The goal of the PAREMPI project is to gain scientific evidence of the real contribution of transport sectors’ emissions to ambient particulate matter (PM2.5) levels, and to recommend policies to prevent these emissions. The particles emitted directly from tailpipe not only contribute to pollution immediately but also through chemical reactions in ambient air over minutes, hours and days, leading to formation of new particles and additional particle mass. Both direct tailpipe emissions and the secondary aerosols (SecA) that form later in atmosphere have a significant impact on ambient PM2.5 levels, often exceeding the effect of the initially emitted tailpipe particles alone. The harmful environmental and health impacts of transportation are being addressed through electrification, energy efficiency and carbon-neutral fuels. The tailpipe pollutants are addressed particularly with advanced exhaust aftertreatment systems (EATS). However, some transport sectors, notably aviation and shipping, are difficult to electrify, or adapt for EATS.
Understanding of the total contribution of transport emissions to ambient PM2.5 levels, along with related health aspects, is essential to justify policy recommendations. Therefore, the following specific objectives have been defined:
• Improved estimates of externalities for PM2.5 representing contribution of transport sources.
• A health impact assessment (HIA) for PM2.5 concentrations representing urban/rural regions with different shares of different transport fleet characteristics.
• Development of a digital “ePMI module” (equivalent total PM index) to estimate SecA mass potential based on emissions from transport sources.
• Estimate of European and global scale PM2.5 and nanoparticles from transport with global simulations of SecA and high resolution SecA assessment for two urban regions in Europe.
Furthermore, quantifying of total PM2.5 mass emissions from transport sources, including SecA (organic and inorganic), and estimating the associated externalities, necessitates reliable data. To achieve this, the following specific objectives are set:
• A database on precursor emissions, SecA and toxicity (in-vitro and in-vivo) based on literature, partners’ earlier results and filling the gaps with new complementary measurements combined in database.
• Determining of toxicity of exhaust from transport sectors by measurements with the in vitro exposure system.
During the reporting period, work progressed well. The first version of the database was established using relevant studies from literature for SecA and toxicity related to the transport. Measurements were conducted with seven cars and two trucks. Additionally, the first version of a digital “ePMI module” was developed to estimate SecA mass potential based on emissions from transport sources. The study on aerosol dynamics and experiments on secondary reactions were also completed. Furthermore, a European level evaluation of transport related PM2.5 including SecA, was carried out, and the HIA on PM2.5 progressed. With continued efforts in the next reporting period, the PAREMPI project is expected to generate knowledge, evidence, models, tools to recommend policies to reduce ambient PM2.5 concentrations derived by transport sectors. These results will also assist further research to find solutions and initiate actions to prevent these emissions and gain savings in the related external costs and delivering benefits for both society and the economy.
