Occurrence and risk of human exposure to organophosphate flame retardants in indoor air and dust in Hanoi, Vietnam

The presence and distribution of thirteen organophosphate flame retardants (OPFRs) were investigated in indoor air and dust samples collected in Hanoi, Vietnam. The total OPFRs (EOPFRs) concentrations in indoor air and dust samples were 42.3-358 ng m- 3 (median 101 ng m-3) and 1290-17,500 ng g-1 (median 7580 ng g-1), respectively. The profile of OPFRs in both indoor air and dust indicated that tris(1-chloro-2-propyl) phosphate (TCIPP) was the most dominant compound with a median concentration of 75.3 ng m- 3 and 3620 ng g-1, contributing 75.2% and 46.1% to EOPFRs concentrations in indoor air and dust, respectively, followed by tris(2-butoxyethyl) phosphate (TBOEP), with a median concentration of 16.3 ng m- 3 and 2500 ng g- 1, contributing 14.1% and 33.6% to EOPFRs concentrations in indoor air and dust, respectively. The levels of OPFRs in the indoor air samples and corresponding indoor dust samples showed a strong positive correlation. The total estimated daily intakes (EDItotal) of EOPFRs (via air inhalation, dust ingestion, and dermal absorption) for adults and toddlers under the median and high exposure scenarios were 36.7 and 160 ng kg- 1 d-1, and 266 and 1270 ng kg- 1 d-1, respectively. Among the investigated exposure pathways, dermal absorption was a primary expo-sure pathway to OPFRs for both toddlers and adults. The hazard quotients (HQ) ranged from 5.31 x 10-8 to 6.47