McClean Michael D, Osborn Linda V, Snawder John E, Olsen Larry D, Kriech Anthony J, Sjödin Andreas, Li Zheng, Smith Jerome P, Sammons Deborah L, Herrick Robert F, Cavallari Jennifer M
Boston University School of Public Health, 715 Albany Street, Boston, MA 02218, USA.
Ann Occup Hyg. 2012 Nov;56(9):1013-24. doi: 10.1093/annhyg/mes058. Epub 2012 Sep 20.
Paving workers are exposed to polycyclic aromatic compounds (PACs) while working with hot-mix asphalt (HMA). Further characterization of the source and route of these exposures is necessary to guide exposure-reduction strategies.
Personal air (n=144), hand-wash (n=144), and urine (n=480) samples were collected from 12 paving workers over 3 workdays during 4 workweeks. Urine samples were collected at preshift, postshift, and bedtime and analyzed for 10 hydroxylated PACs (1-OH-pyrene; 1-, 2-, 3-, 4-OH-phenanthrene; 1-, 2-OH-naphthalene; 2-, 3-, 9-OH-fluorene) by an immunochemical quantification of PACs (I-PACs). The air and hand-wash samples were analyzed for the parent compounds corresponding to the urinary analytes. Using a crossover study design, each of the 4 weeks represented a different exposure scenario: a baseline week (normal conditions), a dermal protection week (protective clothing), a powered air-purifying respirator (PAPR) week, and a biodiesel substitution week (100% biodiesel provided to replace the diesel oil normally used by workers to clean tools and equipment). The urinary analytes were analyzed using linear mixed-effects models.
Postshift and bedtime concentrations were significantly higher than preshift concentrations for most urinary biomarkers. Compared with baseline, urinary analytes were reduced during the dermal protection (29% for 1-OH-pyrene, 15% for I-PACs), the PAPR (24% for 1-OH-pyrene, 15% for I-PACs), and the biodiesel substitution (15% for 1-OH-pyrene) weeks. The effect of PACs in air was different by exposure scenario (biodiesel substitution>dermal protection>PAPR and baseline) and was still a significant predictor of most urinary analytes during the week of PAPR use, suggesting that PACs in air were dermally absorbed. The application temperature of HMA was positively associated with urinary measures, such that an increase from the lowest application temperature (121°C) to the highest (154°C) was associated with a 72% increase in ΣOH-fluorene and 1-OH-pyrene and an 82% increase in ΣOH-phenanthrene. Though PACs in hand-wash samples were not predictors of urinary analytes, the effects observed during the PAPR scenario and the week of increased dermal protection provide evidence of dermal absorption.
Our results provide evidence that PACs in air are dermally absorbed. Reducing the application temperature of asphalt mix appears to be a promising strategy for reducing PAC exposure among paving workers. Additional reductions may be achieved by requiring increased dermal coverage of workers and by substituting biodiesel for diesel oil as a cleaning agent.
铺路工人在使用热拌沥青（HMA）工作时会接触到多环芳烃化合物（PACs）。进一步确定这些暴露源和暴露途径，对于指导减少暴露的策略至关重要。
在4个工作周内，对12名铺路工人在3个工作日内采集个人空气样本（n = 144）、洗手样本（n = 144）和尿液样本（n = 480）。在班前、班后和就寝时间采集尿液样本，并通过免疫化学定量分析PACs（I-PACs）来检测10种羟基化PACs（1-羟基芘；1-、2-、3-、4-羟基菲；1-、2-羟基萘；2-、3-、9-羟基芴）。对空气和洗手样本分析与尿液分析物对应的母体化合物。采用交叉研究设计，4周中的每一周代表不同的暴露场景：基线周（正常条件）、皮肤防护周（防护服）、动力空气净化呼吸器（PAPR）周和生物柴油替代周（提供100%生物柴油以替代工人通常用于清洁工具和设备的柴油）。使用线性混合效应模型分析尿液分析物。
大多数尿液生物标志物的班后和就寝时间浓度显著高于班前浓度。与基线相比，在皮肤防护周（1-羟基芘降低29%，I-PACs降低15%）、PAPR周（1-羟基芘降低24%，I-PACs降低15%）和生物柴油替代周（1-羟基芘降低15%），尿液分析物减少。不同暴露场景下空气中PACs的影响不同（生物柴油替代>皮肤防护>PAPR和基线），并且在使用PAPR的那一周，空气中的PACs仍是大多数尿液分析物的显著预测因子，这表明空气中的PACs可经皮肤吸收。HMA的施工温度与尿液检测指标呈正相关，即施工温度从最低（121°C）升至最高（154°C）时，ΣOH-芴和1-羟基芘增加72%，ΣOH-菲增加82%。虽然洗手样本中的PACs不是尿液分析物的预测因子，但在PAPR场景和皮肤防护增强的那一周观察到的影响提供了经皮肤吸收的证据。
我们的结果表明空气中的PACs可经皮肤吸收。降低沥青混合料的施工温度似乎是减少铺路工人PAC暴露的一个有前景的策略。通过要求增加工人的皮肤覆盖面积以及用生物柴油替代柴油作为清洁剂，可能会进一步减少暴露。
