Application of the Key Characteristics Framework to Identify Potential Breast Carcinogens Using Publicly Available in Vivo, in Vitro, and in Silico Data.

BACKGROUND: Chemicals that induce mammary tumors in rodents or activate estrogen or progesterone signaling are likely to increase breast cancer (BC) risk. Identifying chemicals with these activities can prompt steps to protect human health. OBJECTIVES: We compiled data on rodent tumors, endocrine activity, and genotoxicity to assess the key characteristics (KCs) of rodent mammary carcinogens (MCs), and to identify other chemicals that exhibit these effects and may therefore increase BC risk. METHODS: Using authoritative databases, including International Agency for Research on Cancer (IARC) Monographs and the US Environmental Protection's (EPA) ToxCast, we selected chemicals that induce mammary tumors in rodents, stimulate estradiol or progesterone synthesis, or activate the estrogen receptor (ER) in vitro. We classified these chemicals by their genotoxicity and strength of endocrine activity and calculated the overrepresentation (enrichment) of these KCs among MCs. Finally, we evaluated whether these KCs predict whether a chemical is likely to induce mammary tumors. RESULTS: We identified 279 MCs and an additional 642 chemicals that stimulate estrogen or progesterone signaling. MCs were significantly enriched for steroidogenicity, ER agonism, and genotoxicity, supporting the use of these KCs to predict whether a chemical is likely to induce rodent mammary tumors and, by inference, increase BC risk. More MCs were steroidogens than ER agonists, and many increased both estradiol and progesterone. Enrichment among MCs was greater for strong endocrine activity vs. weak or inactive, with a significant trend. DISCUSSION: We identified hundreds of compounds that have biological activities that could increase BC risk and demonstrated that these activities are enriched among MCs. We argue that many of these should not be considered low hazard without investigating their ability to affect the breast, and chemicals with the strongest evidence can be targeted for exposure reduction. We describe ways to strengthen hazard identification, including improved assessments for mammary effects, developing assays for more KCs, and more comprehensive chemical testing. https://doi.org/10.1289/EHP13233.

Moving Forward with Reporting Back Individual Environmental Health Research Results.

BACKGROUND: The practice of reporting back individual results to participants in environmental health research has evolved significantly over the past 20 years. Research findings support the potential of report-back to enhance the ethics, quality, and impact of environmental health research. Nonetheless, implementation of environmental health report-back practices is not yet routine. OBJECTIVES: We propose a framework for institutionalizing appropriate report-back to participants of their individual results across the environmental health research enterprise. We provide a brief overview of the rationales for report-back, social science research on report-back experiences over the past two decades, and recent efforts to synthesize guidance in this field. We also describe barriers to be addressed in moving toward widespread implementation of report-back. DISCUSSION: Report-back of individual results is increasingly recognized as an ethical responsibility and essential component of impactful environmental health research. Experience shows that when personal results are returned with appropriate contextual information, report-back can increase environmental health literacy, promote individual actions, and enhance engagement in policy change. Therefore, report-back can promote environmental justice and reduce disparities in access to science. Despite this evidence base, report-back is not widely implemented. We recommend the collaborative development of guidelines, training, and resources to build capacity for appropriate report-back to study participants across the environmental health research enterprise, and we identify research priorities to advance the field. Development of tools and shared infrastructure for report-back holds promise for reducing barriers while ensuring high-quality personalized reports. Disseminating successful case studies could also advance excellence. We recommend including diverse scientific disciplines, community partners, representatives of study populations, clinicians, institutional review boards (IRBs), legal experts, public health professionals, and government officials in further developing this critical aspect of environmental health research. https://doi.org/10.1289/EHP12463.

The Effect of Individual or Study-Wide Report-Back on Knowledge, Concern, and Exposure-Reducing Behaviors Related to Endocrine-Disrupting Chemicals.

