Impacto dos microplásticos atmosféricos: ambientes urbanos e rurais e eventos extremos

MPs are a hot topic in the scientific community, mainly associated to water bodies. But their presence in the atmosphere was also recorded and being small (1 um–5 mm) low-density particles, their transport capacity is deemed high, as is the possibility of penetrating the respiratory and digestive tract of living beings, carrying also other contaminants that raise the potential toxicity. Considering the numerous possible mechanisms of MPs release to the air, there is still a lot to unravel. The framework of this proposal is key to tackle some of the questions that arise from the gaps in the state-of-the-art: To what extent are airborne MPs present in urban and rural areas? Which are the differences between both areas? Are there marked temporal and geographical trends? Are the potential toxic effects of MPs different? Can extreme events like wildfires influence the presence and distribution of MPs in the atmosphere? Can pine needles and soils complement active air sampling to provide a much wider coverage of the target domain? Are CTMs able to reproduce the current behaviour of MPs under baseline and extreme conditions and estimate future climate change scenarios in the whole country? Answering these questions is ensuring an outstanding outcome to fulfil PlasURE’s drive. Some hypotheses are put forward: - Airborne MPs are likely more abundant in urban areas, as are other indicators of human or natural activities like PAHs, which will be studied in parallel to act as a well-known reference of atmospheric micropollution dynamics - Extreme events like wildfires may significantly increase the levels of MPs in the affected areas, but also impact more distant locations due to the atmospheric transport, increasing the harmful effects to the exposed populations. - Pine needles and soils are reliable biomonitors of micropollutants and can also provide data on the presence of airborne MPs in areas where active air sampling is difficult/impossible to establish - Modelling strategies using CTMs will be able to have airborne MPs as an input contaminant and outline present estimations and future projections of their occurrence. To address these challenges, PlasURE proposes an innovative multidisciplinary vision with 6 main efforts: - Assess the levels and potential sources of airborne MPs/PAHs with active air sampling in urban and rural spots, via seasonal sampling campaigns, complemented with the nearby sampling of pine needles and soils - Validate an expedite method to identify and quantify MPs in pine needles and optimize the protocols for air samples and soil - Identify the impact of the 2017 wildfires in Portugal in the presence of MPs/PAHs using country-wide samples of pine needles and soils collected in 2017 and 2018 in affected and unaffected areas (see Annex 2) - Whenever possible, collect air, pine needles and soil samples during controlled and real-life wildfire events - Estimate the effects of airborne MPs to humans using exposure models (inhalation, ingestion) and toxicity assays with simulated lung cell kits - Create a model application to incorporate airborne MPs for the first time (with a representative type of particle) in tools like WRF-CHIMERE with data from active sampling and biomonitors to describe the current situation and future scenarios, under baseline conditions and extreme events. These objectives represent significant advancements to the current knowledge and will pave new roads to the understanding of airborne MPs.