钨合金企业工人钨与钴职业接触评估

Occupational exposure assessment of tungsten and cobalt in tungsten alloy manufacturing enterprises

[目的]调查钨合金企业工人钨、钴内外暴露水平,分析其分布特征,为进一步研究钨及其合金致硬金属肺病的职业健康风险评估提供基础数据。[方法]根据企业规模选择有代表性的4家钨合金生产企业,按随机抽样法选择直接接触钨及其合金且工龄≥1年的在职职工489人为观察组,325名无钨及其合金接触的职工作为对照组。对其工作场所进行职业卫生调查和钨、钴浓度检测,同期采集两组人群血样本,采用电感耦合等离子体质谱法测定样品中钨、钴含量。[结果]工人工作场所钨暴露水平为<0.03~4.42 mg/m(3中位数0.11 mg/m^3),钴暴露水平为<0.013~0.677 mg/m^3(中位数0.017 mg/m^3),其中湿磨、喷雾干燥、烧结、机加、成品检验包装工种钴暴露水平超标。观察组人群全血中钨检出率为12.5%(浓度<0.5~21.0μg/L,中位数<0.5μg/L);血钴检出率为61.1%(浓度<0.5~15.7μg/L,中位数0.7μg/L),与对照组人群相比,差异均有统计学意义(P<0.01)。不同工种工人血钨、血钴水平差异有统计学意义(P<0.01)。工人全血中钨与空气中钨相关系数为0.106(P<0.05),全血中钴与空气中钴的相关系数为0.197(P<0.01)。[结论]工人作业场所钨浓度未超标,钴浓度存在超标。工人全血中钨、钴含量分别与空气中钨、钴水平呈正相关关系。

[ Objective ] To investigate the internal and external exposure levels of tungsten and cobalt in workers in tungsten alloy manufacturing enterprises, and analyze their distribution characteristics in order to provide data support for occupational health risk assessment of hard metal lung disease induced by tungsten alloy.[ Methods ] Four tungsten alloy manufacturing enterprises of different sizes were selected, in which 489 workers exposed to tungsten and its alloys for more than one year were enrolled as exposure group by random sampling, and 325 workers without exposure as control group. Occupational health conditions of workplaces were investigated and the levels of airborne tungsten and cobalt were detected. The whole blood samples of the workers were collected to determine the tungsten and cobalt levels by inductively coupled plasma mass spectrometry. [ Results ] The exposure ranges of tungsten and cobalt in workplace air were 〈0.03-4.42 mg/m3 （median, 0.11 mg/m3） and 〈0.013-0.677 mg/m3 （median, 0.017 mg/m3）, respectively. Wet-grinding, drying, sintering, machining, and product packaging workers had higher air cobalt exposure levels than corresponding national standard limits. In the exposed group, the positive blood tungsten rate was 12.5% （concentration, 〈0.5-21.0 μg/L; median, 〈0.5 μg/L）, and the positive blood cobalt rate was 61.1% （concentration, 〈0.5-15.7 μg/L; median, 0.7 μg/L）, which were both higher than those in the controls （P〈0.01）. There were significant differences in blood tungsten and cobalt levels between the workers with different types of job （P〈 0.01）. Blood tungsten was positively correlated with airborne tungsten （r=0.106, P〈0.05）. Blood cobalt was also positively correlated with airborne cobalt （r=0.197, P〈0.01）. [ Conclusion ] The tungsten concentrations in workplace air meet the national health requirement, but the cobalt concentrations exceed the national standard limit. The tungsten and cobalt levels in blood are positively correlated with the airborne tungsten and cobalt levels respectively.