The ever-changing industrial processes which are becoming more globalised as well as the merging of markets in different economies, led to an increased focus on the health and safety of workers in the industries and the mining sector over the past decades. Occupational exposure limits (OELs) have been used for more than half a century as a risk management tool for the prevention of work-related illnesses which may arise from the exposure to a wide variety of hazardous chemical substances in the working environment. Aim: The aim of this study is to analyse comparatively occupational exposure limits (OELs) of hazardous chemical substances from selected groups contained in the Hazardous Chemical Substance Regulations (HCSR) and the Mine Health and Safety Regulations (MHSR) with those of selected developed countries and organisations. Method: The two lists of OELs from South Africa – HCSR and MHSR – were compared with 11 different developed countries and/or organisations namely: Canada (British Colombia), United Kingdom (Health and Safety Executive, HSE), Australia (National Occupational Health and Safety Commission, NOHSC), New Zealand (Ministry of Business, Innovation and Employment), Japan (Japan Society for Occupational Health, JSOH), Finland (Ministry of Social Affairs and Health), Germany (Deutsche Forschungsgemeinschaft-DFG), Sweden (Swedish Work Environment Authority) and United States of America (American Conference of Governmental Industrial Hygienists, ACGIH, Occupational Safety and Health Administration, OSHA and National Institute for Occupational Safety and Health, NIOSH). The selection of these countries and organisations was done on the basis of their dominance in the literature as well as the availability of the lists containing OELs. The OELs from each country and/or organisation, depending on the nature and characteristics of the said element and/or compound, were categorised into one of four groups, namely: pesticides, metals, dusts and fibres. The geometric means of each country and/or organisation were calculated from the ratios of each list by using the HCSR and MHSR as the denominator respectively. Results: It became evident that South Africa performed poorly when compared to other countries and/or organisations, indicated in this study. OSHA overall had the highest set OELs, in five out of the six comparisons that could be made, thus being less stringent than South Africa’s. Countries and organisations such as Sweden, Japan and Finland have the lowest overall set OELs for the different groups respectively. Conclusion: South African OELs legislated by both the HCSR and MHSR, are overall higher (less stringent) when compared to those of developed countries and/or organisations. The less stringent nature of South African OELs may be attributed to infrequent rate at which they are updated. The failure to incorporate recent scientific knowledge into OELs may impact on the health of workers. South Africa should follow international best practice and increase the frequency at which OELs are updated. Recommendations: The effectiveness of having two sets of OELs within a country; each applicable to its own industry should be investigated. Attention with regards to the groups lacking attention, i.e. fibres and pesticides should be given priority when revised. Although the other groups should not be disregarded. Duplicate OELs identified in the HCSR should be removed. To prevent duplicate OELs from being established it would be prudent to utilise CAS numbers when referring to substances in addition to their common and chemical names, thus this supports the recommendations made in an earlier study. / MSc (Occupational Hygiene), North-West University, Potchefstroom Campus, 2015

Background: The aim of this study was to investigate the use and management of hazardous chemical substances (HCS) at a chemistry department in a selected Higher Education Institution in Gauteng province. Method: A quantitative, baseline descriptive study was conducted using a structured survey checklist. The population consisted of the chemistry department. Other than purposive observation by the researcher, employees present during data collection were approached for further clarifying comment to survey questions. Results: It emerged that physical-, health- and environmental hazard classes of HCS were present; and that hazard types included flammable liquids, HCS with acute toxicity and carcinogenicity. Selected exposure control measures were lacking which created risks of fire and explosion. Conclusion: The study reflected the use and management of HCS, the actual and potential human exposure and the exposure control measures. Varying degrees of compliance were found, which, if attended to, should mitigate risks to health and safety. / Health Studies

Background: The aim of this study was to investigate the use and management of hazardous chemical substances (HCS) at a chemistry department in a selected Higher Education Institution in Gauteng province. Method: A quantitative, baseline descriptive study was conducted using a structured survey checklist. The population consisted of the chemistry department. Other than purposive observation by the researcher, employees present during data collection were approached for further clarifying comment to survey questions. Results: It emerged that physical-, health- and environmental hazard classes of HCS were present; and that hazard types included flammable liquids, HCS with acute toxicity and carcinogenicity. Selected exposure control measures were lacking which created risks of fire and explosion. Conclusion: The study reflected the use and management of HCS, the actual and potential human exposure and the exposure control measures. Varying degrees of compliance were found, which, if attended to, should mitigate risks to health and safety. / Health Studies

