Millions of Americans may be exposed to brain-destroying chemicals in common household products that could increase the risk of autism.
A new study in the journal Nature Neurology has found that personal care and cleaning products containing two ingredients damage structures in the brain that protect nerve cells to keep them functioning properly, called oligodendrocytes, which play a role in neurological diseases such as multiple sclerosis .
The chemicals are found in nail polish, baby wipes, hand soaps, cleaning products, furniture, carpet, shampoo, sunscreen, body wash, disinfectant sprays, certain electronics and dryer sheets.
Damage to brain structures prevents nerve cells from communicating properly with each other. Researchers said their findings could help determine whether environmental factors are linked to chronic neurological conditions that cannot be attributed solely to genetics.
The team linked exposure to the chemicals to poor neurological outcomes in children in the US through urinalysis, history of exposure to the substances and reports of motor dysfunction and children using special education services.
The study’s lead researcher, Paul Tesar, said: ‘We now show that specific chemicals in consumer products can directly damage oligodendrocytes, representing a previously unknown risk factor for neurological diseases.’
The chemicals, organophosphate flame retardants and quaternary ammonium compounds, are found in nail polish, baby wipes, hand soaps and cleaning products (stock image)
Research analyzed more than 1,800 chemicals that people can be exposed to and identified two classes of chemicals that specifically targeted brain structures: organophosphate flame retardants (OFRs) and quaternary ammonium compounds (QACs).
QACs are a type of chemical used to kill bacteria, viruses and fungi. Many types of these substances are found in cleaning products and disinfectants commonly used in hospitals, daycares, homes and restaurants.
OFRs are chemical additives that reduce the risk of fire and combustion in products. There are a large number of types that are commonly used in building materials, fabrics and furniture, as well as in electronics.
Researchers from Case Western Reserve University School of Medicine used biological samples from mice to determine that OFRs hinder oligodendrocyte development and QACs cause the structures to die.
The team also used data from the CDC and the National Health and Nutrition Examination Survey to identify children’s exposure levels to the chemicals to determine links between exposure and abnormal cognitive and motor development.
They analyzed data from 2013 to 2018 on children aged three to 11 years old and found that some type of OFR was present in 99 percent (1,753) of urine samples.
And the levels were significantly higher in children than in adults.
The data showed that a large proportion of children in the US who required special education services or had motor dysfunction reported had the highest levels of the substance in their systems.
The researchers said: ‘Neurological problems affect millions of people, but only a fraction of cases can be attributed to genetics alone, indicating that unknown environmental factors are major contributors to neurological diseases.’
Lead author Erin Cohn added: ‘We found that oligodendrocytes – but not other brain cells – are surprisingly vulnerable to quaternary ammonium compounds and organophosphate flame retardants.
‘Understanding human exposure to these chemicals may help explain a missing link in how some neurological diseases develop.’
Autism affects one in 36 children, meaning more than 90,000 children are born with the developmental disorder in the US every year.
It is characterized by problems with social communication and interaction, difficulty expressing oneself, and repetitive behaviors and interests.
Scientists are still not entirely sure what causes autism, although they think it is likely a combination of genetic and environmental factors.
The severity of the condition also varies widely across the spectrum, meaning there is likely no silver bullet treatment option.
MS is a chronic autoimmune disease that affects nearly 1 million Americans.
It can cause loss of balance, muscle cramps, vision and memory loss, and impaired motor function.
Some therapies can control symptoms, but there is no cure.
Based on their findings, the scientists emphasize that more research is needed into how these chemicals affect brain structures, including monitoring chemical levels in people’s brains to determine the amount and duration of exposure to OFRs and QACs needed to cause or worsen diseases.
Tesar said: “Our findings suggest that more extensive research into the impact of these common household chemicals on brain health is necessary.
‘We hope that our work will contribute to informed decisions about regulatory measures or behavioral interventions to minimize chemical exposure and protect human health.’