Vinyl chloride: an example for evaluating mutagenic effects in mammals in vivo after exposure to inhalation.

As part of a programme of investigations on the mutagenic effects in mammals in vivo after inhalation of environmental chemicals, the effects of the industrial compound vinyl chloride (VC) was analysed. Chinese hamsters were exposed to 1.25%, 2.5% or 5% (v/v) VC in air for 6, 12 or 24 hr. Bone marrow chromosomes were analysed for induced chromosome aberrations and sister-chromatid exchanges (SCEs) 26 h after beginning of exposure. The frequency of VC-induced chromosome aberrations and SCEs both depend on dose and length of exposure. The highest measured effects were 33.25 SCEs/ cell after an exposure to 2.5% VC for 24 h and 25.7% metaphases with aberrations, when exposed to 5% VC for 24 h.