O desenvolvimento de instrumentos endodônticos em ligas de níquel-titânio (Ni-Ti) derivou maior rapidez na modelagem do canal radicular o que nos leva a questionar se realmente estariam as substâncias químicas auxiliares tendo oportunidade de agir convenientemente, considerando que o tempo de atuação das mesmas foi significantemente encurtado. Tendo em vista esse aspecto foi objeto deste trabalho avaliar, com auxílio de microscopia eletrônica de varredura (MEV) e leituras computadorizadas, a limpeza da superfície dentinária radicular, terços cervical, médio e apical, em canais radiculares de incisivos inferiores humanos, preparados pelo sistema rotatório K3?ENDO diante do uso de hipoclorito de sódio a 2,5%, (pH 11,0), do creme de Endo PTC reagindo com hipoclorito de sódio a 0,5%, (pH 11,0), empregando-se essa substância em duas diferentes consistências; sua consistência normal (Endo PTC-N) e uma outra de menor densidade (Endo-PTC-L); e, de um gel de clorexidina (Endogel®) com dois tipos de irrigação final. Concluída a fase de preparo todos os grupos receberam irrigação-aspiração final com soluções de hipoclorito de sódio a 0,5%, (pH 11,0) e de EDTA-T a 17%, exceção feita ao grupo em que se empregou o Endogel®, para o qual seguiu-se dois regimes de irrigação, em um grupo, irrigação-aspiração final com 20 mL de soro fisiológico, conforme recomendações do fabricante e em outro grupo empregou-se irrigação com EDTA-T. As amostras foram então preparadas para MEV e suas imagens analisadas pelo programa Scion Image. Os resultados revelaram haver diferença estatisticamente significante entre os grupos, sendo que o grupo do Endo-PTC-L se mostrou superior aos demais grupos testados no terço médio e apical já o grupo do Endogel seguido da irrigação final com EDTA-T apenas no terço médio, não havendo diferença estatística entre eles. / The development of nickel-titanium (NiTi) endodontic instruments results in more quickness during the root canal shaping phase that induce us to discuss if really would be the chemical substances are having opportunities to act properly, considering that the time of action of the same was significantly reduced. The object of this research was evaluate, using the scanning electron microscopy (SEM) and computerized analysis, the cleaning on root canal walls in coronal, middle and apical thirds in mandibular human incisives prepared with K3 NiTi rotary instruments and different chemical substances: 2,5% sodium hypochlorite (pH 11,0), Endo PTC cream at normal consistency (Endo PTC-N) neutralized by 0,5% sodium hypochlorite (pH 11,0), Endo PTC cream with lower density (Endo PTC-L) neutralized by 0,5% sodium hypochlorite (pH 11,0) and chlorhexidine gel (Endogel). Concluded the cleaning and shaping phase, all the groups received a final irrigation with of 0,5% sodium hypochlorite solution (pH 11,0) followed by 17% EDTA-T solution, except the Endogel group that received two different regimens of final irrigation, one group with 20 ml of physiological serum and another with the 17% EDTA-T solution. The samples were prepared for the SEM analysis and the images obtained were analyzed using the Scion Image program. The results showed a significant difference between the groups tested seeing that the Endo PTC-L group, in middle and apical thirds and Endogel followed by the final irrigation with EDTA-T group, in middle third were superiors in comparation with the other groups.

