Levels and profiles of organochlorines and flame retardants in car and house dust from Kuwait and Pakistan: Implication for human exposure via dust ingestion

There are only few studies documenting indoor pollution in the Middle East and the Indian subcontinent. In present study, we have evaluated the occurrence of various organochlorines (OCs) and flame retardants (FRs) in dust from cars and houses of Pakistan and Kuwait. Polybrominated diphenyl ethers (PBDEs), novel brominated flame retardants (NBFRs), organophosphate FRs (PFRs), polychlorinated biphenyls (PCBs), and organochlorine pesticides (OCPs) were investigated in indoor dust from urban houses (N = 15 per country) and cars (N = 15 per country). PFRs were the major analytes in all four microenvironments, followed by PBDEs > NBFRs > OCPs > PCBs. For all classes of analytes, relatively lower levels were observed in car and house dust from Pakistan than Kuwait. Levels of ∑ PBDEs, ∑ NBFRs and ∑ PFRs were higher in car dust, while ∑ OCPs and ∑ PCBs were higher in house dust from both countries. ∑ PFRs occurred at average concentrations of 16,900, 87,900, 475, and 2500 ng/g in Kuwaiti house and car, and Pakistani house and car dust, respectively. For both countries, the profiles of analytes in car dust were different from those in the house dust. Different exposure scenarios using 5th percentile, median, mean, and 95th percentile levels were estimated for adult, taxi drivers and toddlers. For Kuwaiti toddlers, assuming high dust intake and mean and 95th percentile concentrations, the values computed for ∑ OCPs (1500 ng/kg bw/day) were higher than RfD values, while for ∑ PCBs (14.5 ng/kg bw/day) it was only two-fold lower than the corresponding RfDs.