Hydrogen cyanide gas (HCN{g)) is formed during the process of extracting gold from ore and may pose a risk to the health of the workers at the gold refinery (Mill/plant), especially the risk of detrimental effects on the central nervous system and the cardiovascular system. The measurement of the personal airborne HCN(g) exposure of a worker using sorbent tubes, provides the concentration of the chemical that the worker breaths in. The measurement of the urinary thiocyanate (SCN~) concentration provides the total HCN exposure experience by the worker through all possible routes of exposure. The study's aim was to determine if the workers were exposed to HCN(g) concentrations that was higher than the occupational exposure limit (OEL) , which would mean that the workers are exposed to excessive and possibly harmful levels of HCN. The monitored workers were divided into three homogenous exposure groups or HEGs, according to the their potential level of exposure. The results were compared between the three HEGs and between three work description groups, namely the Mill/plant workers, SGS laboratory assistants and members of the environmental department. The study found that all the workers were exposed to personal airborne HCN(9) concentrations below the OEL. A statistical significant difference was found the personal airborne exposure experienced by the three HEGs and between the Mill/plant workers and the members of the environmental department. No statistical significant difference was found between the urinary SCN" concentration found in the three HEGs or the between the three work description groups. Confounding factors such as smoking, the consumption of cassava, the exposure to fire smoke and the amount of time worked at the mine did not influence the urinary SCN~ concentration. The implementation of a biological monitoring program would enable the identification of any worker that is exposed to excessive levels of HCN. / Thesis (M.Sc. (Occupational Hygiene))--North-West University, Potchefstroom Campus, 2009.

Appendix 7, (3 leaves) in pocket / Includes bibliography / 1 v. (various foliations) : ill ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Clinical and Experimental Pharmacology, 1984

Thesis (Ph.D.) -- University of Rhode Island, 2008. / Typescript. Includes bibliographical references (leaves 140-144).

Thesis (M.S.)--Oregon State University, 2007. / Printout. Includes bibliographical references (leaves 44-45). Also available on the World Wide Web.

Thesis (M.S.)--University of Missouri-Columbia, 2007. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on October 25, 2007) Vita. Includes bibliographical references.

Este trabalho tem por objetivo uma revisão analítica da determinação de cobalto no sangue e/ou urina para fins de monitorização biológica. A proposta de alternativas viáveis para tal metodologia está fundamentada num estudo crítico dos métodos estudados, associados a um Sistema da Qualidade. Os efeitos tóxicos observados nas exposições a diferentes compostos de cobalto, a relação dose-efeito e dose-resposta, bem como os valores de referência para a população sadia e não ocupacionalmente exposta, levou a ACGIH (American Conference of Governmental Industrial Hygienists) dos Estados Unidos a propor desde 1995 a utilização de um BEI (Biological Exposure Indice) para este tipo de exposição. Apesar de o Brasil ainda não ter incluído o cobalto no Programa de Controle Médico de Saúde Ocupacional da Norma Regulamentadora-7, a utilização de um indicador biológico pode constituir-se numa necessidade devido a estudos toxicológicos e analíticos revistos e relatados na literatura. / This work