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Item A study of respirator fit and face sizes of National Health Laboratory Service (NHLS) respirator users during 2013-2014(2015-09-08) Manganyi, Mafanato JeannethIn the hierarchy of controls, the use of respirators is listed as the least preferable means of exposure or infection control; however it is often the primary means of protection in many industries including the health care industry. The National Health Laboratory Service (NHLS) provides diagnostic pathology laboratory services to the national and provincial health departments in nine South African Provinces. NHLS staff includes N95 respirator users working with infectious diseases such as tuberculosis (TB). It has been shown that an individual‟s facial structure influences their chances of achieving respirator fit. Study aim This study aims to describe the proportion of NHLS respirator users with adequate quantitative respirator fit while wearing their currently supplied respirators. Study objectives 1. To determine the proportion of NHLS respirator users achieving an adequate fit 2. To describe facial characteristics of NHLS respirator users and to group these faces into three face sizes (small, medium and large) based on the NIOSH fit test panel and two facial dimensions (face width and face length) 3. To explore the relationship between face size and demographic variables (sex, age, and race) of tested NHLS respirator users 4. To explore the influence of face size on respirator fit obtained by NHLS respirator users wearing their current respirator Materials and methods This was a cross sectional study with descriptive and analytical components. NHLS employees from selected laboratories in Gauteng, Cape Town and Durban were invited to participate. Study participants were respirator users and the majority were exposed to hazardous biological agents (HBA) including tuberculosis (TB). The NHLS employees included the four common South African race groups (as per Statistics South Africa) namely African, White, Coloured and Asian. A minimum sample size of 240 study participants was calculated for the study based on 30 participants per race group and sex. At the close of data collection 610 employees participated in this study. Quantitative respirator fit testing was conducted using a Portacount fit testing machine. Four facial dimensions were taken using callipers and a tape measure. STATA 12 was used to perform descriptive and interferential statistics. The associations between pass and fail and key predictors were investigated by chi-square tests. Student‟s t-tests and Kruskal-Wallis one way analysis of variance were used to investigate the overall fit factor in groups by face size, sex, race, age group and nose bridge width. The effect of the independent variables was explored using multiple linear regressions stratified by sex. Results and discussion Of the 610 employees who participated, a large percentage (78%) of NHLS respirator users failed fit testing and was not protected by their currently supplied medium size respirator. Ninety one percent of the respirators supplied were medium. The race group which achieved a highest proportion of fit factor passes was White (27%) followed by Africans (26%), a drop of pass rate was seen in Coloureds (21%) while the Asians achieved the lowest proportion at 7%. These poor pass rates indicate that a respiratory protection programme is needed in the NHLS, with focus on supplying the correct size and style of respirators. When the measured face length and face width of participants were plotted against the new bivariate NIOSH fit test panel, it was found that 35%, 58% and 7% of the participants had small, medium and large faces respectively. Our study population did fall within the panel but the distributions were different between cells compared to the American population. In the South African population Asians were more likely to be associated with a small face than Africans (p=0.00), Whites (p=0.00) and Coloureds (p= 0.00). While the Coloureds were not significantly different from the Whites or Africans (p= 0.397 p=0.713). The study showed that in addition to face length and face width, nose bridge width play a role in respirator fit. Multiple linear regression analysis showed that face size and nose bridge width were both significant predictors of overall fit. Although both sex and race predicted respirator fit in unadjusted analysis, these fell away when facial characteristic measurements were placed in the model. This suggests that sex and race maybe proxies for facial characteristics in predicting respirator fit. Conclusion and recommendation The high percentage of employees in this study sample achieving poor fit with their current respirator indicates a need for immediate testing of all NHLS respirator users and for a range of sizes and styles of respirators to be provided to all staff requiring respirators. The use of poorly fitting respirators could create a false impression of protection in the laboratories where employees are possibly exposed to HBA‟s including all types of TB. This also leads to in a large amount of funds being spent on purchasing ineffective respirators at the NHLS. A respiratory protection programme including respirator fit testing needs to be compiled, implemented and reviewed regularly to ensure sustainability. Future studies may include the investigation of the relevance of panels used in designing respirators to be worn by South Africans.Item Assessment of indoor air quality in an office building in South Africa(2012-01-17) Brits, Paul JacobusIntroduction The problems associated with poor indoor air quality and the possible subsequent effects thereof on workers, as experienced by the Department of Health in the Regional office situated