BACKGROUND: To make informed decisions about endocrine-disrupting chemicals (EDCs), people need functional understanding of exposures and health and an ability to act on their knowledge. The return of biomonitoring results is an opportunity to educate people about EDCs and motivate exposure reduction. OBJECTIVES: This study investigates environmental health knowledge about EDCs, concerns about health effects, and exposure-reducing behaviors before and after the return of individual-level exposure results or only study-wide results. METHODS: Women in the Child Health and Development Studies who were biomonitored for 42 EDCs were randomly assigned to receive a report with personal chemical results or only study-wide findings. We interviewed participants before and after report-back about their knowledge and concerns about EDCs and how frequently they performed exposure-related behaviors. We investigated baseline differences by education and race and examined changes after report-back by race and report type. RESULTS: Participants (n=135) demonstrated general understanding of exposure pathways and health impacts of EDCs. For 9 out of 20 knowledge questions, more than 90% of participants (n≥124) gave correct responses at baseline, including for questions about chemicals' persistence in the body and effects of early-life exposure. Most participants held two misconceptions-about chemical safety testing in the United States and what doctors can infer from EDC results-although errors decreased after report-back. Initially, concern was higher for legacy pollutants, but report-back increased concern for consumer product chemicals. After report-back, participants took some actions to reduce exposures, particularly to per- and polyfluoroalkyl substances, and total behavior was associated with knowledge and concern but not race, education, or report type. DISCUSSION: This study demonstrated that participants had foundational knowledge about EDCs and that report-back further built their environmental health literacy. We conclude that future communications should target misconceptions about chemicals regulation in the United States, because information about regulations is crucial for people to evaluate risks posed by consumer product chemicals and decide whether to engage with public policy. https://doi.org/10.1289/EHP12565.

Translating community-based participatory research into broadscale sociopolitical change: insights from a coalition of women firefighters, scientists, and environmental health advocates.

BACKGROUND: We report on community-based participatory research (CBPR) initiated by women firefighters in order to share successful elements that can be instructive for other community-engaged research. This CBPR initiative, known as the Women Worker Biomonitoring Collaborative (WWBC) is the first we are aware of to investigate links between occupational exposures and health outcomes, including breast cancer, for a cohort of exclusively women firefighters. METHODS: In order to be reflective of the experiences and knowledge of those most intimately involved, this article is co-authored by leaders of the research initiative. We collected leaders' input via recorded meeting sessions, emails, and a shared online document. We also conducted interviews (N = 10) with key research participants and community leaders to include additional perspectives. RESULTS: Factors contributing to the initiative's success in enacting broadscale social change and advancing scientific knowledge include (1) forming a diverse coalition of impacted community leaders, labor unions, scientists, and advocacy organizations, (2) focusing on impacts at multiple scales of action and nurturing different, yet mutually supportive, goals among partners, (3) adopting innovative communication strategies for study participants, research partners, and the broader community, (4) cultivating a prevention-based ethos in the scientific research, including taking early action to reduce community exposures based on existing evidence of harm, and (5) emphasizing co-learning through all the study stages. Furthermore, we discuss external factors that contribute to success, including funding programs that elevate scientist-community-advocacy partnerships and allow flexibility to respond to emerging science-policy opportunities, as well as institutional structures responsive to worker concerns. CONCLUSIONS: While WWBC shares characteristics with other successful CBPR partnerships, it also advances approaches that increase the ability for CBPR to translate into change at multiple levels. This includes incorporating partners with particular skills and resources beyond the traditional researcher-community partnerships that are the focus of much CBPR practice and scholarly attention, and designing studies so they support community action in the initial stages of research. Moreover, we emphasize external structural factors that can be critical for CBPR success. This demonstrates the importance of critically examining and advocating for institutional factors that better support this research.

Mi PROTECT: A personalized smartphone platform to report back results to participants of a maternal-child and environmental health research cohort program in Puerto Rico.

BACKGROUND: The PROTECT Center is a multi-project initiative that studies the relationship between exposure to environmental contaminants and preterm births during the prenatal and postnatal period among women living in Puerto Rico. PROTECT's Community Engagement Core and Research Translation Coordinator (CEC/RTC) play a key role in building trust and capacity by approaching the cohort as an engaged community that provides feedback about processes, including how personalized results of their exposure to chemicals should be reported back. The goal of the Mi PROTECT platform was to create a mobile-based application of DERBI (Digital Exposure Report-Back Interface) for our cohort that provides tailored, culturally appropriate information about individual contaminant exposures as well as education on chemical substances and approaches to exposure reduction. METHODS: Participants (N = 61) were presented with commonly used terms in environmental health research related to collected samples and biomarkers, followed by a guided training on accessing and exploring the Mi PROTECT platform. Participants evaluated the guided training and Mi PROTECT platform answering a Likert scale in separated surveys that included 13 and 8 questions, respectively. RESULTS: Participants provided overwhelmingly positive feedback on the clarity and fluency of presenters in the report-back training. Most participants reported that the mobile phone platform was both accessible and easy to navigate (83% and 80%, respectively) and that images included in the platform facilitated comprehension of the information. Overall, most participants (83%) reported that language, images, and examples in Mi PROTECT strongly represented them as Puerto Ricans. CONCLUSIONS: Findings from the Mi PROTECT pilot test informed investigators, community partners and stakeholders by demonstrating a new way to promote stakeholder participation and foster the "research right-to-know."

