Air pollutant concentrations and comfort index in commercial buses within Abeokuta Metropolis, South-Western Nigeria

This study assessed the level of air pollutants and comfort index in public buses from selected parks in Abeokuta metropolis. Sixty commercial buses were randomly selected across the four major motor parks in the city for the monitoring of comfort index (temperature and relative humidity) and air pollutants (carbon monoxide, volatile organic compounds and particulate matter) within one month using low-cost hand-held portable meters. The average temperature and relative humidity ranged between 35.6 - 36.0 degrees C and 57.9 - 62.4% respectively. The average concentrations of in-vehicle air pollutants ranged from 29.8 - 32.7 mg/m(3) (CO), 58.3 - 76.3 mu g/m(3 )(VOCs), 25.3 - 44.2 mu g/m(3 )(PM2.5) and 108.3 -117.4 (PM10). Significant spatial variations among in-vehicle RH and VOCs were observed across the sampling locations. The Air quality index of air pollutants within the vehicles was rated hazardous (CO), unhealthy (PM2.5) and moderate (PM10) across the motor parks. The passengers and drivers exposed to this poor air quality could be at risk of breathing discomfort and other respiratory illnesses, hence the need for specific measures to reduce the air pollutant concentrations within the buses.