PCB118, PCB153, and sum PCBs, and marginally significant for trans-nonachlor. Concerning breakfast cereals and muesli, no clear trends were observed.

A toxicogenomics-based identification of potential mechanisms and signaling pathways involved in PFCs-induced cancer in human

Introduction

The number of new diagnosed cancer cases and cancer deaths are increasing worldwide. Perfluorinated compounds (PFCs) are synthetic chemicals, which are possible inducers of cancer in human and laboratory animals. Studies showed that PFCs induce breast, prostate, kidney, liver and pancreas cancer by inducing genes being involved in carcinogenic pathways.

Methodology

This study reviews the association between PFCs induced up-regulation/down-regulation of genes and signaling pathways that are important in promoting different types of cancer. To obtain chemical-gene interactions, an advanced search was performed in the Comparative Toxicogenomics Database platform.

Results

Five most prevalent cancers were studied and the maps of their signaling pathways were drawn, and colored borders indicate significantly differentially expressed genes if there had been reports of alterations in expression in the presence of PFCs.

Conclusion

In general, PFCs are capable of inducing cancer in human via altering PPARα and PI3K pathways, evading apoptosis, inducing sustained angiogenesis, alterations in proliferation and blocking differentiation. However, more epidemiological data and mechanistic studies are needed to better understand the carcinogenic effects of PFCs in human.

Per- and Polyfluoroalkyl Substances (PFAS) Affect Female Reproductive Health: Epidemiological Evidence and Underlying Mechanisms

PFAS (per- and polyfluoroalkyl substances) have been extensively used across numerous industries and consumer goods. Due to their high persistence and mobility, they are ubiquitous in the environment. Exposure to PFAS occurs in people via multiple pathways such as dermal contact, water supply, air inhalation, and dietary intake. Even if some PFAS are being phased out because of their persistent presence in the environment and harmful impacts on human health, mixes of replacement and legacy PFAS will continue to pollute the ecosystem. Numerous toxicological investigations have revealed harmful effects of PFAS exposure on female reproductive health, e.g., polycystic ovaries syndrome, premature ovarian failure, endometriosis, reproductive system tumors, pregnancy complications, and adverse pregnancy outcomes. Despite extensive epidemiological studies on the reproductive toxicity of PFAS, research findings remain inconsistent, and the underlying mechanisms are not well understood. In this review, we give an in-depth description of the sources and pathways of PFAS, and then review the reproductive toxicity of PFAS and its possible mechanisms.

Exposure to per- and polyfluoroalkyl substances and breast cancer risk: a systematic review and meta-analysis of epidemiologic studies

We synthesized the epidemiologic evidence on the associations between per- and polyfluoroalkyl substances (PFAS) exposure and breast cancer risk. Our systematic review and meta-analysis included 18 and 11 articles, respectively, covering studies up to February 2023. The summary relative risks (RRs) estimated by random-effects meta-analyses did not support an association between PFAS and overall breast cancer risk (eg, a natural log (ln)-unit increase in serum/plasma concentrations [ng/mL] for perfluorooctanoate [PFOA] RR = 0.95; 95% CI, 0.77-1.18; perfluorooctane sulfonate [PFOS] RR = 0.98; 95% CI, 0.87-1.11). However, when limiting to studies that assessed exposures prior to a breast cancer diagnosis, we observed a positive association with PFOA (a ln-unit increase, RR = 1.16; 95% CI, 0.96-1.40). We also observed some possible heterogeneous associations by tumor estrogen and progesterone receptor status among postmenopausal breast cancer cases. No meaningful changes were observed after excluding the studies with high risk of bias (Tier 3). Based on the evaluation tool developed by the National Toxicology Program, given the heterogeneity across studies and the variability in timing of exposure measurements, the epidemiologic evidence needed to determine the association between PFAS exposure and breast cancer remains inadequate. Our findings support the need for future studies with improved study designs to determine this association.

