Objective To analyze the level and distribution characteristics of chromosome aberration rate and micronucleus rate in the pre-job occupational health examination of radiation workers in Shenzhen from 2015 to 2020 and to provide scientific basis for strengthening the radiation protection and occupational health management among radiation workers.

Methods A cross-sectional study was conducted among 2 777 radiation workers who received pre-job occupational health examinations in the Shenzhen Prevention and Treatment Center for Occupational Disease from 2015 to 2020, including 2 210 males and 567 females with age range of 17–69 (27.6±6.8) years. The subjects were divided into five groups by age (17–20, 21–30, 31–40, 41–50, and 51–69 years old). The lymphocyte micronuclei and chromosomes of the subjects were prepared by whole-blood microculture method. Chromosomal aberrations, including dicentric, rings, and acentric segments, in the chromosomal metaphases of 100 lymphocytes of each subject were scored by the automatic chromosome analysis system. The differences in chromosome aberrations and micronuclei were compared between different age groups and subjects of different genders in the same age group. The measurement data that conformed to the normal distribution were compared between groups by analysis of variance. The distribution of chromosome aberrations and micronuclei obeyed the Poisson distribution, and nonparametric test was used. Comparison between two groups was performed using Mann-Whitney U test, and comparison between multiple groups was performed using Kruskal-Wallis rank-sum test. Spearman rank correlation analysis was used to analyze the correlation between subjects' age and chromosome aberration and micronucleus rates.

Results The chromosome aberration (dicentric + ring + acentric segment) rate of 2 777 subjects was (0.072±0.005)%, and the dicentric + ring aberration rate was (0.016±0.002)%, the chromosome aberration cell rate was (0.068±0.005)%, the micronucleus rate was (0.43±0.01)‰, the micronucleated cell rate was (0.40±0.01)‰, and the lymphocyte transformation rate was (85.07±3.16)%. All of the above results were within the background level range of healthy people reported in domestic literature. No statistical difference was found in the chromosome aberration rate, dicentric + ring aberration rate, and chromosome aberration cell rate among different age groups, as well as the chromosome aberration rate and chromosome aberration cell rate among different genders in each age group (χ²=1.193, 0.931, 0.691; Z=−0.929 to −0.059; all P>0.05). Compared with the 17–20-year-old age group, the micronucleus rate and micronucleated cell rate of the subjects in the other age groups were higher, and the lymphocyte transformation rate was lower, and the differences were statistically significant (Z=−6.981 to −2.510, F=4.922–52.860, all P<0.05). The micronuclei rate and micronucleated cell rate of the subjects were positively correlated with age (r=0.166, 0.168; both P<0.001), whereas the lymphocyte transformation rate was negatively correlated with age (r=−0.197, P<0.001). The micronuclei rate, micronucleated cell rate, and lymphocyte transformation rate of female subjects in the 17–20- and 21–30-year-old age groups was significantly higher than those of the male subjects in the same age group, and the differences were statistically significant (Z=−4.826 to −3.516; F=6.947, 14.563; all P<0.01).

Conclusions The chromosome aberration rate and micronucleus rate in the pre-job occupational health examination of radiation workers in Shenzhen from 2015 to 2020 did not exceed the background level range of healthy people reported in domestic literature, but they tended to increase with age. The results of this study suggested that attention should be paid to strengthening the radiation protection and occupational health management of radiation workers.