Liu , S L , Luo , Y M , Cao , Z H , Wu , L H , Ding , K Q & Christie , P 2004 , ' Degradation of benzo[a]pyrene in soil with arbuscular mycorrhizal alfalfa ' Environmental Geochemistry and Health , vol 26 , no. 2 , pp. 285-293 . DOI: 10.1023/B:EGAH.0000039592.80489.e5