In this paper, we conducted a survey to reveal the general perception of parents toward outdoor air quality, particulate matter (PM), and indoor air quality (IAQ) at schools where their children attend. A total of 1,030 parents participated in this survey, where the age of their children ranged between 7 years to over 19 years of age. Each participant was either a member of a non-governmental organization (NGO) with a keen interest in air quality or an ordinary public panel member with less interest. The result of the survey indicated that the participants had a negative perception of air quality, and parents believed that the outdoor and indoor air is extremely polluted. The participants pointed out that they believe that the main reason for the pollution is due to particulate matter (PM) and school classrooms are the location where their children are exposed to PM the most. Based on our study, the majority of the participants prefer a mechanical ventilation system to reduce indoor air pollutants in schools. Our study should be referred to by school officials in order to maintain IAQ and as a way of addressing the concerns of parents who want to protect their children’s health.

The performance of various air-cleaning devices and an assembled air cleaner has been evaluated for the removal of biological pollutants in indoor air. Bacteria, fungi, and viruses were sprayed in a test chamber, and air samples in the chamber were taken for analysis. Air-cleaning devices - UV lamp, ion generator, an UV LED and plasma electricity dust collector - were tested for their ability in the removal of microorganisms in the air. The UV lamp and the ion generator tested exhbited complete sterilization effect within 4hrs of operation. Other devices were less effective: The extent of removal by the UV LED and the plasma electricity dust collector after 6hrs of operation was about 20% to 82%, depending on the microorganisms tested. The performance of an assembled air cleaner was much superior to individual air-cleaning devices: the extent of removal being 97.6%, 99.1%, 98.7%, and 93.7% for Staphylococcus aureus (Gram(+) bacteria), Escherichia coli (Gram(-) bacteria), Aspergillus niger and Penicillium funiculosum (fungi), respectively, after 3hrs of operation. The removal of influenza virus was even more effective, with 99.9% of removal within 25min of operation. The results show that the air cleaner is effective for the removal of microbial and viral pathogens in the air.

Vehicle occupant exposure to volatile organic compounds (VOCs) has been a subject of concern in recent years because of higher levels of VOCs inside vehicles as compared to the surrounding ambient atmosphere and because of the toxicity of VOCs. The effectiveness of two commercial ACDs for the removal of selected VOCs in the interior of automobiles was evaluated on 115 commutes through urban (Taegu) commutes by two cars and 9 idles. The idling and commuting studies conducted under four different driving conditions showed that the two commercial ACDs were not effective for the removal of VOCs in the interior of vehicles. The concentrations of all target VOCs except benzene were significantly higher (p<0.05) in the interior of older car than of newer car. The mean levels of benzene and toluene measured in this study were well excess of earlier other studies in the United States, besides Los Angeles with which was comparable. It was reported that the in-vehicle exposure to benzene and corresponding upper-bound cancer risk were about 8 times higher than those for outdoor environment, while they were about half of those from indoor environment.