Atmospheric Polybrominated Diphenyl Ethers Research Articles

A level IV fugacity-based multimedia model based on steady-state particle/gas partitioning theory and its application to study the spatio-temporal trends of PBDEs in atmosphere of northeast China

Particle/gas (P/G) partitioning can significantly affect the environmental behavior of atmospheric pollutants. In this study, we established a large-scale level IV fugacity-based multimedia model (the S-L4MF Model) based on the steady-state P/G partitioning theory. The spatial and temporal trends with the atmospheric contamination of polybrominated diphenyl ethers (PBDEs) in northeastern China under various climate conditions were simulated by the model. There is a reasonable agreement between the simulated and measured gaseous and particulate concentrations of 3 selected PBDE congeners (BDE-47, -99 and -209). For BDE-47, -99 and -209, 91.9 %, 94.8 % and 86.2 % of data points in the evaluation of the spatial trend, whereas 97.4 %, 98.2 % and 91.6 % of data points in the evaluation of the temporal trend, exhibit discrepancies between the modeled and measured data within 1 order of magnitude. The S-L4MF Model performed better than the other model with the same configuration but an equilibrium-state P/G partitioning assumption. The sensitivity and uncertainty analysis indicated that the air temperature and hexadecane-air partition coefficient were the dominant influencing factors on atmospheric concentrations. In addition, the model was successfully applied to study the inter-annual and seasonal variations of gaseous and particulate concentrations of the three PBDEs during 1971–2020 in Harbin, a northeastern Chinese city. Finally, we illustrated the potential to use the model to understand P/G partitioning behavior and the effects of snow and ice on atmospheric concentrations. In summary, the S-L4MF Model provided a powerful and effective tool for studying the environmental behavior of atmospheric organic pollutants, especially in cold regions.

Occurrence, air-sea exchange, and gas-particle partitioning of atmospheric polybrominated diphenyl ethers from East Asia to the Northwest Pacific Ocean

The occurrence, air–sea exchange, and gas–particle partitioning of polybrominated diphenyl ethers (PBDEs) were analyzed during a 2015 research expedition from the East China Sea (ECS) to the open Northwest Pacific Ocean (NWP). The sum of 13 PBDEs (Σ13PBDEs) in air and surface seawater varied in the range of 0.54–14.5.pg m−3 and 0.60–13.5 pg L−1, respectively, with the highest concentrations observed in the ECS. The Clausius–Clapeyron approach and air mass origin analysis indicated that continued primary emissions of PBDEs, particularly BDE-209, from East Asian sources governed the spatial variability of air PBDEs over the NWP through long-range atmospheric transport (LRAT). Net air-to-seawater gas deposition of PBDEs was evidenced based on the fugacity calculation with sum fluxes of seven selected PBDEs ranging from −45 to −582 pg m−2 d−1. Following the substantial advection of aerosol phase BDE-209 over the ECS, dry particle deposition dominated the input pathway of PBDEs into the ECS, whereas in the open NWP, relatively free from the influence of the land emissions, fluxes in PBDE absorption and in dry particle deposition were comparable. This suggests an impact of continental outflow on the fate of atmospheric PBDEs over the NWP. Regarding gas–particle partitioning, PBDEs over the NWP were obviously absorbed into continental organic aerosols during atmospheric transport, except for BDE-209, which tended to remain within the steady state.

Study on arbor leaf and ring as a potential biological indicator for atmospheric polybrominated diphenyl ethers (PBDEs) distribution at e-wastes recycling sites