Unveiling the intricate connection between per- and polyfluoroalkyl substances and prostate hyperplasia

The presence of perfluoroalkyl and polyfluoroalkyl substances (PFAS) in various everyday products has raised concerns about their potential impact on prostate health. This study aimed to investigate the effects of different types of PFAS on prostate health, including PFDeA, PFOA, PFOS, PFHxS, and PFNA. To assess the relationship between PFAS exposure and prostate injury, machine learning algorithms were employed to analyze prostate-specific antigen (PSA) metrics. The analysis revealed a linear and positive dose-dependent association between PFOS and the ratio of free PSA to total PSA (f/tPSA). Non-linear dose-response relationships were observed between the other four types of PFAS and the f/tPSA ratio. Additionally, the analysis showed a positive association between the mixture of PFAS and prostate hyperplasia, with PFNA having the highest impact followed by PFOS. These findings suggest that elevated serum levels of PFDeA, PFOA, PFOS, and PFNA are linked to prostate hyperplasia. Therefore, this study utilized advanced machine learning techniques to uncover potential hazardous effects of PFAS exposure on prostate health, specifically the positive association between PFAS and prostate hyperplasia.

Novel frontiers in urogenital cancers: from molecular bases to preclinical models to tailor personalized treatments in ovarian and prostate cancer patients

Over the last few decades, the incidence of urogenital cancers has exhibited diverse trends influenced by screening programs and geographical variations. Among women, there has been a consistent or even increased occurrence of endometrial and ovarian cancers; conversely, prostate cancer remains one of the most diagnosed malignancies, with a rise in reported cases, partly due to enhanced and improved screening efforts.Simultaneously, the landscape of cancer therapeutics has undergone a remarkable evolution, encompassing the introduction of targeted therapies and significant advancements in traditional chemotherapy. Modern targeted treatments aim to selectively address the molecular aberrations driving cancer, minimizing adverse effects on normal cells. However, traditional chemotherapy retains its crucial role, offering a broad-spectrum approach that, despite its wider range of side effects, remains indispensable in the treatment of various cancers, often working synergistically with targeted therapies to enhance overall efficacy.For urogenital cancers, especially ovarian and prostate cancers, DNA damage response inhibitors, such as PARP inhibitors, have emerged as promising therapeutic avenues. In BRCA-mutated ovarian cancer, PARP inhibitors like olaparib and niraparib have demonstrated efficacy, leading to their approval for specific indications. Similarly, patients with DNA damage response mutations have shown sensitivity to these agents in prostate cancer, heralding a new frontier in disease management. Furthermore, the progression of ovarian and prostate cancer is intricately linked to hormonal regulation. Ovarian cancer development has also been associated with prolonged exposure to estrogen, while testosterone and its metabolite dihydrotestosterone, can fuel the growth of prostate cancer cells. Thus, understanding the interplay between hormones, DNA damage and repair mechanisms can hold promise for exploring novel targeted therapies for ovarian and prostate tumors.In addition, it is of primary importance the use of preclinical models that mirror as close as possible the biological and genetic features of patients' tumors in order to effectively translate novel therapeutic findings "from the bench to the bedside".In summary, the complex landscape of urogenital cancers underscores the need for innovative approaches. Targeted therapy tailored to DNA repair mechanisms and hormone regulation might offer promising avenues for improving the management and outcomes for patients affected by ovarian and prostate cancers.

Suspect, Nontarget Screening, and Toxicity Prediction of Per- and Polyfluoroalkyl Substances in the Landfill Leachate

Landfills are the final stage of urban wastes containing perfluoroalkyl and polyfluoroalkyl substances (PFASs). PFASs in the landfill leachate may contaminate the surrounding groundwater. As major environmental pollutants, emerging PFASs have raised global concern. Besides the widely reported legacy PFASs, the distribution and potential toxic effects of numerous emerging PFASs remain unclear, and unknown PFASs still need discovery and characterization. This study proposed a comprehensive method for PFAS screening in leachate samples using suspect and nontarget analysis. A total of 48 PFASs from 10 classes were identified; nine novel PFASs including eight chloroperfluoropolyether carboxylates (Cl-PFPECAs) and bistriflimide (HNTf2) were reported for the first time in the leachate, where Cl-PFPECA-3,1 and Cl-PFPECA-2,2 were first reported in environmental media. Optimized molecular docking models were established for prioritizing the PFASs with potential activity against peroxisome proliferator-activated receptor α and estrogen receptor α. Our results indicated that several emerging PFASs of N-methyl perfluoroalkyl sulfonamido acetic acids (N-MeFASAAs), n:3 fluorotelomer carboxylic acid (n:3 FTCA), and n:2 fluorotelomer sulfonate (n:2 FTSA) have potential health risks that cannot be ignored.

