Abstract: BACKGROUND ＆ AIM： To study the adverse effect of coal tar pitch(CTP)on DNA damage of peripheral blood lymphocyte in occupationally exposed workers. MATERIAL AND METHODS： Micronucleus (MN)and single cell gel electrophoresis(SCGE)were used to determine DNA damage of peripheral blood lymphocyte in 43 workers exposed CTP and 21 controls. RESULTS: The frequencies of comet-like tail and MN of peripheral blood lymphocytes were(3.26±1.12)×10-2 and (1.23±0.27)×10-3 , significantly higher in CTP-exposed group than those in control group(P<0.01；P<0.01)， and these effects could increase with the extension of time exposed CTP(P<0.01;P<0.05). CONCLUTION: Exposing to CTP for a long-term may induce DNA damage in peripheral blood lymphocyte in workers, and thus SCGE and MN may be used as early monitoring markers for high-risk individual of occupational lung cacer.

Key words: coal tar pitch, micronucleus, single cell gel electrophoresis, DNA damage, monitoring markers