Perspectives of peripartum people on opportunities for personal and collective action to reduce exposure to everyday chemicals: Focus groups to inform exposure report-back.

Participants in biomonitoring studies who receive personal exposure reports seek information to reduce exposures. Many chemical exposures are driven by systems-level policies rather than individual actions; therefore, change requires engagement in collective action. Participants' perceptions of collective action and use of report-back to support engagement remain unclear. We conducted virtual focus groups during summer 2020 in a diverse group of peripartum people from cohorts in the Environmental influences on Child Health Outcomes (ECHO) Program (N = 18). We assessed baseline exposure and collective action experience, and report-back preferences. Participants were motivated to protect the health of their families and communities despite significant time and cognitive burdens. They requested time-conscious tactics and accessible information to enable action to reduce individual and collective exposures. Participant input informed the design of digital report-back in the cohorts. This study highlights opportunities to shift responsibility from individuals to policymakers to reduce chemical exposures at the systems level.

Outcomes from Returning Individual versus Only Study-Wide Biomonitoring Results in an Environmental Exposure Study Using the Digital Exposure Report-Back Interface (DERBI).

BACKGROUND: Study participants want to receive their biomonitoring results for environmental chemicals, and ethics guidelines encourage reporting back. However, few studies have quantitively assessed participants' responses to individual exposure reports, and digital methods have not been evaluated. OBJECTIVES: We isolated effects of receiving personal results vs. only study-wide findings and investigated whether effects differed for Black participants. METHODS: We randomly assigned a subset of 295 women from the Child Health and Development Studies, half of whom were Black, to receive a report with personal environmental chemical results or only study-wide (aggregate) findings. Reports included results for 42 chemicals and lipids and were prepared using the Digital Exposure Report-Back Interface (DERBI). Women were interviewed before and after viewing their report. We analyzed differences in website activity, emotional responses, and intentions to participate in future research by report type and race using Wilcoxon rank sum tests, Wilcoxon-Pratt signed ranks tests, and multiple regression. RESULTS: The personal report group spent approximately twice as much time on their reports as the aggregate group before the post-report-back interview. Among personal-report participants (n=93), 84% (78) viewed chemical group information for at least one personal result highlighted on their home page; among aggregate-report participants (n=94), 66% (62) viewed any chemical group page. Both groups reported strong positive feelings (curious, informed, interested, respected) about receiving results before and after report-back and mild negative feelings (helpless, scared, worried). Although most participants remained unworried after report-back, worry increased by a small amount in both groups. Among Black participants, higher post report-back worry was associated with having high levels of chemicals. CONCLUSIONS: Participants were motivated by their personal results to access online information about chemical sources and potential health effects. Report-back was associated with a small increase in worry, which could motivate appropriate action. Personal report-back increased engagement with exposure reports among Black participants. https://doi.org/10.1289/EHP9072.

Rethinking Environmental Carcinogenesis.

The 2010 report of the President's Cancer Panel concluded that the burden of cancer from chemical exposures is substantial, while the programs for testing and regulation of carcinogens remain inadequate. New research on the role of early life exposures and the ability of chemicals to act via multiple biological pathways, including immunosuppression, inflammation, and endocrine disruption as well as mutagenesis, further supports the potential for chemicals and chemical mixtures to influence disease. Epidemiologic observations, such as higher leukemia incidence in children living near roadways and industrial sources of air pollution, and new in vitro technologies that decode carcinogenesis at the molecular level, illustrate the diverse evidence that primary prevention of some cancers may be achieved by reducing harmful chemical exposures. The path forward requires cross-disciplinary approaches, increased environmental research investment, system-wide collaboration to develop safer economic alternatives, and community engagement to support evidence-informed action. Engagement by cancer researchers to integrate environmental risk factors into prevention initiatives holds tremendous promise for reducing the rates of disease.See all articles in this CEBP Focus section, "Environmental Carcinogenesis: Pathways to Prevention."