Evidence-based identification of breast cancer and associated ovarian and uterus cancer risk components in source waters from high incidence area in the Pearl River Basin, China

Breast cancer, ovarian cancer, and uterus cancer are among the most common female cancers. They are suspected to associate with exposures to specific environmental pollutants, which remain unidentified in source waters. In this work, we focused on the Pearl River Basin region in China, which experienced a high incidence of breast, ovarian, and uterus cancers. Combining cancer patient data, mammalian cell cytotoxicity analyses, and exhaustive historical and current chemical assessments, we for the first time identified source water components that promoted proliferation of mammalian cells, and confirmed their association with these female cancers via the estrogen receptor mediated pathway. Therefore, the components that have previously been found to enhance the proliferation of estrogen receptor-containing cells through endocrine disruption could be the crucial factor. Based on this, components that matched with this toxicological characteristic (i.e., estrogen-like effect) were further identified in source waters, including (1) organic components: phthalates, bisphenol A, nonylphenols, and per-/polyfluoroalkyls; (2) inorganic components: Sb, Co, As, and nitrate. Moreover, these identified water components were present at levels comparable to other regions with high female cancer prevalence, suggesting that the potential risk of these components may not be exclusive to the study region. Together, multiple levels of evidence suggested that long-term co-exposures to source water estrogenic components may be important to the development of breast, ovarian, and uterus cancers.

Case-Cohort Study of the Association between PFAS and Selected Cancers among Participants in the American Cancer Society's Cancer Prevention Study II LifeLink Cohort

BACKGROUND

Previous epidemiological studies found associations between exposure to per- and polyfluoroalkyl substances (PFAS) and some cancer types. Many studies considered highly exposed populations, so relevance to less-exposed populations can be uncertain. Additionally, many studies considered only cancer site, not histology.

OBJECTIVES

We conducted a case-cohort study within the American Cancer Society's prospective Cancer Prevention Study II (CPS-II) LifeLink cohort to examine associations between PFAS exposure and risk of selected cancers, considering histologic subtypes.

METHODS

Serum specimens were collected from cohort participants during the period 1998-2001. This study included a subcohort (500 men, 499 women) randomly selected from participants without prior cancer diagnoses at serum collection, and all participants with incident (after serum collection) first cancers of the breast (females only, n = 786 ), bladder (n = 401 ), kidney (n = 158 ), pancreas (n = 172 ), prostate (males only, n = 1,610 ) or hematologic system (n = 635 ). PFAS concentrations [perfluorooctanoic acid (PFOA), perfluorooctane sulfonate (PFOS), perfluorohexane sulfonic acid (PFHxS), and perfluorononanoic acid (PFNA)] were measured in stored serum. We assessed associations between PFAS concentrations and incident cancers, by site and histologic subtype, using multivariable Cox proportional hazards models stratified by sex and controlling for age and year at blood draw, education, race/ethnicity, smoking, and alcohol use.

RESULTS

Serum PFOA concentrations were positively associated with renal cell carcinoma of the kidney among women [hazard ratio (HR) and 95% confidence interval (CI) per PFOA doubling: 1.54 (95% CI: 1.05, 2.26)] but not men. Among men, we observed a positive association between PFHxS concentrations and chronic lymphocytic leukemia/small lymphocytic lymphoma [CLL/SLL, HR and 95% CI per PFHxS doubling: 1.34 (95% CI: 1.02, 1.75)]. We observed some heterogeneity of associations by histologic subtype within sites.

DISCUSSION

This study supports the previously observed association between PFOA and renal cell carcinoma among women and suggests an association between PFHxS and CLL/SLL among men. Consideration of histologic subtypes might be important in future studies of PFAS-cancer associations. https://doi.org/10.1289/EHP13174.

