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Persistent organic pollutants in the atmosphere - spatial and temporal variations

Backe, Cecilia LU (2001)
Abstract (Swedish)
Popular Abstract in Swedish

Avhandlingen bygger på en studie av halter av stabila organiska miljögifter (PCB) i luften, i nederbörd och i jord. Studien har utförts vid 11 provtagnings platser i Skåne. Vidare behandlas global transport av stabila miljögifter i avhandlingen.
Abstract
In these thesis I have studied the spatial and temporal variations of PCBs in the atmosphere and in precipitation in southern Sweden. Further, soil-air exchange processes of PCBs were investigated. Finally, the long-range transport of PCBs and DDT was studied in the Baltic Sea region and in a tropical vs. a temporal region. On the regional scale there were significant differences in PCB concentration in the atmosphere, in precipitation and in soil between nearby sampling-areas. Differences in PCB concentrations between areas probably originated from varying geographical and meteorological conditions that affected exchange processes between air and soil/vegetation surfaces. Temporal variations in PCB concentration in atmosphere and... (More)
In these thesis I have studied the spatial and temporal variations of PCBs in the atmosphere and in precipitation in southern Sweden. Further, soil-air exchange processes of PCBs were investigated. Finally, the long-range transport of PCBs and DDT was studied in the Baltic Sea region and in a tropical vs. a temporal region. On the regional scale there were significant differences in PCB concentration in the atmosphere, in precipitation and in soil between nearby sampling-areas. Differences in PCB concentrations between areas probably originated from varying geographical and meteorological conditions that affected exchange processes between air and soil/vegetation surfaces. Temporal variations in PCB concentration in atmosphere and precipitation were also found. For PCBs in the air, a systematic pattern in the deviation from the yearly median value for the region was observed. Wind direction played an important role for PCB concentration in precipitation in coastal areas, while at the inland sites this variable seemed to have a minor influence. To examine the intensity of precipitation scavenging, the total washout ratios were calculated and the highest ratios were observed at the two sites where PCB concentration in the air was high. Further, high concentrations of PCB in precipitation correlated with a composition of highly chlorinated PCB congeners, as shown by principal component analysis. For most of the sites there was a significant negative relationship between PCB concentration and rain volume. Soil type and soil organic matter content was found to be important for the variations in PCB concentration between nearby areas. Highest concentrations were found at two sites with sandy soils, one with an extremely high organic carbon content. Soils with similar soil textures (i.e. sandy silt moraine) did not show any significant differences in PCB concentrations. PCB congener composition was shown to differ between sites, with site-specific congener patterns. No significant relationships were found between air and soil concentrations of PCBs, or between deposition and soil concentrations. From fugacity quotient calculations it was shown that the soil- and air compartments for most of the sampling-areas were close to equilibrium. However, for some areas there was an outgassing of PCBs from the soil and at one site a tendency for a transport of PCBs from the air to the soil was observed. Within the Baltic Sea region a latitudinal gradient of PCBs in the atmosphere was revealed, with higher levels in the south. Further evidence of the global distillation theory was shown in a study with higher atmospheric levels of DDT in a tropical region in comparison with DDT levels in a temperate region. In accordance with the theory, DDT levels were high in fish from the temperate region, but low in fish from the tropical region. (Less)
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author
opponent
  • Prof Bidleman, Terry.F
organization
publishing date
type
Thesis
publication status
published
subject
keywords
tropical and temperate regions, global transport, temperature, latitudinal fractionation, fugacity, soil organic matter, soil-air exchange, washout ratio, rain, precipitation, atmosphere, spatial and temporal variations, DDT, PCB, persistent organic pollutants, polychlorinated biphenyls, Environmental chemistry, Miljökemi, Ecology, Ekologi, Chemistry, Kemi
pages
100 pages
publisher
Department of Ecology, Lund University
defense location
Lund
defense date
2001-05-04 10:15
external identifiers
  • other:ISRN: SE-LUNBDS/NBKE-01/1022+111 pp
ISBN
91-7105-153-8
language
English
LU publication?
yes
id
e93b04e8-bbcb-4f1b-ae75-1c6b22b87383 (old id 41530)
date added to LUP
2007-06-20 11:04:32
date last changed
2016-09-19 08:45:11
@phdthesis{e93b04e8-bbcb-4f1b-ae75-1c6b22b87383,
  abstract     = {In these thesis I have studied the spatial and temporal variations of PCBs in the atmosphere and in precipitation in southern Sweden. Further, soil-air exchange processes of PCBs were investigated. Finally, the long-range transport of PCBs and DDT was studied in the Baltic Sea region and in a tropical vs. a temporal region. On the regional scale there were significant differences in PCB concentration in the atmosphere, in precipitation and in soil between nearby sampling-areas. Differences in PCB concentrations between areas probably originated from varying geographical and meteorological conditions that affected exchange processes between air and soil/vegetation surfaces. Temporal variations in PCB concentration in atmosphere and precipitation were also found. For PCBs in the air, a systematic pattern in the deviation from the yearly median value for the region was observed. Wind direction played an important role for PCB concentration in precipitation in coastal areas, while at the inland sites this variable seemed to have a minor influence. To examine the intensity of precipitation scavenging, the total washout ratios were calculated and the highest ratios were observed at the two sites where PCB concentration in the air was high. Further, high concentrations of PCB in precipitation correlated with a composition of highly chlorinated PCB congeners, as shown by principal component analysis. For most of the sites there was a significant negative relationship between PCB concentration and rain volume. Soil type and soil organic matter content was found to be important for the variations in PCB concentration between nearby areas. Highest concentrations were found at two sites with sandy soils, one with an extremely high organic carbon content. Soils with similar soil textures (i.e. sandy silt moraine) did not show any significant differences in PCB concentrations. PCB congener composition was shown to differ between sites, with site-specific congener patterns. No significant relationships were found between air and soil concentrations of PCBs, or between deposition and soil concentrations. From fugacity quotient calculations it was shown that the soil- and air compartments for most of the sampling-areas were close to equilibrium. However, for some areas there was an outgassing of PCBs from the soil and at one site a tendency for a transport of PCBs from the air to the soil was observed. Within the Baltic Sea region a latitudinal gradient of PCBs in the atmosphere was revealed, with higher levels in the south. Further evidence of the global distillation theory was shown in a study with higher atmospheric levels of DDT in a tropical region in comparison with DDT levels in a temperate region. In accordance with the theory, DDT levels were high in fish from the temperate region, but low in fish from the tropical region.},
  author       = {Backe, Cecilia},
  isbn         = {91-7105-153-8},
  keyword      = {tropical and temperate regions,global transport,temperature,latitudinal fractionation,fugacity,soil organic matter,soil-air exchange,washout ratio,rain,precipitation,atmosphere,spatial and temporal variations,DDT,PCB,persistent organic pollutants,polychlorinated biphenyls,Environmental chemistry,Miljökemi,Ecology,Ekologi,Chemistry,Kemi},
  language     = {eng},
  pages        = {100},
  publisher    = {Department of Ecology, Lund University},
  school       = {Lund University},
  title        = {Persistent organic pollutants in the atmosphere - spatial and temporal variations},
  year         = {2001},
}