Distribution and Health Risk Assessment on Dietary Exposure of Polycyclic Aromatic Hydrocarbons in Vegetables in Nanjing, China

Table 2

PAH isomer ratios commonly used in the identification of PAH sources.

Ratio	⁢PAH source
	Petroleum (unburned)	Petroleum (combustion)	Petroleum and combustion (mixed)	Combustion	Biomass/coal combustion
BaA/(BaA + Chr)	<0.20		0.20–0.35	>0.35
IcdP/(IcdP + BghiP)	<0.20	0.20–0.50			>0.50