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2025
Iran J of Pub Health
This study of nearly 5,000 U.S. women found that exposure to triclosan—an antibacterial chemical once commonly found in soaps, toothpaste, and other personal care products—was associated with more than double the breast cancer risk at moderate exposure levels, while propylparaben (a preservative in cosmetics and foods) showed a protective association. However, when researchers examined the combined effect of multiple phenols and parabens together, they found no significant association with breast cancer, suggesting these chemicals may have complex and sometimes opposing effects. These mixed findings highlight the need for more research to understand how individual chemicals versus chemical mixtures affect breast cancer risk, especially since people are typically exposed to multiple chemicals simultaneously in everyday products.
2022
Crit Rev Food Sci Nutr
A systematic review of 131 epidemiological studies examining endocrine-disrupting chemicals (EDCs) and breast cancer risk found evidence that exposure to various EDCs—including pesticides (DDT/DDE, atrazine, dioxin), synthetic chemicals (BPA, phthalates, PFAS, PCBs, PBDEs), and other compounds found in everyday products—may elevate breast cancer risk, particularly when exposure occurs during early life. The review identified food as a major route of EDC exposure and emphasized that because most EDCs persist in the environment and accumulate in the body over time, long-term multi-generational health impacts need to be assessed. The authors call for improved exposure assessments of EDCs in food and food packaging, along with careful evaluation of their links to breast cancer development to inform policy-making and regulations aimed at protecting public health.
2022
Environ Res
This case-only study included 2,998 women with breast cancer from the Women’s Circle of Health Study and examined how characteristics of hair dye and hair relaxer use were related to tumor features. Compared with women who only used salon-applied permanent hair dye, those using home dye kits or both salon and home dye had higher odds of having poorly differentiated (more aggressive) tumors, especially among Black women (for Black women: home kits OR 2.22, 95% CI: 1.21–5.00; combination use OR 2.46, 95% CI: 1.21–5.00) and among women with ER-positive tumors (combination use OR 2.98, 95% CI: 1.62–5.49). Combination use of hair relaxers was also associated with larger tumors (>2.0 cm vs <1.0 cm; OR 1.82, 95% CI: 1.23–2.69). Although some associations did not remain statistically significant after strict multiple-comparison correction, the overall pattern suggests that frequent, mixed use of hair dyes and relaxers may be linked to more aggressive breast tumor characteristics.
2022
Cancer Epiemiol
The first Indian case-control study examining phthalates (chemicals widely used in plastics, cosmetics, and food packaging) and breast cancer found that women with higher urinary levels of di-butyl phthalate (DBP) had 1.5 times increased breast cancer risk, while those with higher DEHP levels had nearly 3 times increased risk. Analysis of breast tumor tissue revealed mutations in several genes known to respond to phthalate exposure, affecting pathways involved in hormones, metabolism, and cancer development. These findings suggest that exposure to certain phthalates may increase breast cancer risk through genetic changes, though larger studies are needed to confirm these results and understand how early-life exposures might contribute to cancer development later in life.
2021
Cancer Epi
This study of nearly 48,000 women found that frequent use of chemical hair straighteners and perms during adolescence (ages 10-13) was associated with more than double the risk of premenopausal breast cancer, though no increased risk was seen for postmenopausal breast cancer. Black women who used permanent hair dye during adolescence had a 77% increased breast cancer risk, though permanent dye use was uncommon overall in the study population. The findings are particularly concerning because adolescence is a critical developmental window when breast tissue may be more vulnerable to chemical exposures, and these hair products contain hormonally active and potentially carcinogenic compounds that may have long-lasting effects on breast cancer risk decades later.
2019
Environ Int
A population-based study of 711 breast cancer cases and 598 controls from the Long Island Breast Cancer Study Project measured seven urinary phenol biomarkers (environmental endocrine disruptors from personal care and consumer products) in spot urine samples collected within three months of diagnosis, with 17.6-year median follow-up identifying 271 deaths including 98 from breast cancer. The highest versus lowest quintiles of methylparaben, propylparaben, and sum of parabens (Σparabens) were associated with 31-50% increased breast cancer risk (ORs: 1.31-1.50) but paradoxically with 23-32% reduced all-cause mortality after diagnosis (HRs: 0.68-0.77), with associations for incidence stronger among women with BMI <25 kg/m² and associations for mortality stronger among women with BMI ≥25 kg/m². These findings—the first to examine phenol biomarkers in relation to both breast cancer incidence and subsequent mortality—reveal complex differential associations suggesting that select parabens may increase risk of developing breast cancer but be associated with better survival outcomes, though the mechanisms underlying these paradoxical associations remain unclear and may relate to BMI-dependent metabolic or hormonal factors, reverse causation, or unmeasured confounding.
