Carolyn Payus

Indoor air quality at shopping malls in Kota Kinabalu, Sabah (particulate matter and ozone)

Background: Indoor air quality (IAQ) in shopping malls is an interesting case of study since a shopping mall is a public place where people favor to spend their time. This study was conducted to investigate the IAQ of shopping malls in Kota Kinabalu, Sabah, whereby three shopping malls were selected as investigation sites. Methods: The parameters being studied include particulate matter (PM0.3-∞, PM0.5-∞, PM2-∞ and PM5-∞) and ozone. Indoor and outdoor air measurements were performed in the three shopping malls on weekdays and weekends to determine the I/O ratios. Results: In this study, overall average indoor PM concentrations on weekends were higher than weekdays, reaching maxima average concentrations of 421.44 ± 102.96 µg/m3 for PM0.3-∞, 41.75 ± 15.54 µg/m3 for PM0.5-∞, 1.30 ± 0.41 µg/m3 for PM2-∞, and 0.21 ± 0.09 µg/m3 for PM5-∞. Correlation between indoor and outdoor PM concentrations mostly showed poor relationship in the three shopping malls, showing that indoor sources such as re-suspension phenomena due to occupants activities were clearly the main contributors to indoor PM concentrations. Poor ventilation system also affected IAQ by increasing the PM accumulation. However, I/O ratios were often less than 1.0, indicating that PM in indoor air arises predominantly from outdoor air transported to indoors. Average indoor ozone concentration at all the shopping malls was measured to be below the 0.05 ppm of ICOP-IAQ 2010. Conclusion: The overall assessment of IAQ in the three shopping malls showed that SM2 has a better IAQ compared to SM1 and SM3.

CONSUMPTION OF RAINWATER HARVESTING IN TERMS OF WATER QUALITY

Rainwater harvesting is seen as part of solution to avoid water shortage in the future as it offers a sufficient supply and more economical if compare to the conventional way. The scarcity of water supply is becoming a concern due to the growing population of human along with environment pollutions. Rainwater harvesting is considered the most accessible source which could be easily used for potable purposes both for household and commercial activities. Therefore, in this study, the physical, microbiological and chemical rainwater quality samples were analyzed using membrane filtration technique (ELE Paqualab 50), ICP-OES and Hach methods, to ensure the suitability of rainwater harvesting for domestic consumption. The study reveals that overall quality of the rainwater is quite satisfactory as per WHO and Malaysian standards, where the pH, turbidity, total dissolved solids, salinity, NO 3- , SO4 2- , Zn and Pb were still under the permissible limits. However, the microbiological parameters (total coliform, fecal coliform and E. coli) and chemical (Cr) were found exceeded the standards, due to poor hygienic practices of the harvesting system. It can be concluded that the rainwater harvesting is still safe to drink and can be a potential alternative source of water supply in the future.