Particulate matter inhalation during hay storing activity induces systemic inflammation and platelet aggregation

The aim of this study was to investigate possible pathomechanisms behind the cardiovascular morbidity caused by inhalation of particulate matter (PM10). For that purpose, healthy volunteers were exposed to high PM10 concentrations during a 2 h hay storing activity. Blood was drawn in the evening before and after PM10 exposure and in the morning and evening of the day after exposure. The leukocyte count increased after PM10 exposure with an initial increase of segmented neutrophils followed by banded forms. C-reactive protein increased over time. Fibrinogen and plasma viscosity became increased in the evening of the day after PM10 exposure. Platelet aggregation was increased in the evening after PM10 exposure. At the same time von Willebrand factor and factor VIII were increased, reflecting endothelial activation. These results confirm that acute inhalative exposure to high PM10 concentrations during hay storage activity leads to a systemic inflammatory reaction, endothelial activation, and platelet aggregation.