Coal workers’ pneumoconiosis (CWP), commonly referred to as black lung, is a chronic lung disease that results from the inhalation and deposition of coal dust in the lungs. While this disease continues to afflict coal miners, its prevalence has steadily declined over three decades since 1970. Based on a voluntary X-ray surveillance program, conducted by the National Institute for Occupational Safety and Health (NIOSH), this downward trend, however, ended in 2000 and has actually begun to rise. The Mine Safety and Health Administration (MSHA) instituted a Comprehensive Initiative to “End Black Lung” to combat the reported upturn in black lung disease. Rulemaking, with the intent of strengthening respirable dust regulations, is a major part of this initiative. This thesis addresses a controversial aspect of the newly proposed rules – single-shift compliance sampling. Establishing new requirements for respirable dust compliance requires an understanding of both the accuracy and variability of measurements. Measurement variability is especially important in underground mining where the workplace is constantly moving and ventilation controls are continually changing. The results of a ventilation study performed in three underground coal mines are presented in this thesis. A total of 600 dust-concentration measurements were obtained in this study using Continuous Personal Dust Monitors (CPDMs). The data was analyzed to determine the variability associated with taking dust measurements in the mining workplace. The Johnson transformation was found to produce the best-fit distribution model for the data. This thesis summarizes the results of this study and presents a statistical procedure for establishing an exposure limit.

<p>Occupational Exposure Limits (OELs) are used as an important regulatory instrument to protect workers’ health from adverse effects of chemical exposures. The OELs mirror the outcome of the risk assessment and risk management performed by the standard setting actor. In paper I the OELs established by 18 different organisations or national regulatory agencies from the industrialised world were compared. The comparison concerned: (1) what chemicals have been selected and (2) the average level of exposure limits for all chemicals. In paper II the OELs established by 7 different national regulatory agencies of EU member states are compared to those of the European Commission (EC). In addition to the same comparisons as performed in the first study a comparison level was introduced (3) the similarity between the OELs of these EU member states and the OELs recommended by the EC.</p><p>List of OELs were collected through the web-pages of, and e-mail communication with the standard-setting agencies. The selection of agencies was determined by availability of the lists. The database of paper I contains OELs for a total of 1341 substances; of these 25 substances have OELs from all 18 organisations while more than one third of the substances are only regulated by one organisation alone. In paper II this database was narrowed down to the European perspective.  The average level of OELs differs substantially between organisations; the US OSHA exposure limits are (on average) nearly 40 % higher than those of Poland. Also within Europe there was a nearly as large difference. The average level of lists tends to decrease over time, although there are exceptions to this. The similarity index in paper II indicates that the exposure limits of EU member states are converging towards the European Commission’s recommended OELs. These two studies also showed that OELs for the same substance can vary significantly between different standard-setters. The work presented in paper III identifies steps in the risk assessment that could account for these differences. Substances for which the level of OELs vary by a factor of 100 or more were identified and their documentation sought for further scrutiny. Differences in the identification of the critical effect could explain the different level of the OELs for half of the substances. The results reported in paper III also confirm the tendency of older OELs generally being higher. Furthermore, several OELs were more than 30 years old and were based on out-dated knowledge. But the age of the data review could not account for all the differences in data selection, only one fifth of the documents referred to all available key studies. Also the evaluation of the key studies varied significantly.</p>

No description available.

