Cavallari Jennifer M, Osborn Linda V, Snawder John E, Kriech Anthony J, Olsen Larry D, Herrick Robert F, McClean Michael D
Harvard School of Public Health, Department of Environmental Health, 665 Huntington Avenue, Boston, MA 02215, USA.
Ann Occup Hyg. 2012 Mar;56(2):138-47. doi: 10.1093/annhyg/mer088. Epub 2011 Oct 24.
We evaluated personal airborne exposures to polycyclic aromatic compounds (PACs) and total organic matter (TOM) among hot-mix asphalt (HMA) paving workers. The primary objectives of this study were to identify predictors of airborne PAC exposures, identify PAC exposure sources, and characterize how work practices may affect personal airborne exposure to PACs.
Four workers were recruited from each of three asphalt paving crews (12 workers) and were monitored for three consecutive days over 4 weeks for a total of 12 sampling days per worker (144 worker-days). Three sampling weeks were conducted while maintaining standard working conditions with regard to airborne exposures. The fourth week included the substitution of biodiesel for diesel oil used to clean tools and equipment. Linear mixed-effects models were used to evaluate predictors of airborne exposures including weather parameters (air temperature, wind speed, and relative humidity), worksite conditions (HMA application temperature, work rate, asphalt grade, and biodiesel use), and personal factors (minutes sampled, minutes of downtime, and smoking status).
Concentrations of the 33 individual PACs measured in personal air samples were generally below detection limits under all conditions with the exception of fluorene [geometric mean (GM) = 65 ng m(-3)], naphthalene (GM = 833 ng m(-3)), phenanthrene (GM = 385 ng m(-3)), and pyrene (GM = 57 ng m(-3)). The summary measures of TOM (GM = 864 μg m(-3)) and four- to six-ring PAC (GM = 0.13 μg m(-3)) were detected in the majority of air samples. Although task was not a predictor of airborne exposures, job site characteristics such as HMA application temperature were found to significantly (P ≤ 0.001) affect summary and individual PAC exposures. Based on the results of multivariate linear mixed-effects models, substituting biodiesel for diesel oil as a cleaning agent was associated with significant (P ≤ 0.01) reductions in TOM, four- to six-ring PACs, and naphthalene and pyrene concentrations that ranged from 31 to 56%. Using multivariate linear mixed-effects models under standard conditions, reducing the application temperature of HMA from 149°C (300°F) to 127°C (260°F) could be expected to reduce airborne exposures by 42-82%, varying by analyte.
Promising strategies for reducing airborne exposures to PACs among HMA paving workers include substituting biodiesel for diesel oil as a cleaning agent and decreasing the HMA application temperature.
我们评估了热拌沥青（HMA）铺路工人个人空气中多环芳烃化合物（PACs）和总有机物（TOM）的暴露情况。本研究的主要目的是确定空气中PAC暴露的预测因素，识别PAC暴露源，并描述工作实践如何影响个人空气中PAC暴露。
从三个沥青铺路队中各招募四名工人（共12名工人），连续4周每天监测3天，每名工人共12个采样日（144个工人日）。在保持空气暴露标准工作条件的情况下进行了三个采样周。第四周包括用生物柴油替代用于清洁工具和设备的柴油。使用线性混合效应模型评估空气暴露的预测因素，包括天气参数（气温、风速和相对湿度）、工作现场条件（HMA施工温度、工作速率、沥青等级和生物柴油使用情况）以及个人因素（采样分钟数、停机分钟数和吸烟状况）。
在所有条件下，个人空气样本中测量的33种单个PACs的浓度一般低于检测限，但芴[几何均值（GM）=65 ng m⁻³]、萘（GM = 833 ng m⁻³）、菲（GM = 385 ng m⁻³）和芘（GM = 57 ng m⁻³）除外。大多数空气样本中检测到了TOM的汇总指标（GM = 864 μg m⁻³）和四环至六环PAC（GM = 0.13 μg m⁻³）。虽然任务不是空气暴露的预测因素，但发现诸如HMA施工温度等工作现场特征会显著（P≤0.001）影响汇总和单个PAC暴露。基于多变量线性混合效应模型的结果，用生物柴油替代柴油作为清洁剂与TOM、四环至六环PAC以及萘和芘浓度显著（P≤0.01）降低相关，降低幅度在31%至56%之间。在标准条件下使用多变量线性混合效应模型，将HMA的施工温度从149°C（300°F）降至127°C（260°F），预计空气暴露可降低42%至82%，具体因分析物而异。
减少HMA铺路工人空气中PAC暴露的有前景的策略包括用生物柴油替代柴油作为清洁剂以及降低HMA施工温度。
