Background Study on the Estimation of Horizontal Dilution Potential of air Pollutants in North-Central Nigeria, Using Wind Data

The study gives a background estimate of the dilution potential of air pollutants (SO2, NO2 and CO) in three selected North Central States of Nigeria. The research was carried out using wind impact area diagram, obtained by using standard deviation to calculate  analysis of pollutants and other variables of spread whose concentration were determined downwind. The results indicate that Makurdi and Lafia have varying wind direction persistence (p) approximately 1.0m2 for all the months. This can cause variation in wind directions. It also indicate unstable pattern of wind observation in this cities. For Makurdi, lowest and highest value of potential stands at M (12.15 m2) and (42.5 m2) were observed in April and May accordingly. For Lafia, values obtained by potential impact stands at M (2.20m2) and (67.50 m2) for the months indicated. Finally, Jos has (p) equal to 1.2m2 through all months, showing steady wind compared to two cities of Makurdi and Lafia and the predominant wind direction during the period  of October 2018 to February 2019. Lowest and largest values of dilution potentials M (1.50m2 and 113.37m2) were obtained for February and December of the same year under review. Lowest values of m (dilution potential) indicate lower dilution potentials in these cities which indicate high concentration of inert pollutants while larger value of M predicts high volume of wind speed with a big impact area. The study showed that, dilution potential can be applied in comparing the wind data in line and space. It also portrays that wind impact diagram gives a good representation of wind along with area of high pollutants concentration as compared to wind rose. Finally, the information obtained from the research suggests air quality monitoring stations are required in Makurdi, Lafia and Jos for effective monitoring of air pollutants in these cities.