OBJECTIVETo investigate the inhalation of sulfur dioxide (SO(2)) on the DNA damage of brain cells in mammalian animals.

METHODSingle cell microgel electrophoresis technique (comet test) was used to test the DNA damage of brain cells.

RESULTS(1) After the exposure to SO(2) at 0, 7, 14, 28 mg/m(3), the tail lengths of nuclear DNA in brain cells from male mice were 8.02, 23.14, 46.43 and 53.49 micro m respectively; and that from female mice were 7.23, 12.43, 20.39 and 54.83 micro m respectively. The results showed that: (1) SO(2) inhalation caused damage on DNA of brain cells in a dose-dependent manner; (2) Even under lower concentration of SO(2) as 7 mg SO(2)/m(3), the damage on DNA of brain cells was also reached to 98.8%. It implied that the brain cells of mammalian animals were very sensitive to SO(2) inhalation; (3) The DNA damage of brain cells from male mice is more serious than that from female mice. The reasons remain to be further studied.

CONCLUSIONSSO(2) pollution even at lower concentrations also had a potential risk to the genetic material DNA of brain cells from mammalian animals. The results of our study might explain the recently published epidemiological studies that the workers exposed to SO(2) or SO(2) derivatives had suffered an increase of mortality from brain cancer.