2025
Sci Rep
A large U.S. study of 4,455 people found that exposure to triclosan (TRS)—an antibacterial chemical commonly found in soaps, toothpaste, and personal care products—was associated with more than double the risk of breast cancer at moderate exposure levels, with the relationship following an inverted U-shape pattern. The association was strongest among overweight individuals, people under 60 years old, and white participants, while other tested chemicals (including bisphenol A, benzophenone-3, and parabens) showed no significant link to breast cancer risk. These findings suggest that triclosan exposure may be an important modifiable risk factor for breast cancer, particularly for certain population groups, though more research is needed to understand the underlying mechanisms and confirm causality.
2024
Environ Sci Technol
A study of 751 reproductive-aged Black women found that the relationship between personal care product (PCP) use and exposure to endocrine-disrupting chemicals (EDCs) varied significantly by socioeconomic status (SES), with different patterns of chemical exposure from the same products depending on women’s education, income, and employment. For example, vaginal powder use was associated with higher phenol exposure (a class of EDCs) among lower SES women but showed no such association in higher SES women, suggesting that product formulations, brands, or usage patterns may differ across SES groups. These findings highlight that Black women face inequitable EDC exposures that are influenced by both race and socioeconomic factors, underscoring the need for targeted public health interventions that address these intersecting disparities in chemical exposures from everyday products
2024
Int J Env Res Pub Health
This study surveyed 746 Kenyan women about their hair product use and found that nearly 60% had used chemical relaxers and one-third had used hair dyes, despite many expressing concerns about health risks including breast cancer. Older women and those working in sales and service industries were more likely to use these products, which may contain endocrine-disrupting chemicals linked to breast cancer. Surprisingly, women’s awareness of potential health risks did not consistently lead to reduced use of these products, suggesting that concern alone may not be enough to change behavior. These findings are particularly important for Kenya, where breast cancer rates are rising, and highlight the need for better education about chemical exposures in hair products and strategies to reduce potentially harmful exposures.
2024
Environ Res
Endocrine Disrupting Chemicals (EDCs)—including bisphenol A, phthalates, parabens, pesticides, and heavy metals commonly found in pharmaceuticals, cosmetics, and packaging—are widespread environmental pollutants that interfere with the body’s hormone system. Research shows EDCs have harmful effects on women’s reproductive health, contributing to conditions such as endometriosis, polycystic ovary syndrome, uterine fibroids, premature ovarian failure, menstrual irregularities, and infertility. This review emphasizes the need for healthcare professionals to consider environmental exposures when evaluating patients, highlights potential mechanisms by which EDCs affect female reproduction, and discusses how nutritional interventions and stricter environmental regulations could help reduce EDC-related health risks. Understanding the link between EDCs and women’s health is crucial for developing protective strategies, informing treatment approaches, and shaping public policies to safeguard reproductive and overall well-being. The study seeks to advise that couples attempting to conceive should avoid endocrine disrupting chemicals (EDCs) such as BPA, pesticides, and phthalates. Following this advice is found to be crucial during the prenatal and periconceptional periods, where fetal development and growth are critical in this window.
2023
Chemosphere
A community-based intervention study (REDUXE) examined the effects of discontinuing paraben and phthalate-containing personal care products over 28 days by collecting paired fine needle aspirates of breast tissue from healthy volunteers before and after intervention, finding striking reversal of cancer-associated phenotypes including PI3K-AKT/mTOR pathway alterations, autophagy, and apoptotic signaling networks, along with significant reductions in urinary paraben and phthalate metabolites. Post-intervention breast tissue showed “normalizing” changes in estrogen-modulated gene expression pathways, estrogen receptor alpha:beta ratios, and cell cycle S-phase fraction when treated with 17β-estradiol in vitro, demonstrating functional improvement in cellular responses. This paradigm-shifting study reveals that persistent exposure to xenoestrogens from daily-use personal care products produces unfavorable pro-carcinogenic cellular changes in human breast tissue that can be reversed through short-term avoidance, suggesting that reducing xenoestrogen exposure from consumer products may suppress cancer-promoting phenotypes and represents a viable approach for breast cancer prevention.
