4.1
Ozone Generator
The generator installed by Ozone Services was operated under the following specification.
The ozone generator used was an Airzone Port O Go Maxi, which provides 1000 mg ozone per hour. This unit was incorporated into a ducted system whereby clean air was drawn with an inline fan form the outside through a filter, through the generator, split into 5 ducts and channelled through louvers into 5 different strategic positions with the pub. A remote digital controller was installed within easy reach of management and ozone output adjusted according to the level of contamination manually.
Normally, a level of between 0.04 ppm and 0.1 ppm. which are the recommended levels, would be achieved. Output was limited during occupied hours and flooded when unoccupied using a timer type system.
4.2
Environmental Tobacco Smoke (ETS)
ETS, a significant indoor air pollutant with serious healthy effects, is composed of a large variety of contaminants. When a cigarette is smoked, approximately one half or more of the smoke generated is sidestream smoke emitted from the smouldering cigarettes. The principal contributor to ETS is “sidestream smoke”. Other components of ETS include exhaled mainstream smoke and compounds dif fused through the wrapper. “Mainstream smoke” is the complex mixture that exists from the mouthpiece of a burning cigarette when a puff is inhaled by the smoker.
The chemical composition of mainstream smoke has been more extensively characterized than th at of sidestream smoke, but they are produced by the same fundamental process, such that many chemical constituents are present in both. Over 4,000 individual constituents have been identified in mainstream smoke, and approximately 400 compounds have been measured quantitatively in both mainstream and sidestream smoke. Health effects linked with ETS include eye, nose and throat irritation, headaches and lung cancer. For children it may lead to an increased risk of lower respiratory tract infections (e.g. bronchitis and pneumonia), ear infections, build up of fluid in the ear, increased severity and frequency of asthma episodes and decreased lung function (US EPA 1996).
High exposure to ETS can be expected in public buildings where smoking is prevalent, however, effects can be experienced anywhere tobacco is smoked. The most commonly used measure of ETS is respirable suspended particulates (RSP).
Therefore for the purpose of this stage of the assessment RSP were used as a surrogate measurement the effectiveness and efficiency of the control measures installed (ozone generator), although other measures were conducted to backup these measurements (formaldehyde, volatile organic compounds).
Measurements of RSP in buildings with smokers have been found
to be 150 430 ug/m3 (micrograms). Poor ventilation exacerbates the situation and therefore an increase in fresh air intake in building were smoking is allowed would reduce concentrations of ETS. The US EPA National Ambient Air Quality Standards, have been employed during the course of this assessment. The PM10 (Particulate Matter less than 10 micron in diameter) Standard 3 for a 24 hour period is set as 150 ug/m3.
The South African Standard set by the Department of Environmental Affairs and Tourism is 180 ug/m. All speciated substances measured have been compared to The US EPA National Ambient Air Quality Standards.
4.3
Ozone
Ozone is an irritant and affects mucous membranes, lung tissue and lung functions. At levels above 100 parts per billion, sensitive individuals, particularly during exercise, can experience impaired lung function accompanied by respiratory symptoms. Ozone is not a carcinogen (a cancer forming substance).
The US EPA National Ambient Air Quality Standard for ozone is 80 ppb.
5.
Evaluation of Results
5.1
Respirable Suspended Particulates: As can be seen from the results there was a marked decrease in RSP once the ozone generator had been installed (Table 1)
5.2
There was a decrease in total volatile organic compounds (Table 4) and in formaldehyde (Table 3).
5.3
Obviously there was an increase in ozone concentration (Table 2) once the ozone generator had been installed. However, the US EPA National Air Quality Standards 4 were not exceeded at any of the Sampling Locations.
