Dioxin-like activities, halogenated flame retardants, organophosphate esters and chlorinated paraffins in dust from Australia, the United Kingdom, Canada, Sweden and China

•CPs were found in the highest concentrations in dust from all countries, followed by OPEs, HFRs and PBDEs.•PBDEs showed different congener profile in dust from North America with predominance of the penta-mixture.•CPs in dust from Sweden were predominated by the long-chain CPs while for other countries, medium-chain CPs predominated.•PBDEs and CPs showed positive correlation with dioxin-like-activity in dust.

The concentrations of organic flame retardants (FRs) and dioxin-like activities in dust collected from five countries were investigated. The correlations between the concentrations of the different groups of FRs and dioxin-like activities were examined. Chlorinated paraffins (CPs, C9 to C31) were found in the highest concentration (median ∑CP 700 μg/g, range 280-4750 μg/g), followed by organophosphate esters (median ∑13OPEs 56 μg/g, range 21-110 μg/g), halogenated flame retardants (median ∑17HFRs 3.3 μg/g, range 0.87-14 μg/g) and polybrominated diphenyl ethers (median ∑17PBDEs 2.8 μg/g, range 0.46-11 μg/g). There were no significant differences in concentrations of the FRs among the countries but differences in PBDE and CP congener profiles were found. BDE209 predominated in dust from Australia, the UK, Sweden and China, ranging from 50 to 70% of total PBDEs. The lowest percentage of BDE209 was found in the dust from Canada, representing only 20% of total PBDEs. For CPs in dust from Sweden, the long-chain CPs (especially C18 congeners) predominated, while for other countries, medium-chain CPs (especially C14 congeners) predominated. The dioxin-activities of the dusts ranged from 58 to 590 pg CALUX-TEQ/g, and had a median of 200 pg CALUX-TEQ/g. There were significant positive correlations between concentrations of PBDEs and CPs with dioxin-like activities. The dioxin-like activity may be due to the presence of polychlorinated or polybrominated dioxin/furans (PBDD/DFs) or polychlorinated naphthalenes (PCNs) in the dust. The PBDD/DFs are known impurities and degradation product of the penta-BDE mixture, and PCNs are known impurities of CPs which exhibit dioxin-like activities.