Polybrominated diphenyl ethers (PBDEs) are considered to be the main pollutants at e-wastes recycling sites (EWRSs). Exploring the excellent and efficient bio-indicators of atmospheric PBDEs is attracting the more and more researchers to aforementioned direction in all over the globe. Arbor leaf and air samples were collected in four EWRSs located in Taizhou city, Zhejiang province of China, and PBDEs concentrations in local atmosphere at four sampling sites generally followed a trend as follows: Mukengcun (1940.83–18,545.12 ng/g) > Yanggongao (1017.56–7740.93 ng/g) > Wenqiaozhen (420.47–3146.9 ng/g) > Changyudongtian (36.39–69.54 ng/g). The accumulated contents of absorbing the atmospheric PBDEs in eight arbor species were observed by the following trend: Magnoliagrandiflora > Ilexchinensis > Cinnamomumcamphora > Cedardeodara > Sabinachinensis > Cunninghamialanceolata > Metasequoiaglyptostroboides > Salixbabylonica. BDE47, BDE99, and BDE209 were evaluated as the main PBDEs congeners. Additionally, ∑PBDEs accumulation showed the increasing trend with leaf age and lipid content. The concentrations of PBDEs congeners in arbor leaf/ring at four sampling sites also indicated the good relationship in atmospheric gas phase, fine particulate matter (PM2.5), and total suspended particulate. The coefficients of correlations were determined in the range of 0.957–0.999. On the other hand, the sampling height and tree age were not observed as an ideal indicator. Moreover, the longitudinal distribution of PBDEs showed a little difference, while its radial distribution seemed to be fluctuated during the growth period. We believe that our conducted research will open up the new avenues about the remediation of PBDEs contents and its derivatives from the atmosphere by using the arbor leaf and ring as a biological indicator at EWRSs.

Impact of organic matter and meteorological factors on the long-term trend, seasonality, and gas/particle partitioning behavior of atmospheric PBDEs

We extended our knowledge of the impact of organic matter (OM) and meteorological factors on the long-term trend, seasonality and gas/particle partitioning behavior of polybrominated diphenyl ethers (PBDEs). In Lake Chaohu, PBDEs had an increasing trend, with a doubling time of 13.4 years at the urban site, and a decreasing trend, with a halving time of 6.1 years at the rural site. At the urban site, the negative association of OM with most congeners indicated that the graphene-like carbonaceous components might carry or release PBDEs, and the negative association of long-term rain fall and wind speed with most congeners was suggested to dilute or increase the transport speed of PBDEs in the atmosphere. At the rural site, the negative association with PM10 and positive association with OM indicated that the PBDEs-buried OM was mainly from non-local sources. Restricted to the temperature seasonality, the frequency of PBDE congeners decreased with seasonality from 64% and 43% to 50% and 43% at the urban and rural sites, respectively. The slope of the simplified Pankow adsorption model in samples with larger absolute OM content (>10 μgC m−3) was steeper than that with lower absolute OM content (<5 μgC m−3), indicating that OM facilitated the gas-particle partitioning equilibrium. Interestingly, the theoretic partitioning coefficients were much lower than the measured ones for less brominated BDEs, whereas the highly brominated BDEs did the opposite. The theoretic partitioning coefficient should be further modified by considering the molecular weight distribution of the OM and the corresponding activity coefficients of the target compound in a specific type of OM phase.

Are atmospheric PBDE levels declining in central Europe? Examination of the seasonal and semi-long-term variations, gas–particle partitioning and implications for long-range atmospheric transport

Abstract. This study presents multi-year monitoring data on atmospheric polybrominated diphenyl ethers (PBDEs) in central Europe. Air was sampled on a weekly basis at a background site in the central Czech Republic from 2011 to 2014 (N = 114). Σ8PBDEs (without BDE209) total (gas and particulate) concentrations ranged from 0.084 to 6.08 pg m−3, while BDE209 was at 0.05–5.01 pg m−3. BDE47, BDE99 and BDE183 were the major contributors to Σ8PBDEs.Overall, the atmospheric concentrations of individual PBDEs were controlled by deposition processes, meteorological parameters and long-range atmospheric transport. Regarding gas–particle partitioning, with the exception of BDE28 (gaseous) and BDE209 (particulate), all congeners were consistently detected in both phases. Clear seasonal variations with significantly higher measured particulate fraction (θmeasured) in winter compared to summer was found for all PBDEs except BDE209. For example, while the average θmeasured of BDE47 was 0.53±0.19 in winter, this was only 0.01±0.02 in summer. Similarly, for BDE99, θmeasured was 0.89±0.13 in winter, while it was only 0.12±0.08 in summer. The observed gas–particle partitioning coefficient (Kp, in m3 µg−1) was compared with three model predictions, assuming equilibrium or a steady state. None of the models could provide a satisfactory prediction of the partitioning, suggesting the need for a universally applicable model.Statistically significant decreases of the atmospheric concentrations during 2011–2014 were found for BDE99, 100, 153 and 209. Estimated apparent atmospheric halving times for these congeners ranged from 2.8 (BDE209) to 4.8 (BDE153) years. The results suggest that photolytic debromination to lower brominated congeners may significantly influence PBDE concentration levels and patterns in the atmosphere.

