Thesis (M.S.)--University of Michigan, 1975.

Thesis (M.S.)--University of Michigan, 1975.

The response of macroinvertebrate and protozoan colonization dynamics to industrial pollution was determined in a thermal organic effluent and in a metals effluent. The relationship of the time course data to the MacArthur-Wilson model is considered, along with Pinkham and Pearson's community similarity index and traditional community structural parameters. The response of both communities is similar with respect to equilibrium number of taxa at both sites; however, the fitted rate constant, G, was accelerated in the organic effluent for the protozoans. The macroinvertebrate G in the same effluent showed a dose response. There were no differences in rate between stations in the metals effluent for either the protozoans or the macroinvertebrates, although the equilibrium number of taxa was decreased downstream. Community similarity indices shows similar macroinvertebrate and protozoan communities at all three stations in the organic system at equilibrium, although some differences occur in the early stages of colonization. The communities in the metals effluent are most often significantly different at the downstream station, which was the most impacted. Community diversity indices indicate the same results for the equilibrium community as do the other methods of evaluation. While community colonization studies have been suggested as a method of water quality assessment, colonization dynamics and particularly the fitted rate constant, G, may be misleading unless considered in conjunction with equilibrium information. / Master of Science

Os procedimentos utilizados para reprocessamento e reuso de artigos médicos de uso único não estão normalizados nem avaliados quanto a segurança. Os objetivos deste estudo foram: (i) determinar o tempo de esterilização e aeração de cânulas de perfusão em ambiente industrial; (ii) avaliar os níveis de resíduos de óxido de etileno, concentração de endotoxinas e resistência a tração de cânulas de perfusão após reprocessamento e reuso em ambiente hospitalar. No ambiente industrial as cânulas foram submetidas á esterilização com 450mg/L de 10% de óxido de etileno e 90% de CO2 por um período de 2 horas a uma temperatura de 45 a 55° C, umidade entre 30 e 90% aeração com 26 trocas de ar por hora com temperatura de 35°C. No ambiente hospitalar a cânula aramada TF 36460 foi utilizada em procedimento cirúrgico com circulação extracorpórea; lavada com água potável, desinfecção com detergente enzimático, enxague com água potável, embalada em papel grau cirúrgico e reprocessada por óxido de etileno com concentração de 500mg/L de 12% de óxido de etileno e 88% de Freon com tempo de exposição de 240 minutos, temperatura de 53°C, umidade entre 40-60% e aeração em temperatura ambiente. No ambiente industrial o tempo necessário para redução de 12 ciclos logarítmicos (SAL 10-6), foi de 120 minutos, no ambiente hospitalar foi de 240 minutos. O tempo de aeração variou de 19 a 28 horas na área industrial; e no ambiente hospitalar foi de 28 horas. No segundo reuso a cânula apresentou residual de óxido de etileno de 83,09 ppm; acima do limite especificado (≤_25ppm). Os testes de resistência a tração e determinação da concentração de endotoxinas foram realizados até o quarto reuso não apresentando resultados fora dos limites especificados. O procedimento de reuso nas condições atuais realizado em ambiente hospitalar foi reprovado, pois não atendeu aos requisitos de residual de óxido de etileno descritos na portaria Brasileira Interministerial n° 482. / The procedures used during reprocessing of disposables have not been normalized, nor assessed for safety. The objective of this study is to assess sterility, residual rate of ethylene oxide, pyrogenicity and resistance to traction results observed in perfusion cannulas after the sterilization process in industrial environments and after reprocessing and reuse in the hospital environment. In the industrial environment, the cannulas were submitted to sterilization with 450mg/L of EtO and 90% of CO2 during a period of 2 hours and at a temperature of 45-55°C, humidity ranging from 30 to 90% and aeration of 26 air changes per hour at a temperature of 35°C. For the hospital environment, we selected the TF 36460 wired cannula, and after using it on a surgical procedure with extracorporeal circulation, it was washed with clean water, disinfected with enzymatic detergent, rinsed with clean water, wrapped in surgical paper and reprocessed in 500mg/L ethylene oxide of 12% EtO and 88% Freon and exposed for 240 minutes at a temperature of 53°C, humidity ranging from 40 to 60% and aeration at room temperature. In the industrial environment, the time needed for decreasing 12 logarithm cycles (10-6) was 120 minutes, while in the hospital environment it was 240 minutes. The aeration time ranged between 19 and 28 hours in the industrial area, while in the hospital environment it took 28 hours. In the second reuse the cannula presented residual of ethylene oxide of 83,09 ppm; above of the specified limit (≤25_ppm). The physical test and endotoxins concentration had been carried through until for reuse not presented results out of specified. The currently procedure of reuse in the hospital is disapproved therefore does not take care of the limits of ethylene oxide residues, recommended by Interministerial Brazilian regulation 482.