Heat stress occurs when the body cannot adequately cool itself due to the combined contributions of metabolic heat, environmental factors and clothing. Heat stress found in the workplace puts employees at risk of developing heat-related illnesses, disorders and could be fatal. The wet bulb globe temperature (WBGT) index is the current method used to assess environmental contributions to heat stress in an occupational setting. The purpose of this thesis was to explore whether the National Weather Service's Heat Index (HI) could substitute for the WBGT Index during occupational heat stress exposure assessment. The possibility of using the HI for heat stress exposure assessments was explored by first developing an occupational exposure limit based on the HI and then by comparing the HI to WBGT Index over a range of environments. Data from 10 selected studies were reviewed and categorized into two groups (Classic Data and Progressive Data) based on the method used to determine the upper limit of the prescriptive zone. WBGT and HI values were estimated from the environmental data provided in the 10 studies and the metabolic demands were also noted. These data were used to illustrate the relationship between environment (WBGT and HI) and metabolic rate. Next the relationship between HI and WBGT was compared over a range of environments consisting of combinations of air temperature and percent relative humidity as defined by the NWS's Heat Index Chart. Finally the effects of adding a high radiant heat load (Tg = Tdb+10 °C) to the relationship between WBGT and HI was explored. The HI occupational exposure limits were protective of the upper limit threshold points in a manner similar to WBGT. A greater spread in the Classic and Progressive upper limit data was observed above the occupational exposure limit when expressed as HI. High correlation was observed (R2 = 0.95) between the WBGT Index and HI over a range of environments, assuming no radiant heat. The incremental increase in HI due to high radiant heat indicated a strong dependency on the absolute value of HI, which makes using HI to predict WBGT in radiant heat environments problematic. Findings suggest the Heat Index could be used to assess heat stress exposures and to set occupational exposure limits for hot environments in the absence of high radiant heat.

Occupational Exposure Limits (OELs) are used as an important regulatory instrument to protect workers’ health from adverse effects of chemical exposures. The main objective of this thesis is to study risk assessment practices in the setting of OEL in order to produce knowledge that will help improve the consistency and transparency of OELs. For the purpose of paper I a database of OELs for a total of 1341 substances was compiled. Of these, only 25 substances have OELs from all 18 included organisations while more than one third of the substances are only regulated by one organisation alone. The average level of OELs differs substantially between organisations; the US OSHA exposure limits are (on average) nearly 40 % higher than those of Poland. In paper II six EU member states’ OELs are compared to the European Commission’s OELs. Also within Europe there is a large difference concerning the average level of OELs (35%). The average level of lists tends to decrease over time, although there are exceptions to this. There are also indications that the exposure limits of EU member states are converging towards the European Commission’s OELs. The work presented in paper III identifies steps in the risk assessment that could account for the large differences in OELs for 14 different substances. Differences in the identification of the critical effect could explain the different level of the OELs for half of the substances. But the age of the data review could not account for all the differences in data selection, only one fifth of the documents referred to all available key studies. Also the evaluation of the key studies varied significantly. The aim of paper IV was to investigate how the Scientific Committee on Occupational Exposure Limits (SCOEL) of the European Commission uses assessment factors when proposing health-based indicative OELs. For only one third of the investigated OELs were explicit assessment factors given. On average the safety margin of the recommendations was 2.1 higher when an explicit assessment factor had been used. It is recommended that the SCOEL develop and adhere to a more articulate framework on the use of assessment factors. Paper V focuses on the Derived No-Effect Levels (DNELs) which are to be calculated under the new European Union REACH legislation. It is a comparison of the safety margins of 88 SCOEL recommendations with those of the corresponding worker-DNELs, derived according to the default approach as described in the REACH guidance document. Overall, the REACH safety margins were approximately six times higher than those derived from the SCOEL documentations but varied widely with REACH/SCOEL safety margin ratios ranging by two orders of magnitude, from 0.3 to 58. / QC 20110215

