Occurrence and combined exposure of phthalate esters in urban soil, surface dust, atmospheric dustfall, and commercial food in the semi-arid industrial city of Lanzhou, Northwest China.

A total of 138 samples including urban soil, surface dust, atmospheric dustfall, and commercial food were collected from the semi-arid industrial city of Lanzhou in Northwest China, and 22 phthalate esters (PAEs) were analyzed in these samples by gas chromatography-mass spectrometry for the pollution characteristics, potential sources, and combined exposure risks of PAEs. The results showed that the total concentration of 22 PAEs (ƩPAEs) presented surface dust (4.94 × 10 ng/g) ≫ dustfall (1.56 × 10 ng/g) ≫ food (2.14 × 10 ng/g) ≫ urban soil (533 ng/g). Di-n-butyl phthalate (DNBP), di-isobutyl phthalate, di(2-ethylhexyl) phthalate (DEHP), and di-isononyl phthalate/di-isodecyl phthalate were predominant in the environmental media and commercial food, being controlled by priority (52.1%-65.5%) and non-priority (62.1%) PAEs, respectively. Elevated ƩPAEs in the urban soil and surface dust was found in the west, middle, and east of Lanzhou. Principal component analysis indicated that PAEs the urban soil and surface dust were related with the emissions of products containing PAEs, atmosphere depositions, and traffic and industrial emissions. PAEs in the foods were associated with the growth and processing environment. The health risk assessment of United States Environmental Protection Agency based on the Chinese population exposure parameters indicated that the total exposure dose of 22 PAEs was from 0.111 to 0.226 mg/kg/day, which were above the reference dose (0.02 mg/kg/day) and tolerable daily intake (TDI, 0.05 mg/kg/day) for DEHP (0.0333-0.0631 mg/kg/day), and TDI (0.01 mg/kg/day) for DNBP (0.0213-0.0405 mg/kg/day), implying that the exposure of PAEs via multi-media should not be ignored; the total non-carcinogenic risk of six priority PAEs was below 1 for the three environmental media (1.21 × 10-2.90 × 10), while close to 1 for food (4.74 × 10-8.76 × 10), suggesting a potential non-carcinogenic risk of human exposure to PAEs in food; the total carcinogenic risk of BBP and DEHP was below 1 × 10 for the three environmental media (9.13 × 10-5.72 × 10), while above 1 × 10 for DEHP in food (1.02 × 10), suggesting a significantly carcinogenic risk of human exposure to DEHP in food. The current research results can provide certain supports for pollution and risk prevention of PAEs.