Co-occurrence and distribution of organophosphate tri- and di-esters in indoor dust from different indoor environments in Guangzhou and their potential human health risk

Abstract

In this study, 45 indoor dust samples and four particulate samples from air-conditioner filters were collected from four different indoor environments in Guangzhou, China, and the concentration and composition of organophosphate tri-esters (OPEs) and organophosphate di-esters (Di-OPs) were determined. Eight of the 10 target OPEs were detected in indoor dust at different detection frequencies (DFs), with tris(2-chloroisopropyl) phosphate and tris(2-chloroethyl) phosphate being the main components. Seven target Di-OPs were detected at different DFs, with diphenyl phosphate being the dominant compound. The total OPEs (∑8 OPEs) and total Di-OPs (∑7 Di-OPs) concentrations varied from 726 to 39,312 ng/g and 68.8-14,766 ng/g, respectively. The ∑8 OPEs concentrations in instrumental houses were significantly higher (p < 0.001) than in three other indoor environments. The varying strengths of the correlation between Di-OPs and their respective parent OPEs was suggestive of their emission sources (e.g., direct application, impurities in OPE formulas, and OPE degradation). The hazard index (HI) values of individual OPEs in residential house were lower than 1, the results suggested a limited human health risk from individual OPEs. However, the total HI value (∑HIs) of OPEs was approximately 1 based on a high exposure scenario and suggested a low risk for toddlers.