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2024
PNAS
This study examined the health impacts of three major plastic-associated chemicals—BPA, DEHP, and PBDEs—across 38 countries representing one-third of the global population. The researchers found that in 2015, these chemicals were linked to approximately 5.4 million cases of heart disease, 346,000 strokes, 164,000 deaths among older adults, and 11.7 million lost IQ points in children due to prenatal exposure. The total economic cost of these health impacts was estimated at $1.5 trillion. The study suggests that if exposure levels had been reduced earlier, hundreds of thousands of deaths and millions of IQ points could have been prevented.
2024
Sci Tot Environ
A comprehensive systematic review and meta-analysis of 28 studies including over 2.5 million individuals found that higher levels of outdoor artificial light at night (ALAN) were associated with a 12% increased breast cancer risk, though indoor ALAN showed a non-significant 7% increased risk, with no differences by menopausal status. For prostate cancer, the analysis suggested a 43% increased risk with outdoor ALAN exposure, though this was not statistically significant, and qualitative synthesis revealed positive associations with non-Hodgkin lymphoma, colorectal, pancreatic, and thyroid cancers. The authors note a critical limitation: most studies relied on low-resolution satellite imagery (1-5 km resolution from the Defense Meteorological Program) without information on light color or spectral composition, which may have led to exposure misclassification and underestimation of true effects, highlighting the urgent need for studies using higher-resolution exposure assessment methods and investigation of light pollution effects on cancers beyond breast cancer.
2024
J Hazard Mater
A study analyzing 162 non-alcoholic beverages found that 63 endocrine-disrupting chemicals (EDCs) were present in 144 products, with concentrations highest in metal-canned beverages and significantly lower or absent in glass, plastic, and carton packaging. Bisphenol A (BPA) levels were notably elevated in canned drinks compared to identical products from the same manufacturers packaged in glass or plastic, and researchers identified two previously unknown BPA structural isomers in beverages for the first time. The calculated daily BPA exposure from average beverage consumption (364 mL/day) exceeded the European Food Safety Authority’s revised safety guideline by up to 2,000-fold, suggesting that regular consumption of canned non-alcoholic beverages—particularly by young children—poses a potential health hazard due to EDC exposure from packaging materials.
2024
Cancer Epidemiol
A large collaborative study of 609,880 women from 16 prospective studies, including 9,956 breast cancer cases before age 55, examined when the relationship between body mass index (BMI) and breast cancer risk transitions from protective (before menopause) to harmful (after menopause). During the critical age window of 45-55 years, the study found that a five-unit BMI increment remained associated with reduced or neutral breast cancer risk across all menopausal status groups: HR=0.87 for premenopausal women, HR=1.00 for women after natural menopause, HR=0.99 after interventional loss of ovarian function, and HR=0.88 after hysterectomy without bilateral oophorectomy. The findings indicate that the well-documented reversal from BMI being protective to being a risk factor for breast cancer occurs after age 55, later than previously thought, suggesting that the transition to increased risk with higher BMI is not directly tied to the menopausal transition itself but occurs in the years following menopause. This timing provides important insight into how adiposity influences breast cancer risk across the lifespan and suggests that the hormonal and metabolic changes associated with higher BMI have different effects on breast tissue depending on age and years since menopause.
2024
Environ Toxicol Pharmacol
A comprehensive review examines endocrine-disrupting chemicals (EDCs) classified as carcinogens—compounds recognized for decades as top priority toxicants and persistent organic pollutants due to their ability to disrupt endocrine signaling—analyzing their hazard identification, human exposure routes, carcinogenic potency, and mechanisms of action across different organs. The review discusses major endocrine-disrupting carcinogens and their cancer-causing potential while identifying critical research gaps, methodological bottlenecks, and limitations in analytical detection techniques. This analysis underscores the serious public health concern posed by EDCs with carcinogenic properties, highlighting the need for improved understanding of their mechanisms, better analytical methods for detection and measurement, and addressing research limitations to protect human health from these ubiquitous environmental contaminants that can both disrupt hormonal systems and initiate cancer development.
2023
J Natl Cancer Inst
A large cohort study of 451,945 National Institutes of Health-AARP Diet and Health Study participants used EPA Toxics Release Inventory data to estimate historical environmental ethylene oxide (EtO) exposures based on proximity to EtO-emitting facilities, wind patterns, and emission levels from enrollment in 1995-1996. Among 173,670 postmenopausal women, living within 10 km of EtO facilities was associated with statistically significant breast cancer risk for invasive disease (HR = 1.03; 95% CI: 0.97-1.09); women in the highest quartile of the airborne emissions index showed elevated risk of in situ breast cancer at 10 km (HR = 1.25; 95% CI: 1.02-1.53), with no clear patterns for non-Hodgkin lymphoma risk. These findings reveal a novel potential association between environmental EtO exposure and in situ breast cancer—but not invasive breast cancer or lymphohematopoietic cancers—contrasting with occupational studies that found associations with invasive disease. The differential association with in situ versus invasive disease suggests EtO may influence early-stage breast carcinogenesis, though the mechanism remains unclear and warrants further investigation to understand why environmental exposures show different patterns than occupational exposures and why the effect appears limited to pre-invasive lesions.
