Persistent micro- and nanoplastics as triggers for interstitial lung disease

Plastic is the third most abundant manmade material on Earth. It degrades and sheds particles or fibres too small to see with the naked eye, known as 'micro- and nanoplastic' (MNP). These particles are a newly recognised part of pollution in indoor and outdoor air and are of concern due to their potential to cross biological boundaries and enter living cells. This has alerted scientists, government, media and the public: the health effects of air pollution are well defined, but the additional impacts of breathing in plastic dust are poorly understood. This will become increasingly important for public health; plastic materials will continue to shed, even if there are efforts to reduce air pollution from other sources. In some plastic industries, workers exposed to high levels of fine plastic dust can develop lung disease leading to lung tissue scarring and compromised breathing. In this research, we seek to investigate this in greater detail, using a range of experimental (lung) models to determine the level of risk which exposure to environmental MNP air pollution presents, and the associated biological pathways leading to disease. We will do this by: 1. Quantifying exposure to past and present MNP by reanalysing old and analysing new air pollution samples for plastic. 2. Making different microplastic particles and fibres using milling, spinning and cutting techniques to ask controlled questions about the drivers of toxicity. The types of MNP materials will be based on those most commonly produced and found in the environment. 3. Evaluating the toxicity of inhaled MNP in the lung, using human relevant cell models and key markers of hazards posed by MNP to the lung. 4. Assess the longer term impacts of MNP inhalation on the development of lung tissue scarring in an animal model. This novel and multidisciplinary research will advance understanding on whether there are impacts of inhaled MNP in the lung and why. This is an increasingly important knowledge gap. Rising plastic production will contribute to the plastic component of air pollution in the long term. In the short term, plastic materials shed and we have no knowledge of what the impact of inhaling this material might be. The findings will be important for national and international governments because they will allow them to assess the risks of inhaling microplastics. It will highlight whether any interventions are required to minimise exposure in the future. Medical professionals will benefit from being aware of the potential hazards when treating individuals with respiratory illness. The findings will also help industry develop safer alternatives to plastic materials.