Dakar study area

Dakar is the largest city and capital of Senegal in West Africa. Located on the Cape Verde Peninsula on the Atlantic coast (14°40’20“N, and 17°25’22” W at an altitude of 104m), Dakar is a major regional port serving transatlantic and European trade. Approximately 2.5 million people (25% of the national population) live in an area of 550 square kilometres (0.28% of the national territory) with an average population density of 4,122/km2. The total annual rainfall amount is of 380 mm. Two distinct seasons prevail: a hot and humid period from June to November (maximum average temperature of 29°C, 170 mm), and a cool and dry period from December to May (minimum average temperature of 20.4°C in February, 5-20 mm).

Experimental strategy

The experimental strategy of the POLCA programme includes extensive measurements (one year) associated to intensive in situ campaigns (30 days in dry seasons), deployed in Bamako and Dakar cities. In both cities, super sites have been identified to be representative of typical urban activities (industries, traffic, domestic fuels…) of West Africa: downtown crossroads on balconies in the vicinity of markets.

In Dakar, the Guigon pharmacy has been chosen on main street and near the Sanaga market. (photo1).

Extensive measurements concern weekly aerosol chemical composition, real time black carbon measurements, and monthly gases concentrations. During intensive measurements period, atmospheric gases and particles pollution characterization is monitored and detailed (real time gases concentrations, aerosols impactors…). Also, emission factors will be measured for typical motorized vehicles (two wheelers, buses…). Impacts on public health is conducted in parallel through toxicological and epidemiological studies. In vitro analysis are conducted on aerosols impactors. Specific groups of persons present on the super site crossroads are submitted to biological analysis (blood, spirometry…). Moreover, epidemiological data on respiratory and cardiovascular diseases are reported from hospital structures or health medical centers.

Views and Download Table 1 : instrumental set (procedures and equipments).

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