Methyl chloride and diazepam effects on performance.
Putz-Anderson-V; Setzer-JV; Croxton-JS; Phipps-FC
Scand J Work, Environ & Health 1981 Mar; 7(1):8-13
Behavioral effects from ingestion of diazepam (439145) and inhalation of methyl-chloride (74873) were investigated in humans. A total of 17 female and 39 male subjects ranging in age from 18 to 32, with a mean of 22 years, participated in the study. They were exposed to methyl-chloride at 0, 100, and 200 parts per million (ppm) for 3 hours and to diazepam at 0 and 10 milligrams. Each participant was tested in an environmental room for alertness during 5 hours of testing. Three behavioral tests used were visual vigilance, dual task, and time discrimination. Breath and blood samples were taken at various intervals and tested. Degree of impairment on behavioral tests was expressed as the percentage of change between pretreatment and subsequent testing period during exposure. Large interindividual differences in breath and blood levels were found for methyl-chloride. The control group showed an average decline of 27.3 percent in performance between pre control and control test periods. Diazepam treatment showed an average 10.1 percent impairment in task performance. Treatment of 200ppm methyl- chloride showed an average of 4 percent performance impairment and combined diazepam and methyl-chloride treatment showed an average impairment of 13.5 percent. Through univariate analysis, only threshold performance of vigilance test scores and response block measures of time discrimination were sensitive indicators of methyl- chloride impairment. In contrast, diazepam had a significant effect on all test indices except the response block measures of time discrimination. The authors conclude that potential hazards from combined central nervous system depressants can affect alertness and coordination of exposed workers.
NIOSH-Author; Pulmonary-function; Toxic-effects; Physiological-response; Chemical-properties; Lethal-concentrations; Respiratory-hypersensitivity; Biological-effects; Exposure-levels; Behavioral-testing; Lung-function
Scandinavian Journal of Work, Environment and Health