SEASONAL VARIATION OF MONTHLY AIR QUALITY INDICES FOR CALABAR, NIGERIA
Air Quality Index (AQI) for the city of Calabar has been computed for the different seasons of the year covering December 2015 to November 2016. The values obtained from the calculation of the combined AQI shows that the AQI for the different months of the year were categorized as “good”. The highest value of 15.87 was obtained in December 2015 and the least value of 5.06 was obtained in April 2016. The coefficient of determination obtained for the period of study shows that total suspended particulate (TSP) had the highest effect on the variation of AQI with the value of 87.3%, while temperature with value 1.8% had the least effect on the variation of AQI within the study period. The AQI calculated from the individual pollutants showed that Ozone had the highest value of 18.75 in December 2015 and its least value of 7.81 in March 2016. Carbon monoxide (CO) had the highest value of 29.7 in September 2016 and its least value of 6.06 in April 2016. Sulphur dioxide (SO2) had the highest value of 22.06 in July 2016 and August its least value of 8.8 in December and January 2016. NOx had the highest value of 93.75 in December 2015 and its least value of 0 in April, July, October and November 2016. All the calculated AQI for the individual pollutants were categorized as “Good” except NOx which was categorized as moderate.
SUNDAY O. UDO, IGWE O. EWONA, MFON DAVID UMOH AND CLETUS NZAN AGBOR