09
Jan
Multiple Studies Link Adverse Effects on Female Reproductive Health with Endocrine Disrupting Chemical Exposure
(Beyond Pesticides, January 9, 2025) In a Frontiers in Public Health review article, researchers report on the wide body of science connecting adverse effects to female reproductive system, such as infertility, with exposure to endocrine-disrupting chemicals (EDCs). The authors call these effects a significant concern for public health, as there has been growing evidence of EDCs with risk factors for decreased fertility. Â
Infertility “affects a substantial proportion of the world’s population with approximately one in six people affected,†the researchers note. They continue: “Over the last 70 years, global fertility has been constantly in decline due to behavioral and societal changes… [E]merging evidence has shown that infertility incidence is linked to exposure to environmental factors such as tobacco, alcohol, and a wide range of endocrine-disrupting chemicals (EDCs) including pesticides (chlorpyrifos, glyphosate, dichlorodiphenyltrichloroethane [DDT] and methoxychlor), phthalates, polychlorinated biphenyls (PCB), dioxins, and bisphenols.â€Â
In this review, over 100 studies are summarized to showcase the link between EDC exposure and reproductive effects in women, including infertility and related diseases such as endometriosis, premature ovarian insufficiency (POI), and endocrine axis dysregulation. The studies included investigating the “mechanisms by which EDCs cause ovarian aging, folliculogenesis, decrease of oocyte quality, ovulation disorders, development and receptivity of endometrium, endometriosis, fetal development abnormalities, and epigenetics modulation,†the authors state.Â
Results from these studies show exposure to EDCs can lead to infertility and reproductive effects through various mechanisms. Altering the balance of any endocrines that impact reproduction can change fertilization outcomes. The researchers say, “One of the most described mechanisms is when EDCs mimic hormones such as estrogen and bind to their receptors leading to hormonal disruption.†This can alter the ovulation process.Â
The authors note: “Additionally, oxidative stress in ovarian tissues, that damages cells and impairs their function, is induced by several EDCs. Thus, EDCs disrupt the development of ovarian follicles and can be directly toxic to gametes, decreasing their numbers and quality… These mechanisms all together lead to abnormalities such as blocked Fallopian tubes, ovarian disorder, uterine disorders, failure to produce an oocyte, abnormal oocyte quality, local inflammation, and endocrine disorders in women.â€Â
Among the studies, findings include:Â
- Pesticide exposure in agricultural regions is “linked with fertility decline, poor IVF outcomes, such as POI, polycystic ovarian syndrome, and endometriosis.â€Â
- EDCs “influence the fertilization process in women by different means. If the oocyte cannot mature, due to an early ovarian aging, impaired folliculogenesis or cannot be expelled due to anovulation, the fertilization cannot occur. Moreover, if the released oocyte quality is impaired due to altered maturation, the fertilization can occur, but oocytes with cytoplasmic anomalies will lead to significantly lower pregnancy rates.â€Â
- Atrazine, a widely used herbicide, is “a common environmental contaminant known with EDC effect and reproductive toxicity.â€Â
- Endosulfan exposure “reduces the expression of the primary endometrial markers of receptivity (such as MUC1, HOXA10, Inn and E-cadherin) and affects the normal endometrial receptivity impairing the adhesion and the implantation process of the blastocyst.â€Â
- Placenta anomalies, which lead to pre-eclampsia, abnormal fetal development, miscarriage, and placental disruption, can occur with EDC exposure as the “placenta is vulnerable to endocrine disruption due to a large presence of hormone receptors and a lack of enzymatic machinery to guard against EDCs.†This study also finds that organochlorine pesticides “impair placenta ability to produce and release hormones and enzymes, transport nutrients, or produce waste. They contribute to preterm birth by disrupting the balance between P4 and E2 during pregnancy.â€Â
- Epigenetic patterns can be deregulated “by altering methylation enzymes (DNMTs) and DNA demethylation enzymes (e.g., ten-eleven translocation TET proteins)†from EDC exposure.Â
- DDT is also “linked to impaired fetal growth, and metabolic dysfunction which can possibly lead to miscarriage.â€Â
- “[A[lmost all major classes of EDCs can target the estrogen pathways as many EDCs display estrogenic activity, and can affect both genetic and epigenetic levels.†(See studies here, here, and here.)Â
As the researchers conclude from these results, “The impact of EDCs extends beyond lowering the rate of a successful pregnancy and increasing the risk of miscarriage in women; they also impair the future reproductive health of the fetus.†Infants and children are at a disproportionate risk with pesticide exposure as this is a critical developmental window. Â
Chemical exposure during this window can lead to lasting health effects into adulthood. The authors note that “the reach of EDCs to the embryo by transplacental transfer can lead to genome alteration during embryonic germ cell precursors reprogramming… These epigenetic modulations by EDCs suggest serious long-term effects on human reproductive health and fertility decline.†Studies find that EDC exposure within the “first 1,000 days of life increases the risk of developing pathologies in adulthood.†(See studies here and here.)Â
As Beyond Pesticides has previously reported, the National Institutes of Environmental Health Sciences explains endocrine disruptors this way: “Endocrine-disrupting chemicals (EDCs) are natural or human-made chemicals that may mimic, block, or interfere with the body’s hormones, which are part of the endocrine system. These chemicals are associated with a wide array of health issues. . . Endocrine glands, distributed throughout the body, produce the hormones that act as signaling molecules after release into the circulatory system. The human body is dependent on hormones for a healthy endocrine system, which controls many biological processes like normal growth, fertility, and reproduction.â€Â
With the ubiquitous use of EDCs, exposure to the general population occurs through contact with contaminated food, soil, and air. Studies continue to link EDCs with cancer, cardiovascular risk, behavioral disorders, autoimmune abnormalities, and reproductive disorders (see here, here, here, and here). These effects are seen in higher rates in areas with increased EDC production and pesticide usage, with chemical industry workers and farmworkers having the most exposure.Â
To abate these impacts, especially in areas with agricultural EDC exposure, organic land management can be implemented. In adopting this holistic solution, farmworker exposure is reduced, and food crops are safer and healthier to eat. Organic agriculture provides both health and environmental benefits, and mitigates the ongoing climate and biodiversity crises.Â
To learn more about endocrine disruption, listen to keynote speaker Tracey Woodruff, PhD from the second session of the 41st National Forum Series — Imperatives for a Sustainable Future. Additional Daily News coverage can also be found here.Â
All unattributed positions and opinions in this piece are those of Beyond Pesticides. Â
Source:Â
Tricotteaux-Zarqaoui, S. et al. (2024) Endocrine disruptor chemicals exposure and female fertility declining: from pathophysiology to epigenetic risks, Frontiers in Public Health. Available at: https://pmc.ncbi.nlm.nih.gov/articles/PMC11672798/.Â