Os procedimentos utilizados para reprocessamento e reuso de artigos médicos de uso único não estão normalizados nem avaliados quanto a segurança. Os objetivos deste estudo foram: (i) determinar o tempo de esterilização e aeração de cânulas de perfusão em ambiente industrial; (ii) avaliar os níveis de resíduos de óxido de etileno, concentração de endotoxinas e resistência a tração de cânulas de perfusão após reprocessamento e reuso em ambiente hospitalar. No ambiente industrial as cânulas foram submetidas á esterilização com 450mg/L de 10% de óxido de etileno e 90% de CO2 por um período de 2 horas a uma temperatura de 45 a 55° C, umidade entre 30 e 90% aeração com 26 trocas de ar por hora com temperatura de 35°C. No ambiente hospitalar a cânula aramada TF 36460 foi utilizada em procedimento cirúrgico com circulação extracorpórea; lavada com água potável, desinfecção com detergente enzimático, enxague com água potável, embalada em papel grau cirúrgico e reprocessada por óxido de etileno com concentração de 500mg/L de 12% de óxido de etileno e 88% de Freon com tempo de exposição de 240 minutos, temperatura de 53°C, umidade entre 40-60% e aeração em temperatura ambiente. No ambiente industrial o tempo necessário para redução de 12 ciclos logarítmicos (SAL 10-6), foi de 120 minutos, no ambiente hospitalar foi de 240 minutos. O tempo de aeração variou de 19 a 28 horas na área industrial; e no ambiente hospitalar foi de 28 horas. No segundo reuso a cânula apresentou residual de óxido de etileno de 83,09 ppm; acima do limite especificado (≤_25ppm). Os testes de resistência a tração e determinação da concentração de endotoxinas foram realizados até o quarto reuso não apresentando resultados fora dos limites especificados. O procedimento de reuso nas condições atuais realizado em ambiente hospitalar foi reprovado, pois não atendeu aos requisitos de residual de óxido de etileno descritos na portaria Brasileira Interministerial n° 482. / The procedures used during reprocessing of disposables have not been normalized, nor assessed for safety. The objective of this study is to assess sterility, residual rate of ethylene oxide, pyrogenicity and resistance to traction results observed in perfusion cannulas after the sterilization process in industrial environments and after reprocessing and reuse in the hospital environment. In the industrial environment, the cannulas were submitted to sterilization with 450mg/L of EtO and 90% of CO2 during a period of 2 hours and at a temperature of 45-55°C, humidity ranging from 30 to 90% and aeration of 26 air changes per hour at a temperature of 35°C. For the hospital environment, we selected the TF 36460 wired cannula, and after using it on a surgical procedure with extracorporeal circulation, it was washed with clean water, disinfected with enzymatic detergent, rinsed with clean water, wrapped in surgical paper and reprocessed in 500mg/L ethylene oxide of 12% EtO and 88% Freon and exposed for 240 minutes at a temperature of 53°C, humidity ranging from 40 to 60% and aeration at room temperature. In the industrial environment, the time needed for decreasing 12 logarithm cycles (10-6) was 120 minutes, while in the hospital environment it was 240 minutes. The aeration time ranged between 19 and 28 hours in the industrial area, while in the hospital environment it took 28 hours. In the second reuse the cannula presented residual of ethylene oxide of 83,09 ppm; above of the specified limit (≤25_ppm). The physical test and endotoxins concentration had been carried through until for reuse not presented results out of specified. The currently procedure of reuse in the hospital is disapproved therefore does not take care of the limits of ethylene oxide residues, recommended by Interministerial Brazilian regulation 482.

