New research has shown that toxic chemicals used to flame-proof plastic materials can be absorbed into the body through the skin, via contact with microplastics. These chemicals, which are present as additives in microplastics, can leach into human sweat and then be absorbed through the skin, into the bloodstream. Many of these chemicals, such as flame retardants and plasticizers, have been banned due to evidence of adverse health effects such as damage to the liver or nervous system, cancer, and risks to reproductive health. However, they are still present in older electronics, furniture, carpets, and building materials, posing a risk to human health.
While the full extent of the harm caused by microplastics is not yet fully understood, there is growing concern over their role as conduits of human exposure to toxic chemicals. Research has shown that chemicals can be leached from microplastics into human sweat, and the latest study demonstrates that these chemicals can be absorbed from sweat across the skin barrier into the body. The research team used innovative 3D human skin models in their experiments, which served as alternatives to laboratory animals and excised human tissues. These models were exposed to two common forms of microplastics containing polybrominated diphenyl ethers (PBDEs), a chemical group commonly used to flame-retard plastics.
The results of the study, published in Environment International, revealed that up to 8% of the chemical exposed could be taken up by the skin, with more hydrated or ‘sweatier’ skin absorbing higher levels of the chemical. This study provides the first experimental evidence of how this process contributes to the levels of toxic chemicals found in the body. Dr. Ovokeroye Abafe, one of the researchers, highlighted the role of microplastics as carriers of harmful chemicals that can enter the bloodstream through the skin, emphasizing the gradual accumulation and potential harm caused by continuous exposure.
Dr. Mohamed Abdallah, Associate Professor of Environmental Sciences at the University of Birmingham, and principal investigator for the project, emphasized the importance of these findings for regulators and policymakers in improving legislation around microplastics to safeguard public health against harmful exposure. Professor Stuart Harrad, co-author of the paper, stressed the significance of the study in understanding the risks of exposure to microplastics on human health, calling for further research to fully comprehend the different pathways of human exposure to microplastics and how to mitigate the associated risks.
Future research plans for the team include investigating other routes through which microplastics could be responsible for toxic chemicals entering the body, such as inhalation and ingestion. The work is funded by a Marie Curie Research Fellowship within the European Union’s Horizon 2020 Research and Innovation Programme. Overall, this research highlights the potential health risks associated with exposure to toxic chemicals leached from microplastics and the need for further research and regulation to protect public health from these harmful substances.