Magistro baigiamajame darbe yra nagrinėjamas dabartinis nanomedicinos teisinis reglamentavimas ES ir JAV. Ši tema Lietuvoje iki šiol dar nebuvo tyrinėjimų objektu. Pirmoji darbo dalis supažindina skaitytoją su nanomedicina bei su ja susijusių sąvokų problematiką. Antroji dalis atskleidžia nanomedicinos teisinio reglamentavimo prielaidas ES, o trečioji dalis – JAV. Be to, atsižvelgiant į gautus rezultatus, yra įvertinamos galimos nanomedicinos teisinio reglamentavimo perspektyvos ateityje. Darbe plačiai analizuojami atitinkami pasirinktų tarptautinės teisės subjektų teisės aktai bei specialioji teisinė literatūra (įvairių institucijų dokumentai, teisės mokslininkų darbai) bei tam tikra mokslinė-techninė literatūra (įvairių institucijų ir organizacijų ataskaitos ir tyrimai, mokslininkų tyrimai). / The master thesis researches the current regulation of nanomedicine in the EU and the US. Until now, this topic has not yet been researched in Lithuania. In the first part of the thesis nanomedicine and the problem of nanomedicine-related definitions are introduced to the reader. The second part reveals the basis of the regulation of nanomedicine in the EU, and the third part – in the US. Furthermore, considering the achieved results, the perspective of the future regulation of nanomedicine is assessed. The thesis extensively analyses the legal acts of the chosen subjects of international law and specific legal literature (documents of various institutions, works of law scholars) as well as some scientific-technical literature (reports and researches of various institutions and organizations, scientists’ researches).

Various hazardous chemical substances are used daily as part of manufacturing and processing. Exposure to these hazardous chemical substances (HCSs) can cause adverse health effects in the exposed workers. Occupational exposure limits (OELs) are used to control exposure to these HCSs and thereby protect workers from the adverse effects that exposure may induce. The aim of this study was to compare South African list of OELs as contained in the Hazardous Chemical Substance Regulations (HCSR) to several developed and developing countries based on two aspects: (1) the number of substances that are selected and regulated by the lists of each country (2) and the overall level of the OELs set by the different countries and jurisdictions. Due to the nature and the large amount of data the study is divided into two parts. The first part is a comparison of South African OELs with nine developed countries and jurisdictions along with the Mine Health and Safety Act Regulation 22.9 (MHSR) of South Africa. The second comparison was conducted between South African and the four developing BRICS countries. BRICS is an acronym for: Brazil, Russia, India, China and South Africa, all are leading developing countries. Substance selection and coverage was compared by analysing the number of overlapping and uniquely regulated OELs that existed between countries. The over-all level of OELs was determined and quantified by using the statistical method, the geometric means of ratios. These ratios were compared in order to establish how the levels of OELs of the South African HCSR compare with the level of the various other countries. Results indicated that there are large and unsystematic differences between the selection of HCSs that are regulated by different countries and jurisdictions. Individual coverage and selection of HCSs between the various developing and developed countries and jurisdictions in the study was inconsistent and dissimilar. A high number of HCSs are regulated by only one of the various countries included in this study. Among the developed countries 20.8% of substances are uniquely regulated, whereas 46% of HCSs are regulated by only one of the various developing countries. According to the geometric means of ratios Occupational Safety and Health Administration (OSHA) is the only jurisdiction in a developed country that has a higher overall level of OELs when compared to South Africa as for the rest of the developed countries they all yielded a lower overall level of OELs. American Conference of Governmental Industrial Hygiene (ACGIH) had the lowest overall level of OELs. When compared with the BRICS countries South Africa had a higher overall level of OELs. The average overall level of OELs differs substantially between the BRICS countries; Russia having the lowest, and Brazil having the highest overall limit when compared relative to South African HCSR. Strong similarities were found between South African HCSR and MHSR indicating national similarity. The South African OELs for HCSs have an overall higher level than the majority of developed and developing countries. Various factors may be responsible for these differences among countries and jurisdictions. These factors include, variations in scientific reasoning, the risk acceptance of the negative impact that various HCSs might induce and the time lags that countries have between updates. Further differences may be explained by the difference in consideration of socio-economical and practical feasibility of an OEL and the predominant industries in a country. / Thesis (MSc (Occupational Hygiene))--North-West University, Potchefstroom Campus, 2013

