Geospatial and Geostatistical Analyses of Particulate Matter (PM₁₀) Concentrations in Imo State, Nigeria

Abstract

Geospatial and geostatistical analysis of particulate matter (PM10) variation in Imo State, Nigeria was carried out. The objectives of the study were to determine and analyze the variation in concentration of ambient PM10 level in Imo State, Nigeria. Air quality sampling was conducted within November 2014 and June 2015, in wet and dry seasons three times daily using Haze Dust Particulate Monitor (10μm). The mean concentration of PM10 level observed in the study varied from 5.22 - 6.63 mg/m3 in wet season and 5.80 - 8.38 mg/m3 in dry season. Coefficient of variation (CV %) revealed that the variability of PM10 level ranged between little and moderate variations in both wet and dry season. Analysis of variance (ANOVA p<0.05) showed statistically significant variation in the mean PM10 level in the study locations. Box and Whisker plots confirmed variation of PM10 in the morning, afternoon and evening. The GIS plots revealed the spatial attributes of the air pollutant in the study locations. Time series plots indicate that the air pollutants fluctuated throughout the study duration. The Wind Rose suggests that the prevailing wind speed and wind directions were responsible for the dispersal migration of the air pollutant in the study area. The highest seasonal mean values were observed in Egbema and Okigwe area in both dry and wet season. The seasonal mean values recorded in the study exceeded the Nigerian National Ambient Air Quality Standards. This calls for urgent response to prevent further air quality deterioration and its negative effects on man and the environment.