Casjens Swaantje, Henry Jana, Rihs Hans-Peter, Lehnert Martin, Raulf-Heimsoth Monika, Welge Peter, Lotz Anne, Gelder Rainer Van, Hahn Jens-Uwe, Stiegler Hugo, Eisele Lewin, Weiss Tobias, Hartwig Andrea, Brüning Thomas, Pesch Beate
1.Institute for Prevention and Occupational Medicine of the German Social Accident Insurance, Institute of the Ruhr-Universität Bochum (IPA), Buerkle-de-la-Camp-Platz 1, 44789 Bochum, Germany;
2.Institute for Occupational Safety and Health of the German Social Accident Insurance (IFA), Alte Heerstrasse 111, 53757 Sankt Augustin, Germany;
Ann Occup Hyg. 2014 Nov;58(9):1143-54. doi: 10.1093/annhyg/meu068. Epub 2014 Sep 15.
Iron is the major metal found in welding fumes, and although it is an essential trace element, its overload causes toxicity due to Fenton reactions. To avoid oxidative damage, excess iron is bound to ferritin, and as a result, serum ferritin (SF) is a recognized biomarker for iron stores, with high concentrations linked to inflammation and potentially also cancer. However, little is known about iron overload in welders. Within this study, we assessed the iron status and quantitative associations between airborne iron, body iron stores, and iron homeostasis in 192 welders not wearing dust masks. Welders were equipped with personal samplers in order to determine the levels of respirable iron in the breathing zone during a working shift. SF, prohepcidin and other markers of iron status were determined in blood samples collected after shift. The impact of iron exposure and other factors on SF and prohepcidin were estimated using multiple regression models. Our results indicate that respirable iron is a significant predictor of SF and prohepcidin. Concentrations of SF varied according to the welding technique and respiratory protection used, with a median of 103 μg l(-1) in tungsten inert gas welders, 125 μg l(-1) in those wearing air-purifying respirators, and 161 μg l(-1) in other welders. Compared to welders with low iron stores (SF < 25 μg l(-1)), those with excess body iron (SF ≥ 400 μg l(-1)) worked under a higher median concentration of airborne iron (60 μg m(-3) versus 148 μg m(-3)). Even though air concentrations of respirable iron and manganese were highly correlated, and low iron stores have been reported to increase manganese uptake in the gastrointestinal tract, no correlation was seen between SF and manganese in blood. In conclusion, monitoring SF may be a reasonable method for health surveillance of welders. Respiratory protection with air-purifying respirators can decrease iron exposure and avoid chronically higher SF in welders working with high-emission technologies.
铁是焊接烟雾中发现的主要金属,虽然它是一种必需的微量元素,但其过载会因芬顿反应而导致毒性。为避免氧化损伤,过量的铁会与铁蛋白结合,因此,血清铁蛋白(SF)是一种公认的铁储存生物标志物,高浓度与炎症以及潜在的癌症有关。然而,关于焊工中铁过载的情况知之甚少。在本研究中,我们评估了192名未佩戴防尘口罩的焊工的铁状态以及空气中铁、体内铁储存和铁稳态之间的定量关联。为了确定工作班次期间呼吸区域可吸入铁的水平,焊工配备了个人采样器。轮班后采集的血液样本中测定了SF、前铁调素和其他铁状态标志物。使用多元回归模型估计铁暴露和其他因素对SF和前铁调素的影响。我们的结果表明,可吸入铁是SF和前铁调素的重要预测指标。SF的浓度根据焊接技术和使用的呼吸防护而有所不同,钨极惰性气体保护焊焊工的中位数为103μg l(-1),佩戴空气净化呼吸器的焊工为125μg l(-1),其他焊工为161μg l(-1)。与铁储存量低(SF<25μg l(-1))的焊工相比,体内铁过量(SF≥400μg l(-1))的焊工在空气中铁的中位数浓度较高(分别为60μg m(-3)和148μg m(-3))的环境下工作。尽管可吸入铁和锰的空气浓度高度相关,并且据报道铁储存量低会增加胃肠道对锰的吸收,但血液中的SF与锰之间未发现相关性。总之,监测SF可能是焊工健康监测的一种合理方法。使用空气净化呼吸器进行呼吸防护可以减少铁暴露,并避免从事高排放技术工作的焊工长期处于较高的SF水平。