Phthalates in dust collected from various indoor environments in Beijing, China and resulting non-dietary human exposure

Abstract

This study measured concentrations of fifteen phthalates in dust from homes (n = 19), offices (n = 10), kindergartens (n = 5) and public places (n = 7) in Beijing, China, during April 2010 and May 2011. We examined phthalate co-occurrence in dust collected from different indoor surfaces and estimated daily exposure to phthalates via dust ingestion, inhalation, and dermal absorption. Diisobutyl phthalate (DiBP), di-n-butyl phthalate (DnBP) and di (2-Ethylhexyl) phthalate (DEHP) were the most abundant phthalates in each of the investigated environments (medians: 58.1–272 μg/g, 31.2–145 μg/g, and 202–1310 μg/g, respectively), with detection frequencies greater than 90% except for DiBP in dust from homes. Diethyl phthalate (DEP) was detected only in homes, with a detection frequency of 42%. The detection frequency of dinonyl phthalate (DNP) was 80% in public places (median: 78.8 μg/g). DnBP, DiBP and DEHP concentrations in different indoor environments differed significantly (p < 0.05). Our findings suggest that DnBP, DiBP and DEHP originate from the same sources, while DNP has several sources. DEHP exposure is the highest for infants, children and adults. The exposure doses of DnBP and DEHP decrease as age increases. Dermal absorption from air is the main pathway for DiBP and DnBP, contributing from 56.4% to 84.7% of the total exposure. Dust ingestion is the main pathway for DEHP, contributing from 85.6% to 96.6% of the total exposure.