Microplastics can reach the human brain through the nasal passages, raising significant health concerns, a new study has found.
Published in the journal JAMA Network Open, the research identified plastic fragments in the olfactory bulbs – a brain region responsible for detecting smells – in eight out of 15 deceased people who had lived in Sao Paulo, Brazil.
It found 16 synthetic polymer particles and fibres within these brain regions.
Most of the microplastics were particles, with polypropylene being the most common polymer detected. Other materials included nylon and polyethylene.
The discovery adds to a growing body of evidence about the widespread presence of microplastics in the human body, with recent studies finding these pollutants in the lungs, liver, and blood.
First of its kind
This study, published on Tuesday, is the first to document the presence of microplastics in human brain tissue directly.
The potential health implications of microplastics entering the brain are still under investigation, but concerns are mounting over their possible neurotoxic effects.
The analysis used infrared spectroscopy to identify and describe the particles, which showed signs of wear, suggesting they had been in the environment for a while.
“Our findings reveal that microplastics can be present in the olfactory bulbs,” the study authors said.
Negotiating an end to plastic pollution, with global treaty
The study suggests that the olfactory pathway, through which sensory information is transmitted to the brain, might be a significant route for microplastics.
“The anatomy of the olfactory system may allow microplastics to enter the brain,” the researchers noted.
The researchers emphasise the need for further investigation into how microplastics might affect neurological health.
As microplastic pollution becomes increasingly widespread, understanding its implications for human health remains a critical area of study.