Occupational Exposure Limits (OELs) are used as an important regulatory instrument to protect workers’ health from adverse effects of chemical exposures. The OELs mirror the outcome of the risk assessment and risk management performed by the standard setting actor. In paper I the OELs established by 18 different organisations or national regulatory agencies from the industrialised world were compared. The comparison concerned: (1) what chemicals have been selected and (2) the average level of exposure limits for all chemicals. In paper II the OELs established by 7 different national regulatory agencies of EU member states are compared to those of the European Commission (EC). In addition to the same comparisons as performed in the first study a comparison level was introduced (3) the similarity between the OELs of these EU member states and the OELs recommended by the EC. List of OELs were collected through the web-pages of, and e-mail communication with the standard-setting agencies. The selection of agencies was determined by availability of the lists. The database of paper I contains OELs for a total of 1341 substances; of these 25 substances have OELs from all 18 organisations while more than one third of the substances are only regulated by one organisation alone. In paper II this database was narrowed down to the European perspective.  The average level of OELs differs substantially between organisations; the US OSHA exposure limits are (on average) nearly 40 % higher than those of Poland. Also within Europe there was a nearly as large difference. The average level of lists tends to decrease over time, although there are exceptions to this. The similarity index in paper II indicates that the exposure limits of EU member states are converging towards the European Commission’s recommended OELs. These two studies also showed that OELs for the same substance can vary significantly between different standard-setters. The work presented in paper III identifies steps in the risk assessment that could account for these differences. Substances for which the level of OELs vary by a factor of 100 or more were identified and their documentation sought for further scrutiny. Differences in the identification of the critical effect could explain the different level of the OELs for half of the substances. The results reported in paper III also confirm the tendency of older OELs generally being higher. Furthermore, several OELs were more than 30 years old and were based on out-dated knowledge. But the age of the data review could not account for all the differences in data selection, only one fifth of the documents referred to all available key studies. Also the evaluation of the key studies varied significantly.

Syftet med arbetet var att samla in mätdata för att kontrollera luftkvalitén ombord på två svenska fartyg, för att sedan jämföra resultaten med Arbetsmiljöverkets hygieniska gränsvärden och den svenska normalbefolkningens exponering för olika ämnen. Resultatet från studien var också tänkt att vara till hjälp för att utforma nya råd och rekommendationer för att minimera exponeringen och även till att bidra med material för fler framtida studier. Under cirka en vecka ombord på fartygen samlades data in med hjälp av passiva provtagare för att registrera halter av bensen, kvävedioxid och polycykliska aromatiska kolväten. Resultaten visade att luftkvalitén ombord på de två fartygen generellt sett är god. Samtliga uppmätta halter låg långt under Arbetsmiljöverkets gränsvärden och det skiljde sig inte mycket varken mellan fartyg eller jämfört med den svenska normalbefolkningens exponering. Därför är inte svensk sjömän ombord på svenskflaggade fartyg i större fara för toxiska luftföroreningar ombord jämfört med när de är hemma. / The main purpose of this study was to measure and evaluate the air quality onboard two Swedish ships, and compare the results with the exposure limits laid out by the Swedish Work Environment Authority (Arbetsmiljöverket) and the Swedish population’s exposure to various substances. The results of this study were also meant to be helpful to form new advice and recommendations to minimize exposure and also to provide material for future studies. During approximately one week onboard the two ships data were collected using passive samplers to register levels of benzene, nitrogen dioxide and polycyclic aromatic hydrocarbons. The results indicated that the air quality onboard the two ships were generally good. All measured concentrations were well below safety applications and it did not differ very much neither between ships nor compared with the Swedish population’s exposure. In conclusion, Swedish sailors onboard Swedish ships are not in greater danger of toxic air pollutants onboard compared to when they are at home.

