沥青烟中16种PAHs组成及毒性当量变化规律研究

Change law and toxicity analysis of 16 PAHs in asphalt fume

因含有“三致作用”的多环芳烃(Polycyclic Aromatic Hydrocarbons,PAHs)类物质,沥青烟对人体健康具有潜在威胁。为更合理评价沥青烟产生的健康风险,基于室内试验对沥青产烟规律进行分析,并采用气相色谱-质谱联用法,对不同温度下产生沥青烟中美国环保署(Environmental Protection Agency,EPA)优先控制的16种PAHs进行了定性定量检测,同时结合等效毒性当量法对沥青烟气毒性当量及其变化规律进行分析。研究表明,在试验温度区间,沥青产烟量随温度升高呈非线性增大的变化趋势,随暴露面积增大呈线性增大的变化趋势。沥青烟中16种优控PAHs质量比随温度升高呈增长的变化趋势,其中,低相对分子质量PAHs增长速率随温度升高显著增大,高相对分子质量PAHs增长速率随温度升高增长较为稳定。在16种PAHs总量中,高相对分子质量PAHs质量比最低,低相对分子质量PAHs质量比最高。16种PAHs的毒性与其质量比相反,高相对分子质量PAHs对沥青烟毒性当量贡献值超过83%,低相对分子质量PAHs对沥青烟毒性当量贡献值低于4%,几乎可忽略不计。降低产烟温度可显著降低沥青烟毒性当量;当沥青加热温度由170℃降低10℃、20℃和30℃时,相同质量沥青产生的烟气对从业人员健康威胁降低率分别为57.9%、75.1%和86.7%。

As it contains a variety of Polycyclic Aromatic Hydrocarbons(PAHs)with mutagenesis,carcinogenesis,and teratogenesis,asphalt fumes have potential threats to human health.To evaluate the health risks of asphalt fume more reasonably,this study analyzed the law of asphalt fume production based on indoor tests.By using gas chromatographymass spectrometry,16 PAHs proposed by the Environmental Protection Agency(EPA)in asphalt fume produced at different temperatures were carried out qualitatively and quantitatively.The asphalt fume toxicity equivalents and its variation law were also analyzed in conjunction with the toxic equivalence method.The results indicate that in the study temperature range,the fume production of asphalt shows a non-linear increase trend with the increase of temperature and a linear increasing trend with the increase of the exposed area.The PAHs mass ratio of 16 species in asphalt fume shows an increasing trend with increasing temperature.Among them,the growth rate of low molecular weight PAHs increases significantly with the increase in temperature,and the growth rate of high molecular weight PAHs is more stable with the increase in temperature.Among the total 16 PAHs,the mass ratio of high molecular weight PAHs is the lowest,and the mass ratio of low molecular weight PAHs is the highest.The toxicity of PAHs with different molecular weights is opposite to its mass ratio.The contribution of high molecular weight PAHs to asphalt fume toxicity equivalent exceeds 83%,and the contribution of low molecular weight PAHs to asphalt fume toxicity equivalent is less than 4%,which can be ignored.Lower temperature can significantly reduce the toxic equivalent of asphalt fume.When the asphalt heating temperature(from 170℃)is reduced by 10℃,20℃,and 30℃respectively,the reduction in health risk to workers from the same mass of asphalt is 57.9%,75.1%,and 86.7%,respectively.