Spatio-temporal variations of atmospheric and soil polybrominated diphenyl ethers (PBDEs) in highly industrialized region of Dilovasi

Polybrominated diphenyl ethers (PBDEs) were investigated in ambient air of a highly industrialized region at 23 different sampling sites for 12 months. Total concentrations of 8 PBDE congeners (Σ8PBDE) were found to be between 5.73 and 520 pg m−3 (94.7 ± 78.9; average ± SD) and BDE-209 was the predominant congener, followed by BDE-47 and/or BDE-99. Their contributions to Σ8PBDE were 71 ± 13, 9 ± 4% and 8 ± 4%; respectively. Compared to previous studies around the world, high concentrations detected in Dilovasi demonstrated the severity of atmospheric PBDE pollution in the area. For all sampling sites, average PBDE concentration obtained in summer (118.5 ± 98.7 pg m−3) was higher than one found in winter period (79.7 ± 59.1 pg m−3) and this seasonal difference was more obvious in industrial/urban sites (p < 0.05), probably due to enhanced volatilization from ongoing PBDE sources such as waste incineration and iron-steel plants. The soil-air exchange tendencies of PBDEs did not show substantial differences between the sampling periods with small variations for each congener. All congeners either tend to deposit to soil or to be within the equilibrium range for all seasons. This reflects the impact of local ongoing sources rather than temperature on the direction of soil-air exchange of PBDEs in this region. Specific congener ratios such as BDE-47/-99 and -99/-100 confirmed the impact of local sources rather than long-range transport on PBDE congeners in the study area. According to the Positive Matrix Factorization (PMF) results, the BDE-209 content of the first factor was found to be 91.7% and this factor was attributed to the deca-BDE technical formulations. The second factor was highly rich with both BDE-183 (%61) and BDE-28 (%52) and identified as octa-BDE technical products. The last factor was highly loaded with BDE-99, BDE-47, BDE-100, BDE-154 and BDE-153 and has been determined as the penta-BDE commercial formulations.

Gas/particle partitioning, particle-size distribution of atmospheric polybrominated diphenyl ethers in southeast Shanghai rural area and size-resolved predicting model

A size-segregated gas/particle partitioning coefficient KPi was proposed and evaluated in the predicting models on the basis of atmospheric polybrominated diphenyl ether (PBDE) field data comparing with the bulk coefficient KP. Results revealed that the characteristics of atmospheric PBDEs in southeast Shanghai rural area were generally consistent with previous investigations, suggesting that this investigation was representative to the present pollution status of atmospheric PBDEs. KPi was generally greater than bulk KP, indicating an overestimate of TSP (the mass concentration of total suspended particles) in the expression of bulk KP. In predicting models, KPi led to a significant shift in regression lines as compared to KP, thus it should be more cautious to investigate sorption mechanisms using the regression lines. The differences between the performances of KPi and KP were helpful to explain some phenomenon in predicting investigations, such as PL0 and KOA models overestimate the particle fractions of PBDEs and the models work better at high temperature than at low temperature. Our findings are important because they enabled an insight into the influence of particle size on predicting models.

