COMPARISON OF PM10 TEMPORAL DISTRIBUTION AND HORIZONTAL VISIBILITY IN A BUSINESS DISTRICT AREA OF ABUJA, NIGERIA

Abstract

Daily, monthly and annual average monitoring data for PM10, meteorological parameters and horizontal visibility at Area 11 Garki, Abuja from April 2013 to March 2015 were analyzed using statistical methods to investigate the effect of particulate matter on horizontal visibility in the business district of Garki, Abuja. The temporal variation of PM10 and horizontal visibility; and correlation between, PM10 and meteorological parameters was analyzed. Additionally, the relationship between particulate matter (PM10) and certain meteorological parameters was also analyzed. The results show that variations in the average mass concentrations of PM10, and horizontal visibility generally have similar distributions (except for July-August 2013), with peak values of PM10 average mass concentrations appearing in July/August 2013 and November/January 2014, respectively. The correlation of daily concentrations of PM10 with Wind speed, Temperature, Wind direction and Relative humidity were high, reaching 0.98, 0.99, 0.97 and 0.98, respectively. Low wind speed led to the highest PM10 concentrations in SW directions, while high wind speed blew air parcels with the highest concentrations from SE direction into the study area. Temperature and wind speed influenced the transport and accumulation of PM10 by affecting convection. The level of PM indicate that human activities are already the main source of pollutant, and the relation between visibility and PM means that fine particles are the most important factor affecting visibility. There was no correlation between PM10 and visibility except in the month of February (at 0900hr); the most important cause of visibility degradation was due to the light extinction of aerosol particles. In general, Particulate matter (PM10) concentration is mostly affected by anthropogenic activity.