Deposition Of Polybrominated Diphenyl Ethers Research Articles

Polybrominated diphenyl ethers in the environment: a wake-up call for concerted action in India

Polybrominated diphenyl ethers (PBDEs) are a class of persistent organic pollutants (POPs) used as flame retardants in the products utilized in day-to-day life. Their bioaccumulation, low volatility, and high persistence in the environment have led to their global spread even to remote and distant regions. The present study identifies gaps in the investigation of the neurotoxic potential of PBDEs, their effects on brain development, toxicokinetic, and their potential as a carcinogen. In India, to date, only human breast milk was assessed for levels of PBDEs, and it is suggested that other human tissues can also be explored. No data on the reproductive toxicity of PBDEs are reported from Indian cohorts. Long-range transport and deposition of PBDEs in colder regions necessitates monitoring of Himalayan regions in India. An inventory of PBDEs is required to be made for addressing the worrisome situation of the unregulated import of E-waste from the developed countries in India. The study also emphasizes providing guidelines for the articulation of policies regarding sound surveillance and management of PBDE production, consumption, and release in the Indian context. It is recommended that a separate cell for monitoring and follow-up of PBDEs should be established in India. Also, the development of better alternatives and environment-friendly remediation technologies for PBDEs is the need of the hour.

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.

The effect of hydrodynamic forcing on the transport and deposition of polybrominated diphenyl ethers (PBDEs) in Hangzhou Bay

Surface sediment samples (n = 92) were collected from Hangzhou Bay to investigate the transport and deposition of polybrominated diphenyl ethers (PBDEs) and to assess the ecological risks in Hangzhou Bay. The concentrations of ∑7PBDEs (sum of BDE-28, 47, 99, 100, 153, 154, 183) and BDE-209 ranged from 3.61 to 91.09 pg g−1 and from non-detectable to 2007.52 pg g−1 (dry weight), respectively. The high values of ∑7PBDEs and BDE-209 were commonly occurred at the northeast of Hangzhou Bay and the Nanhui Spit coast of Shanghai. Compared with the south part of the bay, the dominance of BDE-209 was more prominent and the linear correlations between PBDEs concentrations and TOCs as well as median grain size were more significant in the northern Hangzhou Bay. Hydrodynamic forcing on the transport and deposition of PBDEs is primarily responsible for the discrepancy of this spatial distribution in these two parts. In addition to BDE-209, BDEs-153, 99, 47, and 100 were also the abundant congeners. Three principal components were extracted using principal component analysis (PCA), mainly attributed to human activities, erosion of polluted soils via surface runoff and release from products for PC1, PC2 and PC3, respectively. The calculation results of mass inventories, hazard quotients (HQs) and risk quotients (RQs) indicated that the ecological risk of PBDEs in Hangzhou Bay was low. The multiple effect of hydrodynamic forcing with complicated and large-scope tidal currents made it hard to deposit for organic matters and contaminants in Hangzhou Bay.

Influence of human activities and organic matters on occurrence of polybrominated diphenyl ethers in marine sediment core: A case study in the Southern Yellow Sea, China

The Southern Yellow Sea (SYS) is an important reservoir of anthropogenic organic contaminants, such as polybrominated diphenyl ethers (PBDEs). To reconstruct the historical records of PBDEs and examine their relationships with the human activities and organic matters, a210Pb-dated sediment core was collected from the central mud area in the SYS. The concentrations of tri-to hepta-BDEs (∑7PBDEs) and BDE-209 ranged from 9.8 to 99.8 pg g−1 d.w. and from 12.1 to 855.4 pg g−1 d.w., respectively, both displaying the increasing trends from the bottom to the surface. More importantly, there was a faster increase for PBDEs since the 1990s, especially for BDE-209, which responded well with the rapid economic growth, and the increases of urbanization and industrialization in the local areas of the SYS. The analogously vertical patterns and significant relationships between PBDEs and total organic carbon (TOC) implied the TOC-dependent deposition of PBDEs in the core. Furthermore, multiple biomarker-based proxies of terrestrial organic matter (TOM) and marine organic matter (MOM) were introduced to systematically investigate the different effects of TOM and MOM on PBDE deposition in the SYS. The similarly down-core profiles and significant correlations were found between PBDEs and the MOM proxies (sum of rassicasterol, dinosterol and C37 alkenones (∑A + B + D) and marine TOC) as well as the branched and isoprenoid tetraether (BIT), but not for TOM proxies (∑C27+C29+C31n-alkanes, terrestrial and marine biomarker ratio (TMBR) and terrestrial TOC), indicating that MOM was an important factor driving PBDE deposition in the sediment core from the SYS.

