(Beyond Pesticides, August 12, 2022) Gestational (during pregnancy) exposure to endocrine disrupting chemicals (EDCs) like pesticides, per- and polyfluoroalkyl substances (PFAS), among others, may increase pediatric (child) liver injury and non-alcoholic fatty liver disease (NAFLD) risk, according to a¬†study published in¬†Environmental Health. Past¬†studies¬†associate exposure to EDCs with increased susceptibility to adverse health effects during critical fetal and childhood developmental periods. The World Health Organization (WHO),¬†European Union (EU), and endocrine disruptor expert (deceased) Theo Colborn, Ph.D., classify over 55 to 177 chemical compounds as endocrine disruptors, including various¬†household products¬†like detergents, disinfectants, plastics, and pesticides. Endocrine disruption can lead to several¬†health problems, including hormone-related cancer development (i.e., thyroid, breast, ovarian, prostate, testicular), reproductive dysfunction, and¬†diabetes/obesity that can span generations. Because EDCs are ubiquitous because they are found in many products, studies report that these toxic chemical compounds are detectable in infants, children, and pregnant women. Furthermore, pregnant women can readily transfer compounds to the developing fetus through the placenta. Therefore, it is essential to understand the mechanism behind how harmful chemical exposure induces endocrine disruption during critical developmental periods. Researchers note, ‚ÄúConsidering the lack of studies on endocrine disruption and pediatric NAFLD, research like this highlights the need to understand the underlying mechanisms that contribute to growing endocrine disease incidents.‚ÄĚ
Researchers used the Human Early-Life Exposome population-based cohort study involving 1108 mother and child pairs across 6 European countries to determine how prenatal chemical exposure impacts liver health. The study examined the effect of three organochlorine pesticides, four organophosphate pesticides, five polychlorinated biphenyls, two polybrominated diphenyl ethers (PBDEs), three phenols, four parabens, ten phthalates, five PFAS, and nine metals on the liver. Using the Bayesian weighted quartile sum and machine regression, researchers compare the associations between liver injury (or cytokeratin 18 [CK-18]) levels and mixtures of EDC groups in maternal blood and urine samples. The results confirm that all EDCs increase the odds of liver injury or liver cell apoptosis, except phthalates and phenols, due to high molecular weight.
Organochlorine compounds (OCs), such as organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs), are well-known persistent organic pollutants (POPs). Banned by the Stockholm Convention treaty in 2001 because of persistence, toxicity, and adverse effects on environmental and biological health, these pollutants have a global distribution, with evaporation and precipitation facilitating long-range atmospheric transport, deposition, and bioaccumulation of hazardous chemicals in the environment. Organochlorines¬†remain in the environment for decades‚ÄĒpossibly centuries, post-final application, as OCPs have higher chemical stability and gradual attenuation. However, these chemicals have profound adverse impacts on human health, especially on the endocrine system. Although some, but not all manufacturing and use of specific OCPs have declined in the U.S., OCPs remain a global issue, as much of the developing world still report usage. However, organophosphate insecticides continue to have global uses, despite being associated with neurotoxicity, learning and developmental disorder, and immune/hormone disruption, especially among children.
Per- and polyfluoroalkyl substances are a group of¬†over 9,000¬†human-made chemicals present in various consumer products that people use daily. Although some PFAS compound manufacturing has ceased, these chemicals last forever in the environment as their chemical structure makes them resistant to breakdown. Thus, PFAS contamination is significantly underrepresented and much more perverse that previously thought, polluting storage and transportation containers, food and water resources, and other chemical products. For instance, independent research by Public Employees for Environmental Responsibility PEER) finds that widely used insecticide Anvil 10+10 contains high levels of PFAS from contamination. Although EPA¬†does not regulate¬†PFAS in pesticide formulas, the agency lists these substances in the inert ingredient database. However, product labels do not require disclosure of contaminants fundamental for pesticide products through the manufacturing or packaging process. Contamination of a toxic product with other harmful chemicals is glaringly problematic for public health and the environment. Moreover, PFAS chemical residues are persistent in food and drinking water, with over¬†six million¬†U.S. residents regularly encountering drinking water with PFAS levels above the U.S. Environmental Protection Agency health advisory of 70 ng/L. Therefore, PFAS are detectable in almost all of the U.S. population‚ÄĒdisproportionately afflicting people of color communities‚ÄĒand have implications for human health.¬†
Since EPA fails to regulate PFAS and other underrepresented EDCs, the depth and scope of the contamination may be difficult to assess. The International Agency for Research on Cancer (IARC) and the U.S. National Toxicology Program (NTP) classify many EDCs as¬†possible carcinogens¬†based on epidemiological studies identifying instances of kidney, ovarian, testicular, prostate, and thyroid cancer, as well as non-Hodgkin lymphoma and childhood leukemia. Considering EDCs like PFAS are anatomically similar to fatty acids and may impair fatty acid metabolism and lipid synthesis in the liver, there may be an underestimation of toxicity effects on human, animal, and environmental health.
The study demonstrates an increase in pediatric NAFLD disease incidence among children exposed to EDCs during prenatal development. This study adds to the growing body of research demonstrating exposure EDCs during the sensitive pregnancy period may increase the risk for adverse health effects. Particularly, researchers attribute endocrine-induced liver injury and liver cell death during childhood to the growing epidemic of pediatric NAFLD. Similar to this study, mixtures of various EDCs can induce synergism that may increase pesticide toxicity or result in changes to its characteristics, like penetrative abilities. Endocrine disruption can promote obesity, insulin resistance, type 2 diabetes, and elevated liver enzyme, that all have an¬†association with NAFLD. Therefore, gestation represents a window of increased vulnerability to EDC exposure. The researchers conclude, ‚ÄúThese results advance the current limited understanding of pediatric NAFLD etiology and support the need for more investigation in this area. Our findings can inform more efficient early-life prevention and intervention strategies to address the current NAFLD epidemic.‚ÄĚ
The endocrine disrupting effects of pesticides and other chemicals have extensive documentation. Beyond Pesticides tracks the most recent studies on pesticide exposure through our¬†Pesticide-Induced Diseases Database (PIDD). This database supports the clear need for strategic action to shift from pesticide dependency. For more information on the multiple harms that pesticides can cause, see PIDD pages on¬†Endocrine Disruption¬†and other diseases.
One way to reduce human and environmental contamination from pesticides is to¬†buy,¬†grow, and¬†support organic. Numerous studies find that¬†levels of pesticides in urine significantly drop¬†when switching to an all-organic diet. Furthermore, given the¬†wide availability of non-pesticidal alternative strategies, families, from rural to urban, can apply these methods to promote a safe and healthy environment, especially among chemically vulnerable individuals or those with health conditions. For more information on why organic is the right choice for consumers and the farmworkers that grow our food, see the Beyond Pesticides webpage,¬†Health Benefits of Organic Agriculture.
All unattributed positions and opinions in this piece are those of Beyond Pesticides.