Oligodendrocyte production begins during fetal development, with the majority of these cells being made during the first 2 years of life. Mature oligodendrocytes are responsible for manufacturing and maintaining the myelin sheathsTrusted Source that protect nerve cells and speed up the transmission of nerve impulses.

“Oligodendrocytes are a type of glial cells in the brain that can regulate various vital physiological functions, including myelin sheath production. Hence, studying how environmental chemicals regulate these cells is important and critical to understanding various disease etiology,” Dr. Sarkar told Medical News Today.

In this study, the researchers generated oligodendrocyte progenitor cells (OPCs) from mouse pluripotent stem cellsTrusted Source (cells that can develop into all cells in the body). They then exposed these cells to 1,823 different chemicals to assess whether these affected their ability to develop into oligodendrocytes.

More than 80% of the chemicals had no effect on oligodendrocyte development. However, 292 were cytotoxicTrusted Source — killed the oligodendrocytes — and 47 inhibited oligodendrocyte generation.

Chemicals from 2 groups had an adverse effect on oligodendrocytes. Organophosphate flame retardants, which are commonly found in electronics and furniture, inhibited the generation of oligodendrocytes from OPCs. Quaternary ammonium compounds, which are in many personal-care products and disinfectants, killed the cells.

The researchers also tested whether the chemicals had a similar effect on developing oligodendrocytes in mouse brains. They found that quaternary ammonium compounds (QACs), when given orally to mice, successfully crossed the blood-brain barrier and built up in brain tissue.

The mice lost oligodendrocyte cells in many areas of the brain, showing that these chemicals may pose a risk to the developing brain.

Following the mouse findings, they tested the organophosphate flame retardant tris (1,3-dichloro-2-propyl) phosphate (TDCIPP) on a human cortical organoid model. The chemical reduced the numbers of mature oligodendrocytes by 70%, and the OPCs by 30%, suggesting that it was preventing the cells from maturing.

People may come into contact with these chemicals daily, as Dr. Jagdish Khubchandani, professor of public health at New Mexico State University, who was not involved in the study, explained to MNT:

“The findings of this study suggest that we did not come up with good alternatives for earlier classes of chemicals (e.g. PBDEs). While the study uses a mouse model and lab cultures, there could be profound human health implications,” he added.

The researchers then assessed the levels of organophosphates that children aged 3-11 were exposed to using datasets from the National Health and Nutrition Examination Survey (NHANES)Trusted Source of the CDC, which recorded levels of the metabolite bis (1,3-dichloro-2-propy) phosphate (BDCIPP) in their urine.

They found that children with the highest levels of BDCIPP were 2–6 times more likely to have special educational needs or motor dysfunction than those with the lowest levels.

They suggest this is strong evidence of a positive association between organophosphate flame retardant exposure and abnormal neurodevelopment.