2023
Reprod Toxicol
A review of epidemiologic literature examining environmental chemical exposures during pregnancy and three maternal health outcomes (preeclampsia, gestational diabetes, and breast cancer) found that pregnancy represents a unique critical period when biological changes can heighten women’s susceptibility to chemicals from air, food, water, and consumer products—including flame retardants, plasticizers, pesticides, and lead—though research has disproportionately focused on fetal outcomes rather than maternal health risks, which remain poorly characterized for most chemicals. While evidence shows that lead exposure increases risk of pregnancy-induced hypertensive disorders and pregnancy can amplify women’s vulnerability to environmental chemicals, variations in study design, exposure assessment methods, and inconsistent adjustment for confounders limited comparability across studies. The authors emphasize that future research must recognize pregnancy as a critical window for women’s lifelong health, calling for incorporation of biomarkers of exposure and effect, deliberate timing and methods of measurement, and consistent confounder adjustment to strengthen understanding of the pregnancy exposome and its impacts on maternal health outcomes beyond the immediate postpartum period.
2023
Breast Cancer Res
A study of over 3,000 Ghanaian women found that using insect repellent room sprays was associated with a 42% increased breast cancer risk compared to women who didn’t use any mosquito control products, while widely-used mosquito coils and insecticide-treated bed nets showed no significant association with breast cancer. The lack of association with bed nets and coils is reassuring given their critical importance for preventing malaria in regions where mosquito-borne diseases are a major health threat, but the findings regarding repellent sprays—used by about half of participants—require further investigation to understand which chemical ingredients may be driving the increased risk. The study had limited ability to assess repellent skin creams due to low usage, and researchers could not determine whether more frequent spray use increased risk, highlighting the need for additional research on insecticide exposures and breast cancer in low- and middle-income countries where these products are essential for disease prevention.
2023
Foods
A review of regulations for endocrine-disrupting chemicals and persistent organic pollutants in infant formula found that while breast milk remains the healthiest option, infant formula must be strictly monitored to ensure it is pollutant-free, particularly given the vulnerability of newborns to chemical exposures. Current regulations and upper limits for contaminants in infant formula vary worldwide, though standardized policies exist to protect infants, and continuous monitoring is required to maintain safety standards. The authors emphasize that risk assessment studies are limited but urgently needed to better understand exposure variations and evaluate the health risks infants face from dietary exposure to pollutants during this critical developmental period.
2023
Front Oncol
A study of 80 Black and White women with breast cancer at Emory University Hospitals (2008-2017) examined associations between contemporary neighborhood redlining—a structural racism measure derived from Home Mortgage Disclosure Act data—and DNA methylation patterns in breast tumor tissue. Contemporary redlining was significantly associated with aberrant methylation at 5 CpG sites (FDR<0.10) in genes implicated in breast carcinogenesis, inflammation, immune function, and stress response (ANGPT1, PRG4), with additional top sites showing interaction by ER status and association with mortality; redlining was also associated with epigenetic age acceleration (β=5.35; 95% CI: 0.30-10.4 by Hannum metric). These novel findings suggest that structural racism—manifested through discriminatory housing policies leading to inequitable social and environmental exposures—may biologically embed in the breast tumor epigenome through altered DNA methylation patterns, potentially contributing to documented racial disparities in breast cancer outcomes and highlighting the need for further research on epigenetic mechanisms linking neighborhood-level structural racism to cancer prognosis.
2023
Environ Res
A meta-analysis of 17 epidemiological studies examining cadmium exposure and breast cancer risk found no statistically significant associations overall or when examining specific exposure routes separately (dietary cadmium or biomarker-based studies), with substantial heterogeneity between studies and no clear patterns by menopausal status. The inconclusive findings leave critical questions about whether specific exposure routes (occupational, air pollution, smoking) pose different risks than dietary intake or whether residual confounding by tobacco smoke constituents may influence observed associations. These results highlight the need for future research with better exposure assessment methods that can distinguish between different cadmium sources and routes of exposure, particularly occupational and environmental air pollution exposures that may be more relevant than diet for populations living near industrial areas where cadmium contamination is prevalent.
2023
Eur J Nutr
A large prospective cohort study of 67,879 French women followed for 21 years found that higher dietary inflammatory potential was associated with a 4% increased breast cancer risk per standard deviation increase in DII score, with women in the highest versus lowest quintile showing a 13% increased risk in a linear dose-response relationship. The association was slightly stronger among non-smokers (6% increased risk per standard deviation) and low alcohol consumers (5% increased risk per standard deviation), suggesting that inflammatory diet effects may be most pronounced in women without other pro-inflammatory exposures. These findings from one of the largest and longest prospective studies provide strong evidence that promoting anti-inflammatory dietary patterns—rich in fruits, vegetables, whole grains, legumes, nuts, and fish while limiting processed foods, red meat, refined carbohydrates, and saturated fats—could contribute meaningfully to breast cancer prevention as part of comprehensive public health strategies.
2023
Endocrinol Metab Clin North Am
Multiple social and structural determinants of health undoubtedly contribute to the marked racial/ethnic-, gender-, and socioeconomic-based disparities in endocrine health; however, the contribution of environmental injustice is vastly underappreciated. Indeed, those groups disproportionately burdened by endocrine disorders are often exposed to higher levels of various EDCs, including PCBs, phthalates, bisphenols, OC pesticides, air pollutants, PFASs, toxic metals/metalloids, and BFRs. These chemicals threaten our reproductive and metabolic health, contributing to diabetes prevalences, obesity, and disorders related to hormonal regulation. This review increases awareness of these disparities and encouraged equitable healthcare for those who are disadvantaged.