Various hazardous chemical substances are used daily as part of manufacturing and processing. Exposure to these hazardous chemical substances (HCSs) can cause adverse health effects in the exposed workers. Occupational exposure limits (OELs) are used to control exposure to these HCSs and thereby protect workers from the adverse effects that exposure may induce. The aim of this study was to compare South African list of OELs as contained in the Hazardous Chemical Substance Regulations (HCSR) to several developed and developing countries based on two aspects: (1) the number of substances that are selected and regulated by the lists of each country (2) and the overall level of the OELs set by the different countries and jurisdictions. Due to the nature and the large amount of data the study is divided into two parts. The first part is a comparison of South African OELs with nine developed countries and jurisdictions along with the Mine Health and Safety Act Regulation 22.9 (MHSR) of South Africa. The second comparison was conducted between South African and the four developing BRICS countries. BRICS is an acronym for: Brazil, Russia, India, China and South Africa, all are leading developing countries. Substance selection and coverage was compared by analysing the number of overlapping and uniquely regulated OELs that existed between countries. The over-all level of OELs was determined and quantified by using the statistical method, the geometric means of ratios. These ratios were compared in order to establish how the levels of OELs of the South African HCSR compare with the level of the various other countries. Results indicated that there are large and unsystematic differences between the selection of HCSs that are regulated by different countries and jurisdictions. Individual coverage and selection of HCSs between the various developing and developed countries and jurisdictions in the study was inconsistent and dissimilar. A high number of HCSs are regulated by only one of the various countries included in this study. Among the developed countries 20.8% of substances are uniquely regulated, whereas 46% of HCSs are regulated by only one of the various developing countries. According to the geometric means of ratios Occupational Safety and Health Administration (OSHA) is the only jurisdiction in a developed country that has a higher overall level of OELs when compared to South Africa as for the rest of the developed countries they all yielded a lower overall level of OELs. American Conference of Governmental Industrial Hygiene (ACGIH) had the lowest overall level of OELs. When compared with the BRICS countries South Africa had a higher overall level of OELs. The average overall level of OELs differs substantially between the BRICS countries; Russia having the lowest, and Brazil having the highest overall limit when compared relative to South African HCSR. Strong similarities were found between South African HCSR and MHSR indicating national similarity. The South African OELs for HCSs have an overall higher level than the majority of developed and developing countries. Various factors may be responsible for these differences among countries and jurisdictions. These factors include, variations in scientific reasoning, the risk acceptance of the negative impact that various HCSs might induce and the time lags that countries have between updates. Further differences may be explained by the difference in consideration of socio-economical and practical feasibility of an OEL and the predominant industries in a country. / Thesis (MSc (Occupational Hygiene))--North-West University, Potchefstroom Campus, 2013

This paper deals with the current world-wide problem of excessive production of tires, especially in the context of emerging high-volume waste after the end of their life. It aims to map the possibilities of how to dispose of old tires and to assess their applicability in practice. Another task is to compare the tire production process with how the tires are treated as a waste product in the Czech Republic over the last nine years. Finally, it is discussed tire fires in the Czech Republic between 2006-2011, which have been dangerous for local residents and the environment. Statistics of production of used tires and treatment with them have shown that in recent years there has been a large increase in both the production of tires, as well as methods and ways to effectively get rid of them once they become waste. The next section outlines the methods which the loading and removal of tires occur, and which should be avoided in the future. The last part contains statistics on tire fires in the last 6 years in the Czech Republic and an evaluation of the most endangered sites and the most common causes of these fires.