Systematic review and meta-analysis of breast cancer risks in relation to 2,3,7,8-tetrachlorodibenzo-p-dioxin and per- and polyfluoroalkyl substances

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) and per- and polyfluoroalkyl substances (PFAS) are endocrine disrupting chemicals that may cause breast cancer. However, there lacks consistent research on the association between TCDD, PFAS exposure, and breast cancer. To this end, a meta-analysis was carried out in this review to explore the relationship between these two endocrine disruptors and breast cancer. Relevant literature was searched from 5 databases: Medline, Scopus, Embase, PubMed, and Web of Science. Odds ratios (OR) with 95% confidence intervals (CIs) were pooled by fixed-effects and random-effects meta-analysis models. A total of 17 publications were finally included for quantitative evaluation. Meta-analysis showed that TCDD (OR = 1.00, 95% CI = 0.89-1.12, I2 = 39.3%, P = 0.144), PFOA (OR = 1.07, 95% CI = 0.84-1.38, I2 = 85.9%, P < 0.001), PFOS (OR = 1.01, 95% CI = 0.95-1.08, I2 = 65.7%, P < 0.001), PFNA (OR = 0.89, 95% CI = 0.67-1.19, I2 = 74.4%, P < 0.001), and PFHxS (OR = 0.90, 95% CI = 0.72-1.13, I2 = 74%, P < 0.001) were not significantly correlated with breast cancer. Internal exposure, however, showed a significant positive correlation between TCDD and BC (OR = 2.85, 95% CI = 1.23-6.59, I2 = 0.0%, P = 0.882). No statistically significant association between TCDD, PFAS exposure, and breast cancer was observed in this meta-analysis.

Effective communications strategies to increase the impact of environmental health research

BACKGROUND

Per- and polyfluoroalkyl substances (PFAS) are the subject of a growing body of research with the potential to positively impact public and ecological health. However, to effect positive change, findings must be communicated beyond the scientific community.

OBJECTIVE

We sought to (a) evaluate the relationships between communications strategy, media attention, and scholarly citations of PFAS research and (b) offer guidance for researchers and communications professionals who would like to publicize future work and increase its impact.

METHODS

We analyzed 273 peer-reviewed epidemiological studies on PFAS human health impacts with publication years 2018-2020, as collected by a pre-existing database. We investigated whether a press release was issued, open-access status, abstract and press release readability, timing of publication and press release distribution, journal impact factor, study type and sample size, statistical significance of finding(s), number of scholarly citations, and the Altmetric Attention Score (a measure of media attention).

DISCUSSION

Of papers reporting a statistically significant association with health harm, those with a press release received 20 times more media attention (as assessed by Altmetric scores) than those that did not. However, only 6.2% of all papers and 7.8% of significant papers issued one. Among papers with a press release, media attention was positively correlated with better abstract and press release readability and speed in issuing the press release. Scholarly citations were positively correlated with media attention, presence of a press release, and open-access status.

CONCLUSION

Most papers with significant findings on PFAS are published without a press release and receive little or no media attention. This reduces the likelihood that important research is reaching the public and decisionmakers who can translate science into action. Issuing a press release and receiving media attention also appear to increase scholarly citations. We provide recommendations for authors to increase the reach and impact of future papers.

Perfluoroalkyl substances promote breast cancer progression via ERα and GPER mediated PI3K/Akt and MAPK/Erk signaling pathways

Perfluoroalkyl substances (PFASs) are a classic environmental endocrine disruptor with carcinogenic risk. Epidemiological studies have shown that PFASs contamination is associated with breast cancer development, but the mechanism remains largely unknown. This study first obtained complex biological information about PFASs-induced breast cancer through the comparative toxicogenomics database (CTD). The Protein-Protein Interaction (PPI) network, Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) analysis were utilized to investigate molecular pathways. The ESR1 and GPER expression levels at different pathological stages and the prognosis of Breast Cancer patients were confirmed using the Cancer Genome Atlas (TCGA) database. Furthermore, we verified this by cellular experiments and the results showed breast cancer cell migration and invasion were promoted by PFOA. Two estrogen receptors (ER), ERα and G protein-coupled estrogen receptor (GPER), mediated the promoting effects of PFOA by activating MAPK/Erk and PI3K/Akt signaling pathways. These pathways were regulated by ERα and GPER in MCF-7 cells or independently by GPER in MDA-MB-231 cells. Overall, our study provides a better overview of the mechanisms associated with PFASs-induced breast cancer development and progression.