2023
Environ Sci Technol
The following study discusses a strategic framework to improve how chemicals are managed in North America. The Essential-Use Approach is a policy that prioritizes restricting the use of chemicals based on necessity and safety. It proposes three guiding questions: Is the chemical essential to the product’s function? Is it the safest option? Is it necessary for health and safety? They also prioritize speed of assesments so that chemicals can be quickly phased out if evidence suggests danger to human health. This study is a call for change and aims to become a tool to simplify decision-making for regulating organizations, help businesses avoid liability related to harmful chemicals, and ultimately improve public health by ensuring only the safest substances are used in consumer products.
2023
JAMA Oncol
A retrospective analysis of 60,137 women with early-stage, ER-positive, node-negative breast cancer found that Black women had an 82% increased risk of breast cancer death compared to White women, with social determinants of health (neighborhood disadvantage and insurance status) mediating 19% of this disparity and tumor biological characteristics (including genomic recurrence scores) mediating 20%. When all factors were combined in a fully adjusted model, 44% of the racial survival disparity was explained, suggesting that social determinants and aggressive tumor biology contribute roughly equally to worse outcomes in Black women, though over half of the disparity remains unexplained. Notably, neighborhood disadvantage itself mediated 8% of racial differences in high-risk recurrence scores, indicating that social factors may influence tumor biology, and highlighting that addressing breast cancer disparities requires dual approaches targeting both structural barriers to healthcare access and quality while investigating the biological mechanisms—including ancestry-related genetic variants and molecular pathways—that may drive more aggressive disease in Black women.
2023
Cancer Epidemiol Biomark Prev
A pooled analysis of six European cohorts including 199,719 women followed for 3.6 million person-years found that long-term exposure to fine particulate matter (PM₂.₅) was associated with a 6% increased breast cancer risk per 5 μg/m³ increase. The association was strongest among middle-aged women (ages 50-54) and never-smokers, and notably, the cohorts studied represented the lower range of air pollution concentrations in Europe, suggesting that even relatively low levels of air pollution may contribute to breast cancer risk. These findings add to mounting evidence that air pollution—particularly fine particulate matter from traffic, industry, and combustion sources—is an environmental breast cancer risk factor operating independently of established risk factors, with important implications for public health policy, urban planning, and air quality regulations aimed at reducing population-level cancer burden, especially given that air pollution exposure is largely involuntary and affects entire populations.
2023
Environ Sci Technol
This review investigates the migration of bisphenols and alternative color developers from thermal labels on cling-wrapped fresh food, identifying them as significant dietary sources of these compounds. While no BPA was found in packaging, high concentrations of bisphenol S (BPS) and other alternatives were detected, particularly in thermal labels. Migration studies revealed that BPS and related compounds leach into food, especially fish, raising potential health concerns. These findings highlight the need for further risk assessments regarding these alternative chemicals in food packaging due to past findings about BPA being an endocrine disruptor. This will help mitigate exposure risks and ensure consumer safety.
2023
Frontiers
This meta-analysis aimed to evaluate the association between exposure to endocrine-disrupting chemicals (EDCs), including phthalates and other common environmental pollutants, and breast cancer risk. The study found that certain EDCs—such as p,p′-DDT, chlordane, HCH, and specific PCBs—were positively associated with increased breast cancer risk, while a few compounds like BBP and PFDoDA showed a negative association.
2023
Compr Rev Food Sci Food Saf
A systematic review of phthalate contamination in food identified 19 phthalates across multiple food categories, with 57 measurements exceeding legal limits and DEHP showing the highest incidence; risk assessment revealed high probability of exceeding tolerable daily intake for DEHP and DBP in fish, oils/fats, cereals, and dairy for both children and adults, with fats/oils being the most critical category. Migration from food contact materials is positively correlated with temperature, contact time, fat content, and acidity, with contamination occurring throughout the production chain. The widespread contamination exceeding safe exposure limits—particularly for vulnerable populations including children—highlights the urgent need for stricter regulation of phthalates in food packaging and production materials.
2023
Environ Pollut
A study analyzing breast milk from 50 U.S. mothers ten years after the PBDE phaseout detected 25 brominated flame retardants including 9 PBDEs (found in 100% of samples), 8 bromophenols (88% of samples), and 8 other BFRs, with PBDE concentrations showing a significant 70% decline since 2002 (median 15.0 ng/g lipid, halving time 12.2 years) but bromophenols and replacement flame retardants reaching concentrations up to 71.1 and 278 ng/g lipid respectively. This represents the first measurement of bromophenols and replacement flame retardants in U.S. breast milk, revealing that while legacy PBDE levels have declined substantially following regulatory action, current-use flame retardants are now contaminating breast milk at concerning levels. The persistent presence of phased-out PBDEs alongside emerging bromophenols and replacement BFRs—many of which are persistent, toxic, and bioaccumulative—indicates ongoing prenatal exposure through breastfeeding and increased risk for adverse impacts on infant neurodevelopment; however, it’s important to note that breastfeeding remains recommended and is still considered safer and more beneficial than formula feeding despite the presence of these contaminants, highlighting the urgent need for policies to reduce flame retardant contamination at the source rather than discouraging breastfeeding.