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
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
Endocrinology
Methylparaben (MP) and propylparaben (PP) are preservatives commonly found in food, and cosmetics which activate estrogen receptors (ER) in the body. Research shows that these parabens can promote mammary tumor growth and metastasis. This study tested female mice with exposure to MP and PP within levels deemed safe by the FDA. Even within FDA approved levels, there was significant increase in mammary tumor volume. Cellular analysis revealed that these parabens affected the expression of genes, some linked to breast cancer. This research highlights potential risks of parabens in promoting breast cancer.
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
Molec Carcinogen
A case-control study of 708 breast cancer patients and 598 controls from Long Island found that paraben exposure—particularly methylparaben—was associated with significantly increased breast cancer risk among women with hypomethylated (undermethylated) DNA, showing a 46% increased risk in the highest versus lowest exposure group and a 32% increased risk per one-quantile increase in combined paraben exposure. Importantly, paraben exposure was specifically associated with breast tumors characterized by hypomethylation of the CCND2 gene promoter, with methylparaben showing a 25% increased risk and combined parabens showing a 55% increased risk for this tumor subtype. These findings suggest that parabens—ubiquitous preservatives in personal care products—may contribute to breast cancer development through epigenetic mechanisms, particularly in women with pre-existing DNA methylation abnormalities, identifying a potentially vulnerable subpopulation and a specific molecular pathway through which these chemicals may promote carcinogenesis.
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
Biomed Pharmacother
A review of endocrine-disrupting chemicals (EDCs)—ubiquitous substances found in cosmetics, plastic food packaging, and medicines that enter the body through skin, digestive, or respiratory routes—examined their toxic effects even at microgram doses on the female reproductive system and genetic mechanisms. EDCs disrupt endocrine functions by binding to steroid hormone receptors, interfering with hormone synthesis and secretion, and modulating epigenetic processes that can lead to gene expression disturbances, contributing to neoplastic diseases, neurological disorders, circulatory problems, and reproductive dysfunction. Prenatal exposure can affect offspring development, with particular impacts on ovarian function leading to reduced fertility through disturbances in steroid receptor function, steroidogenesis, and gametogenesis. The review emphasizes that despite widespread exposure to these chemicals in everyday products, continued research is needed to fully understand their effects on the female reproductive system and potential transgenerational impacts mediated through epigenetic mechanisms.
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
Molecules
A review of endocrine-disrupting compounds (EDCs) in drinking water examines this emerging class of environmental contaminants—ranging from naturally occurring to synthetic compounds—that exist as complex mixtures at trace levels but can cause adverse health effects even at low concentrations. The review covers the perceived and actual health risks of EDC exposure through water ingestion (a major human exposure route), regulatory efforts to limit contamination, and analytical methods including advanced sample preparation, instrumentation, and bioassays for multiclass EDC identification and quantitation. Given that human exposure to EDCs via drinking water poses significant health concerns even at trace concentrations, the ability to detect and evaluate EDC contamination with high sensitivity and accuracy is critically important for protecting public health and informing regulatory policy.
2022
Ecotoxicology
An experimental study using wild-type and thyroid hormone receptor alpha knockout (thrαa⁻/⁻) zebrafish embryos/larvae found that avobenzone and octinoxate—organic UV filters commonly used in sunscreens and widely detected in water—disrupt the thyroid endocrine system, with significantly lower survival rates in thrαa⁻/⁻ fish exposed to ≥3 μM of either compound, indicating the thyroid hormone receptor plays a crucial role in their toxicity. Avobenzone exposure increased the T3:T4 ratio with upregulation of the deio2 gene, while both chemicals decreased T4 levels and triggered compensatory upregulation of hypothalamus and pituitary genes (trh, tshβ, tshr), indicating feedback mechanisms attempting to maintain hormonal homeostasis. These findings demonstrate that two widely used sunscreen ingredients act as thyroid endocrine disruptors by affecting thyroid hormone receptors and disrupting the hypothalamus-pituitary-thyroid (HPT) axis, raising concerns about aquatic environmental contamination from these chemicals and potential impacts on thyroid function in exposed organisms, including implications for human exposure through water and dermal application.
2021
Environ Res
Biodegradable polymers are emerging as a promising solution for removing endocrine-disrupting chemicals (EDCs) from wastewater. EDC’s, found in pharmaceuticals, pesticides, and personal care products pose serious health risks, impacting the endocrine system and disrupting reproductive health. Traditional water treatments often fail to fully remove EDCs. Biodegradable polymers, with strong adsorptive properties, offer a sustainable and effective method, helping to minimize EDC exposure and protect human and environmental health.
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.
