Objective To analyze the results of occupational health examinations of benzene and X-ray combination workers in Suzhou Industrial Park in 2016 and provide theoretical basis for occupational protection.

Methods A total of 219 workers who underwent occupational health examinations at the Suzhou Industrial Park Centers for Disease Control and Prevention in 2016 were selected and retrospectively analyzed. Workers included 64 benzene workers, 52 X-ray workers, 50 benzene and X-ray combination workers, and 53 people without history of exposure to occupational disease hazard factors (control group). The basic information of inspected personnel was collected through questionnaires. Benzene concentrations in the workplace were detected by solvent desorption-gas chromatography, and the X-ray ambient dose equivalent rate around the workplace and the individual effective dose of the inspected personnel were determined to judge whether occupational disease hazard factors exceeded the exposure limit. Occupational health examinations, including internal medicine examinations, blood routine examinations, thyroid function examinations, lymphocyte chromosomal micronucleus rate determination and lens opacity were carried out. The occupational health examination results of different working groups were compared. The measurement data were compared between two groups by independent-samples t test and least significant difference t test, and the comparison between multiple groups was by one-way analysis of variance and Kruskal-Wallis H test. Pearson χ² test or Fisher's exact probability method was used in the comparison of enumeration data between groups.

Results The ages of workers in the X-ray and benzene and X-ray combination groups were significantly higher than those of workers in the control group (29.8±4.4) years old vs. (27.8±4.5) years old, (30.3±3.6) years old vs. (27.8±4.5) years old; t=−2.015, −2.546; both P<0.05). The per capita annual effective dose of workers and the ambient dose equivalent rate of the workplace in the X-ray and benzene and X-ray combination groups, and the time weighted average concentrations of benzene of workers in the benzene and benzene and X-ray combination groups were all lower than the prescribed limits. The red blood cell (RBC) count and hemoglobin level of the benzene group; the hemoglobin level and lymphocyte count of the X-ray group; and the hemoglobin level, white blood cell count, lymphocyte count and platelet count of the benzene and X-ray combination group were significantly lower than those of the control group (t=−0.747 to 62.388, all P<0.05). The RBC and lymphocyte counts of the benzene and X-ray combination group were significantly higher and significantly lower, respectively, than those of the benzene group (t=−38.298, 0.230; both P<0.01). Compared with the control group, the X-ray and the benzene and X-raycombination groups had significantly lower serum free triiodothyronine (FT₃) level and significantly higher serum free thyroxine level (t=−42.441 to −18.997, all P<0.05). The serum FT₃ level of the benzene and X-ray combination group was significantly higher than that of the X-ray group (t=−23.662, P<0.01). There was no significant difference in the chromosomal micronucleus rate of peripheral blood lymphocytes between the control group, X-ray group and benzene and X-ray combination group (H=1.268, P>0.05). The incidence of lens opacity in the X-ray group was significantly higher than that in the control group (χ²=7.644, P<0.01).

Conclusions Benzene and X-rayhave a certain degree of influence on blood routine indices, thyroid function indices, lymphocyte chromosomal micronucleus rate and lens opacity of workers and may show a certain combined effect. The radiation protection and health monitoring of benzene and X-ray combination workers should be strengthened.