Gas-phase and PM2.5-bound phthalates in nail salons: characteristics, exposure via inhalation, and influencing factors.

Abstract

This study aimed to investigate the characteristics of, exposure to, and factors influencing gas-phase and PM2.5-bound phthalates (PAEs) in nail salons. Data on both indoor and outdoor gas-phase and PM2.5-bound PAEs, carbon dioxide (CO2), temperature, and relative humidity were collected in nail salons. We also used questionnaires to survey building characteristics and occupants' behaviors. The average total gas-phase and PM2.5-bound PAE concentrations indoors were higher than those outdoors by 6 and 3 times, respectively. Diethyl phthalate, diisobutyl phthalate (DiBP), di-n-butyl phthalate (DnBP), and di-(2-ethylhexyl) phthalate (DEHP) were the predominant compounds among both the gas-phase and PM2.5-bound PAEs in indoor air. The volume of the salon's space or the difference of indoor and outdoor CO2 concentrations (dCO2) was significantly associated with indoor PAE concentrations. The ratios of PM2.5-bound to gas-phase PAEs, especially high-molecular-weight PAEs, were positively associated with the dCO2 concentrations. Higher ratios of indoor to outdoor PM2.5-bound DiBP, DnBP, and DEHP concentrations were discovered when more clients visited each day. Building characteristics, ventilation conditions, and occupants' activities have influences on the gas-phase and particle-phase PAEs. The study identifies the characteristics of gas-phase and PM2.5-bound PAEs in nail salons and their influencing factors.