Single-strand breaks (SSB) and DNA repair were detected in peripheral
lymphocytes derived from workers of a furniture factory in a non-pollu
ted region of Poland. The workers were exposed to wood dust (n = 19),
or to the dust and varnishes or lacquers together (n = 5). Four groups
were studied simultaneously: (a) exposed workers smokers of cigarette
s (n = 14), (b) nonexposed smokers - control (n = 14), (c) exposed wor
kers' nonsmokers (n = 14), (d) exposed nonsmokers (n = 10). In exposed
workers DNA SSB and DNA repair were statistically significantly incre
ased, DNA SSB was clearly higher in the smoking workers than in the sm
oking controls. Cigarette smoking itself has produced no evident incre
ase in the frequency of DNA SSB in the control group. Occupational exp
osure had a significant effect on DNA repair in non stimulated lymphoc
ytes both in smoking and nonsmoking workers.