Atmospheric deposition of PBDEs and DPs in Dongjiang River Basin, South China.

The atmospheric deposition fluxes of polybrominated diphenyl ethers (PBDEs) and Dechlorane Plus (DPs) in Dongjiang River Basin of the Pearl River Delta in South China were investigated during winter and summer, respectively. The total deposition fluxes varied from 4.74 to 27.0ng/m2/day for PBDEs and 8.77 to 206ng/m2/day for DPs, respectively. The fractions of anti-DP to the total DPs (f anti) varied from 0.28 to 0.63 (mean=0.43±0.06), i.e., generally lower than those in commercial products, which might be attributed to the different environmental fates of the two isomers. Significant seasonal and spatial variations of PBDEs and DPs were observed. The deposition fluxes in summer were generally higher than those in winter, which may be due to the relatively high temperature and rainfall in summer under the influence of prevailing subtropical monsoon climate. Moreover, high deposition fluxes of PBDEs and DPs in urban areas and significant urban/rural gradient implied that local industrial activities in the urban areas were primary sources, which were further confirmed by the results of principal component analysis. The highest deposition of PBDE and DP fluxes was found at different sampling sites, suggesting PBDEs and DPs may be derived from different industries or products.

Concentrations, Fluxes, and Residence Time of PBDEs Across the Tropical Atlantic Ocean

Little is known about the fate of polybrominated diphenylethers (PBDEs) across the Oceans. Air and water were sampled using both active and passive polyethylene samplers on an east-west transect across the tropical Atlantic Ocean in 2009 and analyzed for PBDEs. Typical particle-bound concentrations of PBDEs in the surface water were low, at <1 pg L(-1). Truly dissolved concentrations from passive samplers were ∼0.5 pg L(-1) for BDE 47 and around 0.1 pg L(-1) for BDEs 28, 99, and 100 (results from active samples were compromised). In the atmosphere, particle-bound BDE 209 dominated overall concentrations (median 1.2 pg m(-3)), followed by BDE 99 (0.13 pg m(-3)). Gas-phase concentrations based on passive samplers were 1-8 pg m(-3) for BDE 47 and ≤ 4 pg m(-3) for BDE 99. Net air-water exchange gradients strongly favored gas-phase deposition of PBDEs into the water. Net gas-phase deposition fluxes ranged from tens of pg m(-2) day(-1) for BDEs 28 and 85 to around 1 ng m(-2) day(-1) for BDE 47, 99, and 209. Settling fluxes of particle-bound PBDEs in the atmosphere and surface water were around 50 pg m(-2) day(-1) for BDE 47 and <10 pg m(-2) day(-1) for the other congeners.

Polybrominated diphenyl ethers in farmland soils: Source characterization, deposition contribution and apportionment

Polybrominated diphenyl ethers (PBDEs), a group of persistent organic pollutants (POPs), are caused for concern recently due to their adverse health effects and environmental ubiquity. In this study, atmospheric and soil PBDE levels in Taizhou, one of the largest WEEE dismantling areas in the world, were measured, ranging from 884 to 2791pgm−3 with an average of 1968pgm−3 for atmosphere and 2.96 to 200ngg−1dry weight (dw) with the mean of 65.2ngg−1dw for farmland soils, respectively. The close connection between soil PBDE accumulation and atmospheric deposition was also revealed by the estimation of the annual PBDE deposition flux (3.1±0.9mgm−2a−1) and the similarity between deposited congener pattern and soil congener profile. Positive matrix factorization (PMF) was conducted to extract possible sources of farmland soil PBDEs and to calculate their contributions. Based on the measured source profiles of PBDE-related activities, five sources were identified representing WEEE dumping, WEEE dismantling, WEEE open burning, residential waste dismantling, and residential waste open burning. WEEE-related recycling activities contributed primary percentage (52%) to farmland soil PBDE concentration, and open burning was an important pathway for PBDEs entering the environment.