2022
J Occup Environ Med
A systematic review and meta-analysis of 9 studies found that female flight attendants had a 43% increased breast cancer incidence compared to the general population, but surprisingly, neither cosmic radiation exposure nor circadian rhythm disruption—the two primary occupational hazards hypothesized to drive this excess risk—showed clear associations with breast cancer in the available studies. Three studies suggested a possible link with cosmic radiation while none found associations with circadian disruption, leaving the underlying cause of the elevated breast cancer risk among flight attendants unexplained. These findings highlight a critical gap in occupational health research: while flight attendants clearly face elevated breast cancer risk, the mechanisms remain unclear, potentially involving unmeasured factors such as reproductive patterns (delayed childbearing, fewer children), lifestyle factors associated with the profession, cumulative effects of multiple low-level exposures, or limitations in exposure assessment methods—underscoring the urgent need for studies with detailed individual-level data on occupational exposures, work schedules, and lifestyle factors to identify modifiable risk factors for this vulnerable workforce.
2022
Endocrinology
A review examining PFAS (found in nonstick cookware, food packaging, and stain-resistant fabrics) and parabens (used in personal care products) found that exposure to these endocrine-disrupting chemicals is linked to breast cancer development, with marginalized and socially disadvantaged communities facing disproportionately higher exposures due to structural racism and inequitable environmental conditions. These disparities in chemical exposure may contribute to poorer breast cancer outcomes in these populations, yet breast cancer research continues to underrepresent these communities, limiting our ability to address treatment disparities and improve survival rates. The authors emphasize the urgent need to both reduce EDC exposures in vulnerable communities and increase research inclusion of diverse populations to understand how environmental injustices intersect with breast cancer risk and develop interventions that address these health inequities.
2022
Environ Int
A large prospective study within the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort examined 318,607 women from nine European countries over a median 14.9 years of follow-up, identifying 13,241 incident invasive breast cancer cases, to assess whether dietary intake of 17 dioxins and 35 polychlorobiphenyls (PCBs)—persistent organic pollutants with endocrine-disrupting and carcinogenic properties—was associated with breast cancer risk. Dietary exposures to dioxins, dioxin-like PCBs (DL-PCBs), non-dioxin-like PCBs (NDL-PCBs), and combined dioxins + DL-PCBs showed no associations with breast cancer incidence (all HRs approximately 1.00-1.01 per 1 SD increase), with results remaining consistent when analyzed by quintile groups, by country, by estrogen receptor status, or after adjusting for contributing food groups and nutritional factors. These findings from one of the largest prospective studies on this topic do not support an association between dietary intake of dioxins and PCBs—the main exposure route for these chemicals in the general population—and breast cancer risk. Despite the established endocrine-disrupting properties of these pollutants and some previous suggestions of positive associations, this comprehensive European study provides reassuring evidence that typical dietary exposures to dioxins and PCBs are not linked to increased breast cancer incidence.
2022
Int J Epidemiol
A prospective cohort study of 45,923 never-smoking Norwegian women aged 34-70 followed for a mean 19.8 years (2,185 invasive breast cancer cases) found that exposure to second-hand smoke (SHS) from parents during childhood was associated with an 11% increased breast cancer risk (HR=1.11; 95% CI: 1.02-1.22) compared to unexposed women, with no difference by estrogen (p-heterogeneity=0.31) or progesterone (p-heterogeneity=0.95) receptor status. Among exposed women, the attributable fraction was 10.3% (95% CI: 1.8-18.0), indicating that approximately 1 in 10 breast cancer cases among those exposed could be attributed to parental SHS during childhood. These findings provide evidence that childhood exposure to parental second-hand smoke increases breast cancer risk decades later, highlighting childhood as a critical window of susceptibility to environmental tobacco smoke carcinogenesis and suggesting that the cancer burden attributable to SHS may be substantially underestimated when focusing only on adult exposures rather than early-life exposures.
2022
Cancer Epidemiol Biomark Prev
A study of 1,268 women from the Long Island Breast Cancer Study Project with measurements of 22 urinary phthalate and phenol analytes and leukocyte telomere length (LTL)—a biomarker of biological aging—found that LTL significantly modified associations between 11 of 22 analytes and breast cancer risk (p<0.05), with a general pattern showing inverse associations at shorter LTL and positive associations at longer LTL, though no modifying effects were observed for breast cancer mortality. This first study examining biological aging's role in environmental chemical-breast cancer associations reveals complex interactions where the same phthalate/phenol exposures may have opposite effects depending on an individual's telomere length and biological aging status. These findings suggest that biological aging markers like telomere length may help identify women who are more or less susceptible to breast cancer from environmental chemical exposures, highlighting the importance of considering individual variation in biological aging when assessing environmental risk factors and potentially explaining some of the inconsistent associations between phthalates/phenols and breast cancer reported in previous studies that did not account for biological aging heterogeneity.
2022
Crit Rev Food Sci Nutr
This systematic review of 131 epidemiological studies evaluated the association between various endocrine-disrupting chemicals, including phthalates and hormonal exposures like contraceptive pills, and the risk of breast cancer. It found that several EDCs, particularly phthalates and oral contraceptive use, were consistently associated with increased breast cancer risk across multiple studies.