Passive air sampling of polybrominated diphenyl ethers in New Delhi, Kolkata, Mumbai and Chennai: Levels, homologous profiling and source apportionment

Several studies in the recent past reported new sources for industrial persistent organic pollutants (POPs) from metropolitan cities of India. To fill the data gap for atmospheric polybrominated diphenyl ethers (PBDEs), polyurethane foam disk passive air sampling (PUF-PAS) was conducted along urban-suburban-rural transects in four quadrilateral cities viz., New Delhi, Kolkata, Mumbai and Chennai from northern, eastern, western and southern India respectively. Average concentration of Σ8PBDEs in pg/m3 for New Delhi, Kolkata, Mumbai and Chennai were 198, 135, 264 and 144 respectively. We observed a distinct urban > suburban > rural trend for atmospheric PBDEs in Mumbai. Principal component analysis (PCA) attributed three different source types. BDE-47, -99, −100, −153 and −154 loaded in the first component were relatively high in the sites where industrial and informal electronic waste (e-waste) recycling activities were prevalent. Penta congener, BDE-99 and tetra congener, BDE-47 contributed 50%–75% of total PBDEs. Ratio of BDE-47 and -99 in Indian cities reflected the usage of penta formulations like Bromkal −70DE and DE-71 in the commercial and electrical products. PC-2 was loaded with BDE-28 and -35. Percentage of BDE-28 and BDE-35 (>10%) were comparatively much higher than commercial penta products. Abundance of BDE-28 in majority sites can be primarily due to re-emission from surface soil. PC-3 was loaded with BDE-183 and elevated levels were observed mostly in the industrial corridor of Indian cities. BDE-183 was notably high in the urban industrial sites of New Delhi. We suspect this octa-BDE congener resulted from recycling process of plastic products containing octa-BDE formulation used as flame retardants.

Temporal and spatial distributions of PBDEs in atmosphere at Shanghai rural regions, China.

Atmospheric samples were collected using polyurethane foam (PUF) passive air sampling device for every 3months from June 2012 to May 2013 in Shanghai rural regions in order to investigate the concentrations, profiles, spatial distributions, and seasonal variations of polybrominated diphenyl ethers (PBDEs). Twelve PBDE congeners (BDE-17, BDE-28, BDE-47, BDE-49, BDE-66, BDE-85, BDE-99, BDE-100, BDE-138, BDE-153, BDE-154, and BDE-183) were measured and analyzed by GC-MS. The results showed that detectable PBDEs were examined in all air samples, which indicated that these pollutants are widespread in the research areas. The ∑12PBDE concentrations in Shanghai rural air ranged from 4.49 to 77.5pgm-3, with mean value up to 26.7pgm-3. The highest concentration was found at Jinshan sampling site in summer (from June to August in 2012). Furthermore, among the PBDE compounds investigated, the most frequently detected and the major congeners were BDE-17, BDE-28, BDE-47, and BDE-99. And the lower brominated diphenyl ethers (accounting for 75.0%) were the majority of the PBDE congeners. Finally, the result of principal component analysis (PCA) revealed that the lower and higher brominated diphenyl ethers in Shanghai rural regions were emitted from different pollutant sources.

Determination of atmospheric polybrominated diphenyl ethers and polybrominated biphenyl 153 using isotope dilution-high resolution gas chromatography/high resolution mass spectrometry

Considering the features and demands of the environmental monitoring, an isotope dilution-high resolution gas chromatography/high resolution mass spectrometry method was developed for the determination of polybrominated diphenyl ethers (PBDEs) and polybrominated biphenyls 153 (BB153) in the ambient air. PBDEs and BB153 were extracted using an accelerated solvent extraction apparatus with a mixture of hexane-dichloromethane (v/v, 1:1) and hexane, respectively. The concentrated extracts were loaded on the composite silica gel column for cleanup. The mean recoveries of native compounds at 10% and 90% of the highest levels of calibration curves were 100% and 104% with 5% and 6% of the mean relative standard deviations (n = 7), respectively. The recoveries of 13C labeled surrogates for di- to deca-brominated diphenyl ethers and BB153 were in the range of 36.5%-133%. However, the recoveries of 13C-monobrominated diphenyl ethers were relatively low, maybe due to the different physicochemical properties compared with the other homologues. No breakthrough of pollutants was estimated under real sampling volume of 300 m3. The limits of detection were lower than 2 x 10(-4) ng/Nm3. The recoveries of 13C labeled surrogates were between 56% and 126%, except monoBDEs. The results demonstrated that the method is suitable for the analysis of di- to decabrominated diphenyl ethers and BB153 in the ambient air with precise quantification.

