Particulate Matter and Staff Exposure in an Air-Conditioned Office in Akwa Ibom State University – Nigeria

Abstract

Indoor air quality parameters were investigated in an occupied air–conditioned office and unoccupied air–conditioned office located in the Faculty of Natural and Applied Sciences Complex in Akwa Ibom State University – Nigeria, during the rainy (June – July) and dry (November – December) seasons of 2016. Particulate matter (PM1, PM2, PM5, PM10), temperature, relative humidity, carbon monoxide (CO) and carbon dioxide (CO2) levels were simultaneously measured in fourteen (14) sampling days using Fluke 985 Particle Counter and Fluke 975 AirMeter. The concentrations of particulate matter in the occupied air–conditioned office during the rainy season ranged from 5152 – 5984 μg/m3 for PM1; 2744 – 3015 μg/m3 for PM2; 137 – 149 μg/m3 for PM5 and 36 – 50 μg/m3 for PM10 and in the unoccupied air–conditioned office, the concentrations of particulate matter ranged from 1898 – 2556 μg/m3 for PM1; 987 – 1311 μg/m3 for PM2; 38 – 59 μg/m3 for PM5 and 15 – 24 μg/m3 for PM10. During the dry season, the concentrations of particulate matter in the occupied air–conditioned office ranged from 5852 – 6510 μg/m3 for PM1; 4490 – 4992 μg/m3 for PM2; 335 – 362 μg/m3 for PM5 and 59 – 69 μg/m3 for PM10 and in the unoccupied air–conditioned office, the concentrations of particulate matter ranged from 2598 – 3112 μg/m3 for PM1; 1168 – 1694 μg/m3 for PM2; 153 – 257 μg/m3 for PM5 and 29 – 42 μg/m3 for PM10. This study has revealed that the particulate matter (PM1, PM2, PM5, PM10) concentrations in an occupied air–conditioned office were significantly (P 10 obtained in the present study were found to be much lower than the ambient maximum contaminant level for airborne PM10 standard promulgated by the United States Environmental Protection Agency (USEPA) (150 μg/m3 daily average and 50 μg/m3 annual average) and World Health Organization (WHO) PM10 guidelines values (50 μg/m3 daily average and 20 μg/m3 annual average). Although there were no significant relationships among PM1, PM2, PM5, and PM10 in occupied air-conditioned office, correlation analysis indicated that PM1, PM2 and PM5 were significantly correlated at P 2 were below detection limit (BDL), they indicated adequate air exchange at the time of the assessment in the air–conditioned office during the sampling period. The results obtained have revealed important contributions towards the understanding of particulate matter distribution patterns and provided baseline data that can be used for potential identification of human health risks associated with airborne particulate matter in air–conditioned offices in Akwa Ibom State University – Nigeria.