Induction effects of sulfur dioxide inhalation on chromosomal aberrations in mouse bone marrow cells.

To investigate the induction of chromosome aberrations (CA) in mouse bone marrow cells by sulfur dioxide (SO(2)) inhalation, mice were treated by SO(2) exposure for 4 h/day for 7 days at various concentrations of SO(2), then mitotic indices and CA in mouse bone marrow cells were analyzed. The present results show that SO(2) might increase the frequencies of CA and aberrant cells in mouse bone marrow in a dose-dependent manner. The frequencies (%) of aberrant cells in mouse bone marrow induced by SO(2) at concentrations of 0, 7, 14, 28 and 56 mg/m(3) were 1.81, 3.00, 3.58, 4.26, 4.86, respectively. At low concentrations SO(2) induced only chromatid-type CA, while at high concentrations SO(2) induced both chromatid-type and chromosome-type CA. SO(2) inhalation decreased the mitotic indices of bone marrow cells. The results imply that SO(2) inhalation may inhibit mitoses and increase CA frequencies of bone marrow cells and that it is a clastogenetic and genotoxic agent. Long exposure to SO(2) pollution at low concentrations in the environment may be a potential risk for induction of cytogenetic damage in vivo in humans.