Associations of phthalates with prostate cancer among the US population

Human exposure to harmful phthalates has raised global health concerns. According to cellular and molecular investigations, phthalates and their metabolites can promote prostate cancer (PCa). Despite being a prevalent cancer afflicting the global male population, the epidemiological association between phthalates and prostate cancer remains understudied. This work aims to investigate whether phthalate metabolites are related to prostate cancer. Moreover, we sought to understand whether their elevated concentrations are associated with increased serum concentrations of prostate-specific antigen (PSA), among non-prostate cancer interviewees. According to National Health and Nutrition Examination Survey (NHANES) data from 2003 to 2010, we screened eligible men aged 20 years or older. Then, crude and multivariate regression models were constructed to assess the relationship. The phthalates significantly related to PCa were analyzed based on variables associated with PCa status and PSA. The molar sum ∑di-2-ethylhexyl phthalate (∑DEHP) was simultaneously associated with increased risk of PCa and increasing PSA concentrations. Among PCa-related phthalates, high molecular weight phthalate metabolites included mono-benzyl phthalate (MBzP) and three metabolites of DEHP. In summary, phthalates are potentially associated with prostate tumorigenesis in the US population. However, additional in-depth prospective studies in different ethnic groups are required to validate the causality between both.

Association between serum concentrations of perfluoroalkyl substances and global DNA methylation levels in peripheral blood leukocytes of Japanese women: A cross-sectional study

Global DNA methylation levels in peripheral blood leukocytes can be a biomarker for cancer risk; however, levels can be changed by various factors such as environmental pollutants. We investigated the association between serum concentrations of perfluoroalkyl substances (PFASs) and global DNA methylation levels of leukocytes in a cross-sectional study using the control group of a Japanese breast cancer case-control study [397 women with a mean age of 54.1 (SD 10.1) years]. Importantly, our analysis distinguished branched PFAS isomers as different from linear isomers. The serum concentrations of 20 PFASs were measured by in-port arylation gas-chromatography negative chemical ionization mass spectrometry. Global DNA methylation levels in peripheral blood leukocytes were measured using a luminometric methylation assay. Associations between log₁₀-transformed serum PFAS concentrations and global DNA methylation levels were evaluated by regression coefficients in multivariable robust linear regression analyses. Serum concentrations of 13 PFASs were significantly associated with increased global DNA methylation levels in leukocytes. Global DNA methylation was significantly increased by 1.45 %-3.96 % per log₁₀-unit increase of serum PFAS concentration. Our results indicate that exposure to PFASs may increase global DNA methylation levels in peripheral blood leukocytes of Japanese women.

Endocrine-disrupting chemicals and endocrine neoplasia: A forty-year systematic review

INTRODUCTION

Endocrine disrupting chemicals (EDCs) are exogenous substances recognised as relevant tumourigenic chemicals. Studies show that even EDCs which were long abolished are still contributing to the increasing incidence of neoplasia.

AIM

To investigate the association between human exposure to EDCs and the risk of endocrine-related tumours: breast, prostate, thyroid, uterus, testis, and ovary.

METHODS

A systematic review using PubMed, Scopus, and Embase was conducted, searching for original observational studies published between 1980 and 2020, approaching EDCs exposure and endocrine tumourigenic risk in humans. We comprised neoplasia of six endocrine organs. We included all the studies on EDCs reporting tumour odds ratio, risk ratio, or hazard ratio. Study levels of confidence and risk of bias were accessed applying accredited guidelines. Human-made accidents and natural EDCs were not considered in the present study.

RESULTS

Our search returned 3271 papers. After duplicate removal and screening, only 237 papers were included (corresponding to 268 records). EDCs were grouped from the most frequently (pesticides) to the least frequently studied (salts). The most tumourigenic EDC groups were phthalates (63%), heavy metals (54%), particulate matter (47%), and pesticides (46%). Pesticides group comprised the highest number of retrieved studies (n = 133). Increased neoplasia risk was found in 43-67% of the studies, with a lower value for ovary (43%) and a higher value for thyroid (67%).