has the purpose of an analytical review of blood and urine\'s cobalt quantification in order to be used in biological monitoring. A proposal of alternatives and feasible methodologies that habe been found are based upon the crutical study associated with a Quality system. The toxic effects observed in exposure to different cobalt compounds, the dose-effect relationship and dose-response, and the reference values in health and non-exposed population, have brought ACGIH (American Conference of Governmental Industrial Hygienists) of the United States to propose since 1995 a BEI (Biological Exposure Indice) to this kind of exposure. Although Brazil has not included cobalt in the PCMSO (Programa de Controle Médico de Saúde Ocupacional), the use of biological indicator can become a necessity due to toxicological and analytical studies here reviewed and reported in the literature

O aumento de casos de doenças infecto-contagiosas, como hepatite e AIDS, despertou para a necessidade de elaboração de regras mais rígidas para controle de infecções em ambiente odontológico. As práticas de esterilização e desinfecção, entre as medidas de biossegurança, tornaram-se imprescindíveis. Em virtude disto, o objetivo desse estudo foi verificar a qualidade desse processo em 31 consultórios odontológicos da rede pública do município de Porto Velho (Rondônia, BR). Para isso os cirurgiões-dentistas ou auxiliares foram questionados sobre os procedimentos relacionados ao processo de esterilização. Também foi realizado o monitoramento biológico dos equipamentos, utilizando esporos de Bacillus subtilis para a estufa e Geobacillus stearothermophilus para a autoclave. Em 31 dos consultórios investigados foram detectados problemas nos processos de esterilização, como: utilização das relações tempo X temperatura incorretos (100% para autoclaves, 70,4% para estufas), falta de termômetros nos equipamentos (59,3%), entre outros. Embora fossem pouco utilizadas, todas as autoclaves apresentaram resultado negativo na avaliação do monitoramento biológico. Já no monitoramento das estufas, 20% apresentaram resultados positivos, indicando falha no processo de esterilização. Portanto os resultados apontam para existência de problemas na eficácia e nas condições dos processos de esterilização realizados na rede pública do município de Porto Velho, o que coloca em risco a saúde dos pacientes atendidos nessas unidades. / The increase in the number of cases of infectious-contagious diseases, like hepatitis and HIV, has brought to attention the need to elaborate stricter infection controls in the dental environment. The practices of sterilization and disinfection, among the measures of bio-security, became indispensable. For this reason, the objective of this study was to verify the quality of these procedures in 31 dental offices of the public system of the municipality of Porto Velho (Rondônia, BR). For this survey, dentists or their assistants have been questioned on the subject of the procedures related to the sterilization. Biological monitoring of the equipment was also carried out by using Bacillus subtilis for the oven and Geobacillus stearothermophilus for the autoclave. Failures in sterilization were detected in 31 investigated offices, such as: the use of incorrect ratio between time X temperature (100% for autoclaves, 70.4% for ovens), the absence of thermometers on equipment (59.3%), among other factors. Even though infrequently used, all the autoclaves showed negative results in the biological monitoring. In the monitoring of the ovens, 20% showed positive results, indicating failure in the sterilization process. Therefore, the results point to the existence of problems in the effectiveness and in the conditions of the sterilization procedures of the public system of the municipality of Porto Velho, endangering the health of the patients treated in those units.

