Background

Phthalates were detected in various environments due to their widespread application. In this study, indoor dust samples from 94 buildings, including 72 residences and 22 dormitories, were collected in seven geographical regions in China and analyzed for eight phthalate esters (PAEs). Investigation of contamination profiles, geographical distribution, sources, and risks of PAEs in indoor dusts was explored.

Results

The highest Σ₈PAEs concentration in residential buildings was found in Northeast China (median: 164.71 μg·g⁻¹), which was 2.3 and 2.8 times higher than that in South China (median: 71.71 μg·g⁻¹) and Southwest China (median: 58.53 μg·g⁻¹), respectively. Di (2-ethylhexyl) phthalate (DEHP), di-iso-butyl phthalate (DIBP), and di-n-butyl phthalate (DBP) were the dominant compounds of Σ₈PAEs in indoor dusts from residences and dormitories. The administrative levels revealed that the highly serious contamination occurred in the provincial capital, followed by nonprovincial cities and countries. Such an occurrence was related to the usage of PAE products and the level of urbanization. Principal component analysis (PCA) and positive matrix factorization (PMF) showed that the emission from cosmetics and personal care products, plasticizers, and household building materials were the possible PAE sources in indoor dusts. Among three routes of ingestion, dermal adsorption, and inhalation, dust ingestion was the main route of human exposure to PAEs. The health risk of PAE exposure for different populations in descending order of children > women > men. The hazard indexes of noncancer were higher than the threshold value of 10⁻⁶ during human exposure to DBP and DEHP. Children also faced potential noncancer risk due to benzyl butyl phthalate (BBzP) and di-n-octyl phthalate (DnOP) exposure. The carcinogenic risks via exposure to BBzP and DEHP were negligible.

Conclusion

Overall, PAEs were widely presented in indoor dusts. Obvious difference was observed in the distribution of PAEs concentration in indoor dusts due to the differences in economic development and usage of PAEs product. Plasticizers, household building materials, and cosmetics and personal care products were likely PAE sources in indoor dusts. The risk assessment suggested that carcinogenic risks of BBzP and DEHP were negligible, but DBP, DEHP, DnOP, and BBzP may pose noncancer risks to humans.