Pocock S J, Delves H T, Ashby D, Shaper A G, Clayton B E
Department of Clinical Epidemiology and General Practice, Royal Free Hospital School of Medicine, London, UK.
Hum Toxicol. 1988 Mar;7(2):95-103. doi: 10.1177/096032718800700201.
Blood cadmium concentrations were determined for 6919 men aged 40-59 randomly selected from general practice registers in 24 British towns. The mean and median blood cadmium were 1.9 and 1.4 micrograms/1 respectively and the distribution was highly skewed. The mean levels in non-smokers was 1.0 micrograms/l and current smokers showed a marked gradient with the daily amount smoked, with a mean of 3.9 micrograms/l in men smoking 40 or more cigarettes per day. Whereas 95% of men who never smoked had blood cadmium less than 2.0 micrograms/l, 80% of men smoking 20 or more cigarettes a day exceeded this figure. 1% of the men had blood cadmium concentrations greater than or equal to 7 micrograms/l virtually all of whom currently smoked cigarettes. Blood cadmium levels in ex-smokers were much lower than in current smokers even for those who had stopped within the past year. However, the mean levels in ex-smokers remained higher than the 'never smoked' for several years after stopping. There was little evidence that age, social class, or alcohol consumption were associated with blood cadmium levels after allowance for cigarette smoking. There is substantial geographic variation in mean blood cadmium for middle-aged men which could not be completely accounted for by smoking differences. Towns in the south and east of England all had mean levels under 2.0 micrograms/l whereas the majority of towns in other parts of Britain had mean levels greater than 2.0 micrograms/l. Possible reasons for this geographic pattern (e.g. geochemistry, industrial exposure, dietary differences) need further exploration.
对从英国24个城镇的普通诊所登记册中随机选取的6919名年龄在40至59岁之间的男性测定了血液镉浓度。血液镉的均值和中位数分别为1.9微克/升和1.4微克/升，且分布高度偏态。不吸烟者的平均水平为1.0微克/升，当前吸烟者呈现出与每日吸烟量明显的梯度关系，每天吸40支或更多香烟的男性平均水平为3.9微克/升。从未吸烟的男性中95%的血液镉含量低于2.0微克/升，而每天吸20支或更多香烟的男性中80%超过了这一数值。1%的男性血液镉浓度大于或等于7微克/升，几乎所有人当前都吸烟。即使是那些在过去一年内戒烟的人，其血液镉水平也比当前吸烟者低得多。然而，戒烟后几年内，前吸烟者的平均水平仍高于“从未吸烟”者。在考虑吸烟因素后，几乎没有证据表明年龄、社会阶层或饮酒量与血液镉水平有关。中年男性的血液镉均值存在显著的地理差异，这不能完全由吸烟差异来解释。英格兰南部和东部的城镇平均水平均低于2.0微克/升，而英国其他地区的大多数城镇平均水平高于2.0微克/升。这种地理模式的可能原因（如地球化学、工业暴露、饮食差异）需要进一步探究。
