The October 1995 court decision allowing Ethyl Corporation to offer methylcyclopentadienyl manganese tricarbonyl (MMT) for sale to refiners for introduction into unleaded gasoline as an octane enhancer is likely to result in increased fine (PM2.5) manganese (Mn) concentrations in ambient air.
Concern exists regarding possible health effects.
In this paper, recent fine Mn concentrations in three monitoring networks and one U.S. Environmental Protection Agency (EPA) study of personal exposure are analyzed.
One network consists mainly of rural sites in national parks in the United States, a second consists mainly of urban sites in California, and the third consists mainly of urban sites in Canada where MMT has been used for a number of years.
During the late 1980s and early 1990s, mean ambient concentrations ranged from 1 ng/m3 in the mostly rural network to 3 ng/m3 in the mostly urban California network to 12 ng/m3 in the MMT-impacted Canadian network.
Several lines of evidence suggested that some of the fine Mn observed in the United States during the 1986-1992 period was contributed by automobiles using leaded gasoline, for which MMT was a registered fuel additive.
However, the near-disappearance of leaded gasoline has resulted in a very small portion of fine Mn being attributed to automobiles in the years since 1992.
A source apportionment analysis suggested that crustal contributions to ambient fine Mn are on the order of 1-2 ng/m3 in both the United States and Canada.
Mots-clés Pascal : Pollution air, Amérique du Nord, Amérique, Parc national, Zone urbaine, Particule en suspension, Particule fine, Teneur air ambiant, Contrôle, Réseau mesure, Source pollution, Analyse factorielle, Essence sans plomb, Manganèse Composé organique
Mots-clés Pascal anglais : Air pollution, North America, America, National park, Urban area, Suspended particle, Fine particle, Ambient air concentration, Check, Measuring network, Pollution source, Factor analysis, Unleaded gasoline, Manganese Organic compounds
Notice produite par :
Inist-CNRS - Institut de l'Information Scientifique et Technique
Cote : 97-0327433
Code Inist : 001D16C04C. Création : 12/09/1997.