Insights into the Global Distribution of Polychlorinated Dibenzo-p-dioxins and Dibenzofurans

• Published in: Environmental science & technology Vol. 34; no. 14; pp. 2952 - 2958
• Main Authors: Wagrowski, Diane M, Hites, Ronald A
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 15.07.2000
• Subjects: Animal, plant and microbial ecology; Applied ecology; Applied sciences; Arctic; Biological and medical sciences; Biological and physicochemical properties of pollutants. Interaction in the soil; Canada, Vancouver I; Earth sciences; Earth, ocean, space; Ecotoxicology, biological effects of pollution; Effects of pollution and side effects of pesticides on plants and fungi; Engineering and environment geology. Geothermics; Exact sciences and technology; Fundamental and applied biological sciences. Psychology; Germany; Hong Kong; Pollution; Pollution, environment geology; Soil and sediments pollution; USA, Midwest; Dioxin derivatives; Atmospheric fallout; Pollutant behavior; Bark; Soil pollution; Flux density; Chlorine Organic compounds; Environment impact; Content; Long range pollutant transport; Air pollution; Air ground interface; Air-biosphere interactions
• DOI: 10.1021/es991138o
• ISSN: 0013-936X

Polychlorinated dibenzo-p-dioxins and dibenzofurans were measured in 63 pairs of tree bark and soil samples. Maps of lipid-adjusted concentrations in bark and fluxes to soil indicated that Vancouver Island, the Midwestern United States, Germany, and Hong Kong were areas of high PCDD/F deposition. Concentrations and fluxes in the regions north of the 60th parallel, particularly the Canadian Arctic, were low, indicating that PCDD/F do not move appreciably from warm to cold latitudes. Linear regressions of the PCDD/F concentrations in tree bark versus fluxes to soil showed that total concentrations in bark can be used to estimate total fluxes to soil in a particular region. Comparison of the homologue profiles for each pair of bark and soil samples indicated that the pairs fell into three categories:  1. bark and soil both resembled source profiles; 2. bark and soil both resembled sink profiles; and 3. bark resembled a source profile but the soil resembled a sink profile. This variation in homologue profiles may be due to the proximity of sampling locations to sources. We found that anthropogenic NO x emissions are highly correlated to PCDD/F soil fluxes, and we used this regression to estimate global PCDD/F fluxes to soil on the same spatial scale as the NO x data. Multiplying these fluxes by the corresponding land areas, we estimated that total PCDD/F deposition to the earth's land surface is about 2−15 t/yr.