2022
Chemosphere
A study analyzing 12 commercial bottled water brands found that all tested products contained 2-6 different phthalate chemicals at concentrations ranging from 6.3 to 112.2 ng/mL, with di-n-butyl phthalate (DnBP) showing the highest levels followed by DEHP, DiBP, DMP, DEP, and DiPP. Using an optimized solid-phase microextraction method combined with tandem mass spectrometry, researchers detected these endocrine-disrupting chemicals—which leach from plastic bottles into drinking water—at levels detectable with limits as low as 0.3-2.6 ng/mL. These findings raise significant public health concerns given that phthalates are recognized endocrine disruptors with estrogenic properties that have been linked to breast cancer and other hormone-related health effects, and that billions of people worldwide consume bottled water daily with cumulative lifetime exposures potentially reaching harmful levels, highlighting the urgent need for regulatory limits on phthalates in bottled water and increased adoption of alternative packaging materials that don’t leach endocrine-disrupting chemicals.
2022
J Expo Sci Environ Epidemiol
A comprehensive analysis of 6,793 chemicals in commercial use identified 50 high-priority understudied chemicals that frequently co-occur with known breast cancer-associated chemicals in everyday exposure sources like food, consumer products, and personal care items. Using chemical databases and structural similarity analyses, researchers found these understudied chemicals share physicochemical properties with established mammary carcinogens and potential endocrine disruptors, yet have not been adequately evaluated for breast cancer risk. The findings highlight that real-world chemical exposures occur as mixtures rather than isolated compounds, and that focusing solely on individual well-known chemicals may miss important combination effects—underscoring the urgent need for mixtures-based research in clinical, epidemiological, and toxicological studies to better understand and prevent environmentally-driven breast cancer.
2022
Environ Res
A case-control study of 499 breast cancer patients and 499 controls in Northern Mexico found that women with breast cancer had distinct patterns of urinary metal exposure, with higher concentrations of tin and lower concentrations of vanadium, cobalt, and molybdenum compared to controls. Using principal component analysis to identify metal mixtures, researchers discovered two distinct exposure patterns with opposite breast cancer associations: a mixture containing chromium, nickel, antimony, aluminum, lead, and tin showed a 15% increased risk, while a mixture of molybdenum and cobalt showed a 44% reduced risk. This is the first study to identify specific urinary metal mixture profiles associated with breast cancer, highlighting that metals may interact synergistically or antagonistically rather than acting independently, and underscoring the critical need for mixture-based approaches in environmental health research—since real-world exposures involve multiple simultaneous contaminants whose combined effects may differ substantially from predictions based on individual metals alone—along with mechanistic studies to understand how metal interactions influence breast carcinogenesis.
2022
Int Arch Occup Environ Health
A nationwide retrospective cohort study of over 4.7 million Taiwanese workers found that occupational exposure to specific hazardous chemicals was associated with significantly elevated breast cancer risk among female workers, with asbestos showing the highest increase (107% increased incidence, 80% increased risk after adjusting for age and exposure duration). Other notable associations included 1,1,2,2-tetrachloroethane (74% increased incidence, 52% adjusted risk increase), trichloroethylene/tetrachloroethylene (47% increased incidence, 42% adjusted risk increase), benzene (40% increased incidence, 38% adjusted risk increase), and lead (27% increased incidence, 31% adjusted risk increase), with associations remaining robust even after accounting for 2- or 5-year latency periods. These findings from 3,248 breast cancer cases among exposed workers provide compelling evidence that occupational chemical exposures substantially increase breast cancer risk, highlighting the urgent need for enhanced workplace protections, regular breast cancer screening programs for exposed workers, substitution of safer alternatives where possible, and recognition of breast cancer as an occupational disease for workers with documented exposure to these carcinogens.
2022
Int J Env Res Public Health
A large population-based retrospective case-control study in Taiwan examined 103,047 female workers with breast cancer diagnosed between 2008-2017 and matched controls (1:4 ratio) using lifetime labor enrollment records from 1950-2017 to investigate the association between occupational industries and breast cancer risk. The study identified slightly elevated breast cancer risk across nine major occupational classifications, with the highest risks observed in education (OR: 1.199), professional/scientific/technical activities (OR: 1.118), human health and social work (OR: 1.125), and financial/insurance activities (OR: 1.109), while manufacturing, wholesale/retail trade, information/communication, real estate, and public administration sectors showed smaller but statistically significant increases (ORs ranging from 1.027-1.074). The findings suggest that women employed in certain white-collar professions (education, healthcare, finance, professional services) and some industrial sectors (manufacturing, retail) have modestly increased breast cancer risk compared to other Occupations. The authors recommend further investigation into specific risk factors within these industries—such as work schedules, occupational exposures, socioeconomic factors, or lifestyle patterns associated with these professions—that might explain the slightly elevated breast cancer incidence among female workers in these sectors.
