MPH, Occupational Hygiene, School of Public Health, Faculty of Health Sciences, University of the Witwatersrand, 2009 / Introduction: By 2030 silicosis should be eliminated in South Africa. This statement was made by the Labour Minister, Mr. Membathisi Mdladlana on 28 June 2004 during the launch of the National Programme for the Elimination of Silicosis in Johannesburg. Following this launch the mining industry set its own milestone, which is to eradicate this disease by 2014. Historically research has generally focused on the health effects associated with exposures to coal dust, whilst limited work has been done on personal exposures to respirable crystalline silica (commonly known as quartz), which is the main cause of silicosis in the mining industry. Given the number of people that are involved in coal mining, together with the seriousness of diseases associated with respirable quartz exposure, such as silicosis and tuberculosis, it is important to quantify these exposures. The aim of this study was to ascertain the magnitude of employee exposures to respirable quartz, in the Mpumalanga region of the South African coal mining industry, over the period 2002 and 2006. Objectives: The objectives of this study are: • To describe respirable quartz concentrations in 41 coal mines in the Mpumalanga region of South Africa over the period 2002 to 2006; • To compare respirable quartz concentrations in nine magisterial districts of the Mpumalanga region of South Africa over the period 2002 to 2006, to the South African Occupational exposure limit of 0.1 mg/m3 and the American Congress of Governmental Industrial Hygienists (ACGIH) Threshold Limit value of 0.025 mg/m3; • To describe twenty four activity areas in 41 coal mines in the Mpumalanga region of South Africa, over the period 2002 to 2006, which exceed 50 % of the South African Occupational exposure limit of 0.1 mg/m3 (generally referred to as the action limit). 3 Methodology: The study setting comprises the workings of coal mines within the Mpumalanga region, where various types of occupations exist. The research conducted consisted of a descriptive study of retrospective respirable Time Weighted Average quartz concentration results obtained from mines that use the company Colliery Environmental Control Services (CECS) as their occupational hygiene service provider. CECS provided the data that was analysed for this research. Sample collection and analysis for respirable quartz was done using widely accepted International methodologies. Results: The overall median respirable quartz concentration for all mines were 0.007 mg/m3, whilst the mean was 0.038 mg/m3. The highest respirable quartz concentration measured was 2.197 mg/m3 and the lowest 0.000 mg/m3. The majority of the mines, i.e. 30, are situated in the Kriel, Secunda and Witbank magisterial districts, these districts account for 78 % of the total number of measurements taken. A total of 191 measurements (8 %) and 674 (29 %) exceeded the South African OEL of 0.1 mg/m3 and ACGIH TLV of 0.025 mg/m3 respectively with the Secunda district having the most measurements that exceeded both sets of limits (58 and 205 respectively). The majority of measurements, i.e. 1784 (76 %), were from six activity areas and four hundred and ninety one (21 %) of the total measurements taken were from the continuous miner activity area. The highest ranked activity area is the longwall mining one, which has a median respirable quartz concentration of 0.044 mg/m3. The highest respirable quartz concentration, 2.197 mg/m3, was measured in the roving plant activity area, which was followed by measurements of 1.706 mg/m3 and 1.528 mg/m3 in the continuous miner and unknown activity areas respectively. The longwall mining activity area recorded the most measurements that exceeded the 50 % action limit and 0.1 mg/m3 OEL, these been 47 and 38 respectively. 4 Discussion and Conclusion: This research report describes similar exposure findings as has been reported internationally. Persons employed in the high risk activity areas on the 41 mines studied over the period 2002 to 2006 in the Mpumalanga region are at risk of developing quartz-associated diseases, such as silicosis. Recommendations: It is recommended that the effectiveness of implemented interventions need to be investigated and appropriate intervention strategies be implemented. Airborne quartz contents from the nine magisterial districts and 24 activity areas should be analysed and individual samples taken from the high risk tasks should be individually analysed for their percentage airborne quartz content.

The aims of the studies underlying this thesis were to assess the exposure to quartz in Swedish iron foundries and to determine the cancer morbidity for Swedish foundry workers. A cohort of 3,045 foundry workers and a final measurement database of 2,333 number of samples was established. The exposure measurements showed high levels of respirable quartz, in particular for fettlers and furnace and ladle repair workers with individual 8 hr TWA (GM=0.041 and 0.052 mg/m3; range 0.004-2.1 and 0.0098-0.83 mg/m3). In our database, the quartz concentrations as 8hr TWAs of current and historical data varied between 0.0018 and 4.9 mg/m3, averaging 0.083 mg/m3, with the highest exposures for fettlers (0.087 mg/m3) and furnace and ladle repair workers (0.42 mg/m3). The exposure for workers using respirators assuming full effect when used were assessed quantitatively, revealing workers with actual exposure exceeding the occupational exposure limits. Overall cancer morbidity was not increased, but the incidence of lung cancer was significantly elevated (SIR 1.61; 95 % CI 1.20-2.12). In the cohort study, significant associations between lung cancer and cumulative quartz exposure were detected for quartz doses of 1-2 mg/m3 * year (SIR 2.88; 95 % CI 1.44-5.16) and >2 mg/m3 * year (SIR 1.68; 95 % CI 1.07- 2.52). These findings were not confirmed in the case-control analysis. The agreement between the estimated exposure in our early historical model and the development model showed a regression coefficient of 2.42, implying an underestimation of the historical exposure when using the development model data. The corresponding comparison between the development and the validation model based on our survey data showed a B of 0.31, implying an overestimation of present exposures when using data from the validation model. The main conclusions of the thesis are that certain foundry workers are still exposed to high levels of quartz, and the overall excess lung cancer could not be confirmed in the exposure-response analysis.

