PAH Exposure and DNA Damage in Roofers

描述（由申请人提供）：建筑业是最常见的与职业性癌症有关的行业之一，据报道，屋顶工人的癌症风险升高。暴露于致癌的多环芳烃（PAHs）一直是该行业的主要问题，主要是在接触沥青烟雾和煤焦油的工人中。这一领域的大多数流行病学研究因缺乏具体的定量暴露数据和对吸烟等混杂因素的考虑不足而受到批评。据估计，50，000名屋顶工人在平均40%的工作时间内暴露于沥青烟雾中。佛罗里达州的屋顶工人最集中，几乎占美国所有屋顶工人的10%。然而，没有研究调查这一群体的沥青暴露和相关的健康风险。拟议研究的目的是同时量化暴露于多环芳烃（个人和区域测量），其内部剂量（血液中的多环芳烃和尿液中的选定代谢物）和DNA损伤（使用彗星试验，自动图像捕获和无偏见的评分）在南佛罗里达屋顶。将通过问卷调查和在工作期间观察屋顶工人来收集有关工作和任务相关因素、个人防护设备的使用和非职业暴露的信息。将应用多元线性回归模型来研究生物标志物和DNA损伤的变异来源。拟议研究的创新方面是使用萘基生物标志物来提高分析技术的灵敏度和实用性，应用自动图像捕获和无偏彗星分析的新进展，以及在南佛罗里达的屋顶工人中实现暴露、内部剂量和癌症风险标志物之间的直接联系。拟议研究的独特设计，以应对国家职业卫生研究所（NIOSH）国家职业研究议程（诺拉）部门的研究差距，它将响应暴露评估和生物监测研究的需求优先领域的建筑行业。拟议的研究将有助于NIOSH指导的“研究实践工作”，提供有关改变工作场所暴露水平的因素的信息。我们预计，结果将指导未来的战略，以减少和防止多环芳烃暴露在屋顶。 公共卫生相关性：以前的研究报告说，接触沥青的屋顶工人患癌症的风险增加;然而，研究未能衡量每个工人的沥青暴露。使用萘代谢物在尿液中作为替代的沥青中的化学物质，我们建议测量沥青暴露及其潜在的联系，DNA损伤在南佛罗里达屋顶。将调查几种工作、任务和生活方式相关因素（如吸烟）对接触水平和DNA损伤的影响。

DESCRIPTION (provided by applicant): Construction is among the top industries most commonly linked to occupational cancers with elevated cancer risks being reported in roofers. Exposure to the carcinogenic polycyclic aromatic hydrocarbons (PAHs) has been a major concern in this industry, mainly in workers exposed to asphalt fumes and coal tar. Most epidemiology studies in this area have been criticized for lack of specific quantitative exposure data and inadequate consideration of confounding factors such as cigarette smoking. It is estimated that 50,000 on-roof workers are exposed to asphalt fumes during on average 40% of their working hours. The State of Florida has the highest concentration of roofers accounting for almost 10% of all roofers in the U.S. However, no studies have investigated asphalt exposure and the related health risks in this group. The objective of the Proposed Research is to simultaneously quantify exposure to PAHs (personal and area measurements), their internal dose (PAHs in blood and selected metabolites in urine) and DNA damage (using the Comet assay with an automatic image capture and un-biased scoring) in South Florida roofers. Information on work and task related factors, use of personal protective equipment and non-occupational exposures will be collected via questionnaires and also by observing the roofers during work. Multiple linear regression models will be applied to investigate the sources of variation in biomarkers and DNA damage. The innovative aspects of the Proposed Study are the use of naphthalene-based biomarkers to increase sensitivity and practicality of analytical techniques, the application of new advances in the automatic image capture and un- biased Comet assay, and the achievement of a direct linkage between exposure, internal dose and cancer risk marker among roofers in South Florida. The Proposed Study is uniquely designed to respond to research gaps in the National Institute of Occupational Health (NIOSH) National Occupational Research Agenda (NORA) sectors and it will respond to needs in exposure assessment and biomonitoring research priority areas for the construction sector. The Proposed Research will contribute to the NIOSH guided 'research to practice efforts' by providing information on factors altering exposure levels at the workplace. We expect that results will guide future strategies to reduce and prevent PAH exposures in roofers. PUBLIC HEALTH RELEVANCE: Previous studies have reported increased cancer risk among roofers who are exposed to asphalt; however studies have failed to measure asphalt exposures for each worker. Using naphthalene metabolites in urine as a surrogate for the chemicals in asphalt, we propose to measure asphalt exposure and its potential link to DNA damage in South Florida roofers. The contribution of several work, task and lifestyle related factors (e.g. smoking) on the levels of exposure and DNA damage will be investigated.