2022
Sci Rep
A study of drinking water found widespread contamination with phthalates (plastic chemicals) and bisphenol-A, with DEHP—the most common phthalate detected—exceeding safety limits in concentrations up to 8,351 µg/L in winter and 410 µg/L in summer, posing potential health risks to consumers. The research revealed significant seasonal variations with higher contamination in winter than summer, and health risk assessment showed that DEHP exposure from drinking water alone exceeded safe levels (hazard quotient >1), raising concerns about hormone disruption and potential breast cancer risk. These findings highlight an urgent need for water treatment plants to implement better technologies to remove these endocrine-disrupting chemicals and ensure safe drinking water, as current contamination levels may threaten both human and environmental health.
2022
J Hazard Mater
This study investigates human exposure to bisphenol A (BPA) and bisphenol S (BPS) by handling thermal paper receipts. The study analyzed the BPS and BPA concentrations from the fingerprints of individuals who handled thermal paper receipts and compared them to those of people who didn’t handle thermal paper receipts. The results found that 20–40 μg of BPS or BPA is transferred to human skin as seen through the fingerprint after contact with thermal papers containing 100–300 μg. Additionally, the transfer of BPA was 2.9–5.2 times higher than BPS, which is consistent with higher concentrations in receipts. However, washing hands significantly reduced the transfer of both BPS and BPA. This is important because the study also determined lipid metabolism was affected at concentrations greater than 10 mg/L. Additionally, it had adverse effects on the growth of water flees, indicating that it may potentially have some effect on human development as well.
2022
Food Chem
A study analyzing 27 vegetable oils using advanced two-dimensional gas chromatography found phthalates—endocrine-disrupting chemicals used as plasticizers that have been linked to cancer—in vegetable oil products, though specific concentration ranges and detection frequencies were not provided in the abstract. The researchers developed a simple, direct analytical method requiring only dilution with solvent (no complex sample preparation) that achieved good repeatability, low detection limits (0.06-2.10 mg/kg), and high accuracy (-9.2% to 10.4%), making it suitable for routine monitoring of phthalate contamination in edible oils. These findings raise concerns about dietary phthalate exposure through cooking oils—a staple food ingredient consumed daily by billions—particularly since phthalates can migrate into oils from plastic packaging, processing equipment, or storage containers, and given their known endocrine-disrupting properties and associations with hormone-related cancers including breast cancer, highlighting the need for stricter regulations on phthalate use in food contact materials and routine monitoring of edible oils for these contaminants.
2022
Environ Sci Pollut Res
The following study explores the presence of endocrine disruptors such as phthalates (specifically mono-2-ethyl phthalate and mono-n-butyl phthalate), bisphenol A (BPA), and 1-hydroxypyrene in the urine samples of marginalized Indigenous populations. The study found that 100% of the women sampled showed exposure to these harmful chemicals, with higher concentrations than observed in similar studies from other communities. This increased exposure is linked to environmental and cultural factors, such as the common use of plastic containers and practices such as burning garbage. The women sampled were found to have especially high levels of mono-2-ethyl phthalate, which suggests significant exposure to di(2-ethylhexyl) phthalate. These findings highlight the vulnerability of indigenous communities to pollution due to a lack of awareness, limited healthcare access, and inadequate regulatory measures.
2022
Int J Environ Res Public Health
A recent study highlights the risk of Bisphenol A (BPA) exposure from bottled water, emphasizing how temperature can influence BPA leaching into the water. While BPA isn’t used in PET bottle manufacturing, contamination can occur due to recycled materials. Findings indicate that BPA levels in bottled water increase with temperature, even when not at the highest temperatures. BPA, a known endocrine-disrupting chemical (EDC), is linked to reproductive health issues, developmental disorders, and even cancer.
2021
BMC Women's Health
A meta-analysis of 26 studies including over 1.3 million participants found that short-term night-shift work (<10 years) was associated with a 13% increased breast cancer risk, but surprisingly, long-term night-shift work (≥10 years) showed no statistically significant increased risk (8% increase, not significant). Flight attendants with long overnight flights showed elevated breast cancer risk, though unmeasured confounders may have influenced these results, and the increased risk in short-term workers was most robust in case-control studies that adjusted for reproductive factors and family history. The paradoxical finding that short-term but not long-term night-shift work showed significant associations contradicts the expected dose-response relationship and may reflect healthy worker bias (where women susceptible to night-shift effects leave such work before reaching 10 years), methodological limitations in measuring long-term exposures, or unmeasured confounding factors that accumulate differently over time.
2021
Adv Pharmacol
A comprehensive review examining endocrine-disrupting chemicals (EDCs) in breast tissue concludes that hundreds of these environmental chemicals are entering human breast tissue and contributing to the global rise in breast cancer incidence through multiple biological mechanisms. Laboratory studies demonstrate that EDCs can activate all the established “hallmarks of cancer” in human breast cancer cells—even at concentrations measured in actual human breast tissue—with effects amplified when chemicals are present as mixtures rather than individually. The authors argue that EDCs must now be formally recognized as a breast cancer risk factor to enable prevention strategies that include reducing environmental chemical exposures, particularly given that the varied mixtures of EDCs found in individual breast tissues act through overlapping mechanisms to promote cancer development.
