The objective of this study was to investigate the association between chro
mium (Cr) concentrations and sister chromatid exchanges (SCE) formation in
Cr workers and to assess the effects of susceptible genes (glutathione S-tr
ansferase M1 and T1) on the frequency of deletion and SCE/cell. Urinary Cr
concentration was significantly elevated in Cr workers (3.67 +/- 3.89 mug/g
creatinine) compared to control group (1.21 +/- 1.16 mug/g creatinine, P <
0.01). There was also a significant difference of superoxide dismutase (SO
D) levels between Cr workers (6.86 +/- 0.80 U/mg Hb) and controls (7.16 +/-
0.53 U/mg Hb, P < 0.01). The frequencies of SCE and high frequency cells (
HFC) were significantly correlated with smoking habits and with duration of
exposure to Cr. A significantly higher percentage (50%) of Cr workers had
both the null GSTM1 and GSTT1 genotype as compared to 10% of the controls (
P < 0.01). However, the chromosomal DNA damage effect of GSTM1 and GSTT1 ge
notypes, individually or in combination, was not revealed in Cr exposed wor
kers. (C) 2001 Elsevier Science B.V. All rights reserved.