Objectives

Hexavalent chromium (Cr(VI)) is classified as a human carcinogen. Occupational Cr(VI) exposure can occur during different work processes, but the current exposure to Cr(VI) at Swedish workplaces is unknown.

Methods

This cross-sectional study (SafeChrom) recruited non-smoking men and women from 14 companies with potential Cr(VI) exposure (n = 113) and controls from 6 companies without Cr(VI) exposure (n = 72). Inhalable Cr(VI) was measured by personal air sampling (outside of respiratory protection) in exposed workers. Total Cr was measured in urine (pre- and post-shift, density-adjusted) and red blood cells (RBC) (reflecting Cr(VI)) in exposed workers and controls. The Bayesian tool Expostats was used to assess risk and evaluate occupational exposure limit (OEL) compliance.

Results

The exposed workers performed processing of metal products, steel production, welding, plating, and various chemical processes. The geometric mean concentration of inhalable Cr(VI) in exposed workers was 0.15 μg/m³ (95% confidence interval: 0.11–0.21). Eight of the 113 exposed workers (7%) exceeded the Swedish OEL of 5 μg/m³, and the Bayesian analysis estimated the share of OEL exceedances up to 19.6% for stainless steel welders. Median post-shift urinary (0.60 μg/L, 5th-95th percentile 0.10–3.20) and RBC concentrations (0.73 μg/L, 0.51–2.33) of Cr were significantly higher in the exposed group compared with the controls (urinary 0.10 μg/L, 0.06–0.56 and RBC 0.53 μg/L, 0.42–0.72). Inhalable Cr(VI) correlated with urinary Cr (r_S = 0.64) and RBC-Cr (r_S = 0.53). Workers within steel production showed the highest concentrations of inhalable, urinary and RBC Cr. Workers with inferred non-acceptable local exhaustion ventilation showed significantly higher inhalable Cr(VI), urinary and RBC Cr concentrations compared with those with inferred acceptable ventilation. Furthermore, workers with inferred correct use of respiratory protection were exposed to significantly higher concentrations of Cr(VI) in air and had higher levels of Cr in urine and RBC than those assessed with incorrect or no use. Based on the Swedish job-exposure-matrix, approximately 17 900 workers were estimated to be occupationally exposed to Cr(VI) today.

Conclusions

Our study demonstrates that some workers in Sweden are exposed to high levels of the non-threshold carcinogen Cr(VI). Employers and workers seem aware of Cr(VI) exposure, but more efficient exposure control strategies are required. National strategies aligned with the European strategies are needed in order to eliminate this cause of occupational cancer.

中文翻译：

---

六价铬在瑞典仍然是一个令人担忧的问题——来自 SafeChrom 项目的横断面研究的证据

目标

六价铬 (Cr(VI)) 被列为人类致癌物。职业性 Cr(VI) 暴露可能发生在不同的工作过程中，但目前瑞典工作场所的 Cr(VI) 暴露情况尚不清楚。

方法

这项横断面研究 (SafeChrom) 招募了来自 14 家可能接触 Cr(VI) 的公司的非吸烟男性和女性 (n = 113)，以及来自 6 家没有接触 Cr(VI) 的公司的对照组 (n = 72)。通过对接触过的工作人员进行个人空气采样（呼吸防护之外）来测量可吸入 Cr(VI)。在暴露的工人和对照组中测量尿液（班前和班后，密度调整）和红细胞 (RBC)（反映 Cr(VI)）中的总 Cr。贝叶斯工具 Expostats 用于评估风险并评价职业接触限值 (OEL) 合规性。

结果

暴露在外的工人从事金属制品加工、钢铁生产、焊接、电镀和各种化学工艺。暴露工人体内可吸入Cr(VI)的几何平均浓度为0.15 μg/m ³（95%置信区间：0.11–0.21）。113 名暴露工人中有 8 名 (7%) 超过了瑞典 OEL 5 μg/m ³，贝叶斯分析估计不锈钢焊工 OEL 超标比例高达 19.6%。与对照组（尿 0.10 μg/L）相比，暴露组的中位后尿 Cr 浓度（0.60 μg/L，第 5-95 个百分位数 0.10-3.20）和红细胞浓度（0.73 μg/L，0.51-2.33）显着更高。 L，0.06–0.56 和红细胞 0.53 μg/L，0.42–0.72）。可吸入 Cr(VI) 与尿 Cr (r _S  = 0.64) 和 RBC-Cr (r _S  = 0.53) 相关。钢铁生产工人的吸入、尿液和红细胞铬浓度最高。与推断可接受通气的工人相比，推断局部用力通气不可接受的工人的吸入 Cr(VI)、尿液和红细胞 Cr 浓度显着较高。此外，与未正确使用或未使用呼吸防护装置的工人相比，推断正确使用呼吸防护装置的工人暴露于空气中显着更高浓度的 Cr(VI)，并且尿液和红细胞中的 Cr 含量更高。根据瑞典的工作接触矩阵，估计目前约有 17 900 名工人因职业接触六价铬。

结论

我们的研究表明，瑞典的一些工人接触高浓度的非阈值致癌物 Cr(VI)。雇主和工人似乎都意识到 Cr(VI) 暴露，但需要更有效的暴露控制策略。为了消除职业癌的这一原因，需要制定与欧洲战略相一致的国家战略。