Brooks L R, Hughes T J, Claxton L D, Austern B, Brenner R, Kremer F
Environmental Carcinogenesis Division, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina 27711, USA.
Environ Health Perspect. 1998 Dec;106 Suppl 6(Suppl 6):1435-40. doi: 10.1289/ehp.98106s61435.
Soil from a Superfund site (Reilly Tar Site, St. Louis Park, Minnesota) contaminated with polycyclic aromatic hydrocarbons (PAHs) from creosote was treated with several bioremediation technologies including bioslurry (BS), biopile (BP), compost (CMP), and land treatment (LT). These treatment technologies are being evaluated in pilot scale laboratory systems by the U.S. Environmental Protection Agency's National Risk Management Research Laboratory in Cincinnati, Ohio. To evaluate the genotoxicity and identify the mutagens in the soil before and after the various treatments, fractionated extracts of five soils were bioassayed for mutagenic activity with a microsuspension modification of the Salmonella histidine reversion assay. Soils were extracted by sonication using dichloromethane (DCM). The five extracts were fractionated in triplicate (two for bioassay and one for chemical analysis) by reverse-phase high-performance liquid chromatography (HPLC) using hexane/DCM/methanol, and the fraction for bioassay were solvent-exchanged into dimethyl sulfoxide by nitrogen evaporation. Forty HPLC fractions for each sample were bioassayed in strain YG1041 with and without exogenous liver metabolic activation. As shown in a companion paper, the mutagenicity of two treatments (BS and BP) was significantly greater than the mutagenicity of the untreated soil. Mutagenic fractions (> 500 revertants) were analyzed by gas chromatography/mass spectrometry (GC/MS). PAH analysis of the soils indicated that all treatments were effective in reducing the total PAH concentration (48-74%). Qualitative GC/MS analysis of the mutagenic fractions from the BS and BP treatments indicated that they contained azaarenes, which are mutagens. The CMP and LT processes were the most effective and least toxic bioremediation procedures based on mutagenic potency and chemical analysis. This research demonstrated that the combination of bioassays and chemical analysis provided a more accurate determination of toxicity in these complex environmental mixtures.
来自一个超级基金污染场地（明尼苏达州圣路易斯公园的赖利焦油场地）的土壤，被来自杂酚油的多环芳烃（PAHs）污染，采用了几种生物修复技术进行处理，包括生物泥浆（BS）、生物堆（BP）、堆肥（CMP）和土地处理（LT）。美国环境保护局位于俄亥俄州辛辛那提的国家风险管理研究实验室正在中试规模的实验室系统中对这些处理技术进行评估。为了评估各种处理前后土壤的遗传毒性并鉴定其中的诱变剂，对五种土壤的分级提取物进行了沙门氏菌组氨酸回复突变试验的微悬浮改良法的诱变活性生物测定。土壤通过二氯甲烷（DCM）超声提取。这五种提取物一式三份进行分级（两份用于生物测定，一份用于化学分析），采用正己烷/二氯甲烷/甲醇通过反相高效液相色谱（HPLC）进行分级，用于生物测定的分级通过氮气蒸发溶剂交换为二甲基亚砜。每个样品的40个HPLC分级在菌株YG1041中进行生物测定，有无外源肝脏代谢活化。如一篇配套论文所示，两种处理（BS和BP）的诱变性明显大于未处理土壤的诱变性。对诱变级分（>500个回复突变体）进行气相色谱/质谱（GC/MS）分析。土壤的PAH分析表明，所有处理在降低总PAH浓度方面都是有效的（48 - 74%）。来自BS和BP处理的诱变级分的定性GC/MS分析表明，它们含有氮杂芳烃，这些是诱变剂。基于诱变效力和化学分析，CMP和LT工艺是最有效且毒性最小的生物修复程序。这项研究表明，生物测定和化学分析相结合能更准确地测定这些复杂环境混合物中的毒性。