Occurrence of polybrominated diphenyl ethers in soil from the central Loess Plateau, China: Role of regional range atmospheric transport

Very few studies were conducted in highland and depositional areas in studying the transport and behavior of polybrominated diphenyl ethers (PBDEs). In this study, surface soils were collected from Huan County to investigate the level, profile, and potential influence of PBDEs via regional range atmospheric transport in the central part of the Loess Plateau (CLP) of China, one of the most extensive areas of loess deposition in the world. PBDEs were ubiquitous and log-normally distributed in soils from the CLP with mean concentrations of 0.91 and 0.54 ng g −1 for ΣPBDEs (sum of PBDE congeners except for BDE-209) and BDE-209, respectively. BDE-209 was predominated congener (43.5%), followed by BDE-47 (15.7%), 99 (10.7%), and 153 (7.5%). Further principal component analysis on congener profiles showed that PBDEs in the CLP originated from similar source(s). Additionally, significant differences in the ratios of BDE-47 to 99 and BDE-153 to 154 were found between soil samples and commercial products, indicating that they have undergone fractionation during the process of regional range atmospheric transport. The deposition of PBDEs in the CLP could be influenced by the sources from surrounding regions. For example, Xi’an may have potential influence to the CLP based on geographical analysis and concentrations comparison of PBDEs in gaseous. Therefore, more studies are needed to clarify the atmospheric transport and fate of PBDEs in this region.

Bioaccumulation and historical deposition of polybrominated diphenyl ethers (PBDEs) in Deep Bay, South China

To characterize the bioaccumulation and historical trends of polybrominated diphenyl ethers (PBDEs) in Deep Bay, an important water body between Hong Kong and main land China with a Ramsar mangrove wetland (Maipo), marine organisms and core sediments were collected to determine their PBDEs concentrations. Sediment core dating was accomplished using the 210Pb method. PBDEs concentrations in fish ranged from 0.17 to 4.16 ng g −1 wet wt., with a mean value of 2.00 ng g −1 wet wt. Temporal trends of the target PBDE congeners levels in core sediment generally increased from 1948 to 2003, with the highest levels in top sediment, suggesting an ongoing PBDEs input. The average sedimentation flux of PBDEs was 0.25 ng cm −2 a −1, and the double time of total PBDEs concentration was ca. 12.3 a. Correlations between the biota-sediment accumulation factors (BSAF) of PBDEs and their corresponding octanol–water partition coefficient ( K ow) were discussed.

Dry and wet particle deposition of polybrominated diphenyl ethers (PBDEs) in Guangzhou and Hong Kong, South China

