Gas-Phase Oxidation Products of Biphenyl and Polychlorinated Biphenyls

Brubaker, W. Wayne; Hites, Ronald A.

doi:10.1021/es9805021

Cited by 39 publications

(20 citation statements)

References 32 publications

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“…Laboratory studies have demonstrated that PCBs react with hydroxyl (OH) radicals in the gas phase at environmentally significant rates [ Kwok et al , 1995; Anderson and Hites , 1996; Brubaker and Hites , 1998] and it was further confirmed that PCBs containing fewer chlorines react at higher rates than the more highly chlorinated congeners. On the basis of laboratory‐derived rate constants, Anderson and Hites [1996] suggested that the reaction with OH radicals should be the major permanent loss process of PCBs from the atmosphere.…”

Section: Resultsmentioning

confidence: 99%

Mass budget and dynamics of polychlorinated biphenyls in the eastern Mediterranean Sea

Mandalakis

Apostolaki

Stephanou

et al. 2005

Global Biogeochemical Cycles

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[1] Polychlorinated biphenyls (PCBs) were measured in dry deposition and sediment trap samples from the eastern Mediterranean and the results of the present and previous studies were synthesized in order to construct a mass balance budget describing the status and dynamics of PCBs in this region. According to our calculations, the burden of total PCBs in the euphotic zone of the eastern Mediterranean should approach 84,000 kg, while the corresponding pool in the overlying atmosphere should be about 162 kg. The atmospheric input of PCBs in the respective water basin through dry and wet deposition should be 300 and 1300 kg yr À1 , respectively. On the contrary, air-sea exchange should cause a net volatilization of PCBs from seawater to the atmosphere by 3150 kg yr À1 . Moreover, PCBs are removed from the water column with a settling flux of 350 kg yr À1 and under steady state conditions, an additional input of these pollutants should be required to counterbalance the outflows from the water basin. The discharge of urban and industrial sewage, riverine input and transport of more polluted surface waters from western to eastern Mediterranean may account for most of this inflow. In the atmospheric compartment, the removal flux of PCBs due to their destruction by hydroxyl radicals (6650 kg yr À1 ) was approximately 4 times higher than their deposition flux (wet plus dry). On the basis of these data, 5100 kg of PCBs should enter into the atmosphere of eastern Mediterranean annually in order to achieve steady state conditions. This influx may result from long or short range transport of atmospheric PCBs emitted from contaminated terrestrial surfaces.Citation: Mandalakis, M., M. Apostolaki, E. G. Stephanou, and S. Stavrakakis (2005), Mass budget and dynamics of polychlorinated biphenyls in the eastern Mediterranean Sea, Global Biogeochem. Cycles, 19, GB3018,

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Section: Resultsmentioning

confidence: 99%

Mass budget and dynamics of polychlorinated biphenyls in the eastern Mediterranean Sea

Mandalakis

Apostolaki

Stephanou

et al. 2005

Global Biogeochemical Cycles

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“…This compound is used commercially in the production of pharmaceuticals and is an impurity in some herbicides. Low concentrations of 2,4-DCBA measured in groundwater, rivers, and lakes have been attributed to anthropogenic contamination as well as biological and photochemical degradation of anthropogenically produced polychlorinated biphenyls (PCBs) (22)(23)(24)(25)(26). However, 2,4-DCBA in some pristine waters has been attributed to direct biological production (27).…”

Section: Resultsmentioning

confidence: 99%

Structure Elucidation and Characterization of Polychlorinated Biphenyl Carboxylic Acids as Major Constituents of Chromophoric Dissolved Organic Matter in Seawater

Repeta

Hartman

John

et al. 2004

Environ. Sci. Technol.

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Chromophoric or colored dissolved organic matter (CDOM) is one of the principal light adsorbing components of seawater, particularly in the ultraviolet, where it attenuates over 90% of downwelling ultraviolet radiation. In highly productive coastal regions and throughout most of the global ocean, in situ biological production is the major source of CDOM. However, little is known about CDOM composition on the molecular level, and there are only a few reports that link CDOM composition to autochthonous biological sources. Here we report the isolation and characterization of CDOM components from one coastal and two open-ocean sites. Each sample contains a complex mixture of light absorbing (300-400 nm) components, including 2,4-dichlorobenzoic acid and a suite of novel, polychlorinated biphenyl carboxylic acids that closely resemble polychlorinated biphenyls (PCBs) of anthropogenic origin. However, the global inventory and isomer distribution of dissolved chlorinated aromatic acids suggest they are derived from in situ biological production rather than anthropogenic contaminants. These novel chlorinated aromatic acids account for a significant amount of CDOM adsorption in the ultraviolet.

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“…7, 12–24 While it is generally understood that formation of OH-PCBs is the first step in this removal process, their atmospheric lifetimes are predicted to be quite short in comparison to their parent PCB compounds, 15, 25 making them difficult to detect in the air as reaction intermediates. Still, there is no definitive information regarding the presence of OH-PCBs (or lack thereof) in environmental air samples.…”

Section: Introductionmentioning

confidence: 99%

Occurrence and Distribution of Two Hydroxylated Polychlorinated Biphenyl Congeners in Chicago Air

Awad

Martínez

Marek

et al. 2016

Environ. Sci. Technol. Lett.

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We measured hydroxylated polychlorinated biphenyls (OH-PCBs) in both gas and particulate phases in 30 Chicago air samples, the first report of OH-PCBs in environmental air samples. Concentrations of 2OH-PCB2 and 6OH-PCB2 in both phases were similar to PCB2 measured in the same samples, from non-detect to 11 pgm−3 and 12 ngg−1 for the gas and particulate phases, respectively. We found that OH-PCB2s sorbed more to particulates than did PCB2; seasonal variability was larger than spatial variability across Chicago; and partial pressure and temperature strongly correlated with the two OH-PCBs (p<0.0001). Similar 6OH-PCB2:2OH-PCB2 ratios were found in our air samples and Aroclors, suggesting that Aroclors are a legacy source of OH-PCB2s to the atmosphere and appear to be volatilizing proportionally to PCBs in Aroclors. Although degradation by the hydroxyl radical has been proposed as an efficient loss process for airborne PCBs, we found no evidence that this mechanism results in the formation of OH-PCB2s.

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Gas-Phase Oxidation Products of Biphenyl and Polychlorinated Biphenyls

Cited by 39 publications

References 32 publications

Mass budget and dynamics of polychlorinated biphenyls in the eastern Mediterranean Sea

Mass budget and dynamics of polychlorinated biphenyls in the eastern Mediterranean Sea

Structure Elucidation and Characterization of Polychlorinated Biphenyl Carboxylic Acids as Major Constituents of Chromophoric Dissolved Organic Matter in Seawater

Occurrence and Distribution of Two Hydroxylated Polychlorinated Biphenyl Congeners in Chicago Air

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