Health effects of acrylonitrile in acrylic fibre factories.

The relationship between the degree of exposure and biological effects of acrylonitrile (AN) was studied in 102 workers whose exposure period exceeded five years, and in 62 matched controls, all of whom had been randomly sampled from six acrylic fibre factories in Japan. The six factories were classified into three groups on the basis of AN concentration at workplaces. The most highly exposed group of subjects showed an eight-hour average AN concentration of 4-2 ppm by personal sampling, a mean urinary AN concentration of 360 microgram/1 and a mean urinary thiocyanate concentration of 11-4 mg/1. Medical examination, including the indocyanine green excretion test and multiple clinical chemistry determinations, failed to detect any health effect attributable to AN. Slight liver damage may possibly occur in more highly exposed workers. Urinary AN and thiocyanate determinations may provide more accurate estimates of low-grade exposure (less than 5 ppm).