Phthalates in PM2.5 from Shenzhen, China and human exposure assessment factored their bioaccessibility in lung.

Temporal variability of phthalates (PAEs) in PM2.5 from Shenzhen during 2015-2016 was measured and the associated human exposure via inhalation was assessed. The PM2.5 concentrations ranged from 30.7 to 115 μg m-3, greater than the air quality guidelines of interim target-3 (10-15 μg m-3) and interim target-2 (15-25 μg m-3) set by World Health Organization. PAEs were detected in 94.7% samples and the 95th percentile concentrations of total PAEs (∑6PAEs) in Longgang and Nanshan districts were 324 and 44.7 ng m-3, respectively. Di-2-ethylhexyl phthalate was the dominant species, accounting for an average of 81.9% of ∑6PAEs. The mean and 95th percentile concentrations of ∑6PAEs in PM2.5 were used to calculate a "typical" and "high" total daily intake and uptake, respectively. The estimated total daily intakes of PAEs varied and depended on body weight in each age group. Infants had the highest "typical" and "high" daily intake of 43.4 and 179 ng kg-body weight (bw) -1 day-1 for boys, and 42.0 and 173 ng kg-bw-1 day-1 for girls, respectively. However, after taking the bioaccessibility of PAEs in PM2.5 into account, the total daily "typical" and "high" uptakes dropped to 27.3 and 113 ng kg-bw-1 day-1 for male infants, and 29.0 and 120 ng kg-bw-1 day-1 for female infants, respectively. Both of the data on the daily "high" intake and uptake were much lower than the tolerable daily intake set by the European Food Safety Agency. It merits attention that infants were subject to greater PAE exposure than adults.