Researchers have recently highlighted the ability of toxic chemicals used in flame-retardant plastics to penetrate the human body through skin contact with microplastics.
This absorption occurs when these chemicals dissolve in human sweat and then cross the skin barrier to reach the bloodstream. The study, conducted using innovative 3D human skin models, revealed that hydrated skin could absorb significant levels of these chemicals. These findings have major implications for public health and the regulation of microplastics, highlighting their pervasive nature and role as carriers of toxic substances.
The results of a new study indicate that toxic chemicals added to plastic materials for their fire resistance can penetrate the body through the skin upon contact with microplastics. The study provides the first experimental evidence that chemicals present as additives in microplastics can dissolve in human sweat and then be absorbed through the skin into the bloodstream.
Many chemicals used as flame retardants and plasticizers have already been banned due to evidence of harmful health effects, including liver or nervous system damage, cancer, and reproductive health risks. However, these chemicals are still present in the environment in old electronic devices, furniture, carpets, and building materials.
Although the damage caused by microplastics is not fully understood, there is growing concern about their role as vectors for human exposure to toxic chemicals.
Research Findings on Chemical Absorption
The research team demonstrated in a study published last year that chemicals dissolved from microplastics into human sweat. The current study now shows that these chemicals can also be absorbed from the sweat through the skin barrier into the body.
In their experiments, the team used innovative 3D human skin models as alternatives to laboratory animals and excised human tissues. The models were exposed for a period of 24 hours to two common forms of microplastics containing polybrominated diphenyl ethers (PBDE), a chemical group commonly used to fireproof plastics.
Results and Implications for Health
The results, published in
Environment International, showed that as little as 8% of the exposed chemicals could be absorbed through the skin, with more hydrated—or "sweatier"—skin absorbing higher levels of chemicals. The study provides the first experimental evidence of how this process contributes to the levels of toxic chemicals present in the body.
Dr. Ovokeroye Abafe, currently at Brunel University, led the research while he was at the University of Birmingham. He stated: "Microplastics are everywhere in the environment, and yet we still know relatively little about the health problems they can cause. Our research shows that they play a role as 'carriers' of harmful chemicals, which can penetrate our bloodstream through the skin. These chemicals are persistent, so with continuous or regular exposure to them, there will be a gradual build-up until they start to cause damage."
Professor Stuart Harrad, co-author of the paper, added "The study represents a significant advance in understanding the risks of exposure to microplastics on our health. Building on our results, further research is needed to fully understand the different ways human exposure to microplastics occurs and how to mitigate the risk associated with this exposure."
In their future research, the team plans to study other pathways through which microplastics could be responsible for the entry of toxic chemicals into the body, including inhalation and ingestion. The work is funded by a Marie Curie Research Fellowship, part of the European Union's Horizon 2020 research and innovation program.
Article Author: Cédric DEPOND