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Aug
Childhood Development Hurt By Preconception Exposure to Environmental Stressors
(Beyond Pesticides, August 7, 2015) Parental exposure to environmental stressors, such as pesticides, before a child is conceived can alter the way genes are expressed in the mother and father, ultimately harming the child’s health when those genes are passed down to the next generation, according to an article published in the Endocrine Society’s journal Endocrinology.
“In regard to environmental stressors, a good start lasts a lifetime,” said Philippe Grandjean, M.D., Ph.D. Dr. Grandjean is Professor of Environmental Medicine at the University of Southern Denmark and Adjunct Professor of Environmental Health at the Harvard University’s T.H. Chan School of Public Health and an author of the article. “Unfortunately, current testing paradigms do not properly assess the impact of risk factors during vulnerable exposure windows. Without new policies and guidelines, we cannot have a universal healthy start for children.”
The article, titled Life-Long Implications of Developmental Exposure to Environmental Stressors: New Perspectives, summarizes the newest science and key insights from the 4th Conference on Prenatal Programming and Toxicity (PPTOX IV). More than 300 people attended the event in Boston, MA in October 2014. The meeting featured poster presentations discussing the impact of chemical, physical, and biological environmental stressors on the interconnected relationships of endocrine, immune, and nervous systems.
According to a press release from the Endocrine Society, “Exposure to environmental stressors such as endocrine-disrupting chemicals, psychological stress and malnutrition may result in disadvantageous epigenetic “reprogramming” that can echo through multiple generations.” Epigenetics is a relatively new field of genetics that studies the effects environmental factors have on gene expression rather than changes to the underlying DNA sequence. These changes to gene expression can be passed on to offspring. The press release continues, “When these stressors disrupt early developmental processes, they may cause changes in cellular gene expression, cell numbers or locations of cells that persist and lead to increased risk of cognitive disorders, obesity, diabetes and metabolic diseases later in life.” While previous research on environmental stressors focuses primarily on exposures during pregnancy and early childhood and their effects on the health of offspring throughout their lifetime, presentations at the PPTOX IV emphasized that the preconception period in both males and females is also a sensitive developmental window.
Research regarding the effects of pesticides across generations is extensive. Research from Michael Skinner, Ph.D., of Washington State University, finds that exposure to pesticides may have devastating consequences for future generations. The study, Pesticide Methoxychlor Promotes the Epigenetic Transgenerational Inheritance of Adult-Onset Disease through the Female Germline, published in PLOS ONE in 2014, concluded that gestating rats exposed to the pesticide methoxychlor develop a higher incidence of kidney disease, ovary disease and obesity in offspring spanning three generations. The incidence of multiple diseases increased in the third generation or “great-grandchildren.” In 2013, scientists at Washington State University, in a laboratory study titled Ancestral dichlorodiphenyltrichloroethane (DDT) exposure promotes epigenetic transgenerational inheritance of obesity, determined that exposure to the insecticide DDT ””banned in the U.S. since 1972, but is extremely persistent in the environment and is still used today in developing countries for malaria abatement programs”” impacts multiple generations, ultimately contributing to obesity three generations down the line.
Researchers note that regulatory agencies currently may not appropriately take into account the potential for non-linear effects of certain environmental chemicals, meaning that exposure to low levels of a chemical can have different adverse effects than what could be experienced at exposure to higher levels of the same chemical. EPA uses a human health risk assessment, which is a process used to estimate the nature and probability of adverse health effects in humans who may be exposed to chemicals in contaminated environmental areas. EPA’s risk assessment fails to look at chemical mixtures, synergistic effects, certain health endpoints (such as endocrine disruption), disproportionate effects to vulnerable population groups, and regular noncompliance with product label directions. These deficiencies contribute to its severe limitations in defining real world poisoning, as captured by epidemiologic studies in Beyond Pesticides’ Pesticide-Induced Diseases Database.
For more information on this subject, see a talk, Epigenetic Transgenerational Actions of Endocrine Disruptors on Reproduction and Disease, delivered by Michael Skinner, Ph.D.at Beyond Pesticides’ 2014 National Pesticide Forum.
While EPA totes the risk assessment process as necessary and crucial for decision-making about pesticides, Beyond Pesticides advocates for a regulatory approach that prohibits high hazard chemical use and requires alternative assessments. We suggest an approach that rejects uses and exposures deemed acceptable under risk assessment calculations, and instead focuses on safer alternatives that are proven effective, such as organic agriculture. By taking a more enlightened policy approach that eschews toxic pesticide use in favor of widely available alternative products and practices, EPA can promote a path to sustainable organic farming, a restored environment, and healthier communities.
Source: Endocrine Society
All unattributed positions and opinions in this piece are those of Beyond Pesticides
