Inhaled microplastics and lung health

Breathing in microplastics can cause inflammation and damage to the lungs, potentially increasing the risk of respiratory diseases such as asthma, chronic obstructive pulmonary disease (COPD), pulmonary fibrosis and lung cancer, new research suggests.

Air pollution leads to around 7 million premature deaths every year according to the World Health Organisation. The growing presence of microplastics in the air, from items such as synthetic carpets, clothing and household dust, may be increasing the risks to respiratory health.

A newly published review article, Inhaled microplastics and lung health: Immunopathological effects and disease implications, led by Dr Keshav Raj Paudel from the University of Technology Sydney, NICM Health Research Institute, Western Sydney University and the Woolcock Institute of Medical Research, highlights how inhaled microplastics can trigger lung inflammation and tissue damage.

“Microplastics are tiny fragments of plastic, smaller than 5mm, that are released when larger plastic items break down or shed fibres. These fragments can irritate lung tissue and trigger inflammatory responses,” said Dr Paudel.

“Earlier research on microplastics focused mainly on oceans and human exposure through eating seafood, however growing evidence suggests that inhalation may be an equally, if not more significant route," he said.

“The lungs are particularly vulnerable to microplastic damage due to their large surface area and limited ability to clear particles, particularly smaller ones that travel deep into the lungs. Lung cancer tumours have been found to contain more microplastics than healthy tissue.

"Different plastics also have varying degrees of toxicity. For example, polystyrene microplastics can stick to the lungs’ protective coating, disrupt air sac function and trigger chemical reactions that may damage lung tissue."

The researchers also highlight the ability of microplastics to act as carriers for other pollutants and carcinogens. Plastic surfaces can attract chemicals and microorganisms, so inhaled particles deliver these toxins and pathogens directly into the lungs.

The project received initial funding from the Sydney Partnership for Health, Education, Research and Enterprise (SPHERE) in 2023 to investigate the impacts of microplastic inhalation.  

The research team is currently working on advanced in vitro models to simulate lung exposure and provide insight into molecular mechanisms. Dr Paudel is also seeking further funding to investigate the genetic and therapeutic targets for microplastic-induced cellular damage using a CRISPR-Cas9 (gene-editing) approach.