Stroo Hans F, Nakles David V, Kreitinger Joseph P, Loehr Raymond C, Hawthorne Steven B, Luthy Richard G, Holman Hoi-Ying, LaPierre Adrienne
The RETEC Group, Monroeville, Pennsylvania 15146, USA.
Integr Environ Assess Manag. 2005 Jul;1(3):259-66. doi: 10.1897/2004-009r.1.
Remediation of soils at oil-gas manufactured gas plant (MGP) sites is driven primarily by the human health risks posed by the carcinogenic polycyclic aromatic hydrocarbons (PAHs), particularly benzo[a]pyrene (BaP), that are associated with lampblack residues. Although PAHs on lampblack are tightly sorbed, risk assessments do not account for this reduced availability. A multi-investigator study of 7 oil-gas MGP site soil samples demonstrated that the dermal and ingestion absorption factors are far lower than current default assumptions used in risk assessments. Using these sample-specific absorption factors in standard risk assessment equations increased risk-based cleanup levels by a factor of 72 on average (with a range from 23 to 142 times the default level). The rapidly released fraction of the BaP in each sample, as measured by supercritical fluid extraction, was closely correlated (r2 = 0.96) to these calculated cleanup levels. The weight of evidence developed during this research indicates that the risks posed by PAHs on lampblack are far less than assumed when using default absorption factors and that a tiered evaluation protocol employing chemical analyses, chemical release data, and in vitro bioassays can be used to establish more realistic site-specific criteria.
油气制气厂（MGP）场地土壤的修复主要是由与灯黑残渣相关的致癌多环芳烃（PAHs），特别是苯并[a]芘（BaP）所带来的人类健康风险驱动的。尽管灯黑上的PAHs被紧密吸附，但风险评估并未考虑到这种有效性的降低。一项针对7个油气MGP场地土壤样本的多研究者研究表明，皮肤和摄入吸收系数远低于风险评估中目前使用的默认假设。在标准风险评估方程中使用这些特定样本的吸收系数，基于风险的清理水平平均提高了72倍（范围为默认水平的23至142倍）。通过超临界流体萃取测量的每个样本中BaP的快速释放部分与这些计算出的清理水平密切相关（r2 = 0.96）。本研究期间得出的证据表明，灯黑上PAHs带来的风险远低于使用默认吸收系数时的假设，并且采用化学分析、化学释放数据和体外生物测定的分层评估方案可用于建立更符合实际的特定场地标准。