Seasonal deposition fluxes and removal efficiency of atmospheric polybrominated diphenyl ethers in a large urban center: importance of natural and anthropogenic factors.

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.

Depositional characteristics of atmospheric polybrominated diphenyl ethers on tree barks.

ObjectivesThis study was conducted to determine the depositional characteristics of several tree barks, including Ginkgo (Ginkgo biloba), Pine (Pinus densiflora), Platanus (Platanus), and Metasequoia (Metasequoia glyptostroboides). These were used as passive air sampler (PAS) of atmospheric polybrominated diphenyl ethers (PBDEs).MethodsTree barks were sampled from the same site. PBDEs were analyzed by highresolution gas chromatography/high-resolution mass spectrometer, and the lipid content was measured using the gravimetric method by n-hexane extraction.ResultsGingko contained the highest lipid content (7.82 mg/g dry), whereas pine (4.85 mg/g dry), Platanus (3.61 mg/g dry), and Metasequoia (0.97 mg/g dry) had relatively lower content. The highest total PBDEs concentration was observed in Metasequoia (83,159.0 pg/g dry), followed by Ginkgo (53,538.4 pg/g dry), Pine (20,266.4 pg/g dry), and Platanus (12,572.0 pg/g dry). There were poor correlations between lipid content and total PBDE concentrations in tree barks (R2=0.1011, p =0.682). Among the PBDE congeners, BDE 206, 207 and 209 were highly brominated PBDEs that are sorbed to particulates in ambient air, which accounted for 90.5% (84.3-95.6%) of the concentration and were therefore identified as the main PBDE congener. The concentrations of particulate PBDEs deposited on tree barks were dependent on morphological characteristics such as surface area or roughness of barks.ConclusionsTherefore, when using the tree barks as the PAS of the atmospheric PBDEs, samples belonging to same tree species should be collected to reduce errors and to obtain reliable data.

대기 중 폴리브롬화디페닐에테르의 소나무 잎, 소나무 껍질 및 토양으로의 침착 특성

Objective: This study was carried out in order to determine the depositional characteristics of pine needles, pine bark, and soil used as a passive air sampler (PAS) for atmospheric polybrominated diphenyl ethers (PBDEs). Methods: All three media were sampled from the same site. The PBDE concentrations were analyzed by HRGC/HRMS, and the lipid contents were measured using the gravimetric method by n-hexane extraction. Results: The total PBDE concentration was the highest in soil (22,274.57 pg/g dry), followed by pine bark (20,266.39 pg/g dry), and then pine needles (7,380.22 pg/g dry). Pine needles contained the highest lipid contents (21.31 mg/g dry), whereas soil (10.01 mg/g dry), and pine bark (4.85 mg/g dry) contained less. There were poor correlations between lipid content and total PBDE concentrations in the media (

Atmospheric PBDEs at rural and urban sites in central China from 2010 to 2013: Residual levels, potential sources and human exposure

Atmospheric polybrominated diphenyl ethers (PBDEs) were monitored monthly from 2010 to 2013 at rural and urban sites near a large shallow Chinese lake (Lake Chaohu). The urban areas had higher air PBDEs than the rural areas because of endogenic pollution. The highest and lowest concentrations of Σ13BDEs were observed in the winter and in the summer, respectively. A weak temperature dependence and significant positive correlations between certain PBDE congeners and the PM10 (p < 0.01) suggest transport with particulate matter. Using air-mass back-trajectories, we determined that the main sources of the PBDEs were the areas to the north, such as Shandong Province, and to the east, such as Zhejiang Province. PBDEs did not pose an appreciable risk to human health based on the inhalation exposure assessment. The residents in urban areas were exposed to higher levels of PBDEs, and wintertime exposures posed the greatest human health risk.

