25
Mar
Over 100 Chemicals Detectable in Pregnant Women, Including 98 “New” or Unknown Compounds
(Beyond Pesticides, March 25, 2021) A new University of California San Francisco (UCSF) study, published in Environmental Science & Technology, finds over 100 chemicals present in U.S. pregnant women’s blood and umbilical cord samples. This discovery ignites concerns over prenatal exposure to chemicals from consumer and industrial products and sources. Furthermore, 89 percent of these chemical contaminants are unknown sources and uses, lacking adequate information, or are not previously detectable in humans. The National Health and Nutrition Examination Survey (NHANES) finds U.S. pregnant women experience frequent exposure to environmental pollutants that pose serious health risks to both mother and newborn. Many known environmental pollutants (i.e., heavy metals, polychlorinated biphenyl, and pesticides) are chemicals that can move from the mother to the developing fetus at higher exposure rates. Hence, prenatal exposure to these chemicals may increase the prevalence of birth-related health consequences like natal abnormalities and learning/developmental disabilities.
Current chemical biomonitoring methods only analyze a targeted few hundred chemicals—a small portion of the over 8000 chemicals the U.S. manufactures and imports. However, this study employs new technology that identifies a more comprehensive range of industrial chemicals. Therefore, research like this is essential for future technological development that can identify likely omnipresent chemical exposures for future health risks. UCSF scientists note, “Our study is an important methodological approach for future studies that will aim at characterizing the presence and toxicity of newly detected chemical compounds in the human body and assess the fate of these compounds in various human tissues, particularly between the mother and the fetus. Understanding these exposures and how they may contribute to adverse health outcomes is crucial in characterizing the human exposome and eventually preventing the development of disease.”
This research represents a new proof-of-concept study that develops a suspect screening technique to characterize chemicals. The method combines non-target data from high-resolution mass spectrometry (HRMS) with target data from an industrial chemical database of approximately 3500 high-production volume chemicals. Researchers assessed maternal and umbilical cord blood samples for differences in chemical presence and enrichment. Lastly, chemical identification compared the structure of chemicals found in blood samples to those within the industrial chemical database.
The study detects 109 chemicals within blood samples of mothers and newborns, including pesticides, plasticizers, compounds in cosmetics and consumer products, pharmaceuticals, flame retardants, and per- and polyfluoroalkyl substances (PFAS) compounds. Of the 109 chemicals, 55 lack preceding reports on their presence in humans, and 42 chemical compounds have little to no information regarding chemical classification, use, and source of contamination.
Environmental contaminants like pesticides are ubiquitous in the environment, with 90 percent of Americans having at least one pesticide compound in their body. The presence of pesticides in the body has implications for human health, especially during vulnerable life stages like childhood, puberty, pregnancy, and old age. Pesticide exposure during pregnancy is of specific concern as health effects for all life stages can be long-lasting. Just as nutrients are transferable between mother and fetus, so are chemical contaminants. Studies find pesticide compounds present in the mother’s blood can transfer to the fetus via the umbilical cord. Therefore, pesticide exposure during pregnancy has implications for both mother and child’s health. Many studies indicate prenatal and early-life exposure to environmental toxins increases susceptibility to disease. A 2020 study finds the first few weeks of pregnancy are the most vulnerable periods during which prenatal exposure to pesticides can increase the risk of the rare fetal disorder holoprosencephaly. This disorder prevents the embryonic forebrain from developing into two separate hemispheres. Moreover, women living near agricultural areas experience higher exposure rates that increase the risk of birthing a baby with abnormalities. Some of these birth abnormalities include acute lymphoblastic leukemia and Attention-Deficit/Hyperactivity Disorder (ADHD). Even regular household pesticide use during pregnancy can increase nephroblastoma (kidney cancer) and brain tumor risk in children.
