Rollins School of Public Health, Atlanta, Georgia, USA.
Finnish Cancer Registry, Helsinki, Finland.
Occup Environ Med. 2019 Sep;76(9):603-610. doi: 10.1136/oemed-2019-105786. Epub 2019 Jul 11.
Study carcinogenicity of inorganic lead, classified as 'probably carcinogenic' to humans by the International Agency for Research on Cancer (brain, lung, kidney and stomach).
We conducted internal and external analyses for cancer incidence in two cohorts of 29 874 lead-exposed workers with past blood lead data (Finland, n=20 752, Great Britain=9122), with 6790 incident cancers. Exposure was maximum measured blood lead.
The combined cohort had a median maximum blood lead of 29 μg/dL, a mean first blood lead test of 1977, and was 87% male. Significant (p<0.05) positive trends, using the log of maximum blood lead, were found for brain cancer (malignant), Hodgkin's lymphoma, lung cancer and rectal cancer, while a significant negative trend was found for melanoma. Borderline significant positive trends (0.05≤p≤0.10) were found for oesophageal cancer, meningioma and combined malignant/benign brain cancer. Categorical analyses reflected these trends. Significant interactions by country were found for lung, brain and oesophageal cancer, with Finland showing strong positive trends, and Great Britain showing modest or no trends. Larynx cancer in Finland also showed a positive trend (p=0.05). External analyses for high exposure workers (maximum blood lead >40 μg/dL) showed a significant excess for lung cancer in both countries combined, and significant excesses in Finland for brain and lung cancer. The Great Britain data were limited by small numbers for some cancers, and limited variation in exposure.
We found strong positive incidence trends with increasing blood lead level, for several outcomes in internal analysis. Two of these, lung and brain cancer, were sites of a priori interest.
研究无机铅的致癌性，国际癌症研究机构（IARC）将其归类为“对人类可能致癌”（脑、肺、肾和胃）。
我们对两组有过去血铅数据的 29874 名铅暴露工人（芬兰，n=20752；英国，n=9122）进行了癌症发病率的内部和外部分析，共发现 6790 例癌症。暴露量为最大血铅值。
合并队列的最大血铅中位数为 29μg/dL，首次血铅检测的平均值为 1977 年，且 87%为男性。使用最大血铅的对数，发现脑癌（恶性）、霍奇金淋巴瘤、肺癌和直肠癌呈显著（p<0.05）正相关趋势，而黑色素瘤呈显著负相关趋势。食管癌、脑膜瘤和脑恶性/良性癌的正相关趋势具有边缘显著性（0.05≤p≤0.10）。按国家划分的分类分析反映了这些趋势。肺、脑和食管癌存在显著的交互作用，芬兰显示出强烈的正相关趋势，英国则显示出适度或没有趋势。芬兰的喉癌也表现出正相关趋势（p=0.05）。对高暴露工人（最大血铅>40μg/dL）的外部分析显示，两国合并的肺癌发病率显著升高，芬兰的脑癌和肺癌发病率也显著升高。英国的数据受到某些癌症数量较少和暴露变化有限的限制。
我们在内部分析中发现，随着血铅水平的升高，几种结果的发病率呈明显上升趋势。其中两个，即肺癌和脑癌，是事先关注的部位。
