Gas emissions, minerals, and tars associated with three coal fires, Powder River Basin, USA.

Ground-based surveys of three coal fires and airborne surveys of two of the fires were conducted near Sheridan, Wyoming. The fires occur in natural outcrops and in abandoned mines, all containing Paleocene-age subbituminous coals. Diffuse (carbon dioxide (CO(2)) only) and vent (CO(2), carbon monoxide (CO), methane, hydrogen sulfide (H(2)S), and elemental mercury) emission estimates were made for each of the fires. Additionally, gas samples were collected for volatile organic compound (VOC) analysis and showed a large range in variation between vents. The fires produce locally dangerous levels of CO, CO(2), H(2)S, and benzene, among other gases. At one fire in an abandoned coal mine, trends in gas and tar composition followed a change in topography. Total CO(2) fluxes for the fires from airborne, ground-based, and rate of fire advancement estimates ranged from 0.9 to 780mg/s/m(2) and are comparable to other coal fires worldwide. Samples of tar and coal-fire minerals collected from the mouth of vents provided insight into the behavior and formation of the coal fires

Polybrominated diphenylethers in the environment - Local and long range transport

I have studied the sources, long range transport, and rates of flow of polybrominated diphenyl ethers (PBDEs), from the technosphere to the Baltic ecosystems. PBDEs are mainly used in polymers, which are applied in electrical equipment to prevent overheating or flashover and are produced in large quantities. PBDEs have become widely spread in the environment, where they are able to accumulate in biota (i.e. concentrations of PBDEs in human milk increase similar to that observed in wildlife) and induce toxic effects, such as thyroid disruption and neurological damage. To identify sources of PBDEs, air and precipitation were sampled at a municipal solid waste treatment plant (MSW) with an electronics recycling facility. Concentrations in both precipitation and air were higher at the MSW than at a reference station. Concentrations in air and rain at the reference station were depending on wind direction and higher levels were found when winds were blowing from the MSW area. It was concluded that treatment of waste and electronics recycling is presently a source of “old” PBDEs (Tetra-BDE47 and Penta-BDE99) to the environment, whereas Deca-BDE209 concentrations are more a result of proximity to potential diffuse sources. A negative relationship between the particulate PBDE concentration and rain volume was found, suggesting a dilution effect and indicating the importance of particle scavenging for wet deposition. To examine the distribution of PBDEs over Sweden, common frogs (Rana temporaria) were used as bioindicators. BDE47 was found in almost all frogs analysed, whereas BDE99 was detected in less than half of the frogs. PBDE concentrations were compared with that of PCBs. The fate of PCBs is well documented and believed to be similar to that of the PBDEs. I showed that PBDE and PCB concentrations in frogs were latitude related, supporting the global distillation theory. PBDE concentrations were significantly correlated with PCB concentrations, indicating similar contaminant sources and an analogous environmental fate. The PCB concentrations were one to two orders of magnitude higher than that of the PBDEs at southern latitudes, but the difference decreased to the north. To assess the long range transport and input of PBDEs to the Baltic Sea, air and atmospheric deposition were sampled on Gotska Sandön, situated in the central basin of the Baltic Sea. As predicted by their physicochemical properties, low brominated congeners were in the gas/dissolved phase, whereas higher brominated PBDEs were more in the particle phase, affecting their respective modes of transport. BDE209 was compared to PCBs and other PBDEs and shown to be the most dominant pollutant in the atmosphere of the Baltic Sea region. This could be attributed to DecaBDE's currently high consumption volume. I found that PBDE and PCB concentrations were highly correlated, indicating that their overall atmospheric transport is likely driven by the same mechanism. However, a difference was observed between the commercial DecaBDE formulation, BDE209 and the Penta-BDEs BDE47, 100, and 99. This suggested different underlying processes between "old" commercial PentaBDE and "new" DecaBDE formulations when transported over long distances through the atmosphere

Polybrominated diphenyl ethers in precipitation in Southern Sweden (Skane, Lund)

