Effects of work place carbon monoxide exposure on blood viscosity.

Both blood viscosity and carbon monoxide (CO) has been associated with cardiovascular diseases (CVDs). In order to investigate the effects of chronic low-level CO exposure on the determinants of blood viscosity (hematocrit, plasma viscosity, erythrocyte deformability, and erythrocyte aggregation), 10 men exposed to CO at work for at least 6 months and 10 healthy controls were included in the study. Plasma viscosity was determined by a cone-plate viscometer, erythrocyte deformability and erythrocyte aggregation by laser-assisted optical rotational cell analyzer. Mean plasma viscosity of the group exposed to CO (1.4 +/- 0.1 mPa.sn) was significantly higher than that of the controls (1.2 +/- 0.06 mPa.sn) (p < .05). Plasma fibrinogen level of the CO group (275 +/- 11 mg/dL) was slightly higher than that of the controls (263 +/- 14 mg/dL). The rise in plasma viscosity by chronic low-level CO exposure may be the mechanism of CO-induced increase in the risk for CVDs.