Calcutta is known to have serious air pollution problems.
Benzene, toluene and xylene (BTX) in the ambient air were monitored during the winter from 1992 to 1994 inclusive.
Activated carbon traps were used for sampling and a simple packed column gas chromatography methodology was used for analyses in this study.
Samples were collected in 5 locations in Calcutta.
Concentrations were found to be much higher than that found in similar studies performed elsewhere.
The average benzene concentrations during the winter in 1992,1993 and 1994 were 1004 mug m-3,7082 mug m-3 and 491 mug m-3 respectively.
The average compositional ratios of benzene : toluene : xylene (B : T : X) in winter were 1 : 0.39 : 0.05,1 : 0.16 : 0.04 and 1 : 0.26 : 0.13 for 1992,1993 and 1994 respectively.
The toluene/benzene concentration ratio in the samples varied from 1.033 at the end of summer to 0.092 at the end of winter.
This variation has been determined to be the result of variation in atmospheric persistence of the released compounds due to thermal inversion.
It is estimated that 5280 coal buming stoves per square kilometre are used for cooking in Calcutta.
The median concentration of benzene, toluene and xylene in the smoke plume above the coal buming stove used for cooking, was found to be 5497 mug m-3,4080 mug m-3, and 962 mug m-3 respectively.
The compositional ratio of B : T : X for the coal buming cooking stoves was therefore 1 : 0.74 : 0.18. (...)
Mots-clés Pascal : Pollution air, Zone urbaine, Hydrocarbure, Composé aromatique, Source pollution, Analyse chimique, Echantillonnage, Impact environnement, Air, Composé BTEX
Mots-clés Pascal anglais : Air pollution, Urban area, Hydrocarbon, Aromatic compound, Pollution source, Chemical analysis, Sampling, Environment impact, Air, BTEX compounds
Notice produite par :
Inist-CNRS - Institut de l'Information Scientifique et Technique
Cote : 97-0213666
Code Inist : 001D16C03. Création : 21/05/1997.