Consumer behavior and exposure to parabens, bisphenols, triclosan, dichlorophenols, and benzophenone-3: Results from a crowdsourced biomonitoring study.

Nearly all Americans have detectable concentrations of endocrine disrupting chemicals from consumer products in their bodies, and expert panels recommend reducing exposures. To inform exposure reduction, we investigated whether consumers who are trying to avoid certain chemicals in consumer products have lower exposures than those who are not. We also aimed to make exposure biomonitoring more widely available. We enrolled 726 participants in a crowdsourced biomonitoring study. We targeted phenolic compounds-specifically parabens, bisphenol A (BPA) and analogs bisphenol F (BPF) and bisphenol S (BPS), the UV filter benzophenone-3, the anti-microbial triclosan, 2,4-dichlorophenol, and 2,5-dichlorophenol-and collected survey data on consumer products, cleaning habits, and efforts to avoid related chemicals. We investigated associations between 68 self-reported exposure behaviors and urine concentrations of ten chemicals, and evaluated whether associations were modified by intention to avoid exposures. A large majority (87%) of participants reported taking steps to limit exposure to specific chemicals, and, overall, participants achieved lower concentrations than the general U.S. population for parabens, BPA, triclosan, and benzophenone-3 but not BPF and BPS. Participants who reported avoiding all four ingredient groups-parabens, triclosan, bisphenols, and fragrances-were twice as likely as others to be in the lowest quartile of cumulative exposure. Avoiding certain products and reading ingredient labels to avoid chemicals was most effective for parabens, triclosan, and benzophenone-3. Avoiding BPA was not effective for reducing bisphenol exposures. Avoiding certain chemicals in products was generally associated with reduced exposure for chemicals listed on labels. Greater ingredient transparency will help consumers who read labels to reduce their exposure to a wider range of potentially harmful chemicals. In order to more equitably address public health, labeling policies should be complemented by regulations that exclude harmful chemicals from consumer products.

Barriers and opportunities for breast cancer organizations to focus on environmental health and disease prevention: a mixed-methods approach using website analyses, interviews, and focus groups.

BACKGROUND: Breast cancer is the most commonly diagnosed cancer among women worldwide and most cases are not due to high risk inherited genes. In response, breast cancer activists successfully advocated for innovative research on environmental chemical exposures as a possible cause. Since then, new evidence supports hypotheses that common industrial and consumer chemicals are linked to the disease, and expert panels recommend reducing exposures. We evaluated whether these research results and recommendations are translated back into the work of breast cancer organizations and what barriers and opportunities influence their ability to focus on environmental factors. METHODS: We used a Python script to evaluate the frequency of environmental terms on the websites of 81 breast cancer organizations (> 14,000 associated URLs) and conducted two focus groups and 20 interviews with leaders of breast cancer organizations. We also analyzed the frequency of terms on two trusted, national cancer websites. RESULTS: 40% of organizations include information on environmental chemicals on their websites, but references are infrequent and rarely cite specific chemicals of concern. Most organizations (82%) discuss other risk factors such as exercise, diet, family history, or genetics. From interviews and focus groups, we identified four types of barriers to addressing environmental chemicals: 1) time and resource constraints, 2) limited knowledge of the state of the research and lack of access to experts, 3) difficulties with messaging, including concern that cultural and economic factors make it difficult for individuals to reduce their exposures, and 4) institutional obstacles, such as the downplaying of environmental risks by industry interests. Participants expressed the desire for easy-to-adopt educational programs and increased federal funding for scientist-advocate research partnerships. CONCLUSION: Our research underscores the need for environmental breast cancer experts and trusted cancer organizations to increase research translation activities so that breast cancer organizations can communicate new science on environmental factors in their online and in-person work. Moreover, our research highlights how most groups are focusing on providing resources to diagnosed women, including addressing problems with healthcare access, which displaces their ability to work on breast cancer prevention.

Perceived Risks, Benefits, and Interest in Participating in Environmental Health Studies That Share Personal Exposure Data: A U.S. Survey of Prospective Participants.

