Determination of the Types of Air Pollutants Prepondering in the City of Lome in Togo (West Africa)

Abstract

The increase in the urban population and the high concentration of many anth ropogenic activities in certain regions of the world lead to atmospheric disturbances. The excess concentration of several chemical elements leads to air pollution. In order to identify the types of air pollutants, a study was carried out in the city of Lomé, the capital of Togo. The objective of this study is to achieve a better knowledge of the types of air pollutants in the city of Lomé. The identification of the various atmospheric pollutants linked to the sources of pollution was made using micro-sensors. The standardized method was used to access target gas concentration levels. The average concentrations of NO 2 gaseous pollutants at landfills are on average 0.333 μg/m 3 ; 0.403 mg/m 3 at the industrial level, at the transport level they are on average 0.434 mg/m 3 for the morning and 0.457 mg/m 3 for the evening. Concentrations of carbon dioxide (CO 2 ) are higher in industrial areas than in others sources of pollution . The average concentration measured at this level is 1632.79 mg/m 3 . In terms of road transport, in the mornings the average concentration is 1493.23 mg/m 3 , in the evening the average concentration is 1354.09 mg/m 3 . On the other hand, they are lower at the level of the landfills, the average of which is 1265.08 ppm. The highest SO 2 concentrations are also observed only in the landfills of Port 1 and Bè_Kpota 2 with concentrations respectively and relatively low and equal to 0.081 mg/m 3 and 0.1616 mg/m 3 . The concentration of ground-level ozone is zero in industries and landfills. On the other hand, at the level of road transport, some values were recorded at the level of two road transports. These are Carrefour Attikoumé Djidjole (17.03 mg/m 3 ) and Carrefour 2 Lions (0.001 mg/m 3 ). The concentrations of carbon monoxide (CO) in the capital at the industrial level are on average 22.57 mg/m 3 ; at landfills it is on average 0.24 mg/m 3 . In terms of road transport, they are on average 7.890 mg/m 3 for the morning and 8.23 mg/m 3 for the evening. These results constitute a database for biomonitoring.