Yassi A, Cheang M, Tenenbein M, Bawden G, Spiegel J, Redekop T
Department of Community Health Sciences, University of Manitoba, Winnipeg.
Am J Public Health. 1991 Jun;81(6):736-40. doi: 10.2105/ajph.81.6.736.
While regulations for workplace lead exposure become more strict, their effectiveness in decreasing blood lead concentrations and the method by which this is attained have not been evaluated.
An analysis was conducted of 10,190 blood lead samples from employees of 10 high-risk workplaces collected in Manitoba, 1979-87, as part of regulated occupational surveillance.
A significant decrease in blood lead concentrations was observed overall as well as for each individual company. A 1979 government regulation to reduce blood lead to below 3.38 mumol/L (70 micrograms/dl) was followed by a drop in blood lead concentrations; a 1983 order to reduce blood leads to below 2.90 mumol/L (60 micrograms/dl) was not followed by such a drop. Longitudinal analysis by individual workers suggested that companies were complying by use of administrative control, i.e., removing workers to lower lead areas until blood lead levels had fallen, then returning them to high lead areas.
Focusing upon blood lead as the sole criterion for compliance is not effective; regulations must specifically require environmental monitoring and controls. Biological surveillance serves as "back-up" to environmental surveillance and this database illustrates the usefulness of a comprehensive centralized surveillance system.
尽管工作场所铅暴露的相关规定变得更加严格，但这些规定在降低血铅浓度方面的有效性以及实现这一目标的方法尚未得到评估。
对1979 - 1987年在曼尼托巴省收集的10个高风险工作场所员工的10190份血铅样本进行了分析，作为规定的职业监测的一部分。
总体以及每个公司的血铅浓度均有显著下降。1979年政府规定将血铅水平降至3.38微摩尔/升（70微克/分升）以下后，血铅浓度下降；1983年要求将血铅降至2.90微摩尔/升（60微克/分升）以下的命令发布后，血铅浓度并未下降。对个体工人的纵向分析表明，公司通过行政控制来遵守规定，即把工人转移到铅含量较低的区域，直到血铅水平下降，然后再将他们返回高铅区域。
仅将血铅作为合规的唯一标准是无效的；规定必须明确要求进行环境监测和控制。生物监测作为环境监测的“后备”，这个数据库说明了全面集中监测系统的有用性。
