Concentrations and Health Risk Assessment of Polycyclic Aromatic Hydrocarbons (PAHs) in Soils and Vegetables influenced by Facility Cultivation

The concentrations, sources, and health risks of 16 United States Environmental Protcction Agency(USEPA) priority polycyclic aromatic hydrocarbons (PAHs) in vegetables (leafy lettuce, amaranth, water spinach, and Shanghai green), in soils inside and outside the vegetable greenhouse, and in wet deposition were investigated by conducting an experiment on facility cultivation. The results showed that the average concentrations of total PAHs in vegetables and soils were 99.27 ng·g^-1and 128.01 ng·g^-1 in the greenhouse, and 109.11 ng·g^-1 and 173.07 ng·g^-1 out of the greenhouse. The concentrations of PAHs in the greenhouse were lower than those outside and the high ring-PAHs were lower than the low ring-PAHs both inside and outside. The PAH concentrations in suspended particular matter in dissolved phases of wet deposition were 2 986.49 ng·g^-1 and 61.9 ng·L^-1, respectively. The low rings were easily enriched by the vegetables based on the shoot concentration factors. PAHs in soils and vegetables mainly originated from oil emissions and grass, wood, and coal combustion, while those in suspended particular matter in wet deposition were from petrogenic sources and the combustion of grass, wood, and coal. Petroleum combustion emissions were the main sources of PAHs in dissolved phases. We used the model of incremental lifetime cancer risks to evaluate the health risk of eating these vegetables. There was a potential risk of cancer for both children and adults for all vegetables except amaranth. The carcinogenic risk of vegetables outside the greenhouse was higher than the risk inside. Amaranth had a low carcinogenic risk with the value of incremental lifetime cancer risk lower than 10^-6, while the risk of Shanghai green ranged between 10^-4 and 10^-6.