This thesis reports on a quantitative exposure assessment and on an analysis of the attributes of the data used in the estimations, in particular distinguishing between its uncertainty and variability. A retrospective assessment of exposure to benzene was carried out for a case control study of leukaemia in the Australian petroleum industry. The study used the mean of personal task-based measurements (Base Estimates) in a deterministic algorithm and applied factors to model back to places, times etc for which no exposure measurements were available. Mean daily exposures were estimated, on an individual subject basis, by summing the task-based exposures. These mean exposures were multiplied by the years spent on each job to provide exposure estimates in ppm-years. These were summed to provide a Cumulative Estimate for each subject. Validation was completed for the model and key inputs. Exposures were low, most jobs were below TWA of 5 ppm benzene. Exposures in terminals were generally higher than at refineries. Cumulative Estimates ranged from 0.005 to 50.9 ppm-years, with 84 percent less than 10 ppm-years. Exposure probability distributions were developed for tanker drivers using Monte Carlo simulation of the exposure estimation algorithm. The outcome was a lognormal distribution of exposure for each driver. These provide the basis for alternative risk assessment metrics e.g. the frequency of short but intense exposures which provided only a minimal contribution to the long-term average exposure but may increase risk of leukaemia. The effect of different inputs to the model were examined and their significance assessed using Monte Carlo simulation. The Base Estimates were the most important determinant of exposure in the model. The sources of variability in the measured data were examined, including the effect of having censored data and the between and within-worker variability. The sources of uncertainty in the exposure estimates were analysed and consequential improvements in exposure assessment identified. Monte Carlo sampling was also used to examine the uncertainties and variability associated with the tanker drivers' exposure assessment, to derive an estimate of the range and to put confidence intervals on the daily mean exposures. The identified uncertainty was less than the variability associated with the estimates. The traditional approach to exposure estimation typically derives only point estimates of mean exposure. The approach developed here allows a range of exposure estimates to be made and provides a more flexible and improved basis for risk assessment.

