The prevalence of neurological and neurodevelopmental conditions such as autism-spectrum and attention-deficit disorders has increased over the past decade, leading experts to suggest that environmental factors may be at play in addition to better diagnosis. A new study from Case Western Reserve University School of Medicine has found that some common environmental chemicals, particularly organophosphate flame retardants and quaternary ammonium compounds, damage oligodendrocytes, specialized brain cells responsible for generating myelin sheaths on nerve cells. This damage could help explain the rise in neurodevelopmental and neurological conditions, including multiple sclerosis.
Oligodendrocyte production begins during fetal development, with the majority of these cells being made during the first 2 years of life. Mature oligodendrocytes play a crucial role in manufacturing and maintaining the myelin sheaths that protect nerve cells and facilitate the transmission of nerve impulses. The researchers generated oligodendrocyte progenitor cells from mouse pluripotent stem cells and exposed them to 1,823 different chemicals to assess their impact on cell development. They found that organophosphate flame retardants inhibited the generation of oligodendrocytes from progenitor cells, while quaternary ammonium compounds caused cell death.
Further testing on mouse brains revealed that quaternary ammonium compounds could cross the blood-brain barrier and accumulate in brain tissue, leading to the loss of oligodendrocyte cells in various parts of the brain. The researchers also observed a significant reduction in mature oligodendrocytes and progenitor cells when a human cortical organoid model was exposed to the organophosphate flame retardant TDCIPP. The findings suggest that these chemicals could prevent oligodendrocyte maturation and potentially impact neurodevelopment in humans.
Analysis of data from the CDC’s National Health and Nutrition Examination Survey showed a positive association between organophosphate flame retardant exposure, as measured by the metabolite BDCIPP in children’s urine, and special educational needs or motor dysfunction. This suggests that reducing exposure to these chemicals, which are commonly found in personal-care products and household items, may be beneficial for overall neurodevelopment. Alternative disinfectants, such as caprylic acid, citric acid, lactic acid, hydrogen peroxide, and alcohol, should be considered to minimize exposure to quaternary ammonium compounds.
While the study provides valuable insights into the potential impact of environmental chemicals on oligodendrocytes and neurodevelopment, caution is advised in interpreting the findings. More epidemiological and fundamental research is needed to establish a direct link between these compounds and neurodevelopmental conditions like autism and multiple sclerosis. Pregnant women, children, and individuals with chronic diseases should take precautions to reduce exposure to harmful chemicals and consider using safer alternatives for disinfection and personal care. Further studies are warranted to validate the findings and explore the broader implications for human health.