To elucidate the health effects of air pollution, the short-term association of criteria pollutants (particles <10 microm in diameter [PM(10)], O(3), CO, NO(2), and SO(2)) with hemostatic and inflammatory markers were examined using a population-based sample of 10,208 middle-age males and females of the biracial cohort of Atherosclerosis Risk in Communities (ARIC) study. For each participant, we calculated the following pollutant exposures 1-3 days prior to the randomly allocated cohort examination date: PM(10), CO, NO(2), and SO(2) as 24-h averages, and O(3) as an 8-h average of the hourly measures. The hemostatic/inflammatory factors included fibrinogen, factor VIII-C, von Willebrand factor (vWF), albumin, and white blood cell count (WBC). Linear regression models were used to adjust for cardiovascular disease (CVD) risk factors, demographic and socioeconomic variables, and relevant meteorological variables. One standard deviation (SD) increment of PM(10) (12.8 microg/m(3)) was significantly (P < 0.05) associated with 3.93% higher of vWF among diabetics and 0.006 g/dl lower of serum albumin among persons with a history of CVD. One SD increment of CO (0.60 p.p.m.) was significantly (P < 0.01) associated with 0.018 g/dl lower of serum albumin. Significant curvilinear associations, indicative of threshold effects, for PM(10) with factor VIII-C, O(3) with fibrinogen and vWF, and SO(2) with factor VIII-C, WBC, and serum albumin were found. This population-based study suggest that the hemostasis/inmflammation markers analyzed, which are linked to higher risk of CHD, are associated adversely with environmentally relevant ambient pollutants, with the strongest associations in the upper range of the pollutant distributions, and in persons with a positive history of diabetes and CHD.