[Air pollution in urban area in Cotonou and Lokossa, Benin]

In some African countries, time of clean environment with no air pollution belongs to the past. From now on, pollution is a problem of public heath in addition to malnutrition and infectious diseases still badly controlled. The sanitary consequences induced by pollution is now a cause for concern in the population. Yet, very few data are available to develop awareness of the population and convince the authorities to implement urgent policy in order to put a brake on the phenomenon. The objective of this document aims at describing the atmospheric pollution recorded in Cotonou and Lokossa as well as possible symptoms linked to exposure of pollutants of the population. Therefore we carried out a transversal study in the city of Cotonou and Lokossa (125 kilometers from Cotonou). Air samples were taken at crossroads levels and motorbikes to measure the different chemical components, 400 taxi drivers were questioned on symptoms affecting them. The toxicological analysis of air and blood sample is carried out at the laboratory of the Université Libre in Brussels. The data analysis revealed a high pollution in Cotonou. The carbon monoxide concentration varies from 26 ppm to 38,6 ppm in the morning and increases in the afternoon (58 to 78,6 ppm). Benzene is found with an average of 7,2 micro/m3 in Cotonou. These concentrations are not so high in the town of Lokossa (carbon monoxide from 45 to 51ppm). In Cotonou motorbike taxis account for 90% of the cases with intoxication symptoms 1,5 time higher than in the non-drivers of these motorbikes. The symptoms recorded on statement are intoxication disorders such as conjunctival hyperemia (18%) among which 12% of lacrimation, respiratory disorders (23%). On the other hand, registered disorders were not so important in Lokossa: conjunctival hyperemia (5,6%), nausea (32%) and other signs as sight disorders (4%). The disorders frequency in non drivers is not so high in Cotonou and Lokossa. In the blood test, the Hbco rate is abnormal in more than 66% of the drivers. The authors suggest the regular checking of imported secondhand cars, measures to reduce exhaust emissions and the reinforcement of the law on air pollution as well as a proper management of crossroads.