Exposure to phthalates in the sleeping microenvironment of university dormitories: A preliminary estimate based on skin wipe and dust sampling

Abstract

Since synthetic materials that might contain phthalates are widely used to fabricate bedding and decorating materials, phthalates are typical pollutants in sleeping microenvironments. Although people spend more than 30% of time sleeping, exposure to phthalates in sleeping microenvironments has not been well characterized. In this study, we measured the occurrence of six commonly-used phthalates (dimethyl phthalate (DMP), diethyl phthalate (DEP), di-n-butyl phthalate (DnBP), butyl benzyl phthalate (BBzP), di-2-ethylhexyl phthalate (DEHP), and di-n-octyl phthalate (DOP)) from skin wipes and settled dust in the sleeping microenvironment of university dormitories. Targeted phthalates were frequently detected (more than 80%) except for DEP (30%–58% and 70% for dermal and dust samples, respectively); and DnBP and DEHP predominated in all samples. Accumulated phthalates on skin surfaces were at similar levels on bare body parts (i.e., hands vs. forearms) during sleeping time. Phthalates in settled dust were significantly correlated with those detected from skin wipes. The estimated average daily intakes of studied phthalates (via inhalation and dermal absorption) ranged from 0.24 μg/kg/day to 1.12 μg/kg/day in the sleeping microenvironment of university dormitories (with the highest doses for DMP and DnBP). Exposure via dermal pathway contributed 38% and 64%, respectively for DMP and DEP, and over 80% for other phthalates during sleeping time. This study provides better understanding of phthalate transport, exposure, and associated control strategies in sleeping microenvironments.