TITLE:
Monitoring of Atmospheric Pollutant Concentrations in the City of Dakar, Senegal
AUTHORS:
Baïdy Sow, Bertrand Tchanche, Ibrahima Fall, Saliou Souaré, Aminata Mbow-Diokhané
KEYWORDS:
Air Quality, Emission, Health, Monitoring, Particulate Matter, Pollutants, Standard
JOURNAL NAME:
Open Journal of Air Pollution,
Vol.10 No.1,
March
29,
2021
ABSTRACT: The lack of data on air quality monitoring and neglected and overlooked
pollutant emissions in the transportation and industrial sectors are motives
for the government of Senegal to set up, in 2009, an air quality management
center, the CGQA (Centre
de Gestion de la Qualité de l’Air). Air quality monitoring at CGQA deals with
mainly six pollutants: carbon monoxide (CO), nitrogen oxides (NOx)
(with nitrogen dioxide (NO2) and nitrogen monoxide (NO)), sulfur dioxide (SO2),
ground-level ozone (O3), Benzene-Toluene-Xylenes (BTX), and
particulate matters (PM) with diameters less than 10 μm (PM10) and
2.5 μm (PM2.5). The concentration levels of gaseous pollutants (CO,
O3, NO2 and SO2) in the city generally remain
below the limit value set by the WHO (World Health Organization). However,
particulate matters (PM10 and PM2.5) are the most
important pollutants observed in Dakar, they far exceed the annual thresholds
set by the WHO and the national standard (NS 05-062). This situation results in
an Air Quality Index (AQI) around bad and very bad during the dry season (November
to May) and good to moderate during the rainy season (June to October). The
concentrations of PM10 and PM2.5 vary respectively from
120 to 180 μg·m-3 and from 25 to 48 μg·m-3. The average concentrations of pollutants therefore vary from one area
to another and depending on the location of the air quality monitoring station
(near industrial sites, traffic, etc.).