Pesticide exposure not only poses a risk to mothers and their offspring but also to future generations. Studies find that although glyphosate (herbicide) exposure has a negligible impact on pregnant rats’ health, incidents of prostate, ovarian, and kidney cancer increase in the two subsequent generations. However, chemical exposure encompasses more than just current-use, toxic pesticides, like glyphosate. Many long-banned pesticides their metabolites still impart adverse effects on human health, indirectly. Researchers at Drexel University report that higher levels of some organochlorine compounds, like DDT, during pregnancy are associated with autism spectrum disorder (ASD) and intellectual disability (ID). Many organochlorine compounds have long been banned in the U.S., underscoring how pervasive and persistent these chemicals are and their continued impact on human health. Not only are these compounds readily present in soil and water samples, but also arctic ice. Therefore, the accompanying glacial melt from the climate crisis will only increase chemical bioavailability in the environment. The increasing ubiquity of pesticides is concerning as current measures safeguarding against pesticide use do not adequately detect and assess total environmental chemical contaminants.
This UCSF study highlights the first successful evaluation of human blood samples using a comprehensive database, screening for industrial chemicals rather than chemicals commonly identified in human samples. Furthermore, the transfer of chemicals from mother to newborn may disrupt epigenetic mechanisms responsible for normal cell function and development. The effects of epigenetic dysfunction can impact individuals for multiple generations. Although the study detects the presents of new chemicals in the body, researchers mention these chemicals may have already been present. Researchers suggest differences in requirements for disclosing chemical uses can explain the detection of chemicals with unknown applications and sources. Furthermore, previous chemical screening research demonstrates only 30.5 percent of chemicals in consumer/industrial products appear on lists of classifiable chemical uses. Co-lead author Dimitri Panagopoulos Abrahamsson, Ph.D., states, “These new technologies are promising in enabling us to identify more chemicals in people, but our study findings also make clear that chemical manufacturers need to provide analytical standards so that we can confirm the presence of chemicals and evaluate their toxicity.”
The study results indicate these newly detectable chemicals lack adequate chemical classification and assessment from environmental health scientists and regulators. Therefore, global leaders need to investigate potential technologies which can help identify unknown or previously undetectable chemical contaminants to safeguard human health from exposure effects. Study co-author, UCSF professor Tracey J. Woodruff, Ph.D., concludes, “It’s very concerning that we are unable to identify the uses or sources of so many of these chemicals.[…]EPA must do a better job of requiring the chemical industry to standardize its reporting of chemical compounds and uses. And they need to use their authority to ensure that we have adequate information to evaluate potential health harms and remove chemicals from the market that pose a risk.”
There a strong consensus among pediatricians that pregnant mothers and young children should avoid pesticide exposure during critical development periods. Therefore, policies should enforce stricter pesticide regulations and increase research on the long-term impacts of pesticide exposure. Beyond Pesticides tracks the most recent studies related to pesticide exposure through our Pesticide Induced Diseases Database (PIDD). This database supports the clear need for strategic action to shift away from pesticide dependency. For more information on the multiple harms pesticides can cause, see PIDD pages on Birth/Fetal Effects, Learning/Developmental Disorders, Endocrine Disruption, Cancer, Body Burdens, and other diseases. To learn more about how the lack of adequate pesticide regulations can adversely affect human and environmental health, see Beyond Pesticides’ Pesticides and You article “Highly Destructive Pesticide Effects Unregulated.”
One way to reduce human and environmental contamination from pesticides is buying, growing, and supporting organic. Numerous studies find that levels of pesticide metabolites in urine drop greatly when switching to an all-organic diet. Furthermore, given the wide availability of non-pesticidal alternative strategies, families and agro-industry workers alike can apply these methods to promote a safe and healthy environment, especially among chemically vulnerable individuals. For more information on how organic is the right choice for both consumers and the farmworkers that grow our food, see Beyond Pesticides webpage, Health Benefits of Organic Agriculture.
All unattributed positions and opinions in this piece are those of Beyond Pesticides.
Source: Environmental Science & Technology, SciTechDaily – UCSF
