ANALYZING INDOOR AIR QUALITY FOR PM 2.5, SECONDHAND SMOKE, INSECTS, AEROALLERGENS AND TESTING THE EFFICIENCY OF NANOTECHNOLOGY BASED AIR PURIFIERS IN MITIGATING THESE IRRITANTS

A good air quality is essential for good health as well as to prevent the spread of diseases. In recent years, people spend 90% of their time indoors. Thus, exposure to pollutants in both occupational and residential environments have drawn much attention due to their health impacts (e.g., infections, respiratory diseases, allergies, and cancer). Indoor air can contain aeroallergens and PM 2.5 (Particulate Matter 2.5 μm). PM 2.5 is a mixture of solid and liquid particles that are suspended in the air. They can be of biological or non-biological origin. It can be composed of metals, products from fuel combustion, dust, spores and pollen and other substances. PM 2.5 can infiltrate from outdoor to indoor and some household activities like cooking, burning of wood, incense sticks, candles and smoking can also add up to indoor PM 2.5. Particulate matter with such lesser aerodynamic diameter poses a greater respiratory risk factor due to its propensity to reach deep down the lungs and enter into the bloodstream. PM 2.5 has been increasing alarmingly in all the major cities of the world. Thus, to mitigate indoor PM 2.5 concentrations, Advanced Hydrated Photocatalytic Oxidation (AHPCO®) and Air For Life Photocatalytic Oxidation (AFLPCO) technology based air purifiers were tested. It was found that AHPCO® technology could cause decay of PM 2.5, 3 times faster than the natural degradation process. Thus, reducing the time of exposure to PM 2.5 for the residents. In further experiments, it was also found that these air purifiers were even effective against high concentration (2000 μg/m3) of PM 2.5 under continuous airflow. Another most dreaded class-A carcinogen and avoidable indoor pollutant is Secondhand smoke (SHS). In the present work, the effect of SHS on PM 1, PM 2.5 and PM 5 concentration was studied. It was found that SHS increased the indoor PM 2.5 concentration by 20 times and PM 5 concentration by about 50 times. The air purifiers under the study were able to decrease the SHS generated PM 2.5 by 50% and PM 5 by 80%. Also with the air purifiers, the rate of decay of PM was also increased. Besides the effect of the air purifiers on the pollutants, the insect-repellent property of the air purifiers was evaluated using fruit flies as a model organism.