No description available.

Rocky intertidal communities support a high biodiversity. However, they are also easily affected by disturbances, especially human induced disturbances like marine pollution. The recovery process would be very long even after abatement actions have been taken. Also, the outcome of this recovery process cannot be readily predictable. Marine environments in Hong Kong are seriously exposed to pollution problems. The rocky intertidal areas along Victoria Harbour have been suffering from marine pollution impacts for a long time. Recently, the Hong Kong Government has implemented the Harbour Area Treatment Scheme (HATS) aimed at improving the water quality of Victoria Harbour. While water quality of this Harbour was reported to have improved after the scheme, whether the natural rocky shores along the Harbour have recovered from the pollution impact remain unclear. Responses of rocky intertidal community assemblages, as well as those of some particular intertidal species, i.e. the barnacle Tetraclitra japonica, in the light of HATS, were the main focuses of the present study. / From June 2004 to May 2007, the community assemblages of six selected rocky shores along the Victoria Harbour were monitored. From west to east, these six natural shores were Peng Chau, Green Island, Causeway Bay, Hoi Xum Park, Heng Fa Chuen and Tung Lung Chau. Results showed that Hoi Xum Park was completely different from the other five sites with the lowest diversity index . In contrast, the diversity indices of the other sites ranged from 2.13 0.37 to 2.25 0.21. During the study period, only 11 species were recorded in Hoi Sum Park. This was far lower than that in the other shores (number of species ranged from 32 to 38). In addition, the community structure of Hoi Xum Park was only 25% similar to that of the other sites. This high dissimilarity was caused by high coverage of the barnacle Balanus amphitrite and cyanobacteria Chroococcus sp., and the absence of the limpet Petalloida saccharina in Hoi Xum Park. Except for Hoi Xum Park, a decreasing similarity of the community assemblages was also observed from west to east (from about 85% to 70% similarity) along the Victoria Harbour, with Tung Lung Chau in the east being least similar with Peng Chau in the west. The community structural differences between sites were found to be related to the gradients of total phosphorus level along the six rocky shores, resulting in a shift in their algal compositions that, with a bottom up effect, eventually altered their whole community structure. Recovery has not taken place in most of the sampling sites after the cessation of pollution input into the Victoria Harbour. However, a weak sign of recovery was recorded in Tung Lung Chau. Temporal increase of relative abundance of the brown pseudo-perennialalgae Sargassum hemiphyllum by 10% and 20% decrease of grazer numbers were observed, suggesting that the water quality in this particular site was improving, and was better than those of the other sites. The location of this site and the direction of seasonal water currents in Victoria Harbour could have contributed to the sign of recovery observed. The physiological or ecological changes of some particular species of marine organisms may provide an indication of the water quality of its habitat. In order to test whether the locally common barnacle T. japonica is a good environmental indicator, its population