Abstract
Urban air pollution presents significant health risks to urban dwellers around the world. Knowledge of the levels of air pollution at various spatial locations in a city, offers insight into the personal exposure of residents and facilitates the control of air pollution. This study investigated ultrafine particles (UFP) in key microenvironments in which people spend a significant amount of their time in three suburbs of Accra (the capital city of Ghana) and in a nearby rural community (Berekuso). The ambient concentrations of UFP across the study area were also mapped. The median daily ambient UFP concentration at a reference site at Kwabenya, a suburb of Accra, was 5.8(IQR:1.6−17.1)×104cm−3. The UFP on the reference site were mainly influenced by vehicular traffic, and open-air burning in communities near the site, and by extention, wind direction. The mean (±SEM) UFP concentrations reported in five school and household microenvironments in two suburbs in Accra (Madina and Agbogbloshie) and in Berekuso ranged between 9.1×103(±7.3×102) and 1.5×105(±1.9×104)cm−3. The microenvironmental concentrations were mainly influenced by lifestyle and sociocultural factors. The results highlight the high levels of UFP in many of the microenvironments investigated, the potential health risks that UFP pose to sensitive groups, and the overall urgency for the control of air pollution in Accra.
•We studied ultrafine particles (UFP) in indoors and outdoors in Ghana.•Traffic and combustion activities were the main drivers of UFP concentration levels.•UFP levels in many Ghanaian microenvironments are among the highest in the world.