PAH Exposure and DNA Damage in Roofers

描述（由申请人提供）：建筑业是最常与职业癌症联系在一起的行业之一，据报道，屋顶工人的癌症风险较高。暴露于致癌的多环芳烃（PAHs）一直是该行业的一个主要问题，主要是暴露于沥青烟雾和煤焦油的工人。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未充分考虑吸烟等混杂因素而受到批评。据估计，5万名屋顶工人平均有40%的工作时间暴露在沥青烟雾中。佛罗里达州是屋顶工人最集中的州，几乎占美国所有屋顶工人的10%。然而，没有研究调查过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南佛罗里达州屋顶工人对多环芳烃的暴露（个人和区域测量），其内部剂量（血液中的多环芳烃和尿液中选定的代谢物）和DNA损伤（使用带有自动图像捕获和无偏评分的Comet测定）。有关工作和任务相关因素、个人防护装备的使用和非职业接触的信息将通过问卷调查和在工作期间观察屋顶工人来收集。多元线性回归模型将用于研究生物标志物和DNA损伤的变异来源。拟议研究的创新方面是使用基于萘的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差彗星测定的新进展，以及在南佛罗里达州屋顶工人中实现暴露，内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是为了回应国家职业健康研究所（NIOSH）国家职业研究议程（NORA）部门的研究空白，它将回应建筑部门暴露评估和生物监测研究优先领域的需求。拟议的研究将通过提供有关改变工作场所暴露水平的因素的信息，为NIOSH指导的“从研究到实践”做出贡献。我们期望结果将指导未来的策略，以减少和防止多环芳烃暴露在屋顶。

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.