2021
Endocrinology
A comprehensive review of bisphenol A (BPA) research spanning over 20 years—from the landmark 1997 study showing reproductive effects in male mouse offspring at 2 µg/kg/day through the CLARITY-BPA study designed to bridge regulatory and scientific disagreements—found that thousands of animal studies and over 100 epidemiological studies report adverse effects at low doses, with CLARITY-BPA showing effects at 2.5 µg/kg/day, leading independent experts to recommend dropping the lowest observed adverse effect level 20,000-fold from 50,000 to 2.5 µg/kg/day. Despite this overwhelming evidence, the FDA continues to assert BPA is safe by rejecting low-dose data as “not biologically plausible” based on four incorrect assumptions criticized by the Endocrine Society as violating basic principles of endocrinology: that dose responses must be monotonic, thresholds exist below which there are no effects, both sexes must respond similarly, and only traditional toxicological guideline studies are valid. The review highlights a fundamental divide between regulatory approaches and endocrine science, demonstrating that traditional toxicology methods are insufficient for evaluating endocrine-disrupting chemicals like BPA, which can cause non-monotonic dose responses, sex-specific effects, and low-dose effects that challenge conventional assumptions about chemical safety, yet regulatory agencies continue to ignore modern endocrinology principles in favor of outdated toxicological paradigms.
2021
Sci Rep
A nested case-control study of 4,401 breast cancer cases and 4,401 matched controls from the French E3N cohort found no overall association between long-term airborne cadmium exposure and breast cancer stage or tumor grade, but identified a striking 240% increased risk of invasive tubular carcinoma (ITC)—a specific breast cancer subtype—among women in the highest versus lowest quintile of cadmium exposure. The dose-response analysis suggested a linear relationship between cadmium exposure and ITC risk specifically, though no associations were found for other histological subtypes or more advanced disease. These findings suggest that cadmium’s estrogenic properties may selectively promote certain breast cancer subtypes rather than broadly increasing all breast cancer risk, highlighting the importance of examining cancer heterogeneity in environmental exposure studies and raising concerns about air pollution from industrial sources, waste incineration, and fossil fuel combustion that release cadmium into the environment.
2021
Water Res
A study of 101 bottled water products sold in the US found that PFAS chemicals were detected in 39% of tested products at concentrations ranging from 0.17 to 18.87 ng/L (median 0.98 ng/L), with 97% of samples below 5 ng/L, though some products approached levels of regulatory concern. Spring water products contained significantly higher PFAS levels than purified water, with reverse osmosis (RO) treatment—used in 71% of purified waters but only 2% of spring waters—effectively removing PFAS contamination across all chain lengths. Notably, perfluoropropanoic acid (PFPrA), an ultrashort-chain PFAS measured for the first time in bottled water, accounted for 42% of detected PFAS mass and was found almost exclusively in spring water products, raising concerns given the lack of enforceable PFAS regulations for bottled water in the US despite these “forever chemicals” being linked to multiple health concerns including potential breast cancer risk, and highlighting the need for mandatory PFAS monitoring and disclosure requirements for bottled water manufacturers.
2020
Environ Res
A systematic review of 100 publications across 56 epidemiologic studies found that research enriched with women at higher baseline breast cancer risk—through family history, early-onset disease, or genetic susceptibility—consistently showed stronger and more frequent associations between environmental chemical exposures and breast cancer compared to average-risk populations. Specifically, 80% of studies enriched with family history or early-onset cases showed significant associations with exposures including PAHs, air pollution, DDT, PCBs, PFAS, metals, personal care products, and occupational chemicals, while 74% of studies examining genetic susceptibility found significant gene-environment interactions for various pollutants in women with variants affecting carcinogen metabolism, DNA repair, and oxidative stress. These findings suggest that the inconsistent evidence for environmental chemicals and breast cancer in the literature may partly stem from studying predominantly average-risk populations who may be less susceptible to environmental carcinogens, highlighting the critical need for future research to focus on high-risk populations and measure exposures during key windows of susceptibility (puberty, pregnancy, menopause) to more accurately capture the role of environmental chemicals in breast cancer development.
2020
Repro Toxicol
A 54-year follow-up study of 102 breast cancer cases and 310 matched controls among 9,300 daughters born 1959-1967 in the Child Health and Development Studies cohort found that high maternal perinatal levels of N-ethyl-perfluorooctane sulfonamido acetic acid (EtFOSAA, a precursor to PFOS) combined with high maternal cholesterol predicted a 3.6-fold increased breast cancer risk in daughters by age 52 (95% CI: 1.1-11.6), while maternal PFOS alone was paradoxically associated with decreased risk. These robust findings—consistent across alternative modeling approaches and independent of other maternal factors—demonstrate that prenatal exposure to specific PFAS compounds during critical developmental windows can influence breast cancer risk decades later, revealing multigenerational health consequences of persistent environmental chemicals. The results emphasize the critical importance of studying internal PFAS doses and chemical mixture exposures during vulnerable early-life periods for breast cancer prevention, particularly as current and future generations face continued ubiquitous exposure to these persistent compounds, though experimental validation and replication in additional epidemiological cohorts are needed to confirm causality and inform prevention strategies.
