Research led by Thais Mauad, an associate professor at the FMUSP Pathology Department, reveals that microplastics have been found in various human organs, including the lungs, placenta, liver, heart, and carotid arteries. Notably, evidence suggests that microplastics can cross the blood-brain barrier and reach the brain in animals.
While the health implications remain unclear, studies indicate that microplastics may alter neurotransmitter levels and lead to behavioral disorders. Mauad cautions that although the olfactory pathway has been confirmed, other contamination routes, such as through the bloodstream, cannot be ruled out.
A study published in the New England Journal of Medicine found micro and nanoplastics in the arteries of 60% of participants, correlating with a 4.5 times higher risk of heart attack, stroke, or death compared to those without microplastics present.
Additionally, research in Environmental Research found that 90% of animal and plant protein samples tested positive for microplastics. These small polymer fragments, ranging from less than 5 millimeters to 1 micrometer, are made from complex chemical combinations, including potentially toxic additives.
Recent analysis identified over 10,000 chemicals used in plastics, with more than 2,400 classified as concerning. Mauad notes that many additives, including bisphenol A (BPA), are known for their potential carcinogenic and endocrine-disrupting properties.
New findings published in Nature Communications suggest a possible link between autism and prenatal exposure to BPA. Researchers from the University of Melbourne found that children of mothers with high urinary BPA levels had a sixfold increased risk of autism diagnosis.
Anderson Nitsche, a neurologist specializing in autism, emphasizes that while autism has multiple causes, this study presents a likely correlation. The association may relate to BPA's effect on aromatase, an enzyme crucial for male fetal brain development. Children with lower aromatase levels were more likely to be diagnosed with autism.
Despite the need for further research, Nitsche indicates that recommendations to avoid BPA during pregnancy may emerge. Previous studies have linked BPA exposure to increased autism and ADHD diagnoses.
While BPA is banned in baby bottles in some countries, it remains allowed in other applications with specific migration limits set by legislation. Mauad stresses the difficulty of completely avoiding plastics but suggests minimizing exposure through simple measures, such as avoiding single-use plastics and preferring glass or natural materials for food storage.