Distribution of Phthalate Acid Esters in Indoor and Outdoor Air Samples Collected from Hanoi Metropolitan Areas in Vietnam

In this study, ten phthalic acid esters (PAEs) were measured in indoor and outdoor air samples collected from Hanoi metropolitan areas. The target compounds were adsorbed onto a solid adsorbent matrix (C18) with a low-speed pump and then analyzed on a gas chromatography tandem mass spectrometry. The recoveries of surrogate standards ranged from 78.5 to 112% (RSD < 15%). The method detection limits of target compounds were in the range of 0.08-0.3 ng/m3. The total mean concentration of 10 PAEs in indoor and outdoor samples were in ranges of 1400-3710 ng/m3 and 178-487 ng/m3, respectively. Among PAEs, di-(2-ethyl)hexyl phthalate (DEHP) was found at the highest abundance and concentration. The distribution of PAEs in indoor air was higher significantly than those in outdoor air samples. Some pairs of PAEs (BzBP vs DCHP, DEHP vs DnHP, DnHP vs DnOP, and DEHP vs DnOP) had strong correlations and suggested that they are from the same source. Human exposure doses to PAEs through inhalation were estimated for two age groups (children and adults) based on the measured concentrations of PAEs in air, inhalation rates, and body weights. The estimated daily intake doses were in ranges of 29.7-750 ng/kg-bw/d and 7.29-181 ng/kg-bw/d for children and adults, respectively.