Little is known about the willingness of prospective study participants to share environmental health data. To fill this gap, we conducted a hypothetical vignette survey among 1,575 women who have volunteered to be contacted about breast cancer studies. Eighty-three percent were interested in participating in the environmental studies, with little difference whether data were restricted to the research team, shared with approved researchers, or publicly accessible. However, participants somewhat preferred controlled access for children's data. Respondents were more interested in studies with environmental rather than biological samples and more interested when researchers would return personal results, a practice of increasing importance. They were more reluctant to share location or to participate if studies involved electronic medical records. Many expressed concerns about privacy, particularly security breaches, but reidentification risks were mentioned infrequently, indicating that this topic should be discussed during informed consent.

Privacy Risks of Sharing Data from Environmental Health Studies.

BACKGROUND: Sharing research data uses resources effectively; enables large, diverse data sets; and supports rigor and reproducibility. However, sharing such data increases privacy risks for participants who may be re-identified by linking study data to outside data sets. These risks have been investigated for genetic and medical records but rarely for environmental data. OBJECTIVES: We evaluated how data in environmental health (EH) studies may be vulnerable to linkage and we investigated, in a case study, whether environmental measurements could contribute to inferring latent categories (e.g., geographic location), which increases privacy risks. METHODS: We identified 12 prominent EH studies, reviewed the data types collected, and evaluated the availability of outside data sets that overlap with study data. With data from the Household Exposure Study in California and Massachusetts and the Green Housing Study in Boston, Massachusetts, and Cincinnati, Ohio, we used k-means clustering and principal component analysis to investigate whether participants' region of residence could be inferred from measurements of chemicals in household air and dust. RESULTS: All 12 studies included at least two of five data types that overlap with outside data sets: geographic location (9 studies), medical data (9 studies), occupation (10 studies), housing characteristics (10 studies), and genetic data (7 studies). In our cluster analysis, participants' region of residence could be inferred with 80%-98% accuracy using environmental measurements with original laboratory reporting limits. DISCUSSION: EH studies frequently include data that are vulnerable to linkage with voter lists, tax and real estate data, professional licensing lists, and ancestry websites, and exposure measurements may be used to identify subgroup membership, increasing likelihood of linkage. Thus, unsupervised sharing of EH research data potentially raises substantial privacy risks. Empirical research can help characterize risks and evaluate technical solutions. Our findings reinforce the need for legal and policy protections to shield participants from potential harms of re-identification from data sharing. https://doi.org/10.1289/EHP4817.

Environmental exposures during windows of susceptibility for breast cancer: a framework for prevention research.

BACKGROUND: The long time from exposure to potentially harmful chemicals until breast cancer occurrence poses challenges for designing etiologic studies and for implementing successful prevention programs. Growing evidence from animal and human studies indicates that distinct time periods of heightened susceptibility to endocrine disruptors exist throughout the life course. The influence of environmental chemicals on breast cancer risk may be greater during several windows of susceptibility (WOS) in a woman's life, including prenatal development, puberty, pregnancy, and the menopausal transition. These time windows are considered as specific periods of susceptibility for breast cancer because significant structural and functional changes occur in the mammary gland, as well as alterations in the mammary micro-environment and hormone signaling that may influence risk. Breast cancer research focused on these breast cancer WOS will accelerate understanding of disease etiology and prevention. MAIN TEXT: Despite the plausible heightened mechanistic influences of environmental chemicals on breast cancer risk during time periods of change in the mammary gland's structure and function, most human studies of environmental chemicals are not focused on specific WOS. This article reviews studies conducted over the past few decades that have specifically addressed the effect of environmental chemicals and metals on breast cancer risk during at least one of these WOS. In addition to summarizing the broader evidence-base specific to WOS, we include discussion of the NIH-funded Breast Cancer and the Environment Research Program (BCERP) which included population-based and basic science research focused on specific WOS to evaluate associations between breast cancer risk and particular classes of endocrine-disrupting chemicals-including polycyclic aromatic hydrocarbons, perfluorinated compounds, polybrominated diphenyl ethers, and phenols-and metals. We outline ways in which ongoing transdisciplinary BCERP projects incorporate animal research and human epidemiologic studies in close partnership with community organizations and communication scientists to identify research priorities and effectively translate evidence-based findings to the public and policy makers. CONCLUSIONS: An integrative model of breast cancer research is needed to determine the impact and mechanisms of action of endocrine disruptors at different WOS. By focusing on environmental chemical exposure during specific WOS, scientists and their community partners may identify when prevention efforts are likely to be most effective.

Serum concentrations of PFASs and exposure-related behaviors in African American and non-Hispanic white women.

