MacLeod Jill S, Harris M Anne, Tjepkema Michael, Peters Paul A, Demers Paul A
Occupational Cancer Research Centre, Prevention and Cancer Control, Cancer Care Ontario, Toronto, Ontario, Canada.
School of Occupational and Public Health, Ryerson University, Toronto, Ontario, Canada.
Saf Health Work. 2017 Sep;8(3):258-266. doi: 10.1016/j.shaw.2016.12.001. Epub 2017 Jan 12.
Welders are exposed to many known and suspected carcinogens. An excess lung cancer risk among welders is well established, but whether this is attributable to welding fumes is unclear. Excess risks of other cancers have been suggested, but not established. We investigated welding cancer risks in the population-based Canadian Census Health and Environmental Cohort.
Among 1.1 million male workers, 12,845 welders were identified using Standard Occupational Classification codes and followed through retrospective linkage of 1991 Canadian Long Form Census and Canadian Cancer Registry (1992-2010) records. Hazard ratios (HRs) were calculated using Cox proportional hazards models based on estimated risks of lung cancer, mesothelioma, and nasal, brain, stomach, kidney, and bladder cancers, and ocular melanoma. Lung cancer histological subtypes and risks by industry group and for occasional welders were examined. Some analyses restricted comparisons to blue-collar workers to minimize effects of potential confounders.
Among welders, elevated risks were observed for lung cancer [HR: 1.16, 95% confidence interval (CI): 1.03-1.31], mesothelioma (HR: 1.78, 95% CI: 1.01-3.18), bladder cancer (HR: 1.40, 95% CI: 1.15-1.70), and kidney cancer (HR: 1.30, 95% CI: 1.01-1.67). When restricted to blue-collar workers, lung cancer and mesothelioma risks were attenuated, while bladder and kidney cancer risks increased.
Excess risks of lung cancer and mesothelioma may be partly attributable to factors including smoking and asbestos. Welding-specific exposures may increase bladder and kidney cancer risks, and particular sources of exposure should be investigated. Studies that are able to disentangle welding effects from smoking and asbestos exposure are needed.
焊工暴露于多种已知和疑似致癌物中。焊工患肺癌风险过高已得到充分证实，但这是否归因于焊接烟尘尚不清楚。有人提出其他癌症存在过高风险，但尚未得到证实。我们在基于人群的加拿大人口普查健康与环境队列中调查了焊接导致癌症的风险。
在110万男性工人中，使用标准职业分类代码识别出12845名焊工，并通过对1991年加拿大长表人口普查和加拿大癌症登记处（1992 - 2010年）记录进行回顾性关联追踪。使用Cox比例风险模型根据肺癌、间皮瘤、鼻癌、脑癌、胃癌、肾癌、膀胱癌以及眼黑色素瘤的估计风险计算风险比（HRs）。检查了肺癌组织学亚型以及按行业组和偶尔焊工的风险。一些分析将比较限制在蓝领工人中，以尽量减少潜在混杂因素的影响。
在焊工中观察到肺癌（HR：1.16，95%置信区间（CI）：1.03 - 1.31）、间皮瘤（HR：1.78，95%CI：1.01 - 3.18）、膀胱癌（HR：1.40，95%CI：1.15 - 1.70）和肾癌（HR：1.30，95%CI：1.01 - 1.67）风险升高。当仅限于蓝领工人时，肺癌和间皮瘤风险减弱，而膀胱癌和肾癌风险增加。
肺癌和间皮瘤的过高风险可能部分归因于包括吸烟和接触石棉等因素。特定于焊接的暴露可能增加膀胱癌和肾癌风险，应调查特定的暴露源。需要能够区分焊接影响与吸烟和石棉暴露的研究。
