Comparative mapping of smellscape clusters and associated air quality in Kano City, Nigeria: An analysis of public perception, hotspots, and inclusive decision support tool

Few studies have effectively analysed the spatial patterns of urban smellscapes, public perception, exposure risks, or design an inclusive decision-support system. The current study coupled multiple methods to measure, map, and compare notable smell emitting spots, associated air quality indices, and public perception in Kano, Nigeria. It has revealed how urban informal activities generate both pleasant and offensive smells that contaminate the air more than the city's transportation and manufacturing. Notably, the most perceived odour hotspots coupled with highly hazardous sites with AQI value of >1200 which were found around the city's main abattoir. Conversely, the most commonly distributed pleasant smell spots are beef and chicken grills whose charcoal burning generate hazardous air quality. The novelty of this study includes its ability to use empirical data to design an inclusive decision support tool that identifies pathways for individuals, vulnerable groups, policymakers, and civil society groups to respond to various exposure risks. The study has identified informality, urban spatial inequalities, densification, and poor spatial planning which appeared to be the key drivers of the observed clustering of pleasant/unpleasant smellscapes juxtaposing with sites of worst air quality.