Hematological abnormalities of acute exposure to hexachloroethane smoke inhalation.

There has been no human epidemiological data regarding potential hematological effects of hexachloroethane-zinc oxide (HC/ZnO) inhalation. This is the first epidemiological study to investigate whether HC/ZnO inhalation exposure can induce hematological abnormalities in exposed soldiers. Twenty soldiers, who were exposed to a high concentration of HC/ZnO smoke for 3-10 min in a narrow tunnel (0.6 m in width) during military training, were recruited as the exposed group (n = 20). Another 64 soldiers, who were not visiting the explosion areas, were recruited as controls. Venous blood was collected from all participants for analyses of hematological parameters. After adjustment for potential confounders, there were significant differences in weekly mean hemoglobin (HB), red blood cell count (RBC), and hematocrit (HCT) between exposed soldiers and controls (p < .01) at the first follow-up through the first 4 weeks following exposure. In addition, mean white blood cell count (WBC) of exposed soldiers was significantly higher than that of controls at the 4-week follow-up. Further analysis showed HB, RBC, and HCT changes during the 1st week after exposure and reach lowest levels during the 2nd week. HB, RBC, HCT, and WBC returned to normal within 11 weeks after the HC/ZnO smoke exposure. All other hematological parameters remained unchanged at 72 weeks after the event. The authors concluded that inhalation of HC/ZnO smoke can induce acute, temporally related hematological abnormalities.