Phthalate Ester Concentrations, Sources, and Risks in the Ambient Air of Tianjin, China

Phthalate esters (PAEs) are excessively used in industries, which have posed a serious threat to human health. In this study, PAEs concentrations, sources, and risks in the ambient air of Tianjin, China were studied. The average concentrations of dimethyl phthalate (DMP), diethyl phthalate (DEP), di-n-butyl phthalate (DBP), butylbenzyl phthalate (BBP), di (2-ethylhexyl) phthalate (DEHP), and di-n-octyl phthalate (DOP) in PM10 were 0.18, 0.08, 2.24, 0.02, 10.79, and 0.10 ng m–3, respectively; in PM2.5 the average concentrations were 0.14, 0.07, 1.93, 0.02, 6.26, and 0.05 ng m–3, respectively. DEHP and DBP were the predominant compounds identified, and the concentrations of PAEs in summer were significantly higher than those in winter. A coefficient of divergence analysis indicated that the PAE composition profiles in PM10 and PM2.5 were significantly different at the HD (Hedong) and HB (Hebei) sites; however, they were similar to each other at the NK (Nankai) and TT (Tieta) sites. A principal component analysis indicated that the emissions from cosmetics, personal care products, industrial processes, plasticizers, and medical devices may be major sources of PAEs in ambient PM in Tianjin. The daily intake (DI) of six PAEs from ambient air inhalation in Tianjin was estimated for five age groups. The results showed that the highest exposure dose was DMP in all age groups. Infants experienced the highest total DI of all six PAEs, whereas adults experienced the lowest total DI. The cancer risks from ambient air inhalation exposure were also estimated on the basis of DEHP concentrations. Although the risks for all population groups were below the U.S. Environmental Protection Agency threshold of 10–6, our result underestimates the actual health risk because only ambient air inhalation exposure to DEHP was considered in this study. Additional studies are necessary to investigate the effects of long-term exposure to air pollution in Tianjin.