Chemicals commonly found in everyday household items such as disinfectants, glues, and furniture textiles might potentially harm brain development, according to a recent study. The research, conducted using human cell cultures and mice, identified two classes of chemicals that either killed or hindered the maturation of oligodendrocytes – cells that provide support to neurons by forming an insulating covering, enabling efficient transmission of brain signals.
The study, led by molecular biologist Erin Cohn from Case Western Reserve University in Ohio, examined 1,823 compounds of unknown toxicity found in the environment. They discovered that quaternary compounds, used in disinfectant sprays, wipes, and personal care products, as well as organophosphates found in textiles and household items, posed potential risks to brain development.
Quaternary compounds are commonly used to eliminate bacteria and viruses in disinfectants and personal care products like toothpaste and mouthwash. The study revealed that these compounds, if used incorrectly or in poorly ventilated spaces, might be ingested or inhaled, potentially causing harm. On the other hand, organophosphates, serving as flame retardants in textiles, glues, and household items such as furniture and electronics, were found to off-gas into the air, making it possible for them to be absorbed through the skin and potentially enter the brain.
Furthermore, the study conducted on mice demonstrated that pups exposed to quaternary compounds had detectable levels of these chemicals in their brain tissue even days following receiving an oral dose. The research revealed that one particular quaternary compound, cetylpyridinium chloride, led to decreased levels of oligodendrocytes in the mice’s brains during a key period of brain development.
This study also examined brain organoids, clusters of stem cells that mimic developing brain tissue. The results showed similar effects to those observed in the mice experiments, underscoring the vulnerability of oligodendrocytes to quaternary ammonium compounds and organophosphate flame retardants.
While the findings of this lab-based study are of concern, it is important to note that the concentrations of chemicals used were higher than what humans would typically be exposed to, and the exposure route does not mirror real-life scenarios. Some experts caution once morest immediate alarm, emphasizing the need to assess toxicity under conditions that reflect human exposure.
Environmental chemist Oliver Jones from RMIT University in Melbourne, Australia, suggests that the focus should be on whether something is toxic under the conditions likely to be encountered by humans. The specific exposure routes and durations used in the study do not align with real-life human exposure.
However, certain individuals, such as school and hospital cleaners, childcare providers, and those in correctional facilities, are more exposed to quaternary compounds due to the prevalent use of industrial-strength disinfectants in these environments. It is worth mentioning that research into the toxicity of quaternary compounds has primarily relied on animal and cell studies until recently.
Notably, studies conducted during the pandemic have shown elevated levels of quaternary compounds in humans compared to pre-pandemic levels. The widespread use of disinfectants during this time might explain the increase. Researchers now view these compounds as an emerging concern due to their structural diversity, which poses challenges in fully understanding their potential human health risks.
Similarly, organophosphate flame retardants have been widely detected in the environment, as well as in human blood, urine, placental tissue, and breast milk. Environmental chemist Ian Rae, an advisor to the United Nations Environment Programme, suggests that in the future, these chemicals may come under the scrutiny of the Stockholm Convention, following its focus on organofluorines (PFAS).
A study mentioned in this report analyzed levels of one flame retardant metabolite, BDCIPP, in children’s urine samples from the National Health and Nutrition Examination Survey. The majority of children aged 3 to 11 years tested positive for BDCIPP, and those with higher exposure levels were found to have a higher likelihood of experiencing adverse neurodevelopmental outcomes.
While observational data can establish associations, it cannot determine direct causes. There are still significant gaps in understanding how these chemicals specifically affect humans, as most existing data originates from animal and cell studies. Therefore, further investigation into the health effects of these compounds, particularly in children, remains imperative.
Overall, this study highlights the potential risks associated with chemicals commonly found in everyday household items. The implications of these findings resonate with ongoing efforts to ensure the safety of consumer products and minimize exposure to potentially harmful substances. As society becomes increasingly conscious of these matters, it is essential for regulatory bodies, manufacturers, and consumers to collaborate in promoting safer alternatives and practices.
This article is based on a study published in Nature Neuroscience.