in the Karel Schoeman building (KSB) in Pretoria, were investigated and are discussed. The possible association between the physical indoor environmental conditions and the sick building syndrome (SBS) like symptoms as well as the seemingly low productivity and the above average rate of absenteeism are included in these discussions. To find a possible association between these poor physical environmental indoor conditions and the potential adverse affects on the health and motivation of workers, a cross sectional survey was conducted to assess the physical, biological and chemical quality of indoor air (Refer to as IAQ – Indoor Air Quality) as well as the chemical and biological quality of the drinking water. Objectives This research report documents a project to measure the environmental conditions which include CO(Carbon Monoxide), CO2(Carbon Dioxide), relative humidity( RH), temperature, air velocity, the microbial and chemical composition of the drinking water and culturable micro organisms in specific work environments within the KSB and to compare the outcome to standards for acceptable indoor working environments. The specific objectives of this study are: To describe the environmental conditions CO, CO2, RH, temperature and air velocity exposures in specific work environments during the period 2003-2004; To describe the microbial exposures to Legionellae (which is actually one of a group of similar diseases collectively known as Legionellosis.) To compare measured environmental exposures to the Environmental Regulations for workplaces promulgated in terms of the Occupational Health and Safety Act 1993 (Act 85 of 1993) (OHSA), the National Institute for Occupational Safety and Health (NIOSH) standards and other national and internationally recognised standards and To compare the microbial monitoring results including the evaluation results of the drinking water for culturable micro organisms and E.coli, to the NIOSH and other national and international recognized standards. Methods To control for confounding, samples of the drinking water as well as from a stagnant pool in the basement were taken and analysed for bacteriological and chemical compliance as well as identification of any microbes and chemicals that can contribute to SBS Environmental conditions which include CO, CO2, RH, temperature, air velocity, the microbial and chemical composition of the drinking water and culturable micro organisms including E.coli, in specific work environments were measured. Measurements were conducted in accordance with the procedures prescribed in the ASHRAE 41.6 of 1994, ACGIH (Handbook for industrial ventilation, EPA building Air quality guidelines, US Department of Labour –OHSA Technical manual),the respective manufacturers recommendations and the SABS Code 0400 of 1990 and sampling of the water in terms of the procedures prescribed by NIOH in the case of sampling for Legionellae and the Microbiological laboratory of the Rietvlei accredited water research laboratory with reference to sampling for identification of micro organisms including E.coli and the chemical composition. Appropriate recognized analytical methods were used to analyse and interpret the data generated from both the chemical and biological sampling results. Results Based on the outcome of the project results, it is clear that the air conditioning system does meet the mentioned minimum prescribed physical environmental national and international norms and standards for indoor air quality. The findings from the study indicate compliance of the physical environmental conditions to universally accepted standards and no association between those poor physical indoor environmental conditions and the sick building syndrome (SBS) like symptoms as well as the seemingly low productivity and the above average rate of absenteeism could therefore be made. The presence of coliform organisms above the norm in the air samples is however a concern. Discussion The OHSA requires employees to access the health and safety risks that hazards pose to their employees in their respective working environments and to take reasonably practicable steps towards eliminating or controlling these hazards. Like any other risks in a workplace environmental conditions need to be identified and controlled based on the principles of risk management. Conclusion The above high rate of absenteeism, as perceived by management, could not be associated with the environmental conditions covered in this project. It could however be ascribed, directly or indirectly to the following variables and assumptions which could be categorised under environmental conditions and the management thereof as well as the management of employees/workers located within the building. Environmental conditions such as substandard quality water supply, the management processes during the decommissioning of the old HVAC system and the commissioning of the replacement system, poor general housekeeping and unacceptable management principles of good quality clean working environments location of the building in the mid city centre of Pretoria and the possible contamination of indoor air by external sources bio quality could be variables contributing to the high rate of absenteeism. The seasonal occurrences of influenza and colds as well as home and external exposures could also possibly be considered as contributing factors in this regard. In addition poor general workers or people‟s management which could have resulted in low staff morale and personal motivation linked to poor supervision during a period of a very serious organizational restructuring which affected many workers could have also being considered as contributing factors to high absenteeism. Substandard ergonomics could have also played a role during this process.