dynamics and reproductive biology were examined. Starting from August 2005，a 14-month monitoring was conducted on samples collected from five of the six sites within the Victoria Harbour, as no T. japonica was found in Hoi Xum Park. On the other hand, samples from Hoi Ha Wan，a site away from Victoria Harbour, were also collected to serve as additional control. Oocytes of the samples collected were examined, their size and density were measured. Both the oocytes size and density were found to vary among sites. Samples from Green Island brooded the largest oocytes (70.50 12.49 μm) and with the highest density (76.08 33.30 eggs per mm2). The smallest mean egg diameter was aobserved in Hoi Ha Wan samples (57.57 18.86 μm) and the lowest mean oocyte density was observed in Peng Chau samples (64.20 38.63 eggs per mm2). There was a decreasing trend of egg diameter across the sampling sites from west to east of the Victoria Harbour. Such phenomenon was closely associated with the water quality variations (silica level) of the sampling sites，which may alter the plankton community structure and thus the effectiveness with which nutrients are transferred as food to T. japonica. This could result in the difference in the sizes of the eggs brooded by the barnacles among sites. Such relationship, however, was not found for oocyte density. The total number of eggs may thus be a more accurate way to reflect the real brooding situation of the barnacles. Oocytes were found to be brooded all year round, which was different from that found in previous studies. Reproductive development of oocytes as a temperature sensitive process maybe triggered by the elevated water temperature in recent years, due to global warming, resulting in prolonged reproductive period. The spawning period, however, remained limited in summer. / For the population dynamics study, the basal diameter and the population density of T. japonica were measured. Results showed that there were spatial variations in these two parameters examined. The mean basal diameter was the smallest for samples collected at Hoi Ha Wan (14.99 7.03 mm) and the largest at Causeway Bay (22.47 4.69 mm). In contrast, Hoi Ha Wan recorded the highest value of mean ( SD) barnacle density (605.11 428.75 individuals / m2) while the lowest density was found at Peng Chau (82.46 26.23 individuals / m2). Regression analysis showed that there was a significant relationship between the spatial monthly mean barnacle basal diameter and density, thus the densest population was found in Hoi Ha Wan with the smallest mean size. Some curvilinear or exponential relationships were detected between the population parameters of T. japonica and the water quality. The level of suspended solids, which maybe a food source of barnacles, was found to be associated with the spatial variations in growth and settlement of this species. Mass settlement event was recorded during early or mid summer. However, new settlers were also observed during mid winter at Hoi Ha Wan, Green Island, Causeway Bay and Tung Lung Chau when this species was not reproductively active. These recruits may have come from populations outside of Hong Kong with temporal variation in their reproductive output. / The present study examined the responses of the rocky intertidal communities along the Victoria Harbour after pollution abatement. Generally, spatial variations of these responses were more obvious than that of temporal variations, for both the community structural changes and the reproductive and recruitment dynamics of T. japonica, the indicator species. A longer duration of monitoring should be continued as recovery from pollution