CONCLUSIONS

The innovative nature of our review comes from including human studies of six endocrine-related neoplasia aiming to understand the contribution of specific EDCs groups to each organ's tumourigenesis. Thyroid was the organ presenting the highest cancer risk after EDC exposure which may explain the increasing thyroid cancer incidence. However, detailed and controlled works reporting the effects of EDCs are scarce, probably justifying conflicting results. Multinational and multicentric human studies with biochemical analysis are needed to achieve stronger and concordant evidence.

Plasma perfluoroalkyl substance exposure and incidence risk of breast cancer: A case-cohort study in the Dongfeng-Tongji cohort

Experimental studies have suggested perfluoroalkyl substances (PFASs) as mammary toxicants, but few studies evaluated the prospective associations of PFASs with breast cancer risk. We performed a case-cohort study within the Dongfeng-Tongji cohort, including incident breast cancer cases (n = 226) and a random sub-cohort (n = 990). Baseline plasma concentrations of four perfluorinated carboxylic acids (PFCAs) [perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA), and perfluoroheptanoic acid (PFHpA)] and two perfluorinated sulfonic acids (PFSAs) [perfluorooctane sulfonic acid (PFOS) and perfluorohexane sulfonic acid (PFHxS)] were measured. Barlow-weighted Cox regression models revealed that each 1-unit increase in ln-transformed PFOA and PFHpA was associated with a separate 35% and 20% elevated incident risk of breast cancer [HR(95%CI) = 1.35(1.03, 1.78) and 1.20(1.02, 1.40), respectively], which were also significant among postmenopausal females [HR(95%CI) = 1.34(1.01, 1.77) and 1.23 (1.02, 1.48), respectively]. Quantile g-computation analysis observed a 19% increased incident risk of breast cancer along with each simultaneous quartile increase in all ln-transformed PFCA concentrations [HR(95%CI) = 1.19(1.01, 1.41)], with PFOA accounting for 56% of the positive effect. Our findings firstly revealed the impact of short-chain PFHpA on increased incident risk of breast cancer, suggested exposure to PFASs as a risk factor for breast cancer, and shed light on breast cancer prevention by regulating PFASs as a chemical class.

Associations between Polyfluoroalkyl Substances Exposure and Breast Cancer: A Meta-Analysis

Polyfluoroalkyl substances (PFASs) are persistent pollutants that may cause breast cancer. However, associations between exposure to PFASs and the risk of breast cancer are controversial. We retrieved studies on the association between PFASs—perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), perfluorohexane sulfonic acid (PFHxS), and perfluorooctane sulfonic acid (PFOS)—and breast cancer risk in women from PubMed, Embase, and the Web of Science. The pooled odds ratios (ORs) or relative risks (RRs) and their 95% confidence intervals (CIs) were extracted or calculated from provided data. Moreover, subgroup and metaregression analyses were performed to distinguish the potential sources of heterogeneity between studies. Lastly, eight original studies were included in the meta-analysis. PFOA and PFHxS were positively correlated with breast cancer risk, and the pooled ORs (and 95% CIs) were 1.32 (1.19 and 1.46) and 1.79 (1.51 and 2.11), respectively. PFNA was negatively correlated with breast cancer risk and the pooled OR (and 95% CIs) was 0.76 (0.6 and 0.96), and PFOS was shown to have no correlation with breast cancer risk and the pooled OR (and 95% CIs) was 1.01 (0.87 and 1.17). All results were merged in a random-effects model with significant heterogeneities (I2 > 90%, p < 0.001). The results demonstrated that PFASs might be potential risk factors for breast cancer, and the compounds in low exposure levels could have a more harmful impact on human health.

Retracted: Exposure to Per- and Polyfluoroalkyl Substances and Mortality in U.S. Adults: A Population-Based Cohort Study

BACKGROUND

Per- and polyfluoroalkyl substances (PFAS) are widespread environmental contaminants associated with diseases such as cancer and dyslipidemia. However, few studies have investigated the association between PFAS mixture exposure and mortality in general populations.

OBJECTIVES

This study aimed to explore the association between PFAS mixture, perfluorooctanoic acid (PFOA), and perfluorooctane sulfonic acid (PFOS) and mortality in U.S. adults by a nationally representative cohort.

