Photocatalytic degradation of volatile organic compounds (VOC) with short-wavelength UVlight (254 nm) is an attractive technique in the view of perfect mineralization to CO2. In thisstudy, shorter wavelength of UV light involving 185 nm which generates O3 was used as a lightsource, and as a photocatalyst, titanium dioxide (TiO2) and its mixture with ozonedecomposition catalyst (ODC) was tested to improve photocatalytic activity. Their validity wasevaluated from the removal ratio of toluene by photocatalysis and the size distribution ofgenerated particles by gas-to-particle conversion.

This study is part of an investigation of the decontamination capabilities of indoor plants.Three internationally used species, Howea forsteriana Becc. (Kentia Palm), Dracaenaderemensis Eng. Janet Craig, and Spathiphyllum Petite (Peace Lily), were evaluated for theability to reduce or remove benzene and n-hexane from indoor air. Plants tested in bothpotting media and hydroponic conditions removed the individual VOCs at concentrationsequal to 2 and 5 times the maximum occupational exposure levels recommended by theWorksafe Australia Time-weighted average exposure standard (TWA), [1].

The goal of this study was to investigate the effectiveness of stand-alone modular airpurification systems in improving air quality in dental practices and certain hospital andlaboratory environments. As air pollutant make-up and concentration may vary significantlyin different indoor enviromnents, the air cleaning technologies utilised should be optimisedfor the pollutants targeted in a particular environment. Reduction of mercury vapours andformaldehyde were examined because of their importance for indoor air quality in dentalpractices.

Air cleaners are unitary devices that contain filtration media and fans. They are marketed for cleaning air in rooms. There is no current method for measuring the effectiveness of these devices in rooms of the size where they are typically installed. The proposed method provides engineers and manufacturers with a tool for evaluating and predicting applied air cleaner performance. Test results provide the effective ventilation rate of the device. This rate can be stated in terms of the whole room average, or for specific regions of concern, such as work areas, within the room.

Avariety of gaseous pollutants in indoor air now are becoming an object to control. Thus, westudied a removal technique using TiO2 photocatalyst under 365 nm or 254 nm UV-lightirradiation for toluene, benzene, formaldehyde and acetaldehyde as examples of hazardousvolatile organic compounds (VOCS), in order to get detailed analytical data for productsderived from these contaminants. Although these compounds were effectively destructed, notonly CO2 but also high concentration of toxic compounds, such as aldehydes were formed inthe case of under 365 nm UV-light irradiation.

Airborne fungi in indoor air has the possibility to cause the air pollution problems of the fungally infection syndrome and the allergy syndrome, etc. in residence environments. Because the carcass of airborne fungi becomes and allergen, it is difficult to remove the allergen effectively only by mere sterilisation. In this research, the pyrolysis of fungi was examined by using the heat of the high temperature from the heater used the combustion of natural gas.

As a result of the recent resurgence in tuberculosis (TB), there has been renewed interest inengineering controls to reduce the spread of TB and other airborne infectious diseases in highrisk settings. This paper presents the results of experimental studies evaluating the efficacy ofultraviolet germicidal irradiation (UVGI) of room air in reducing the concentration of viableairborne bacteria. Bacterial particles (Bacillus subtilis spores and Mycobacteriumparafortuitum) were continuously generated in a 90m room.

A number of studies have shown that approximately 1 in 10 hospital in-patients will acquire a nosocomial infection (NI) '*).These infections are associated with significant mortality rates, and have a large economic impact on health care systems. A Department of Health (DoH) study estimated that in acute care hospitals in England 950000 lost bed days and financial costs off 111 million (1986 rates) were associated with NI '3).Through the use of ultraviolet germicidal irradiation (UVGI) lamps it ii possible to achieve a high degree of pathogen disinfection.

The fractional collection efficiency (FCE) tests of a commercially available two-stageelectrostatic precipitator (ESP) have been performed for six flow rates. The tests covered theparticle size range from 0.018-1.2micrometer using two types of test aerosols, NaCl andenvironmental tobacco smoke (ETS). Measurements were performed by means of twoScanning Mobility Particle Sizers (SMPS) and the Aerodynamic Particle Sizer (APS).

Models are presented for describing the performance of room air cleaners in removing pollutants from indoor air, particularly the levels of removal that can be achieved in practice. Controlled levels of pollutant were generated in a room environmental chamber, and the performance of a commercial room air cleaner was assessed according to the models. The room environmental chamber was operated in static (sealed) or dynamic (ventilated) modes.