impact in nature is a long term process. More detailed studies on the population dynamics of T. japonica is suggested，which may provide a better insight of the responses of this species to environmental changes and the effectiveness of this species as an indicator of water quality. The knowledge obtained in the present study could provide the baseline information for future studies. A good development plan incorporating conservation strategies would certainly be a much better approach than post pollution actions, since alteration of the community structure maybe irreversible, and the original habitat could be lost permanently. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / 岩質潮澗帶群落有著很高的生物多樣性，然而，這些群落的結構很容易受到 騷擾而改變，特別是當受到人爲騒擾時，例如海洋污染。就算減污措施經已實行， 這些群落之復元往往需要很長的時間，後果也不能一槪如所預料。在香港，很多 海洋環境都受到污染，而位於維多利亞港的岩岸亦同樣受海洋污染的威脅有著相 當長的時間。直至近年，香港特區政府實施了「淨化海港計劃」，旨在改善維港 兩岸之水質。計劃實施後，維港水質已見改善，然而，關於沿岸之岩質潮澗帶復 元的狀況，刖仍然很不清楚。因此，是次硏究的重點便集中於測量岩岸生態，包 括整個群落結構及個別品種譬如日本笠藤壺(Tetraclita japonica)對這項措施的 反應。 / 於二零零四年六月至二零零七年五月期間，六個沿著維多利亞港的岩岸被挑 選作群落結構考察之用。由西至東，這些天然岩岸分別爲：坪州、青州、銅鑼灣、 海心公園、杏花村以及東龍州。結果發現海心公園跟其餘岩岸有很大的分別，其 多樣性指數（H´ة）只有0.36 ±0.40，是眾岩岸中最低的，其餘的岩岸的多樣性指 數則徘徊於2.13 ±0.37至2.25 ±0.21之間。在整個硏究期間，只有11種岩岸 生物在海心公園內被發現，遠低於其他岩岸（物種數量於32至38之間）。此外，海心公園的岩岸群落結構跟其他岩岸只有25%之相似度，而這高度的不相似主要是因爲來自紋藤壺與色球藻於海心公園有著很高的覆蓋率，同時也沒有在 該處發現鳥爪擬帽貝。撇除海心公園的資料，其餘岩岸顯示出一個沿著維多利亞 港由西向東的相似度下降趨勢（由85%降至70%相似度），位於最東面的東龍 州之群落結構跟最西面的坪州最爲不相似。硏究發現各考察點之間群落結構上的 不同，是跟六個岩岸水域中的磷含量坡度有關，以致海水中藻類之群落結構有所 轉移，從而透過上行效應改變整個岩岸之群落結構。大部份的考察點於污染物被 停止投入維多利亞港後仍未有復元的跡象。不過，有一個微弱的復元徵兆刖在東 龍州岩岸上出現。結果顯示，僞全年生的褐藻-半葉馬尾藻的相對數量於硏究期 間有10%之增長，而岩岸食植者的數量亦於此期間有20%之下降，此現象顯 示出東龍州的水質有所改善，而且亦相對比其餘的考察點好。這結果可能與此岩 岸的位置及季節性的水流方向有關。 / 個別物種的生理或生態變化可能反映出相應水質的狀態。爲了測試本地常見 的藤壺，日本笠藤壺，是否可以用於此目的，是次硏究也重點地測試其種群動態 和生殖生物學。從二零零五年八月開始，在維多利亞港五個岩岸（海心公園除外) 進行一個爲期十四個月的監測，而離維多利亞港較遠的海下灣的樣本亦被收集以 充當對照。日本笠藤壺的卵母細胞於硏究期間亦被採集，以量度牠們的大小及密度。而這些卵母細胞的大小和密度均有著空間性的變化。青州樣本孵著最大（70.50 ± 12.49微米）與最高密度的卵（每平方毫米76.08 ±33.30顆卵)。而最小的平均卵 母細胞直徑於海下灣樣本中發現(57.57 ± 18.86微米)，最低的平均卵母細胞密度 則於坪州樣本中發現（每平方毫米64.20 ± 38.63顆卵）。從維多利亞港以東至西 面的樣本有著卵母細胞直徑下降之趨勢。而這現象與其空間性的水質差異（矽 含量）有關，而此差異可能會改變浮游生物的群落結構，因此影響到這些浮游生 物被轉換爲日本笠藤壺之食物的營養成效，導致卵母細胞在不同岩岸有著空間性 的大小差異。然而，這種關係並沒有在卵母細胞密度與水質之間被測到，因此， 使用卵母細胞的總數也許更能準確地反映出藤壺的育雛情況。此外，不同於以往 的硏究，採集回來的樣本被發現全年皆有育雛情況。這可能是由於近年來全球暖 化，提升了海水溫度，觸發了卵子發育這個對於溫度比較敏感的生理變化。 / 至於日本笠藤壺之種群動態硏究，其基部直徑和族群密度亦被測量。結果顯 示兩項參數均有著空間性之差異。海下灣樣本之平均基部直徑爲最小（14.99 ± 7.03毫米），最大的則是銅鑼灣的樣本（22.47 ± 4.69毫米）。相反，海下灣記錄 得最高的平均藤壺密度（每平方米605.11 ±428.75個體），而最低的密度則被發 現於坪州（每平方米82.46 ± 26.23個體）。回歸分析顯示每月平均空間性藤壺基 部直徑與其族群密度有著重大的關係，因此最密集的族群被發現在海下灣，但平 均基部直徑卻是最小的。日本笠藤壺之種群動態被檢測到與水質具備了一些曲線或指數的關係。懸浮物ー也許是藤壺的食物來源，被發現到跟此品種的生長及附 著之空間性差異有密切的關係。此品種大規模附著事件於本港之初夏或夏季中段 期間錄得。但是，此品種的新個體亦於中旬冬季在海下灣、青州、銅鑼灣及東龍 州被發現，唯該期間並不是此品種的繁殖活躍期，這些新個體可能來自香港以 外，有著不同繁殖期族群的區域。 / 本硏究展示了沿維多利亞港的岩質潮澗帶群落於污染消減後的反應。普遍 地，整個岩岸群落結構和日本笠藤壺在空間性的反應，比起時態的反應更爲明 顯。更長時間的監測應持續進行，以確認復元是否會真正展現，或是此生態系統 經已達到其新的平衡階段，以致復元並不可能。至於日本笠藤壺，更詳細的硏究， 當可提供更多資料作爲水質指標的參考。因此，在目前的硏究所得的結果可以作 爲基線資料以提供將來硏究之用。然而，這些污染對群落帶來的改善也許是不可 逆轉的，而這些原來的棲息地可能會永久失。因此，一個好的保育計劃或發展 計劃，應該比污染後的減污行動更應被優先的考慮。 / Chiu, Yat Ming. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2009. / Includes bibliographical references (leaves 210-222). / Abstract also in Chinese. / Acknowledgements --- p.i / Abstract (English) --- p.iv / Abstract (Chinese) --- p.x / Contents --- p.xiv / List of Tables --- p.xvii / List of Figures --- p.xix / Chapter Chapter 1 --- General Introduction / Chapter 1.1 --- Intertidal Areas and Rocky Shores --- p.1 / Chapter 1.1.1 --- The Importance of Rocky Shores --- p.2 / Chapter 1.1.2 --- Factors Affecting the Communities of Rocky Shores --- p.3 / Chapter 1.1.3 --- Effects of Pollution on the Rocky Shore Communities --- p.6 / Chapter 1.2 --- Hong Kong Rocky Shores --- p.9 / Chapter 1.2.1 --- Victoria Harbour