Inflammatory effects of exposure to different stone types used in Norwegian asphalt

Abstract

During the winter in Scandinavian countries, up to 90% of traffic-related particulate matter (PM) is from non-exhaust emissions sources such as asphalt wear. Measures to reduce urban PM have focused mainly on exhaust emissions, while the contribution from asphalt has received less attention. In vitro studies suggest that the composition of asphalt can affect the inflammatory potential of road dust. Using a whole-body human exposure chamber, we have explored whether different stone materials used in Norwegian asphalt impose different inflammatory reactions in plasma of healthy volunteers. Our results show no acute increases in the inflammatory markers SP-D, P- selectin, or CC16. However, quartz diorite induced an apparent increase in ICAM-1, not seen for rhomb porphyry or placebo dust (lactose). Although this did not reach statistical significance, it resembles previously observed fibrinogen-effects, and may suggest that different types of stone minerals provoke different inflammatory reactions in humans compared to placebo dust.