Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
Lead and halogens in pollution aerosols and snow from fairbanks, Alaska
Abstract The composition of lead halide pollution aerosol particles was studied in the Fairbanks area during January and February 1965. At this time of year the sun is above the horizon for less than 4 hr and prolonged cold spells (surface air temperature below −40°C) are accompanied by strong (gradients of 20–30°C/100 m) surface inversions which severely restrict the dilution volume for air pollutants. Indeed, these inversions virtually decouple the dense surface air-layer from the overlying air. Accurate quantitative information on the total output of all pollution sources is available because of the isolated location of Fairbanks and the limited, measurable sources of fuel supply. Thus, Fairbanks is a model locality for studying the production, movement, and chemical reactions of air pollutants in what amounts to a simple two-layer atmosphere. Lead was determined by inverse polarography in aerosol particles collected on Millipore filters. Measured values ranged from 6.0 μg of lead/m3 of air in the city center, near the automobile traffic center, to 0.19 at the University of Alaska campus outside the city. These do not represent maximum values because pollutant-concentrating conditions were relatively mild during the sampling periods. Halogens were determined by neutron activation analysis of material in the aerosols and in ground-lying snows, and two components were revealed, a pollution component derived from automotive ethyl fluid combustion and a low-level natural component. In the pollution aerosol component, the weight ratio chlorine/lead averages close to the ethyl fluid value of 0.34, but bromine/lead is up to four times less than the ethyl fluid value of 0.39. Bromide-chlorine of the pollution in the snows is only 15–30 per cent of the ethyl fluid value and exhibits the lower values further from the city center. These data support the interpretation that lead halide particles, formed initially by combustion of ethyl fluid in gasoline, suffer loss of bromine by oxidation and volatilization. The smaller particles, because of greater surface area per unit mass, may suffer the most extensive bromine loss and may migrate farthest from the city center by virtue of their long atmospheric residence time.
Lead and halogens in pollution aerosols and snow from fairbanks, Alaska
Abstract The composition of lead halide pollution aerosol particles was studied in the Fairbanks area during January and February 1965. At this time of year the sun is above the horizon for less than 4 hr and prolonged cold spells (surface air temperature below −40°C) are accompanied by strong (gradients of 20–30°C/100 m) surface inversions which severely restrict the dilution volume for air pollutants. Indeed, these inversions virtually decouple the dense surface air-layer from the overlying air. Accurate quantitative information on the total output of all pollution sources is available because of the isolated location of Fairbanks and the limited, measurable sources of fuel supply. Thus, Fairbanks is a model locality for studying the production, movement, and chemical reactions of air pollutants in what amounts to a simple two-layer atmosphere. Lead was determined by inverse polarography in aerosol particles collected on Millipore filters. Measured values ranged from 6.0 μg of lead/m3 of air in the city center, near the automobile traffic center, to 0.19 at the University of Alaska campus outside the city. These do not represent maximum values because pollutant-concentrating conditions were relatively mild during the sampling periods. Halogens were determined by neutron activation analysis of material in the aerosols and in ground-lying snows, and two components were revealed, a pollution component derived from automotive ethyl fluid combustion and a low-level natural component. In the pollution aerosol component, the weight ratio chlorine/lead averages close to the ethyl fluid value of 0.34, but bromine/lead is up to four times less than the ethyl fluid value of 0.39. Bromide-chlorine of the pollution in the snows is only 15–30 per cent of the ethyl fluid value and exhibits the lower values further from the city center. These data support the interpretation that lead halide particles, formed initially by combustion of ethyl fluid in gasoline, suffer loss of bromine by oxidation and volatilization. The smaller particles, because of greater surface area per unit mass, may suffer the most extensive bromine loss and may migrate farthest from the city center by virtue of their long atmospheric residence time.
Lead and halogens in pollution aerosols and snow from fairbanks, Alaska
Winchester, John W. (Autor:in) / Zoller, William H. (Autor:in) / Duce, Robert A. (Autor:in) / Benson, Carl S. (Autor:in)
04.10.1966
15 pages
Aufsatz (Zeitschrift)
Elektronische Ressource
Englisch
Halogens in aerosols in central Alaska
| British Library Conference Proceedings | 1993
Fairbanks International Airport, Alaska Bettisworth North
| British Library Online Contents | 2010
Fairbanks International Airport, Alaska - Bettisworth North
| Online Contents | 2010
Successful Ice Dusting at Fairbanks, Alaska, 1966
| ASCE | 2021
Thawing and dredging gold at Fairbanks, Alaska
| Engineering Index Backfile | 1933