METHODS

Adults ≥ 18  years of age who were enrolled in the National Health and Nutrition Examination Survey (NHANES) (1999-2014) were included in our study. Baseline serum concentrations of seven PFAS were measured and individuals were followed up to 31 December 2015. Hazard ratios (HRs) and confidence intervals (CIs) were estimated using Cox proportional hazards models. Association between PFAS mixture exposure and mortality was analyzed using the k-means method by clustering PFAS mixtures into subgroups. Association between PFOA/PFOS exposure and mortality was subsequently analyzed in both continuous and categorical models.

RESULTS

During the follow-up period, 1,251 participants died. In the mixture analysis, the k-means algorithm clustered participants into low-, medium-, and high-exposure groups. Compared with the low-exposure group, participants in the high-exposure group showed significantly higher risks for all-cause mortality (HR = 1.38 ; 95% CI: 1.07, 1.80), heart disease mortality (HR = 1.58 ; 95% CI: 1.05, 2.51), and cancer mortality (HR = 1.70 ; 95% CI: 1.08, 2.84). In single PFAS analysis, PFOS was found to be positively associated with all-cause mortality (third vs. first tertile HR = 1.57 ; 95% CI: 1.22, 2.07), heart disease mortality (third vs. first tertile HR = 1.65 ; 95% CI: 1.09, 2.57), and cancer mortality (third vs. first tertile HR = 1.75 ; 95% CI: 1.10, 2.83), whereas PFOA exposure had no significant association with mortality. Assuming the observed association is causal, the number of deaths associated with PFOS exposure (≥ 17.1 vs. < 7.9  ng / mL ) was ∼ 382,000 (95% CI: 176,000, 588,000) annually between 1999 and 2015, and it decreased to 69,000 (95% CI: 28,000, 119,000) annually between 2015 and 2018. The association between PFOS and mortality was stronger among women and people without diabetes.

DISCUSSION

We observed a positive association between PFAS mixture exposure and mortality among U.S. adults. Limitations of this study include the potential for unmeasured confounding, selection bias, a relatively small number of deaths, and only measuring PFAS at one point in time. Further studies with serial measures of PFAS concentrations and longer follow-ups are necessary to elucidate the association between PFAS and mortality from specific causes. https://doi.org/10.1289/EHP10393.

The toxicity of perfluorodecanoic acid is mainly manifested as a deflected immune function

BACKGROUND

Perfluorodecanoic acid (PFDA) is a type of perfluoroalkyl acid (PFAA). PFDA has toxicity similar to dioxin; its effect on the body is not through a single target or a single pathway. However, the mechanism at the global level is still unclear.

METHODS AND RESULTS

We treated mice with PFDA and characterized the global changes in gene expression in the liver using microarray analyses. The enriched KEGG pathways and GO analyses revealed that PFDA greatly affected the immune response, which was different from the response of gastric cells previously studied. As a proof of principle, the expressions of IL-1β and IL-18 were both decreased after PFDA treatment, and qRT-PCR and ELISAs verified the reduction of IL-1β and IL-18 in liver tissues. Mechanistic investigations indicated that PFDA inhibited caspase-1 activation, and decreased the mRNA levels of NLRP1, NLRP3, and NLRC4; thus, suggesting that inflammasome assemblies were suppressed. Further microarray data revealed that cIAP2 and its binding proteins, which are critical for regulating inflammasome assembly, were also repressed by PFDA. In addition, flow cytometry results revealed a significant inhibition of Th1 cell differentiation in the livers of PFDA-treated mice.

CONCLUSIONS

The results of this study suggested that one of the main toxic effects of PFDA on livers was the inhibition of immune response.

Environmental estrogens in surface water and their interaction with microalgae: A review

Environmental estrogens (EEs) have received extensive attention because they interfere with biological endocrine and reproduction systems by mimicking, antagonizing, or otherwise affecting the actions of endogenous hormones. Additionally, harmful algal blooms have become a global problem in surface water. Microalgae, as an essential primary producer, is especially important for aquatic life and the entire ecosystem. The presence of EEs in surface water may be a potential promoting factor for algal blooms, and microalgae may have effects on the degradation of EEs. This review focuses on the distribution and pollution characteristics of EEs in global surface waters, effects of single and mixed EEs on microalgae regarding growth and toxin production, mechanisms of EEs on microalgae at the cellular and molecular level. The impacts of microalgae on EEs were also discussed. This review provides a risk assessment of EEs and identifies essential clues that will aid in formulating and revising the relevant standards of surface water regarding EEs, which is significant for ecosystems and human health.