2019
Environ Int
A systematic review of 342 peer-reviewed articles covering 202 unique chemicals used in consumer products analyzed exposure pathways, functional uses, product applications, exposure routes, and associated health risks, finding that phthalates, bisphenol-A, and polybrominated diphenyl ethers were the most frequently studied chemicals, with frequently reported uses including plasticizers, polymers/monomers, and flame retardants in food contact materials, personal care products, cosmetics, furniture, flooring, and electronics. The analysis revealed that publication volume on chemicals tends to surge following major regulatory changes or exposure incidents rather than before market introduction, indicating a reactive rather than proactive approach to chemical safety assessment. These findings highlight the critical gap between the increasingly diverse array of chemicals used in consumer products and our lagging understanding of their exposure pathways and human health risks, emphasizing the urgent need to develop capacity and mechanisms for identifying health risks prior to chemical releases rather than after exposure incidents or regulatory action, to enable preventive rather than reactive public health protection.
2018
Mol Cell Endocrinol
A review examining parabens—one of the most widely used preservatives worldwide in foods, cosmetics, and pharmaceuticals—found that these easily absorbed chemicals are classified as endocrine-disrupting chemicals (EDCs) that can disrupt hormonal homeostasis and cause multidirectional health implications affecting body fitness and function. The review summarizes current literature on paraben properties, occurrence, metabolism, and particularly their influence on the human endocrine system, emphasizing the importance of assessing their safety given their ubiquitous use and absorption. With parabens now recognized as EDCs capable of disrupting endocrine function, the authors highlight concerns about widespread population exposure through everyday consumer products and the need for precise assessment of their health impacts on human physiology.
2016
Cancer Med
A review examining breast cancer disparities in African American women—who now have similar incidence rates to non-Hispanic White women but significantly higher mortality—found growing evidence linking hair product use to breast cancer risk through exposure to estrogen-like chemicals and endocrine-disrupting chemicals (EDCs). The review identified three converging lines of evidence: environmental estrogen and EDC exposures increase breast cancer risk, these chemicals are present in personal care products including hair products, and certain hair products used disproportionately by African American women may contribute to elevated breast cancer risk in this population. The findings highlight an understudied environmental justice issue and call for additional research using community-collaborative approaches to better understand how culturally specific beauty practices may contribute to health disparities, representing what researchers term the potential “cost of beauty.”
2012
Environ Health Perspect
This study analyzed 213 everyday products, including cosmetics, cleaners, and personal care items, for endocrine-disrupting chemicals (EDCs) and asthma-related compounds. Testing revealed 55 chemicals, with fragranced products and sunscreens containing the highest levels. Vinyl products were also found to contain significant amounts of bis(2-ethylhexyl) phthalate (DEHP), a known EDC. Many harmful chemicals were not listed on product labels, limiting consumer ability to avoid them. These results highlight the presence of potentially harmful chemicals in commonly used products, raising concerns about their widespread use in household and personal care items.
2024
Endocrinology
The researchers in this study aimed to identify certain environmental chemicals that may contribute to the trend of earlier puberty onset in females by stimulating 2 key receptors. These receptors being investigated are kisseptin and gonadotropin-releasing hormone receptors in the hypothalamus which are highly involved in triggering puberty in females. The study identified musk ambrette, a synthetic fragrance commonly used in personal care products like perfumes, soaps, and detergents, as an agonist of KISS1R and triggered the release of Gnrh1, which could be a cause of early puberty as well. Additionally, agonists of GnRHR were investigated and found to be mainly from a group of cholinergic agonists with structures similar to methacholine. These agonists upregulated Fos, Jun, and Egr1 genes in the downstream pathway of GnRHR. Agonists such as musk ambrette and those that stimulate GnRHR may therefore contribute to early puberty due to their stimulation of key pathways involved in puberty.
2022
Int J Pediatr Adolesc Med
A cross-sectional study of 556 U.S. children (mean age 6.33 years) found no association between regular exposure to lavender or tea tree essential oils and endocrine disruption, with prevalence of endocrine disorders (0.016) and rates of precocious puberty, delayed puberty, growth hormone deficiency, and hypothyroidism all consistent with population norms, and no cases of prepubertal gynecomastia identified in either exposed or unexposed groups (risk ratio = 2.796; 95% CI: 0.352-22.163, p = .458). This first epidemiological study addressing concerns about these popular essential oils in pediatric personal care products found that children regularly exposed to lavender or tea tree essential oils experienced the same risk of endocrine disorders as unexposed children, providing no evidence for the previously proposed link between these oils and pediatric endocrine disruption.