O desenvolvimento de instrumentos endodônticos em ligas de níquel-titânio (Ni-Ti) derivou maior rapidez na modelagem do canal radicular o que nos leva a questionar se realmente estariam as substâncias químicas auxiliares tendo oportunidade de agir convenientemente, considerando que o tempo de atuação das mesmas foi significantemente encurtado. Tendo em vista esse aspecto foi objeto deste trabalho avaliar, com auxílio de microscopia eletrônica de varredura (MEV) e leituras computadorizadas, a limpeza da superfície dentinária radicular, terços cervical, médio e apical, em canais radiculares de incisivos inferiores humanos, preparados pelo sistema rotatório K3?ENDO diante do uso de hipoclorito de sódio a 2,5%, (pH 11,0), do creme de Endo PTC reagindo com hipoclorito de sódio a 0,5%, (pH 11,0), empregando-se essa substância em duas diferentes consistências; sua consistência normal (Endo PTC-N) e uma outra de menor densidade (Endo-PTC-L); e, de um gel de clorexidina (Endogel®) com dois tipos de irrigação final. Concluída a fase de preparo todos os grupos receberam irrigação-aspiração final com soluções de hipoclorito de sódio a 0,5%, (pH 11,0) e de EDTA-T a 17%, exceção feita ao grupo em que se empregou o Endogel®, para o qual seguiu-se dois regimes de irrigação, em um grupo, irrigação-aspiração final com 20 mL de soro fisiológico, conforme recomendações do fabricante e em outro grupo empregou-se irrigação com EDTA-T. As amostras foram então preparadas para MEV e suas imagens analisadas pelo programa Scion Image. Os resultados revelaram haver diferença estatisticamente significante entre os grupos, sendo que o grupo do Endo-PTC-L se mostrou superior aos demais grupos testados no terço médio e apical já o grupo do Endogel seguido da irrigação final com EDTA-T apenas no terço médio, não havendo diferença estatística entre eles. / The development of nickel-titanium (NiTi) endodontic instruments results in more quickness during the root canal shaping phase that induce us to discuss if really would be the chemical substances are having opportunities to act properly, considering that the time of action of the same was significantly reduced. The object of this research was evaluate, using the scanning electron microscopy (SEM) and computerized analysis, the cleaning on root canal walls in coronal, middle and apical thirds in mandibular human incisives prepared with K3 NiTi rotary instruments and different chemical substances: 2,5% sodium hypochlorite (pH 11,0), Endo PTC cream at normal consistency (Endo PTC-N) neutralized by 0,5% sodium hypochlorite (pH 11,0), Endo PTC cream with lower density (Endo PTC-L) neutralized by 0,5% sodium hypochlorite (pH 11,0) and chlorhexidine gel (Endogel). Concluded the cleaning and shaping phase, all the groups received a final irrigation with of 0,5% sodium hypochlorite solution (pH 11,0) followed by 17% EDTA-T solution, except the Endogel group that received two different regimens of final irrigation, one group with 20 ml of physiological serum and another with the 17% EDTA-T solution. The samples were prepared for the SEM analysis and the images obtained were analyzed using the Scion Image program. The results showed a significant difference between the groups tested seeing that the Endo PTC-L group, in middle and apical thirds and Endogel followed by the final irrigation with EDTA-T group, in middle third were superiors in comparation with the other groups.

First, this study examined the association of perfluorinated chemicals with 1) cardio-metabolic health outcomes and 2) the association of phthalates with cardiometabolic health outcomes, and 3) cardio-metabolic health outcomes while assessing the possibility of additive interactions between perfluorinated chemicals (PFCs) and phthalates. Second, association with markers of chronic inflammation and oxidative stress were explored. Finally, this study examined the association of these chemicals with estrogenic cancers- Breast cancer, prostate cancer, uterine cancer and ovarian cancer. Using data from the National Health and Nutrition Examination Survey (NHANES), logistic regression models were used to investigate the relationship between PFCs and the cardio-metabolic health outcomes adjusting for covariates. An interaction term between PFCs and phthalates was added to the main effect model to assess the possibility of effect modification. Generalized linear models were used to examine associations between PFCs and inflammatory and oxidative stress markers per unit increase in exposure to PFCs while adjusting for covariates. Binomial logistic regression was used in investigating the association between quartiles of PFCs and presence or absence of cancer while also adjusting for covariates. Discriminant analysis was used to assess the correlation between individual PFCs compounds and individual cancer categories. Perfluorononanoic acid (PFNA) was associated with increased odds of central obesity in females, odds ratio (OR): 1.10; 95% confidence interval (CI): (1.01, 1.21). Perfluorohexane sulfonic acid (PFHS), Perfluorononanoic acid (PFNA), Perfluorooctanoic acid (PFOA), Perfluorooctane sulfonic acid (PFOS), and Perfluorodecanoic acid (PFDE) were all significantly associated with lymphocyte counts. Beta (95% CI); 0.03(0.02,0.05), 0.04(0.02,0.05), 0.05(0.03, 0.07), 0.04(0.03,0.05), 0.03(0.01,0.04) and with serum iron 0.07(0.05,0.09), 0.04(0.02,0.07), 0.10(0.07,0.12), 0.05(0.03,0.07), 0.04(0.02,0.06) and serum albumin 0.02(0.02,0.02), 0.02(0.02,0.03), 0.03(0.03,0.04), 0.02(0.02, 0.023), 0.01 (0.01, 0.05). Only PFHS, PFNA, PFOA and PFOS were associated with serum total bilirubin 0.04(0.03,0.05), 0.02(0.00,0.03), 0.06(0.04,0.08), 0.03(0.02,0.05). PFCs studied were associated with increased odds of breast, prostate, uterine and ovarian cancers, p