Seasonal Deposition Fluxes and Removal Efficiency of Atmospheric Polybrominated Diphenyl Ethers in a Large Urban Center: Importance of Natural and Anthropogenic Factors

Abstract

Wet deposition is an effective and important mechanism for removal of atmospheric pollutants, particularly in urban regions. To examine the effectiveness of natural and anthropogenic factors in such removal mechanisms, we conducted a study in Guangzhou, a mega metropolitan center in South China. Rainwater and dry particle deposition samples were simultaneously collected from Guangzhou during the entire year of 2010, and analyzed for polybrominated diphenyl ethers (PBDEs), a group of pollutants mainly derived from industrial and household consumer products. Concentrations of ΣPBDE (sum of the 21 congeners of PBDEs) and BDE-209 in wet deposition samples ranged from 0.11 to 640 (average: 23 ± 36 ng L −1 ) and 0.071 to 420 (average: 20 ± 31 ng L −1 ), respectively. Assessed by conditional inference tree, particulate matter was recognized as the most important factor controlling concentration levels of PBDEs. The combined wet and dry deposition flux of ΣPBDE (1.4 (±1.2) × 10 4 ng m −2 quarter −1 ) in the first quarter of 2010 was not significantly different from that (1.3 (±0.46) × 10 4 ng m −2 quarter −1 ) in the fourth quarter, indicating that source control measures implemented by local governments for the 16th Asian Games and 10th Asian Para Games (held in November and December 2010, respectively) were ineffective in reducing the loadings of atmospheric PBDEs. In addition, the lower removal efficiency of ΣPBDE was found in the fourth quarter compared to other quarters. This result suggested that rain interventions conducted to maintain clear weather conditions for the Asian Games turned out to lower the efficacy for removal of PBDEs by wet deposition.

Rain Amplification of Persistent Organic Pollutants

“…The log K RP value of PBDEs ranged between 4.01 and 7.0. 49,50,59,60,62,63,68 The K RP value ranged between 3.6 and 8.8 for PFAS. 57,65 We could only compare K RP for various PFAS from two different studies that measured concentrations simultaneously in rain and aerosols.…”

Size-dependent atmospheric deposition and inhalation exposure of particle-bound organophosphate flame retardants

“…It is interesting to note that dry deposition fluxes were greater than wet deposition fluxes in the e-waste recycling zone while the opposite was observed in Guangzhou (Table 1). Such a difference between the e-waste recycling zone and Guangzhou could be explained by different rainfall amounts for the different sampling periods, i.e., dry season in the e-waste recycling zone and wet season in Guangzhou, because rainfall amount was a vital parameter in influencing wet deposition flux [38,39].…”

Metal contamination of bed sediments in the Irwell and Upper Mersey catchments, northwest England: exploring the legacy of industry and urban growth

“…It is also possible to conceptualise key sources of heavy metals through the grouping of trace elements as geochemical signatures and in mapping factor scores geospatially (e.g. Zhang 2006;Guo et al 2014;Yuan et al 2014). Data mining techniques, such as conditional inference trees (CITs), have also been used to identify key explanatory factors influencing heavy metal concentrations Cheng 2013, 2016;Guo et al 2014).…”

“…Zhang 2006;Guo et al 2014;Yuan et al 2014). Data mining techniques, such as conditional inference trees (CITs), have also been used to identify key explanatory factors influencing heavy metal concentrations Cheng 2013, 2016;Guo et al 2014). This method provides a hierarchical splitting of possible impact factors to better understand the relative influence of each source type.…”