Spatial & Temporal Variation of Ambient Air Pollution in Kaduna Metropolis

Abstract

Urban air quality is a major environmental concern around the world, and its significance is increasing as the world becomes more urbanised. Many cities in Nigeria have rapidly growing populations, with increased motorisation and energy use, leading to significant air pollution.  Particulate matter (PM) is an air pollutant which has been identified as a serious risk to human health. Air pollution varies both spatially and temporally. The aim of this study is to assess the spatial and temporal variation of particulate matter (PM) pollution in Kaduna Metropolis, and to map the hotspots of PM pollution. Air quality detector (Model: DZ8600) was used to collect the particulate matter (PM10 and PM2.5) data. Space time sampling technique was used in collecting the data and sampling was done in both wet and dry season. The spatial variation of the pollutants was described using Inverse Distance Weighing tool of Geographical Information Systems (GIS) and satellite imagery of the study area was obtained from Kaduna Geographical Information System. The findings indicate high levels of PM10 and PM2.5 along many of the sample points which conform to high traffic density areas in Kaduna metropolis, and most results exceeded the EPA and NESREA standards. The findings also show a a significant difference in the concentration of the pollutants between the wet and dry seasons, as there is an increase in the area covered by these pollutants from during the dry season. The study recommends the formulation of an urban air quality management plan, and the use of nature-based solutions to improve air quality.