Contamination of indoor dust and air by polychlorinated biphenyls and brominated flame retardants and relevance of non-dietary exposure in Vietnamese informal e-waste recycling sites

This study investigated the occurrence of polychlorinated biphenyls (PCBs), and several additive brominated flame retardants (BFRs) in indoor dust and air from two Vietnamese informal e-waste recycling sites (EWRSs) and an urban site in order to assess the relevance of these media for human exposure. The levels of polybrominated diphenyl ethers (PBDEs), hexabromocyclododecane (HBCD), 1,2-bis-(2,4,6-tribromophenoxy)ethane (BTBPE) and decabromodiphenyl ethane (DBDPE) in settled house dust from the EWRSs (130–12,000, 5.4–400, 5.2–620 and 31–1400 ng g− 1, respectively) were significantly higher than in urban house dust but the levels of PCBs (4.8–320 ng g− 1) were not higher. The levels of PCBs and PBDEs in air at e-waste recycling houses (1000–1800 and 620–720 pg m− 3, respectively), determined using passive sampling, were also higher compared with non-e-waste houses. The composition of BFRs in EWRS samples suggests the influence from high-temperature processes and occurrence of waste materials containing older BFR formulations. Results of daily intake estimation for e-waste recycling workers are in good agreement with the accumulation patterns previously observed in human milk and indicate that dust ingestion contributes a large portion of the PBDE intake (60%–88%), and air inhalation to the low-chlorinated PCB intake (> 80% for triCBs) due to their high levels in dust and air, respectively. Further investigation of both indoor dust and air as the exposure media for other e-waste recycling-related contaminants and assessment of health risk associated with exposure to these contaminant mixtures is necessary.

► Indoor environment in EWRSs was investigated in views of BFR and PCB contamination.
► High levels of BFRs in settled dust and tri–tetraCBs in air were observed.
► The profiles of BFRs reflect the abundance of old electronics and thermal processing.
► Dust was the dominant human exposure source of PBDEs in EWRSs, unlike in other sites.
► High intake of tri–tetraCBs from inhalation was consistent with their levels in human milk.