22 Development of an Integrated Exposure Pathway Model for Health Impact Assessment of Traffic Ultrafine Particles (H2020 Ultrhas-Project)

Abstract Recently, the causal associations between traffic emissions and health effects were strengthened by the systematic reviews by the Health Effects Institute (HEI#23, 2022). According to EuroStat data Europeans spend 87-97% of their time indoors in homes, workplaces, schools and nurseries. Breathing volumes are dominated by the time spent indoors (16 m³ indoors and 1.4 m³ outdoors), even though breathing rates in outdoor environments are higher. This demonstrates the importance of taking into account time activity as well as infiltration to indoor spaces when estimating intake of particles. The ULTRHAS project aims to link in vitro toxicological evidence for particulate matter to health impact assessments to look specifically into this. An integrated exposure pathway model will consider for different microenvironments, and physical activity patterns to quantify the particle intake in selected gender and age groups. Relative to the commonly applied approach using residential address and corresponding outdoor pollution levels we specifically add handling of (i) infiltration into indoor spaces and (ii) variability in breathing volumes based on physical activities. The model will provide inhalation volumes for selected target populations, to be applied in the intake-DALY estimation of burden of disease parameters in the following phases of the project.