Atmospheric concentrations of persistent organic pollutants over the Pacific Ocean near southern Taiwan and the northern Philippines

This study investigates the atmospheric occurrence of persistent organic pollutants (POPs) over the Pacific Ocean near southern Taiwan and the northern Philippines. We determined sixty-six compounds, including polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), dioxin-like polychlorinated biphenyls (DLPCBs), polybrominated diphenyl ethers (PBDEs), as well as polychlorinated diphenyl ethers (PCDEs), polybrominated dibenzo-p-dioxins and dibenzofurans (PBDD/Fs), and polybrominated biphenyls (PBBs), in air samples simultaneously collected from the offshore oceanic atmosphere (n=6) and over a rural area (n=2). We calculated the atmospheric World Health Organization 2005 toxic equivalency levels (WHO2005-TEQ), for the total dioxin-like POPs, including PCDD/Fs, DLPCBs, and PBDD/Fs, being 0.00612pg WHO2005-TEQ/m3 and 0.0138pg WHO2005-TEQ/m3 over the ocean and land, respectively. We found unexpected lower averaged atmospheric PBDE concentrations in the rural area (15.9pg/m3) than over the ocean (31.1pg/m3) due to higher levels of the BDE209 congener, although the difference was not statistically significant. We have compared and reported our field results with previously published datasets over the global oceans, which suggest PCBs and PBDEs are the dominant chemical contaminants in the global oceanic atmosphere among these halogenated POPs (e.g. PCBs and Σdi-hepta PBDEs could be found in the range of 0.09–48.7 and 8.07–94.0pg/m3, respectively, including our dataset). However, there are still very few investigations on the global atmospheric levels of PBDD/Fs, PCDEs and PBBs and our data sums to these earlier studies. Finally, we point out that the halogenated POPs originated from Taiwan or the continental East Asia which could easily reach remote ocean sites via atmospheric transport.

Tree bark as a passive air sampler to indicate atmospheric polybrominated diphenyl ethers (PBDEs) in southeastern China

The different barks were sampled to discuss the influence of the tree species, trunk circumference, and bark thickness on the accumulation processes of polybrominated diphenyl ethers (PBDEs) from air into the bark. The results of different PBDE concentrations indicated that barks with a thickness of 0-3mm collected from weeping willow, Camphor tree, and Masson pine, the trunk circumferences of which were 100 to 150cm, were better PBDEs passive samplers. Furthermore, tree bark and the corresponding air samples were collected at Anji (AJ), Hangzhou (HZ), Shanghai (SH), and Wenling (WL) to investigate the relationship between the PBDE concentrations in bark and those in air. In addition, the significant correlation (r (2) = 0.906; P < 0.05) indicated that atmospheric PBDEs were the principle source for the accumulation of PBDEs in the barks. In this study, the log K BA (bark-air partition coefficient) of individual PBDE congeners at the four sites were in the range from 5.69 to 6.79. Finally, the total PBDE concentration in WL was 5 to 20 times higher than in the other three cities. The result indicated that crude household workshops contributed a heavy amount of PBDEs pollution to the environment, which had been verified by the spatial distribution of PBDEs levels in barks collected at Wenling (range, 26.53-1317.68ng/g dw). The good correlation between the PBDE concentrations in the barks and the air samples and the variations of the PBDE concentrations in tree barks collected from different sites reflected that the bark could be used as a passive sampler to indicate the atmospheric PBDEs.