Per- and polyfluoroalkyl substances (PFASs) are used in a wide range of consumer products for their water- and grease-resistant properties, but few studies have explored this exposure route. We used multiple regression to investigate associations between six self-reported behaviors hypothesized to influence PFAS exposure and serum concentrations of six PFAS chemicals in 178 middle-aged women enrolled in the Child Health and Development Studies, about half of whom are African American. Blood samples were collected in 2010-2013, and participants were interviewed about behavior in 2015-2016. Results showed that African American women had lower levels of perfluorooctanoic acid (PFOA) and perfluorohexanesulfonic acid (PFHxS) compared with non-Hispanic white women. In African Americans, but not others, frequent consumption of prepared food in coated cardboard containers was associated with higher levels of four PFASs. Flossing with Oral-B Glide, having stain-resistant carpet or furniture, and living in a city served by a PFAS-contaminated water supply were also associated with higher levels of some PFASs. Product testing using particle-induced γ-ray emission (PIGE) spectroscopy confirmed that Oral-B Glide and competitor flosses contained detectable fluorine. Despite the delay between blood collection and interview, these results strengthen the evidence for exposure to PFASs from food packaging and implicate exposure from polytetrafluoroethylene (PTFE)-based dental floss for the first time.

Reporting to parents on children's exposures to asthma triggers in low-income and public housing, an interview-based case study of ethics, environmental literacy, individual action, and public health benefits.

BACKGROUND: Emerging evidence about the effects of endocrine disruptors on asthma symptoms suggests new opportunities to reduce asthma by changing personal environments. Right-to-know ethics supports returning personal results for these chemicals to participants, so they can make decisions to reduce exposures. Yet researchers and institutional review boards have been reluctant to approve results reports in low-income communities, which are disproportionately affected by asthma. Concerns include limited literacy, lack of resources to reduce exposures, co-occurring stressors, and lack of models for effective reporting. To better understand the ethical and public health implications of returning personal results in low-income communities, we investigated parents' experiences of learning their children's environmental chemical and biomonitoring results in the Green Housing Study of asthma. METHODS: The Green Housing Study measured indoor chemical exposures, allergens, and children's asthma symptoms in "green"-renovated public housing and control sites in metro-Boston and Cincinnati in 2011-2013. We developed reports for parents of children in the study, including results for their child and community. We observed community meetings where results were reported, and metro-Boston residents participated in semi-structured interviews in 2015 about their report-back experience. Interviews were systematically coded and analyzed. RESULTS: Report-back was positively received, contributed to greater understanding, built trust between researchers and participants, and facilitated action to improve health. Sampling visits and community meetings also contributed to creating a positive study experience for participants. Participants were able to make changes in their homes, such as altering product use and habits that may reduce asthma symptoms, though some faced roadblocks from family members. Participants also gained access to medical resources, though some felt that clinicians were not responsive. Participants wanted larger scale change from government or industry and wanted researchers to leverage study results to achieve change. CONCLUSIONS: Report-back on environmental chemical exposures in low-income communities can enhance research benefits by engaging residents with personally relevant information that informs and motivates actions to reduce exposure to asthma triggers. Ethical practices in research should support deliberative report-back in vulnerable communities.

Measurement of endocrine disrupting and asthma-associated chemicals in hair products used by Black women.

BACKGROUND: Personal care products are a source of exposure to endocrine disrupting and asthma-associated chemicals. Because use of hair products differs by race/ethnicity, these products may contribute to exposure and disease disparities. OBJECTIVE: This preliminary study investigates the endocrine disrupting and asthma-associated chemical content of hair products used by U.S. Black women. METHODS: We used gas chromatography/mass spectrometry (GC/MS) to test 18 hair products in 6 categories used by Black women: hot oil treatment, anti-frizz/polish, leave-in conditioner, root stimulator, hair lotion, and relaxer. We tested for 66 chemicals belonging to 10 chemical classes: ultraviolet (UV) filters, cyclosiloxanes, glycol ethers, fragrances, alkylphenols, ethanolamines, antimicrobials, bisphenol A, phthalates, and parabens. RESULTS: The hair products tested contained 45 endocrine disrupting or asthma-associated chemicals, including every targeted chemical class. We found cyclosiloxanes, parabens, and the fragrance marker diethyl phthalate (DEP) at the highest levels, and DEP most frequently. Root stimulators, hair lotions, and relaxers frequently contained nonylphenols, parabens, and fragrances; anti-frizz products contained cyclosiloxanes. Hair relaxers for children contained five chemicals regulated by California's Proposition 65 or prohibited by EU cosmetics regulation. Targeted chemicals were generally not listed on the product label. CONCLUSIONS: Hair products used by Black women and children contained multiple chemicals associated with endocrine disruption and asthma. The prevalence of parabens and DEP is consistent with higher levels of these compounds in biomonitoring samples from Black women compared with White women. These results indicate the need for more information about the contribution of consumer products to exposure disparities. A precautionary approach would reduce the use of endocrine disrupting chemicals in personal care products and improve labeling so women can select products consistent with their values.