and the Harbour Area Treatment Scheme (HATS) --- p.10 / Chapter 1.2.2 --- Hong Kong Rocky Shores and HATS --- p.13 / Chapter 1.3 --- The Use of Rocky Intertidal Organisms as Pollution Indicators --- p.14 / Chapter 1.3.1 --- Tetraclita japonica --- p.15 / Chapter 1.4 --- Objectives --- p.17 / Chapter 1.5 --- Thesis Outlines --- p.17 / Chapter Chapter 2 --- Comparison of the Community Structure of the Rocky Intertidal Shores along Victoria Harbour / Chapter 2.1 --- Introduction --- p.24 / Chapter 2.2 --- Materials and Methods --- p.28 / Chapter 2.2.1 --- Sampling Sites and Timing --- p.28 / Chapter 2.2.2 --- Detailed Descriptions of the Characteristics of Each Study Sites --- p.29 / Chapter 2.2.3 --- Community Structure Monitoring --- p.32 / Chapter 2.2.4 --- Statistical Analysis --- p.33 / Chapter 2.3 --- Results --- p.36 / Chapter 2.3.1 --- Species Diversity --- p.36 / Chapter 2.3.2 --- Spatial and Temporal Comparison of Rocky Intertidal Community Assemblages --- p.37 / Chapter 2.3.3 --- Correlation of Water Quality with Community Structure --- p.42 / Chapter 2.4 --- Discussion --- p.43 / Chapter 2.5 --- Summary --- p.50 / Chapter Chapter 3 --- Effect of Eutrophication on the Reproduction of Tetraclita japonica / Chapter 3.1 --- Introduction --- p.84 / Chapter 3.2 --- Materials and Methods --- p.87 / Chapter 3.2.1 --- Sampling Sites and Timing of Collection --- p.87 / Chapter 3.2.2 --- Sample Collection and Preparation --- p.89 / Chapter 3.2.3 --- Histological Studies of the Ovaries of Tetraclita japonica --- p.89 / Chapter 3.2.4 --- Statistical Analysis --- p.91 / Chapter 3.3 --- Results --- p.92 / Chapter 3.3.1 --- Histological Studies of the Ovaries of Tetraclita japonica --- p.92 / Chapter 3.3.2 --- Correlation of Water Quality with the Reproductive Biology of Tetraclita japonica --- p.94 / Chapter 3.4 --- Discussion --- p.96 / Chapter 3.5 --- Summary --- p.100 / Chapter Chapter 4 --- Population Dynamics of Tetraclita japonica / Chapter 4.1 --- Introduction --- p.137 / Chapter 4.2 --- Materials and Methods --- p.142 / Chapter 4.2.1 --- Sampling Sites and Timing --- p.142 / Chapter 4.2.2 --- Population Dynamic Studies of Tetraclita japonica --- p.142 / Chapter 4.2.3 --- Statistical Analysis --- p.143 / Chapter 4.3 --- Results --- p.145 / Chapter 4.3.1 --- Population Dynamic Studies of Tetraclita japonica --- p.145 / Chapter 4.3.2 --- Relationship between Water Quality and the Population Structures of Tetraclita japonica --- p.154 / Chapter 4.4 --- Discussion --- p.154 / Chapter 4.5 --- Summary --- p.158 / Chapter Chapter 5 --- Summary and Perspectives --- p.203 / Reference --- p.210

Excess fine sediment from human activity is a major pollutant to streams across the U.S.; however, distinguishing human-induced sedimentation from natural fine sediment is complex. The U.S. Environmental Protection Agency recently implemented a protocol for the quantitative field assessment of human-induced sedimentation using measurements of stream geomorphology. Macroinvertebrate community composition, streambed sediment stability, and sediment composition were studied at 49 sites in the James River watershed in central Virginia. Sediment composition was found to be a stronger driver of community composition than sediment stability. Although I was not able to show that macroinvertebrate metrics were related to sediment stability independently of actual fine sediment composition, some metrics, including percent Ephemeridae, a family of burrowing mayflies (order = Ephemeroptera) show promise as valuable tools for regional biologists and resource managers to discriminate among streams considered impaired for sediment pollution.