PBDEs were measured in wet and dry particle deposition samples collected at the urban sites of Guangzhou and Hong Kong from December 2003 to December 2004. The depositional fluxes of BDE-209 ranged from 273 to 6000 ng m(-2) day(-1) in Guangzhou and from 29.1 to 1100 ng m(-2) day(-1) in Hong Kong. The depositional fluxes for Sigma(9)PBDEs (defined as the sum of BDE-28, -47, -66, -100, -99, 154, -153, -138 and -183) ranged from 0.96 to 604 ng m(-2) day(-1) in Guangzhou and from <LOD to 10.6 ng m(-2) day(-1) in Hong Kong. BDE-209 was the most abundant PBDE congener, showing that deca-BDE accounts for most of the total PBDE emitted in the environment. Distinct seasonal patterns were observed in the PBDE depositional fluxes in Hong Kong, with higher depositional fluxes during the winter monsoon period and lower fluxes during the summer. The air mass back trajectory analysis showed that the high concentrations of PBDEs in deposition samples in Hong Kong originated from the inland of the Pearl River Delta (PRD) region. With the exception of the highest depositional flux of BDE-209 observed during the periods of haze, the seasonal variation in the BDE-209 depositional fluxes in Guangzhou was less strong, suggesting the importance of local sources. The average dry deposition velocities of BDE-47, -99, and -209 were 0.32 +/- 0.12 cm s(-1), 0.24 +/- 0.16 cm s(-1), and 0.28 +/- 0.01 cm s(-1), respectively. The particle washout ratios (W(p)) of PBDEs decreased with increasing rainfall frequency and reached a consistent level afterwards. The median washout ratios of BDE-47, -99 and -209 were 1.1 x 10(5), 3.1 x 10(5), and 5.1 x 10(5), respectively.

Do trans-Pacific air masses deliver PBDEs to coastal British Columbia, Canada?

In order to distinguish between ‘local’ and ‘background’ sources of polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) in coastal British Columbia (Canada) air, we collected samples from two sites: a remote site on western Vancouver Island, and a near-urban site in the Strait of Georgia. Seasonally-integrated samples of vapor, particulate, and rain were collected continuously during 365 days for analysis of 275 PCB and PBDE congeners. While deposition of the legacy PCBs was similar at both sampling sites, deposition of PBDEs at the remote site amounted to 42% (10.4 mg/ha/year) of that at the near-urban site. Additional research into atmospheric circulation in the NE Pacific Ocean will provide more insight into the transport and fate of priority pollutants in this region, but trans-Pacific delivery of PBDEs to the west coast of North America may underlie in part our observations. For example, approximately 40% of >12,000 ten-day back trajectories calculated for the remote site originated over Asia, compared to only 2% over North America.

Current and Historical Deposition of PBDEs, Pesticides, PCBs, and PAHs to Rocky Mountain National Park

An analytical method was developed for the trace analysis of 98 semivolatile organic compounds (SOCs) in remote, high-elevation lake sediment. Sediment cores from Lone Pine Lake (west of the Continental Divide) and Mills Lake (east of the Continental Divide) in Rocky Mountain National Park, CO, were dated using 210Pb and 137Cs and analyzed for polybrominated diphenyl ethers (PBDEs), organochlorine pesticides, phosphorothioate pesticides, thiocarbamate pesticides, amide herbicides, triazine herbicides, polychlorinated biphenyls (PCBs), and polycyclic aromatic hydrocarbons (PAHs) using this method. SOC deposition profiles were reconstructed, and deposition half-lives and doubling times were calculated, for U.S. historic-use pesticides (HUPs) and current-use pesticides (CUPs) as well as PBDEs, PCBs, and PAHs. Sediment records indicate that the deposition of CUPs has increased in recent years, while the deposition of HUPs has decreased since U.S. restriction, but has not been eliminated. This is likely due to the revolatilization of HUPs from regional soils, atmospheric transport, and deposition. Differences in the magnitude of SOC sediment fluxes, flux profiles, time trends within those profiles, and isomeric ratios suggest that SOC deposition in high-elevation ecosystems is dependent on regional upslope wind directions and site location with respect to regional sources and topographic barriers.

Particle-Phase Dry Deposition and Air−Soil Gas-Exchange of Polybrominated Diphenyl Ethers (PBDEs) in Izmir, Turkey

