10th International Aerosol Conference September 2 - September 7, 2018 America's Center Convention Complex St. Louis, Missouri, USA
Abstract View
Observed Levels of Particle and Gas Phase Pollutant inside School Classrooms with Varying Air-Conditioning Systems
SUPREME JAIN, Divyam Garg, Anubha Goel, Indian Institute of Technology Kanpur
Abstract Number: 1188 Working Group: Indoor Aerosols
Abstract With the aim to examine air quality inside school micro-environments so that any possible health impact on students can be ascertained, a study was conducted inside two schools situated in the city of Kanpur, India which is one of the largest city (Inhabitants = 2.5 million) in the Indo-Gangetic plain. The two schools selected differed significantly in student strength, infrastructure, classroom size, ventilation system and proximity to the highways etc. Active air sampling inside classrooms was done continuously during the school timing (8:00 am to 2:00 pm) for particulate matter, and gaseous pollutants i.e. carbon monoxide (CO) and oxides of nitrogen (NOX).
In both schools, more than 99% of the sampling time PM10 mass concentration was higher than permissible limits (100 μg/m3 for ambient air) specified under National ambient air quality standards (NAAQS, India). The average PM10 mass concentration ranged between 200 to 240 μg/m3 during sampling hours (values ~ 2 times higher than permissible levels.) Type of ventilation system installed showed an impact on levels of respirable and finer particles with lesser levels observed in the school with a central cooling system. School which has air-conditioned classrooms were found to have PM3 concentration ~50% higher than permissible limits for PM2.5 (NAAQS, 60 μg/m3). The PM3 levels inside classrooms having a central cooling system were ~ 40% less than AC classrooms. Similarly in case of PM1 school having central cooling system had ~ 50% less mass concentration with respect to the AC classrooms. The average concentrations of gaseous pollutants (CO and NOx) were found to be within permissible limits during sampling hours. Influence of vehicular emissions in the vicinity of the school premises was observed through a sharp increment in finer particles and concentration of NOx inside the air-conditioned classroom during school opening and closing hours. Increased physical activity of the occupants inside classrooms was observed to raise the concentration of particulate matter but had less impact on the gaseous pollutants.
These observations highlight important role design of school building, and ventilation system, manmade or natural, installed play in affecting the indoor air quality. Chemical characterization of respirable particles is needed to enable realistic assessment of their impact on the health of the students. Diurnal variations in air quality in different microenvironments inside schools, such as playgrounds, library, canteen/ mess area, etc. need to be monitored and factors influencing levels and trends observed investigated. Lack of Indoor Air quality standards for different indoor micro-environments is another matter of concern and their development needs urgent attention.
Keywords: school, Indoor air quality, standards, particles, CO, NOx, ventilation, building design, air conditioning