When Air Quality Becomes Deleterious—A Case Study for Kigali, Rwanda

Abstract

Rwanda is a landlocked republic\rin Equatorial Africa. The capital Kigali (1°57'S, 30°04'E) can be\rmentioned as a typical African city due to its rising population and the rising\rrate of motorization. Different pollutants produced e.g. by a highusage rate of\rmopeds or open fireplaces burning wood for cooking and household chores could\rbe detected. Climatological parameters as well as air pollutants were measured\rwithin the urban area. Additionally, highly frequented spatial and temporal\rmobile measurements of particulate matter were taken during different dry\rseasons regarding different conditions. These values indicated an urban heat\risland, which tended to rise for the last four decades. A temporary phenomenon\rfor the air pollution indicators is visible during clear and calm weather\rsituations, e.g. the distinctive relief caused an accumulation within small\rvalleys called “Marais” in the night time. Unfortunately, these are the favourite\rplaces for living and agriculture. So there is no infrequence in values of PM10 > 1.000 μg·m-3. The origin of the different\rairborne particles was verified by using a scanning electron microscope and it\rcould be mentioned that most particles were from the combustion of biomass and\rtraffic.