The particle-phase dry deposition and soil-air gas-exchange of polybrominated diphenyl ethers (PBDEs) were measured in Izmir, Turkey. Relative contributions of different deposition mechanisms (dry particle, dry gas, and wet deposition) were also determined. BDE-209 was the dominating congener in all types of samples (air, deposition, and soil). Average dry deposition fluxes of total PBDEs (sigma7PBDE) for suburban and urban sites were 67.6 and 128.8 ng m(-2) day(-1), respectively. Particulate dry deposition velocities ranged from 11.5 (BDE-28) to 3.9 cm s(-1) (BDE-209) for suburban sites and 7.8 (BDE-28) to 2.8 cm s(-1) (BDE-154) for urban sites with an overall average of 5.8 +/- 3.7 cm s(-1). The highest sigma7PBDE concentration (2.84 x 10(6) ng kg(-1) dry wt) was found around an electronic factory among the 13 soil samples collected from different sites. The concentration in a bag filter dust from a steel plant was also high (2.05 x 10(5) ng kg(-1)), indicating that these industries are significant PBDE sources. Calculated net soil-air gas exchange flux of sigma7PBDE ranged from 11.8 (urban) to 23.4 (industrial) ng m(-2) day(-1) in summer, while in winter it ranged from 3.2 (urban) to 11.6 (suburban) ng m(-2) day(-1). All congeners were deposited at all three sites in winter and summer. It was estimated that the wet deposition also contributes significantly to the total PBDE deposition to soil. Dry particle, wet, and gas deposition contribute 60, 32, and 8%, respectively, to annual PBDE flux to the suburban soil.

Modeling Atmospheric Vegetation Uptake of PBDEs Using Field Measurements

Polybrominated diphenyl ethers (PBDEs) are flame retardants used in a variety of consumables. Models indicate that air-vegetation exchange plays an important role in their global distribution. The present study surveyed PBDEs in spruce needles and air (gaseous and particulate-bound) over an annual cycle to model accumulation of PBDEs in vegetation. Air-particulate distributions revealed that penta and higher BDE congeners were mainly associated with particulates even in warmer temperatures, whereas for the tri- and tetra-BDE congeners, a significant temperature dependence was observed. Using measured vegetation and atmospheric concentrations from bud burst 2004 to June 2005, a modeling concept was developed to determine PBDE deposition velocities to vegetation. Particulate-bound deposition velocity was calculated to be 3.8 m/h. Net gaseous transfer velocities ranged from 2.4 to 62.2 m/h and correlated significantly with log K(OA). These derived values were used to model PBDE accumulation by vegetation through time, and these agreed well with measured values. This study provides the necessary background for modeling PBDE transport between air and coniferous vegetation globally.

Atmospheric deposition of polybrominated diphenyl ethers (PBDEs) in coastal areas in Korea

Atmospheric bulk samples were collected monthly, for one year, from urban, suburban, and rural sites located in the coastal areas of Korea, for the assessment of depositional fluxes and seasonal variations in atmospheric concentrations of PBDEs. Twenty individual PBDE congeners were found in atmospheric samples, and their depositional fluxes varied from 10.1 to 89.0 μg/m 2/year. The highest depositional fluxes were found in two urbanized areas, with a strong urban–rural gradient. The relationship between PBDE and particulate depositional fluxes showed significant correlation for all locations, which suggested the association of PBDEs to particulate phase. Deca-BDE (BDE 209) was the predominant congener (>93%) in all deposition samples, which is consistent with a high consumption of deca-BDE for the flame-retardant market in Korea. Seasonal variability was observed in PBDE concentrations for the two urban sites, whereas no seasonal trend was found for either the suburban or the rural location.

Validation of an passive atmospheric deposition sampler for polybrominated diphenyl ethers

An atmospheric deposition sampler was validated with respect to polybrominated diphenyl ethers (PBDEs), a compound group that is widely used as flame retardants in many types of consumer products. The deposition sampler consists of an adsorption cartridge that is connected to a glass funnel. Extraction tests with spiked cartridges using soxhlet extraction with acetone revealed recoveries of >80% for all of the investigated PBDEs. Once adsorbed, PBDEs are stable, as proven by extractions of spiked cartridges that were stored outdoors and collected after different periods of time, up to 84 days. High recoveries indicate that degradation of adsorbed PBDEs does not play a role under realistic field conditions. Bulk deposition rates of PBDEs were determined in a field test with 3 replicates, and a possible breakthrough of target compounds was assessed in the field using a second adsorption cartridge in series. No breakthrough of target compounds could be observed within a sampling period of 61 days, and a bulk deposition rate of approximately 1 ng m(-2) day(-1) for the sum of all analysed PBDEs was measured. The highest deposition rates were measured for octa-brominated congeners, followed by BDEs 99, 183, 153, and 47. Overall, the sampler was successfully validated regarding the atmospheric deposition of PBDEs.

