Contamination of benzotriazole ultraviolet stabilizers in house dust from the Philippines: implications on human exposure

Abstract

Seven compounds of benzotriazole ultraviolet stabilizers (BUVSs) were determined in house dust samples collected from a residential area (Malate: n = 17) and municipal dumping area (Payatas: n = 20) in the Philippines. Total concentrations of the 7 BUVSs in house dust ranged from ND (not detected) to 1020 ng/g in Malate and ND to 277 ng/g in Payatas. Among the target compounds, the most abundant BUVS was UV-234, with a median value of 84 ng/g (ND-813 ng/g) in Malate and 41 ng/g (ND-212 ng/g) in Payatas, respectively. Significantly higher concentrations of UV-326 (p<0.01) and UV-327 (p<0.05) were found in house dust samples from Malate than those from Payatas, suggesting that the household products are the major sources of contamination in the indoor microenvironment. The estimated daily intakes (EDIs) of BUVSs through house dust ingestion in the Philippines were two to four orders of magnitude lower than the guideline values. However, the EDI of 5 BUVSs for toddlers in this study was 5 times higher than those for adults, suggesting that toddlers are at higher risk. House dust may be an important exposure route of UV-234 (88%) and UV-326 (69%) in worst-case scenarios, which using high dust ingestion and worst-case exposure (P95). To our knowledge, this is the first comprehensive study on BUVSs in house dust samples from Asian developing countries and reporting the occurrence of UV-234 and UV-320 in dust samples.