Per- and poly-fluoroalkyl substances (PFAS) and female reproductive outcomes: PFAS elimination, endocrine-mediated effects, and disease

Per- and poly-fluoroalkyl substances (PFAS) are widespread environmental contaminants frequently detected in drinking water supplies worldwide that have been linked to a variety of adverse reproductive health outcomes in women. Compared to men, reproductive health effects in women are generally understudied while global trends in female reproduction rates are declining. Many factors may contribute to the observed decline in female reproduction, one of which is environmental contaminant exposure. PFAS have been used in home, food storage, personal care and industrial products for decades. Despite the phase-out of some legacy PFAS due to their environmental persistence and adverse health effects, alternative, short-chain and legacy PFAS mixtures will continue to pollute water and air and adversely influence women's health. Studies have shown that both long- and short-chain PFAS disrupt normal reproductive function in women through altering hormone secretion, menstrual cyclicity, and fertility. Here, we summarize the role of a variety of PFAS and PFAS mixtures in female reproductive tract dysfunction and disease. Since these chemicals may affect reproductive tissues directly or indirectly through endocrine disruption, the role of PFAS in breast, thyroid, and hypothalamic-pituitary-gonadal axis function are also discussed as the interplay between these tissues may be critical in understanding the long-term reproductive health effects of PFAS in women. A major research gap is the need for mechanism of action data - the targets for PFAS in the female reproductive and endocrine systems are not evident, but the effects are many. Given the global decline in female fecundity and the ability of PFAS to negatively impact female reproductive health, further studies are needed to examine effects on endocrine target tissues involved in the onset of reproductive disorders of women.

Impact of kidney hyperfiltration on concentrations of selected perfluoroalkyl acids among US adults for various disease groups

Data from the National Health and Nutrition Examination Survey (N = 6141) for the years 2003-2016 for US adults were analyzed to evaluate the impact of glomerular hyperfiltration on the observed concentrations of perfluorooctanoic acid (PFOA), perfluorooctane sulfonic acid (PFOS), perfluorodecanoic acid, perfluorohexane sulfonic acid (PFHxS), and perfluorononanoic acid (PFNA) for several disease groups. Hyperfiltrators were defined as having an estimated glomerular filtration rate (eGFR) ≥ 110 mL/min/1.73 m², and normal filtrators were defined as those having an eGFR between 90 and 110 mL/min/1.73 m². The seven disease groups for which the data were analyzed were as follows: those (i) without any diseases; (ii) with hypertension only; (iii) with albuminuria only; (iv) with anemia only; (v) with diabetes only; (vi) with hypertension and one or more of diabetes, anemia, and albuminuria; and (vii) with two or more of diabetes, anemia, and albuminuria without hypertension. For almost every PFAA, for all seven disease groups except the albuminuria only group, hyperfiltrators had lower adjusted geometric means (AGM) than normal filtrators. For example, for the disease group with hypertension only, for PFOS, the AGMs for hyperfiltrators and normal filtrators were 8.3 and 10.6 ng/mL, respectively, for the total population. For the group with albuminuria only, normal filtrators were found to have higher AGMs than hyperfiltrators for the total population and males. For example, for PFHxS, the AGMs for normal and hyperfiltrators were 0.98 and 1.05 ng/mL, respectively, for the total population. For females, these AGMs for normal and hyperfiltrators were 0.96 and 0.86 ng/mL respectively. Males usually had higher AGMs than females, but the reverse was also true occasionally. Usually, male-female differences were substantially narrower for normal filtrators than hyperfiltrators. Irrespective of the filtration status, the disease group with hypertension only had the highest AGMs for every PFAA. AGMs for the anemia only group were the lowest for every PFAA as compared with other disease groups among hyperfiltrators.