2020
Environ Health
A nested case-control study of 197 incident postmenopausal breast cancer cases and 197 controls with blood samples collected 1994-1999 measured plasma levels of six PBDE congeners (BDE-28, -47, -99, -100, -153, -154) and PBB-153 using gas chromatography-mass spectrometry and found no overall evidence of association between brominated flame retardant (BFR) levels and breast cancer risk (log-concentrations yielding odds ratios of 0.87-1.07). Some analyses showed non-linear inverse associations for BDE-100 and BDE-153 with breast cancer risk (third vs. first quintile: OR=0.42; 95% CI: 0.19-0.93 and OR=0.42; 95% CI: 0.18-0.98, respectively) when exposure was modeled as ng/L plasma but not when lipid-adjusted (OR=0.58 and 0.53), with results unchanged by tumor hormone receptor status or BMI. These findings suggest no clear association between internal PBDE and PBB-153 levels and postmenopausal breast cancer risk, though limitations include small sample size, lack of genetic susceptibility information, single time-point exposure assessment that may not represent critical windows of susceptibility, and the paradoxical inverse associations requiring cautious interpretation, warranting additional larger studies with repeated measurements and assessment of early-life exposures to clarify the relationship between BFR exposure and breast cancer development.
2020
Env Health Persp
A systematic review and meta-analysis of 14 studies found that spending one or more hours per day in the sun during summer months was associated with a 16% reduced breast cancer risk compared to less than one hour daily, with similar protective effects observed for both 1-2 hours and more than 2 hours of sun exposure. Sun exposure during adolescence appeared particularly protective (17% risk reduction), while exposure after age 45 showed no significant benefit, and interestingly, ambient UV radiation levels alone were not associated with breast cancer risk. These findings suggest that active sun exposure—likely through Vitamin D production—may offer modest breast cancer protection when obtained regularly during youth and early adulthood, though the results should be balanced against known skin cancer risks from excessive UV exposure.
2020
Mol Cell Endocrinol
A review of EPA pesticide registration documents found that 28 pesticides cause mammary tumors in animals and five alter mammary gland development, yet the agency’s risk assessments often dismiss these findings or don’t evaluate their implications for breast cancer risk. Many of these pesticides work through hormone-disrupting pathways that could affect breast tissue, including common chemicals like malathion, atrazine, and triclopyr. The authors argue that current testing guidelines don’t adequately assess effects on the mammary gland and call for re-evaluation of several widely-used pesticides based on stronger standards informed by breast cancer biology.
2019
Int J Env Res Public Health
A French population-based case-control study (CECILE study) of 695 breast cancer cases and 1,055 controls measured plasma levels of organochlorine compounds (OCs)—p,p’-DDE and PCB153—at the time of diagnosis and used a physiologically-based pharmacokinetic (PBPK) model to estimate PCB153 exposure levels during adolescence (ages 11-20), when breast tissue may be particularly susceptible to hormonal disruption. The study found no clear association between measured OC levels at diagnosis and breast cancer risk overall, though there was a trend toward decreasing breast cancer odds ratios with increasing OC levels in women aged 50 and over; similarly, negative associations were observed between breast cancer and estimated adolescent PCB153 exposure levels. The PBPK modeling revealed that women born after 1960 had the highest estimated PCB153 exposures during adolescence (coinciding with peak environmental contamination), while older women had very low adolescent exposures, yet the unexpected negative associations between OC levels and breast cancer risk remained unexplained and may represent study artifacts. Despite these puzzling findings, the study demonstrates that PBPK models can be valuable tools in epidemiological research for back-estimating exposures during critical developmental windows, which could help address important questions about how early-life environmental exposures influence cancer risk decades later.
2019
J Occup Environ Med
This case control study was conducted among Hispanic women agricultural workers who are exposed to pesticides. Chemicals associated with BC risk included organophosphates, organochlorines, and a phthalimide, Captan. The study concluded that agricultural work may be associated with increased BC risk in female Hispanic farm workers.
2019
Am J Indust Med
A case-control study of 300 breast cancer cases and 300 age- and residence-matched controls in Morocco examined associations between occupation, industry, and breast cancer risk using detailed occupational histories (jobs held ≥6 months) coded by international standards (ISCO 08, Moroccan Analytical Classification, European Statistical Classification). Women doing only household work showed decreased breast cancer risk (OR=0.32; 95% CI: 0.18-0.55), while agricultural workers—particularly agricultural laborers—had significantly increased risk (OR=2.91; 95% CI: 1.51-5.60) with risk increasing by duration of employment (p-trend=0.01), findings corroborated by industry-level analyses. These results suggest that occupational exposures in agricultural work may substantially increase breast cancer risk among Moroccan women, warranting further investigation with advanced exposure assessment methods to identify specific chemical exposures (likely pesticides and other agricultural chemicals) driving this elevated risk and inform targeted prevention strategies and screening programs for this high-risk occupational group in populations where agriculture employs significant numbers of women.
2019
Environ Int
A case-control study within the California Teachers Study examined 902 women with invasive breast cancer and 936 controls to assess whether serum levels of polybrominated diphenyl ethers (PBDEs)—common environmental contaminants with endocrine-disrupting properties—are associated with breast cancer risk. Blood samples were analyzed for three prevalent PBDE congeners (BDE-47, BDE-100, and BDE-153), with measurements taken an average of 35 months after cancer diagnosis. The study found no significant association between serum levels of any of the three PBDE congeners and breast cancer risk, even when stratified by menopausal status, tumor characteristics, or body weight. However, the authors note important limitations, including that post-diagnosis blood measurements may not reflect pre-diagnostic or lifetime exposures, and the study lacked information on genetic factors that could influence individual susceptibility.