Xing , W Q , Luo , Y M , Wu , L H , Song , J , Qian , W & Christie , P 2006 , ' Spatial distribution of PAHs in a contaminated valley in Southeast China ' Environmental Geochemistry and Health , vol 28 , no. 1-2 , pp. 89-96 . DOI: 10.1007/s10653-005-9017-x