Occurrence and human exposure assessment of organophosphate esters in atmospheric PM2.5 in the Beijing-Tianjin-Hebei region, China.

Organophosphate esters (OPEs) in atmospheric fine particles (PM2.5) were comprehensively investigated in the Beijing-Tianjin-Hebei (BTH) region from April 2016 to March 2017. The concentrations of Σ8OPEs in all the five sampling sites ranged from 90 to 8291 pg/m3 (mean 1148 ± 1239 pg/m3; median 756 pg/m3). The highest level (median 1067 pg/m3) was found at one of the urban sites in Beijing, followed by Tianjin (746 pg/m3) and Shijiazhuang (724 pg/m3). Tris(2-chloroethyl) phosphate (TCEP) and tri[(2R)-1-chloro-2-propyl] phosphate (TCPP) were the dominant compounds across the five sampling locations. Generally, the concentrations of chlorinated OPEs were relatively higher in summer than in winter (p < 0.05), but no significant seasonal difference was discovered for non-chlorinated individual OPEs. The concentrations of tri-n-butyl phosphate (TBP), TCEP, TCPP and triphenyl phosphate (TPP) were positively correlated with the meteorological parameters (i.e. temperature and relative humidity) (p < 0.05), indicating an evident influence of meteorological condition on OPE distribution. We observed a negative correlation (p < 0.05) between octanol-air partition coefficients (logKoa) and the ratio of PM2.5-bound OPE concentrations to total suspended particulates-bound OPE concentrations, suggesting that physicochemical properties affect the particle-size distribution of OPEs. Furthermore, the median value of cancer hazard quotients (HQs) of TCEP was higher than TBP and tris(2-ethylhexyl) phosphate (TEHP). The health risk assessment showed that HQ values for children were ~1.6 times higher than those for adults. Relatively higher health risk induced by PM2.5-bound OPEs via inhalation was found during severe hazy days than in clear days.

Seasonal variation and human exposure assessment of legacy and novel brominated flame retardants in PM2.5 in different microenvironments in Beijing, China.

Indoor exposure to legacy and novel brominated flame retardants (NBFRs) may cause potential risks to human health. Studies on seasonal variations of indoor PM2.5-bound BFRs are scant. This study comprehensively investigated the seasonal variations of PM2.5-bound polybrominated diphenyl ethers (PBDEs) and NBFRs in various indoor environments (i.e. activity room, dormitory, home and office) and outdoor PM2.5 in Beijing, China over one year. The levels of PBDE (226 ±â€¯108 pg m-3) were higher than that of NBFRs (27.0 ±â€¯16.0 pg m-3) in all indoor environments. Decabromodiphenyl ether (BDE-209) and decabromodiphenyl ethane (DBDPE) were the most abundant BFRs. Office showed the highest mean concentrations of Σ15PBDEs (251 ±â€¯125 pg m-3) and Σ9NBFRs (33.0 ±â€¯18.0 pg m-3), which may be related to the higher number density of indoor materials. The concentrations of Σ9NBFRs and Σ15PBDE in indoor PM2.5 were found to be significantly higher than those in the corresponding outdoor PM2.5 (p < 0.05). Two to twenty-fold seasonal variations were observed for levels of PM2.5-bound BFRs during one year, and indoor concentrations increased slightly during the central-heating period (November 2016-March 2017). Seasonal variations of BFRs could be affected by temperature, relative humidity and concentrations of particle matters. The PM2.5-bound BFRs concentrations in PM2.5 were negatively correlated with temperature and relative humidity, while positively correlated with PM2.5 concentrations (p < 0.05). Atmospheric haze pollution could possibly contribute to higher levels of indoor PM2.5-bound BFRs. Human daily intake of BFRs via PM2.5 inhalation showed seasonal differences, and the highest exposure risk occurred in winter. Toddlers were assessed to be more vulnerable to indoor PM2.5-bound BFRs in all seasons. This study provided the first-hand measurements of seasonal concentrations and human exposure to PM2.5-bound BFRs in different indoor scenarios in Beijing.

Brominated flame retardants in atmospheric fine particles in the Beijing-Tianjin-Hebei region, China: Spatial and temporal distribution and human exposure assessment.

Atmospheric fine particle (PM2.5) samples were collected over a whole year (April 2016 - March 2017) across five sampling locations in the Beijing-Tianjin-Hebei (BTH) region, to investigate the occurrence of novel brominated flame retardants (NBFRs) and polybrominated diphenyl ethers (PBDEs). The concentrations of ∑9NBFRs were in the range of 0.63-104 pg/m3 (15.6 ±â€¯16.8 pg/m3) in atmospheric PM2.5, while the levels of ∑9PBDEs (excluding BDE-209) ranged from 0.05 to 19.1 pg/m3 (2.9 ±â€¯3.8 pg/m3) and BDE-209 concentrations ranged from 0.88 to 138 pg/m3 (22 ±â€¯28 pg/m3). Relatively higher levels of NBFRs and PBDEs were found at urban sampling sites in Beijing City and Shijiazhuang City. Decabromodiphenylethane (DBDPE) and BDE-209 were the dominant compounds with the relative abundances of 72% in ∑9NBFRs and 90% in ∑10PBDEs, respectively. Generally, the levels of most target BFRs in summer were lower than those in other seasons. However, there were no notable seasonal differences in levels of DBDPE and BDE-209 in atmospheric PM2.5 samples across the BTH region. Significant and positive correlations were found between the concentrations of BFRs and PM2.5. Daily human exposure via inhalation revealed that children have a higher probability of suffering from the adverse effects of BFRs than that of adults. In addition, residents living near sampling locations across the BTH region may suffer high exposure risks to BDE-209 and NBFRs.