The presence of polybrominated diphenyl ether (PBDE) flame retardants in total deposition (wet + dry) was assessed with the simultaneous use of three bulk samplers during a 2 week period. The particle associated and the 'dissolved' phase were separated during sampling. Volume weighted mean (VWM) concentrations of SigmaPBDE (9 congeners) in rain were 209 pg l(-1). Total deposition rates were 2 +/- 1 ng SigmaPBDE m(-2) day(-1). The total PBDE deposition was dominated by decaBDE(209) and thereafter 2,2'4,4'-tetraBDE(47) and 2,2'4,4',5-pentaBDE(99). Concentrations of particle associated and 'dissolved' PBDEs in total deposition were used to calculate filter/adsorbent ratios (F/A). We found that 65 +/- 18% of the total PBDEs were particle associated. Low F/A ratios for higher brominated congeners (Br > 5) were observed. This is contradictory with predictions based on the PBDEs' physico-chemical properties and was attributed to sampling artefacts, such as particle size distribution, and/or non-equilibrium processes. There was a negative relationship between the particulate SigmaPBDE concentration and rain volume suggesting a dilution effect and the importance of particle scavenging for wet deposition of PBDEs. (C) 2002 Elsevier Science Ltd. All rights reserved

Latitudinal fractionation of polyhrominated diphenyl ethers and polychlorinated biphenyls in frogs in (Rana temporaria)

The flame retardant polybrominated diphenyl ethers (PBDEs) have become ubiquitous environmental pollutants. The environmental distribution of PBDEs is much less studied than that of the polychlorinated biphenyls (PCBs). To compare the environmental fate of the PCBs with their partial substitute, the PBDEs, common frogs (Rana temporaria)were collected along a similar to1500-km-long latitudinal gradient of the Scandinavian Peninsula and their livers analyzed for PCBs and PBDEs. Mean concentrations of total PCBs and BDE47 ranged from 9200 to 92 900 and 30 to 120 ng kg(-1) fresh weight, respectively, whereas BDE99 was detected in less than 50% of the frogs. PCB concentrations were higher than that of the PBDEs, and the differences decreased in the northern latitudes. Moreover, the pollutant concentrations in frog livers were negative functions of latitude. The observed scatter and regression slopes imply several influencing factors (such as habitat, exposure route, uptake, metabolism, excretion, etc.) and indicate release events instead of the grasshopper effect. Biological variables such as gender, age, body size, and lipid content did not influence pollutant concentrations in the frog livers. The total PCB and BDE47 concentrations in frogs were highly correlated. Hence, their environmental fate is analogous and our results highlight the need to examine the potential role of xenobiotics on amphibian populations

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 by the 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

Spatial distribution of polybrominated diphenyl ethers in southern Ontario as measured in indoor and outdoor window organic films

Organic films were collected from indoor and outdoor window surfaces, along an urban-rural transect extending northward from Toronto, Ontario, Canada, and analyzed for 41 polybrominated diphenyl ether congeners (PBDE). For exterior films, urban SigmaPBDE concentrations were similar to10x greater than rural concentrations, indicating an urban-rural gradient and greater PBDE sources in urban areas. Urban films ranged from 2.5 to 14.5 ng/m(2) (mean = 9.0 ng/m(2)), excluding the regional "hotspot" Electronics Recycling Facility, compared to 1.1 and 0.56 ng/m(2) at the Suburban and Rural sites. Interior urban films (mean = 34.4 ng/m(2)) were 3 times greater than rural films (10.3 ng/m(2)) and were representative of variations in building characteristics. Indoor films were 1.5-20 times greater than outdoor films, consistent with indoor sources of HOES and enhanced degradation in outdoor films. Congener profiles were dominated by BDE-209 (51.1%), consistent with deca-BDE as the main source mixture, followed by congeners from the penta-BDE mixture (BDE-99:13.6% and -47:9.4%) and some octa-BDE (BDE-183:1.5%). Congener patterns suggest a degradative loss of lower brominated compounds in outdoor films versus indoor films. Gas-phase air concentrations were back-calculated from film concentrations using the film-air partition coefficient (K-FA). Mean calculated air concentrations were 4.8 pg/m(3) for outdoor and 42.1 pg/m(3) for indoor urban sites, indicating that urban indoor air is a source of PBDEs to urban outdoor air and the outdoor regional environment

A Reply to Keith Schofield: Comment on Ernest et al. Programmable Thermal Dissociation of Reactive Gaseous Mercury, a Potential Approach to Chemical Speciation: Results from a Field Study. Atmosphere 2014, 5, 575–596

Dr. Schofield [1] states that:[...

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