Summer atmospheric polybrominated diphenyl ethers in urban and rural areas of northern China

High levels of polybrominated diphenyl ethers (PBDEs) have been extensively reported in urban areas and at e-waste recycling sites in coastal China. However, data are scarce in northern China and are not available in rural areas at all. In addition, it is often believed that air concentrations in rural areas are lower than those in urban areas without distinguishing rural residential areas and open fields. In this study, air samples were collected at 17 sites covering urban and rural (residential and open field) areas in northern China using active samplers. With BDE-209 dominated in all congeners, the average concentrations of BDE-209 (41 ± 72 pg/m3) and other 13 PBDEs (16 ± 12 pg/m3) were significantly lower than those found in south China, such as in Guangzhou or Hong Kong. On average, the total PBDE concentrations at the urban sites were 2.2 and 2.9 times of those at the rural residential and field sites, respectively.

Atmospheric polybrominated diphenyl ethers (PBDEs) in the United Kingdom

The occurrence of PBDEs has been studied in the atmosphere of four sites in the United Kingdom over a period of ten years. The concentrations have exhibited a sharp decrease after 2001–2003. This is evident in the urban sites of Manchester and London and at the semi-rural site of Hazelrigg. The average ΣPBDE half-lives for these three sites were 3.4, 2.0 and 3.5 years respectively. ΣPBDEs concentrations in the UK (in 2010 ΣPBDEs < 10 pg m−3) are among the lowest reported in literature. Comparison of concentrations to estimated emissions and employment of PBDE profiles suggest that PBDEs in the UK atmosphere originate from primary emissions from products that contain mainly the penta-BDE technical mixture. The detection of BDE-183 in the majority of samples hints that octa-bromodiphenylether has also been used extensively in the UK, however to a smaller extent than the penta- product.

The air–water exchange of polychlorinated biphenyls and polybrominated diphenyl ethers at an urban lake, a receipt water body for the effluent from a municipal sewage treatment plant

The effluents and sludge from municipal sewage treatment plants (MSTPs) are considered as potential sources of many contaminants to the ambient environments. In the present work, the air–water exchange of polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) was studied using passive air samplers at an urban lake, which receives the effluents from a MSTP in Beijing, China. The concentrations of PCBs and PBDEs in atmosphere were in the range 15.5–108 ng sample −1 and 2.37–27.8 ng sample −1, respectively, during the sampling period (August, 2007–July, 2008). The predominant PCBs and PBDEs were lowly halogenated congeners. The calculation for the exchange fluxes of PCBs and PBDEs using fugacity model showed that, the net exchange fluxes in different seasons were closely related to the halogen number of different congeners. Except for CBs-28 and 52, the net exchange fluxes was mainly directed from air to water for most of predominant congeners, which implied that the lower chlorinated CBs were dominated by volatilization process rather than the dry/wet depositions and diffusion between air–water interface, additionally, for heavy congeners, the dry/wet deposition process was an important source of PCBs and PBDEs in this lake.

Atmospheric polybrominated diphenyl ethers (PBDEs) and Pb isotopes at a remote site in Southwestern China: Implications for monsoon-associated transport

A 13-month sampling campaign was conducted at a remote site in southwestern China from October, 2005 to December, 2006. An integrated approach with lead isotopes and air back trajectory analysis was used to investigate the monsoon-associated atmospheric transport of PBDEs in tropical/subtropical Asia regions. The air concentration of PBDEs ranged from 1.6 to 57.5 pg m − 3 (15.9 ± 12.0 pg m − 3 ), comparable to reported levels at other remote sites in the world. BDE-209, followed by BDE-47 and -99 dominated the PBDE compositions, indicating a mixed deca- and penta-BDE source. Air mass back trajectory analysis revealed that the major potential source regions of BDE-47 and -99 could be southern China and Thailand, while those of BDE-209 are widely distributed in industrialized and urbanized areas in tropical Asia. The different lead isotope compositions of aerosols between trajectory clusters further substantiated the observation that the South Asian monsoon from spring to summer could penetrate deep into southwestern China, and facilitate long-range transport of airborne pollutants from South Asia.