WORK AND BLOOD LEAD RELATIONSHIPS AMONG BRIDGE WORKERS

本研究的主要目的是根据特定任务的时间活动数据，制定职业暴露监测和控制策略，将暴露限制在可接受的水平，并最大限度地减少对侵入性生物测量的依赖。最近，一项旨在消除康涅狄格桥梁建筑工人高血铅水平的干预计划被证明是有效的。（Vork等人，提交）（附录A）。这一干预方案使用合同规范要求牵头实施健康保护方案，并支付承包商为确保该方案成功实施而产生的费用。在许多策略中，需要经常监测血铅。这些测试被用来提醒雇主，有时要求他们减少特定工人未来接触空气中的铅。除了血铅监测外，铅健康保护计划还需要全面的工业卫生监测。在血铅和工业卫生监测项目中收集的数据为桥梁修复工作中铅暴露的研究目标提供了所需的详细信息。本研究建议：使用康涅狄格干预计划中参与队列的血铅数据和时间活动模式来估计最近的铅暴露（即过去30天内从工作中累积摄入的铅）；使用分类和回归树（CART）分析一半的康涅狄格队列来确定各种任务、个人和环境变量对具体目标1中估计的累积铅摄入量的预测价值；使用康涅狄格干预项目队列的另一半数据验证特定目标2中导出的回归模型；并探讨回归模型的含义，以确定：a)对正在进行的暴露控制计划的成本效益监测要求，包括康涅狄格州数据集的潜在缺陷；b)有效的控制策略

The broad aim of this research is to develop an occupational exposure monitoring and control strategy, based on time-activity data for specific tasks, to constrain exposures to acceptable levels and minimize reliance on invasive biological measurements. Recently an intervention program developed to eliminate high blood lead levels in Connecticut bridge construction workers was shown to be effective. (Vork et. al., submitted) (Appendix A). This intervention program used contract specifications to require the lead health protection program and paid the expenses incurred by contractors to ensure that it would be successfully implemented. Among many strategies, frequent blood lead monitoring was required. These tests were used to alert employers and sometimes require them to reduce future exposures to airborne lead in specific workers. In addition to blood lead monitoring, the lead health protection program also required comprehensive industrial hygiene monitoring. The data collected during both the blood lead and the industrial hygiene monitoring programs provide the detailed information required for this research goal to be pursued in the context of lead exposure in bridge rehabilitation work. This research proposes to: use the blood lead data and time- activity patterns from the cohort involved in the Connecticut intervention program to estimate recent lead exposure (i.e. the cumulative lead intake from work over the past 30 day period); to use the Categorization and Regression Tree (CART) analysis of one half of the Connecticut cohort to determine the predictive value of various task, personal and environmental variables on cumulative lead intake as estimated in specific aim one; to validate the regression model derived in Specific Aim 2 using the other half of the data from the Connecticut intervention program cohort; and explore the implications of the regression model for identifying: a) cost-effective surveillance requirements for ongoing exposure control programs including the potential deficiencies in the Connecticut data set: and b) efficacious control strategies