Polybrominated diphenyl ethers at a solid waste incineration plant II: atmospheric deposition

In the second of two papers, the atmospheric polybrominated diphenyl ethers (PBDE) deposition (wet and dry) at a municipal solid waste incineration (MSW) plant with electronics recycling is compared with that at an industrial urban reference site (URS) producing asphalt and concrete. Results of BDE209 and SigmaPBDE excluding BDE209 as representatives of new vs. old PBDEs are presented. Volume weighted mean SigmaPBDE and BDE209 concentrations at the MSW were 6.2 and 14.4 ng l(-1), and at the URS were 2.5 and 14.1 ng l(-1). Median SigmaPBDE and BDE209 deposition fluxes were 21.3, 63.8 and 7.0, 14.7 ng m(-2) day(-1) at the MSW and URS, respectively. The concentrations in precipitation and the deposition fluxes were significantly higher at the MSW compared to the URS. Measured total washout- ratios (W-T) were dependent on particle scavenging and the median WT for all congeners was 5.4x 10(5). Median dry particle deposition velocities ranged from 0.4 to 49 cm s(-1), depending on congener, showing that PBDEs are effectively removed from the atmosphere by particle deposition. PBDE fluxes increased at the reference site when winds were blowing from west south-west, i.e. from the direction of the MSW. PBDE deposition and washout ratios were not influenced by temperature or rain volume, suggesting a constant emission from the MSW regardless of weather conditions. Together with the results of paper I (Agrell et al., 2004, Atmospheric Environment, this issue) we therefore suggest that treatment of waste, e.g. electronics recycling, is more a source of old PBDEs to the environment, whereas the rather similar BDE209 concentrations at the two urban sites are more a result of proximity to potential diffuse sources. (C) 2004 Elsevier Ltd. All rights reserved. (Less)

Atmospheric transport of polybrominated diphenyl ethers and polychlorinated biphenyls to the Baltic Sea.

The atmospheric transport of polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) was compared by measuring concentrations in air and deposition on an island located in the central basin of the Baltic Sea. Median sigmaPBDE and sigmaPCB concentrations (gaseous + particle) were 8.6 and 7.4 pg m(-3), respectively. Airborne PCBs were mainly found in the gaseous phase, while most of the PBDEs were detected on particles, which agrees with predicted particle/gas distributions. SigmaPBDE levels were dominated by the decabrominated BDE209 followed bythe tetrabrominated BDE47 and pentabrominated BDE99. BDE209 is a marker for the environmental distribution of the commercial deca-BDE formulation (>99.5% BDE209), whereas BDE47 and BDE99 are markers for the commercial penta-BDE mixture. General correlations between PBDEs and PCBs suggested similarities in sources and transport mechanism, while more detailed examination of the data identified notable behaviors and exceptions. Differences in regression slopes among tetra-, penta-, and decabrominated PBDEs may reflect different transport processes and the change in usage pattern. Tetra- and pentabrominated PBDEs may originate from secondary sources such as air surface exchange in a manner similar to that of the PCBs, while the deca-BDE209 formulation still has primary sources. The tribrominated BDE17 was also detected and is proposed to be a breakdown product due to atmospheric debromination processes. PBDEs had higher washout ratios than PCBs, explaining their higher concentrations compared to PCBs in precipitation (median of 6.0 and 0.5 ng L(-1) for sigmaBDE and sigmaPCB concentrations ("dissolved" + particle), respectively) than in air. The calculated yearly deposition of PBDEs and PCBs indicated that the atmospheric input of PBDEs to the Baltic Proper is currently exceeding that of the PCBs by a factor of 40, while that of the PCBs is decreasing.