Environmental Determinants of Breast Cancer.

In the United States, breast cancer is the most common invasive malignancy and the second most common cause of death from cancer in women. Reproductive factors, estrogen, and progesterone have major causal roles, but concerns about other potential causes in the external environment continue to drive research inquiries and stimulate calls for action at the policy level. The environment is defined as anything that is not genetic and includes social, built, and chemical toxicant aspects. This review covers the scope of known and suspected environmental factors that have been associated with breast cancer and illustrates how epidemiology, toxicology, and mechanistic studies work together to create the full picture of environmental effects on this malignancy. Newer approaches to risk-related evaluations may allow this field to move forward and more clearly delineate actionable environmental causes of this most common of cancers in women.

Environmental chemicals and breast cancer: An updated review of epidemiological literature informed by biological mechanisms.

BACKGROUND: Many common environmental chemicals are mammary gland carcinogens in animal studies, activate relevant hormonal pathways, or enhance mammary gland susceptibility to carcinogenesis. Breast cancer's long latency and multifactorial etiology make evaluation of these chemicals in humans challenging. OBJECTIVE: For chemicals previously identified as mammary gland toxicants, we evaluated epidemiologic studies published since our 2007 review. We assessed whether study designs captured relevant exposures and disease features suggested by toxicological and biological evidence of genotoxicity, endocrine disruption, tumor promotion, or disruption of mammary gland development. METHODS: We systematically searched the PubMed database for articles with breast cancer outcomes published in 2006-2016 using terms for 134 environmental chemicals, sources, or biomarkers of exposure. We critically reviewed the articles. RESULTS: We identified 158 articles. Consistent with experimental evidence, a few key studies suggested higher risk for exposures during breast development to dichlorodiphenyltrichloroethane (DDT), dioxins, perfluorooctane-sulfonamide (PFOSA), and air pollution (risk estimates ranged from 2.14 to 5.0), and for occupational exposure to solvents and other mammary carcinogens, such as gasoline components (risk estimates ranged from 1.42 to 3.31). Notably, one 50-year cohort study captured exposure to DDT during several critical windows for breast development (in utero, adolescence, pregnancy) and when this chemical was still in use. Most other studies did not assess exposure during a biologically relevant window or specify the timing of exposure. Few studies considered genetic variation, but the Long Island Breast Cancer Study Project reported higher breast cancer risk for polycyclic aromatic hydrocarbons (PAHs) in women with certain genetic variations, especially in DNA repair genes. CONCLUSIONS: New studies that targeted toxicologically relevant chemicals and captured biological hypotheses about genetic variants or windows of breast susceptibility added to evidence of links between environmental chemicals and breast cancer. However, many biologically relevant chemicals, including current-use consumer product chemicals, have not been adequately studied in humans. Studies are challenged to reconstruct exposures that occurred decades before diagnosis or access biological samples stored that long. Other problems include measuring rapidly metabolized chemicals and evaluating exposure to mixtures.

Research altruism as motivation for participation in community-centered environmental health research.

Protection of human subjects in research typically focuses on extrinsic rather than intrinsic motivations for participation in research. Recent sociological literature on altruism suggests that multiple kinds of altruism exist and are grounded in a sense of connection to common humanity. We interviewed participants in eight community-centered research studies that sampled for endocrine disrupting compounds and that shared research findings with participants. The results of our analysis of participation in these studies indicate that altruistic motivations were commonly held. We found that these sentiments were tied to feeling a sense of connection to society broadly, a sense of connection to science, or a sense of connection with the community partner organization. We develop a new concept of banal altruism to address mundane practices that work towards promoting social benefits. Further, we offer that research altruism is a specific type of banal altruism that is a multi-faceted and important reason for which individuals choose to participate in community-centered research.