A qualidade do ar é um importante indicador de saúde ambiental, sendo o seu monitoramento contínuo necessário. Apesar da relevância do tema, há muitos países em que os limites de exposição para agentes biológicos ainda não foram estabelecidos ou foram definidos de forma inadequada, podendo comprometer a qualidade ambiental. Os ambientes hospitalares, assim como as salas de necropsia podem apresentar problemas de contaminação do ar por agentes microbiológicos, necessitando de monitoramento contínuo a fim de evitar a ocorrência de doenças nos trabalhadores e na população em geral. Este estudo realizou a avaliação microbiológica do ar em hospitais públicos e IMLs da região metropolitana do Rio de Janeiro em salas cirúrgicas e de necropsia. A pesquisa exploratória e descritiva baseou-se em levantamento bibliográfico e investigação de campo, através de estudos de casos. Os dados foram obtidos por meio de entrevistas e observação direta nos locais de trabalho, onde foram realizadas as avaliações microbiológicas do ar. As variações em salas cirúrgicas para bactérias e fungos foram respectivamente de 14,99 ufc/m3 88,29 ufc/m3 e de 45,93 ufc/m3 - 742,09 ufc/m3. Já nas salas de necropsia os valores para bactérias e fungos variaram respectivamente de 18,96 ufc/m3 54,9 ufc/m3 e de 144,87 ufc/m3 - 1152,01 ufc/m3. Foram identificados tanto no ambiente cirúrgico como nas salas de necropsia a presença dos seguintes fungos: Aspergillus sp., Neurospora sp., Penicillium sp., Fusarium sp., Cladosporium sp., Curvularia sp., e Trichoderma sp. Já em relação às bactérias foram identificadas as presenças de Staphilococcus sp., Streptococcus sp. e Micrococcus sp. Foram traçadas recomendações para melhoria da qualidade ambiental e do ar. Os resultados indicaram que os valores são elevados quando comparados com as recomendações das normas internacionais. Foram encontrados valores inferiores aos sugeridos pela CP n. 109 da ANVISA. A presença de microrganismos patogênicos sugere adoção de medidas de controle ambiental. O estudo apontou a necessidade urgente do estabelecimento de valores de referência para ambientes hospitalares no Brasil a fim de garantir condições seguras que não venham a comprometer a saúde dos pacientes e profissionais de saúde envolvidos. / The indoor air quality is an important environmental health indicator and yours continuous monitoring is necessary. Its depends on, among other factors, of the biological agents exposure limits fixing. Despite this topic relevance, in many countries, the biological exposure limits still dont exist or were inadequately defined. What can compromise the environmental quality. The hospital environments just as the necropsies rooms can have indoor air contamination problems caused by microbiological agents and needs to have continuous monitoring to avoid the occurrence of diseases in the workers and in the overall population. This study realized a microbiological indoor air assessment at surgical rooms of three public hospitals and autopsies rooms of two IMLs located in the city of Rio de Janeiro. The study was descriptive and exploratory based on bibliographic review and camping research though study cases. Data were obtained from interviews with the health workers and cleaning team and direct observation at the selected workplaces. The fungal and bacteria variation in surgical room and autopsy room were respectively of 14,99 88,29 ufc/m3 and 45,93 ufc/m3 742,09 ufc/m3. Were detected in the surgical rooms and necropsy rooms the fungal genera: Aspergillus sp., Neurospora sp., Penicillium sp., Fusarium sp., Cladosporium sp., Curvularia sp., e Trichoderma sp. and bacterial genera: Staphilococcus sp., Streptococcus sp. and Micrococcus sp. Were traced recommendations to improve environment and air quality. The results indicate that the limits can be considered exceed when compared with those proposed by the international organisms. Were identified some values lower than 50 ufc/m3 proposed by the CP n. 109 ANVISA. The presence of pathogenic microorganisms suggest the need of environmental control measures. That indicate the values actually used as reference in Brazil must been revised considering the environments specificities and the urge to create a specific legislation for hospital environments that guarantee security conditions and do not comes to compromise the health and well being of the patients and health professionals involved