Sammanfattning Stendamm förekommer på alla väg och anläggningsprojekt men kunskapen om hur farligt det är att exponeras för de respirabla kvartspartiklar som stendamm innehåller är bristfällig. Det respirabla kvartsdammet kan framkalla bland annat Silikos och cancer i lungorna men även påverka hjärtat negativt då lungornas funktion blir nedsatt. Syftet med rapporten var att undersöka hur bra information och kunskap det finns om kvarts i stendamm samt hur och om olika åtgärder som exempelvis andningsskydd förekommer. Då tiden för examensarbetet är begränsat avgränsas en del informationshämtning till Skanska AB väg och anläggning i region mitt. En enkät arbetades fram och användes som metod för att ta reda på dagens kunskapsnivå hos Skanska samt hur bra Skanska informerar när det gäller kvarts. Denna skickades ut till samtliga anställda på Skanska AB väg och anläggning i region mitt. Intervjuer gjordes också med personer som har en chefsroll eller tillhör arbetsledningen inom Skanska AB. Enkätundersökningens resultat visade att kunskapen om kvarts i stendamm finns hos de flesta anställda men att informationen bör bli bättre och upprepas oftare. Resultatet visade även att användandet av andningsskydd är bristfällig då det är jobbigt att andas i och att det blir varmt att bära det en hel dag. Det framkom även att personlig andningsutrustning inte fanns att tillgå för alla som har ett behov av det. En guide togs fram som ett resultat från enkäten och intervjuer. Guiden ska hjälpa arbetsledningen med hur de kan förebygga exponering för kvartsdamm i sina projekt samt ge yrkesarbetare en information som ska påminna om de enklare sätten att skydda sig mot stendamm. Under rubriken diskussion diskuteras bland annat möjligheterna om att använda olika hygieniska gränsvärden inom olika näringsgrenar, detta för att ett sänkt gränsvärde inom väg och anläggning skulle kunna leda till hårdare arbete för en ännu bättre arbetsmiljö. Kunskapen om hur hälsan kan påverkas av respirabelt kvarts kan alltid bli bättre och det gäller särskilt yrkesarbetare som främst utsätts för stendamm. Slutsatserna för detta examensarbete blev att arbetstagare som riskerar att utsättas för stendamm bör informeras oftare, helst inför varje nyetablerad arbetsplats, samt att behovet av personliga andningsskydd med tillhörande utbildning bör överses. Vidare konstaterades att arbetsberedningen som görs i riskbedömningen bör utföras av personer som har fått en likvärdig utbildning så att tiden för arbetsberedning kan effektiviseras samt att alla arbetsberedningar blir konsekventa i sitt utförande. / Stone dust exists in all road and public work projects yet the knowledge about how dangerous exposure to the respirable quartz particles that stone dust contains is lower than what could be preferred. The respirable quartz can cause silicosis and lung cancer as well as heart diseases when the capacity of the lungs is reduced. The purpose of this project was to investigate if there is sufficient information and knowledge about quartz in stone dust in this business today. The purpose was also to realize whether there are quartz-prohibiting measures, such as the usage of breathing aid, taken or not. Because of the time-limit of this project much of the gathering of information was limited to “Skanska AB väg och anläggning, region mitt”. A survey was produced and used as a method in order to get information about the level of knowledge that Skanska employees have, as well as how good Skanska is at informing their employees, about quartz. This survey was sent to all of Skanska Sweden’s staff members in road and public works, central region. In addition to this, interviews were held with supervisors and managers in the same region. The survey results revealed that most employees have some sort of knowledge about quartz but that the information should be made more extensive and be repeated more often. The results also show that the usage of personal breathing aid is inadequate, this is because the aid is hard to breathe through and during long and warm days they’re an annoyance to wear. In addition, it was also brought to light that not everyone who needs a breathing aid have access to one. As another result of the survey and the interviews a guide was made. This guide was formed as a helping hand for the staff management when they’re making risk evaluations and work preparations but also as a short information for all staff members to make it easier for them to remember the easiest and most efficient ways to avoid and protect yourself from quartz particles. In the discussion the possibilities about lowering the hygienic limits of quartz for different parts of the economy was debated. A lowering of the hygienic limit in road and public works should lead to more work, such as this, being done towards a better work environment. The knowledge about how personal health is affected by respirable quartz can always get better and that goes especially for employees that work in direct contact with stone dust. The conclusions of this project were that employees that are exposed to stone dust should be informed more often, preferably before the start of every project, and also the need for personal breathing aid with appurtenant education should be attended to. Furthermore, the work preparations made with every risk evaluation should always be made by staff members with the same qualifications and information. Thus, all work preparations will look consistent and also, the creation of them will be more time efficient.