In order to evaluate the respiratory health status of spray painters exposed to paints containing hexamethylene diisocyanates (HDI) and to obtain more insight into the relationship between occupational exposures to isocyanates and chronic obstructive airway diseases, a follow up study on 33 of an original cohort of 40 randomly selected workers was undertaken. The original investigation was conducted by the author in 1989. The subjects were studied using a standardised American Thoracic Society (ATS) approved respiratory health questionnaire, baseline pre and post shift spirometry and ambulatory peak flow monitoring. Bronchial hyperresponsiveness tests using histamine (PC20) were performed. Immunological tests including IgE, RAST (HDI), and house dust mite evaluations were also made. The subjects were stratified into exposed (n=20), partially exposed (n=5) and no longer exposed (n=7) groups. One subject was excluded from the group analysis because of his indeterminate isocyanate exposure. Warehouse assistants (n=30) in a non-exposed occupation were used as controls. The worker's compliance with safety regulations and the employers provision of safety requirements was assessed by means of a questionnaire. The environmental conditions in the workplace were measured by the evaluation of the isocyanate concentrations at the worker's breathing zone. Spray booth efficiency was measured using measurements of airflow velocities and airflow patterns within the booth. Longitudinal changes in respiratory health status was assessed by comparison with baseline data studied in 1989. The exposed group showed the largest mean cross-shift declines of 297 ml (± 83.8) in forced expiratory volume in one second (FEV1). The decline in the partially exposed group was 282 ml (± 102.7) and 54 ml (± 140) in the no longer exposed group. The results of the first study, when compared with the second study, showed a mean cross-shift decline in FEV1 of 130.5 ml. (± 203) (p=0.0002) and 297ml. (± 323) (p=0.0001) respectively. Furthermore, of the spray painters examined, 10 (25%) showed clinically significant cross-shift declines in FEV1 viz. decreases >250 ml in the first study (n=40) compared with 9 (45%) in the second study (n=33). In contrast to the HDI exposed spray painters, a closely matched control group (n=30) showed a mean cross-shift increase in FEV1 of 17.4 ml ( ± 63.04). Only 2 subjects had a diagnosis of asthma which was made in childhood and not related to occupation. The mean annual baseline decline in FEV1 was greatest in the exposed group 41.25 ml (25% showed a decline greater than >90 ml per annum). These values exceeded the predicted annual declines for both smokers and non smokers due to age. The decline in the no longer exposed group was 7.85 ml per annum. Immunological tests showed no correlation with declines in FEV1 . This study demonstrates the difficulties in correlating immunological status with clinical and lung function findings in workers exposed to HDI, as a means of predicting occupational asthma. Although measurements in cross-shift declines in FEV1 appear to be a suitable predictor of occupational asthma, in some cases it was found that the forced expiratory flow rate (FEF 25-75 %) was a more sensitive predictor of early changes in the small airways. The mean isocyanate concentration in the spray painter's breathing zone was 14.65 mg/m3 (±12.219), exceeding the current South African Occupational Exposure Limit - Control Limit (OEL-CL) of 0.07 mg/m3 for isocyanates. Fifty per cent of the subjects suffered from eye irritation and 40% had dermatitis of the hand. This was expected since none of the spray painters wore goggles or gloves. Whilst no subject had evidence of clinical asthma related to spray painting, a large proportion demonstrated significant cross- shift changes in lung function implying short- term adverse effects of exposure. In addition longitudinal declines in lung function which was worse in those who continued spray painting in the follow-up study, is of major concern. The lack of cases of clinical or occupational asthma may be due to the healthy worker effect. Recommendations include, routine spirometric lung function testing of all spray painters, the use of high volume-low pressure spray guns and the wearing of positive pressure airline masks complying with the South African Bureau of Standards (SABS) safety standard. In terms of current legislation it was further recommended that spray booths be regularly monitored, including the measurement of HDI concentrations, airflow velocities and airflow patterns within the booth and the implementation and enforcement of stricter control measures. Workers demonstrating excessive declines in both cross-shift and longitudinal spirometry, require special attention. / Thesis (M.Med.Sc.)-University of Natal, 1997.

A indústria do petróleo possui extensa variedade de riscos ocupacionais em virtude da diversidade de atividades necessárias, seja na extração em águas profundas ou em outros locais isolados como em florestas e desertos, seja no processo de refino cada vez mais assemelhado à petroquímica. Para tanto, os trabalhadores desta indústria possui praticamente todos os riscos ocupacionais, ou seja, físico, químico, biológico. A base energética da sociedade atual é o petróleo não havendo fonte de energia alternativa economicamente viável para a sustentação da economia e indústria nos dias atuais, portanto, mecanismos eficazes de gerenciamento do risco devem ser perseguidos continuamente. Com avanço da higiene ocupacional, legislações modernas e restritivas aos riscos, a exposição ocupacional deste setor tem diminuído de forma bastante representativa nos últimos anos, e valores de limites de tolerância de várias substâncias cada vez menores tem obrigado à equipe de saúde ocupacional a desenvolverem estudos mais aprimorados. Conceitos de biomarcadores de exposição há muito é utilizado, porém falta definição de parâmetros para avaliação do Sistema Nervoso. Vários estudos indicam que exposições a baixas concentrações podem acarretar em dano à saúde, especialmente aos indivíduos que possuem uma susceptibilidade aumentada. Outro fator que merece atenção é a exposição a baixas concentrações de múltiplos agentes concomitantemente, que pode acarretar em efeito sinérgico para agressão aos mais variados órgãos e sistemas e para isso são necessários os biomarcadores de efeitos. Este trabalho visa discutir o papel dos biomarcadores de efeito precoce de neurotoxicidade de modo a preservar a saúde e qualidade de vida dos trabalhadores envolvidos no processo de produção. / The Oil industry has activities in forests, seas, deserts, cities, trough the extraction and transportation of crude oil and posterior transformation into products for consumers. This transformation occurs trough refinement Then people who work in oil companies are submitted to all of the occupational\'s risks, that is, physic , chemic and biological. In our society there is no economically practicable alternative source of energy yet, to support economy and industry, therefore efficient mechanisms of risk\'s management should be always pursuited. The improvement of legislation and occupational\'s hygiene have been reducing contact with chemist\'s products in last years and lesser Threshold Limit Values has been encouraging the occupational\'s health staff to develop better controls. Biomarker\'s conceptions are being used for a long time, but there is a lack of standards\' definition to evaluate the nervous system. Many papers indicate that exposures to low concentrations can cause health injury specially in individuals that have an increased susceptibility. Another fact that deserves attention is the exposure to low concentrations of multiple chemists\' substances concomitantly, which can cause an enlargement of the aggression of many organs and systems. The goal of this study is to discuss the role of the biomarkers of neurotoxicities, to preserve health and quality of life of the individuals who work at the production\'s process.

