Emergency Department access rate for venous thromboembolism in relationship with coarse and fine particulate matter air pollution.

Particulate matter (PM) air pollution has been associated with cardiovascular and respiratory disease. Recent studies have proposed also a link with venous thromboembolism (VTE) risk. The aim of this study was to evaluate possible air pollution-related changes in the daily flux of patients referring to Emergency Department (ED) for VTE, dissecting the potentially different effects of coarse and fine PM on the different pathologies. From June 1st, 2007 to May 31st, 2009, data about ED accesses for VTE, as well as environmental data about daily concentrations of PM air pollution in Verona district (Italy) were collected. Coarse PM (PM10-2.5) was calculated by subtracting the finest PM2.5 from the whole PM10. During the considered period a total number of 302 accesses of VTE were observed (135 males and 167 females; mean age 68.3 ± 16.7 years). In multiple regression models adjusted for other atmospheric parameters PM10-2.5, but not PM2.5, concentrations presented a positive correlation with VTE (beta-coefficient=0.237; P= 0.020). During the days with high levels of PM10-2.5 ( 75th percentile) there was an increased risk of ED accesses for VTE (OR 1.69 with 95%CI 1.13 – 2.53). Consistently with these results on VTE risk, in another cohort of subjects without active thrombosis (n=102) an inverse correlation between PM10-2.5 and prothrombin time was found (R= -0.247; P=0.012). Our results suggest that short-time exposure to high concentrations of PM10-2.5 may be related with prothrombotic diathesis and favour an increased rate of ED accesses for VTE.