Biodegradation, Bioaccessibility, and Genotoxicity of Diffuse Polycyclic Aromatic Hydrocarbon (PAH) Pollution at a Motorway Site
详细信息 查看全文
- 作者：Anders R. Johnsen ; Julia R. de Lipthay ; Fredrik Reichenberg ; S
//pubs.acs.org/images/gifchars/oslash.gif" border="0">ren J. S
- 刊名：Environmental Science & Technology
- 出版年：2006
- 出版时间：May 15, 2006
- 年：2006
- 卷：40
- 期：10
- 页码：3293 - 3298
- 全文大小：147K
- 年卷期：v.40,no.10(May 15, 2006)
- ISSN：1520-5851
文摘
Diffuse pollution of surface soil with polycyclic aromatichydrocarbons (PAHs) is problematic in terms of the largeareas and volumes of polluted soil. The levels andeffects of diffuse PAH pollution at a motorway site wereinvestigated. Surface soil was sampled with increasingdistance from the asphalt pavement and tested for totalamounts of PAHs, amounts of bioaccessible PAHs, totalbacterial populations, PAH degrader populations, the potentialfor mineralization of 14C-PAHs, and mutagenicity. ElevatedPAH concentrations were found in the samples taken1-8 m from the pavement. Soil sampled at greater distances(12-24 m) contained only background levels of PAHs.The total bacterial populations (CFU and numbers of 16SrDNA genes) were similar for all soil samples, whereas themicrobial degrader populations (culturable PAH degradersand numbers of PAH dioxygenase genes) were mostabundant in the most polluted samples close to the pavement.Hydroxypropyl-
-cyclodextrin extraction of soil PAHs, asa direct estimate of the bioaccessibility, indicated that only1-5% of the PAHs were accessible to soil bacteria. Thislow bioaccessibility is suggested to be due to sorption totraffic soot particles. The increased PAH level close tothe pavement was reflected in slightly increased mutagenicactivity (1 m, 0.32 ± 0.08 revertants g-1 soil; background/24 m: 0.08 ± 0.04), determined by the Salmonella/microsome assay of total extractable PAHs activated byliver enzymes. The potential for lighter molecular weight PAHdegradation in combination with low bioaccessibility ofheavier PAHs is proposed to lead to a likely increase inconcentration of heavier PAHs over time. These residuesare, however, likely to be of low biological significance.
-cyclodextrin extraction of soil PAHs, asa direct estimate of the bioaccessibility, indicated that only1-5% of the PAHs were accessible to soil bacteria. Thislow bioaccessibility is suggested to be due to sorption totraffic soot particles. The increased PAH level close tothe pavement was reflected in slightly increased mutagenicactivity (1 m, 0.32 ± 0.08 revertants g-1 soil; background/24 m: 0.08 ± 0.04), determined by the Salmonella/microsome assay of total extractable PAHs activated byliver enzymes. The potential for lighter molecular weight PAHdegradation in combination with low bioaccessibility ofheavier PAHs is proposed to lead to a likely increase inconcentration of heavier PAHs over time. These residuesare, however, likely to be of low biological significance.