A indústria do petróleo possui extensa variedade de riscos ocupacionais em virtude da diversidade de atividades necessárias, seja na extração em águas profundas ou em outros locais isolados como em florestas e desertos, seja no processo de refino cada vez mais assemelhado à petroquímica. Para tanto, os trabalhadores desta indústria possui praticamente todos os riscos ocupacionais, ou seja, físico, químico, biológico. A base energética da sociedade atual é o petróleo não havendo fonte de energia alternativa economicamente viável para a sustentação da economia e indústria nos dias atuais, portanto, mecanismos eficazes de gerenciamento do risco devem ser perseguidos continuamente. Com avanço da higiene ocupacional, legislações modernas e restritivas aos riscos, a exposição ocupacional deste setor tem diminuído de forma bastante representativa nos últimos anos, e valores de limites de tolerância de várias substâncias cada vez menores tem obrigado à equipe de saúde ocupacional a desenvolverem estudos mais aprimorados. Conceitos de biomarcadores de exposição há muito é utilizado, porém falta definição de parâmetros para avaliação do Sistema Nervoso. Vários estudos indicam que exposições a baixas concentrações podem acarretar em dano à saúde, especialmente aos indivíduos que possuem uma susceptibilidade aumentada. Outro fator que merece atenção é a exposição a baixas concentrações de múltiplos agentes concomitantemente, que pode acarretar em efeito sinérgico para agressão aos mais variados órgãos e sistemas e para isso são necessários os biomarcadores de efeitos. Este trabalho visa discutir o papel dos biomarcadores de efeito precoce de neurotoxicidade de modo a preservar a saúde e qualidade de vida dos trabalhadores envolvidos no processo de produção. / The Oil industry has activities in forests, seas, deserts, cities, trough the extraction and transportation of crude oil and posterior transformation into products for consumers. This transformation occurs trough refinement Then people who work in oil companies are submitted to all of the occupational\'s risks, that is, physic , chemic and biological. In our society there is no economically practicable alternative source of energy yet, to support economy and industry, therefore efficient mechanisms of risk\'s management should be always pursuited. The improvement of legislation and occupational\'s hygiene have been reducing contact with chemist\'s products in last years and lesser Threshold Limit Values has been encouraging the occupational\'s health staff to develop better controls. Biomarker\'s conceptions are being used for a long time, but there is a lack of standards\' definition to evaluate the nervous system. Many papers indicate that exposures to low concentrations can cause health injury specially in individuals that have an increased susceptibility. Another fact that deserves attention is the exposure to low concentrations of multiple chemists\' substances concomitantly, which can cause an enlargement of the aggression of many organs and systems. The goal of this study is to discuss the role of the biomarkers of neurotoxicities, to preserve health and quality of life of the individuals who work at the production\'s process.

Thesis (Ph.D.) -- University of Western Sydney, Hawkesbury, 2001. / A thesis presented in fulfilment of the requirement for the degree of Doctor of Philosophy, College of Science, Technology and Environment, University of Western Sydney, Richmond, April 2001. Bibliography : leaves 138-148.