OBJECTIVETo study whether the argyrophil nucleolar organizer regions (AgNOR) in T lymphocytes of peripheral blood in coke-oven workers can be used as a biomarker of effect for polycyclic aromatic hydrocarbon (PAH) exposure.

METHODSFifty-two male coke-oven workers were divided into three groups according to exposure levels of coke oven emissions: high-exposure, middle-exposure and low-exposure workers. Additionally 10 men without occupational PAH exposure were chosen as control group. Peripheral blood T lymphocytes were cultured, spread on slides and stained with silver nitrate. The ratio of AgNOR area vs. nuclear area (I/S) in T lymphocytes was analyzed. Urinary 1-hydroxypyrene (1-OHP) was measured as the internal dose of PAH exposure.

RESULTSMean urinary 1-OHP level in high-exposure group (16.56 +/- 2.77 micromol/mol Cr) was significantly higher than those in low-exposure group (3.30 +/- 2.77 micromol/mol Cr, P < 0.001) and control group (3.04 +/- 1.58 micromol/mol Cr, P < 0.01). The mean I/S of AgNOR in T lymphocytes in high-exposure group (0.056 +/- 0.010) was significantly lower than those in middle-exposure group (0.065 +/- 0.013, P < 0.05), low-exposure group (0.067 +/- 0.008, P < 0.01) and control group (0.076 +/- 0.007, P < 0.001). It was also found that I/S of AgNOR were significantly decreased in middle-exposure group and low-exposure group in comparison with control group (P < 0.01, P < 0.05).

CONCLUSIONSThe occupational exposure to PAH resulted in increase of 1-OHP in urine and decrease of AgNOR in T lymphocytes. PAH exposure might lead to damage T lymphocytes function and AgNOR may be considered as a biomarker of effect for PAH exposure.