Background: The Platinum mining operations in South Africa mining platinum containing ore from areas where variable amounts of uranium are found, leading to the possibility of occupational exposure to the radioactive disintegration products of Uranium-238 and in particular the gas Radon-222. No scientific data is available for occupational exposure to Radon-222 in South African platinum mining operations. Objective: To determine the risk of occupational exposure to the radioactive disintegration products of naturally occurring Radon-222 gas in a South African platinum mine. Design: Quantitative sampling (personal and static) to establish baseline data on exposure to radioactive disintegration products of naturally occurring Radon-222 gas in a underground South African platinum mine. Setting: The Bafokeng Rasimone platinum mine located 30 km North West of Rustenburg in the Bushveld complex in the North West Province of South Africa. Study subjects: One hundred and seventy four potentially highest exposed underground employees and one hundred and twelve static underground samples were sampled. Method: Personal and area samples were taken on selected employees and in locations using RGM samplers using CR-39 plastic as a detection medium. Employees were selected to sample the highest exposed occupations and static samples were located to sample returning air from levels underneath the sampling point before it is exhausted to the above ground atmosphere. After analysis by an accredited laboratory, the results were converted to exposure following the National Council on Radiation Protection-78 methodology. Main outcome measures: Quantify the relative risks of potentially highest exposed employee`s exposure to the radioactive disintegration products of naturally occurring Radon-222 gas in underground working areas in milliSievert per year. Results: The mean reference background exposure averaged 0.6168 mSv/a with underground personal exposure averaging 0.6808 mSv/a, and underground static exposure averaging 0.8726 mSv/a. These values are substantially below the 50 mSv/a Occupational Exposure Limit, and only pose a slightly elevated risk for the development of lung cancer above the normal back-ground exposure. Mining Team leaders and rock drill operators were identified as the potentially highest exposed employees due to the close proximity to the working face, large amounts of time spent close to the working face and the lower ventilation volumes at the working face, with Team leaders having the highest exposure of the sampled occupations with a average of 1.16 mSv/a. Conclusions: Occupational exposure to radioactive disintegration products of naturally occurring Radon-222 gas in the underground air of a South African platinum mine does not pose a significant risk to the health of employees working in the platinum mine. / Thesis (MSc (Occupational Hygiene))--North-West University, Potchefstroom Campus, 2013.

Background: The Platinum mining operations in South Africa mining platinum containing ore from areas where variable amounts of uranium are found, leading to the possibility of occupational exposure to the radioactive disintegration products of Uranium-238 and in particular the gas Radon-222. No scientific data is available for occupational exposure to Radon-222 in South African platinum mining operations. Objective: To determine the risk of occupational exposure to the radioactive disintegration products of naturally occurring Radon-222 gas in a South African platinum mine. Design: Quantitative sampling (personal and static) to establish baseline data on exposure to radioactive disintegration products of naturally occurring Radon-222 gas in a underground South African platinum mine. Setting: The Bafokeng Rasimone platinum mine located 30 km North West of Rustenburg in the Bushveld complex in the North West Province of South Africa. Study subjects: One hundred and seventy four potentially highest exposed underground employees and one hundred and twelve static underground samples were sampled. Method: Personal and area samples were taken on selected employees and in locations using RGM samplers using CR-39 plastic as a detection medium. Employees were selected to sample the highest exposed occupations and static samples were located to sample returning air from levels underneath the sampling point before it is exhausted to the above ground atmosphere. After analysis by an accredited laboratory, the results were converted to exposure following the National Council on Radiation Protection-78 methodology. Main outcome measures: Quantify the relative risks of potentially highest exposed employee`s exposure to the radioactive disintegration products of naturally occurring Radon-222 gas in underground working areas in milliSievert per year. Results: The mean reference background exposure averaged 0.6168 mSv/a with underground personal exposure averaging 0.6808 mSv/a, and underground static exposure averaging 0.8726 mSv/a. These values are substantially below the 50 mSv/a Occupational Exposure Limit, and only pose a slightly elevated risk for the development of lung cancer above the normal back-ground exposure. Mining Team leaders and rock drill operators were identified as the potentially highest exposed employees due to the close proximity to the working face, large amounts of time spent close to the working face and the lower ventilation volumes at the working face, with Team leaders having the highest exposure of the sampled occupations with a average of 1.16 mSv/a. Conclusions: Occupational exposure to radioactive disintegration products of naturally occurring Radon-222 gas in the underground air of a South African platinum mine does not pose a significant risk to the health of employees working in the platinum mine. / Thesis (MSc (Occupational Hygiene))--North-West University, Potchefstroom Campus, 2013.