卫生研究

目的 探究影响铬酸盐生产企业中六价铬[Cr(Ⅵ)]职业接触人群尿铬水平的相关影响因素。方法 2021年对某铬酸盐生产企业中725人开展横断面调查研究，将6个接铬车间(焙烧、铬酐、制造、精制、检修和动力)劳动者共651人列为接触组，该企业职能部门劳动者共74人列为对照组。经问卷调查了解人口学信息、职业史、既往病史、生活史等内容；以定点短时间采样结合岗位长时间采样的方式测定主要工序中各岗位劳动者的Cr(Ⅵ)接触水平；采集劳动者的班前尿(5～10 mL),经石墨炉原子吸收光谱法测定尿铬水平；采用Kruskal-Wallis检验分析不同车间空气Cr(Ⅵ)浓度及尿铬水平差异，经多元线性回归分析尿铬水平的相关影响因素。结果接触组男性450人，女性201人，年龄分别为44.25岁和43.39岁，工龄分别为8.61年和9.14年。对照组男性32人，女性42人，平均年龄分别为37.22岁和35.55岁，平均工龄分别为6.88年和7.50年。接触组人群尿铬四分位数水平为3.05(1.09,8.70)μmol/mol肌酐，其中8人超过尿中生物接触限值(1.2%),对照组尿铬水平均小于0.22μmol/mol肌酐。年龄(F=65.82,P<0.01)、性别(χ²=19.97,P<0.01)、工龄(F=5.55,P<0.05)、吸烟(χ²=5.58,P=0.02)、周累计工作时间(χ²=100.77,P<0.01)在不同尿铬水平上差异有统计学意义。6个接铬车间岗位的C_TWA均符合职业接触限值(PC-TWA 0.05 mg/m³)的要求，但铬酐车间Cr(Ⅵ)空气浓度(0.010 mg/m³)及尿铬[18.60(7.07,27.41)μmol/mol肌酐]均显著高于其他车间(P<0.01)。多元线性回归结果显示，年龄与Cr(Ⅵ)空气浓度可显著影响接铬劳动者尿铬水平(P<0.01)。结论 该铬酸盐企业工作场所空气中Cr(Ⅵ)浓度是影响劳动者尿铬水平的重要因素，且铬酐车间Cr(Ⅵ)空气浓度最高，且尿铬水平最显著。

OBJECTIVE To investigate the possible factors affecting the total urinary chromium levels on a group of hexavalent chromium(Cr(Ⅵ)) occupational population in a chromate production factory, which will provide the scientific basis for workers' health promotion and self-protection.METHODS In May 2021, a cross-sectional study was conducted in a chromate production enterprise, in that, the demographic information, occupational history, past disease history as well as life style concerning the Cr(Ⅵ) exposed group(n=651) which cover the roasting, manufacturing, refining, chromic anhydride, power and overhauling sectors and the control group(n=74) which are all from functional department were collected through a questionnaire survey, the ambient Cr(Ⅵ) exposure levels either catched from a short-time detection pattern(C_STE) at certain work places or sampled from a series of typical posts throughout the main processes by aiming at the time-weight average exposure levels(C_TWA) for 8 h. The pre-shift urinary samples(5-10 mL) of all participants were collected and the total Cr(Ⅵ) levels were determined by the graphite atomic absorption spectroscopy method. Kruskal-Wallis test was used to analyze the concentration of hexavalent chromium in air and urine in different workshops. The possible factors who influencing the total Cr(Ⅵ) levels were analyzed by the multiple linear regression.RESULTS There were 448 males and 203 females in the exposed group, with an average age of 44.25 and 43.39 years old, respectively, and an average length of service of 8.61 and 9.14 years, respectively. There were 32 males and 42 females in the control group, with an average of 37.22 and 35.5 years old, respectively, and an average length of service of 6.88 and 7.5 years, respectively. The urinary chromium level in the exposed group(M(P25,P75)) was 3.05(1.09, 8.70) μmol/mol creatinine, with 8 individuals exceeding the biological exposure limit in urine(1.2%), while the urinary chromium level in the control group was all less than 0.22 μmol/mol creatinine. Age(F=65.82,P<0.01), gender(χ²=19.97,P<0.01),working-age(F=5.55,P<0.05), smoking(χ²=5.58,P=0.02) and weekly cumulative working hours(χ²=100.77,P<0.01) were statistically significant at different urinary chromium levels. the C_TWA of the 6 chromium-contacting job positions met the occupational exposure limit(PC-TWA 0.05 mg/m³), but the air chromium concentration(0.010 mg/m³) and urinary chromium(18.60(7.07,27.41)μmol/mol creatinine) in the chromic anhydride section were significantly different from those in other sections(P<0.01). The multivariate linear regression indicated that variables of age and the ambient Cr(Ⅵ) concentrations were noted to contribute to the total urinary chromium levels with significant differences(P<0.05).CONCLUSIONThe ambient Cr(Ⅵ) concentrations at workplaces throughout the main processes in this chromate factory is an important factor affecting the workers' total urinary chromium levels, and the change of chromium anhydride workshop is the most significant.