Passive air samplers (PAS) using XAD-resin were deployed at a wide variety of sites around the world for four years to asses the spatial and temporal trends of legacy organochlorine pesticides (OCPs) and current use pesticides (CUPs) in the global atmosphere. Legacy OCPs are prevalent in developing countries, whereas certain CUPs dominate in North America and Europe. OCP levels are declining world wide. Concentrations from the XAD-based PAS agreed with those from polyurethane foam (PUF) disk PAS within a factor of 4 for most sites. The comparison revealed that the sampling rate of the PUF-based PAS is more dependent on wind speed, whereas that of the XAD-PAS has a higher dependence on temperature. Analysis of PAS deployed across arid, subtropical Botswana showed that recent use has more impact on present day air concentrations than historical use. Year-long measurements by high volume air sampling in Botswana yielded higher HCB levels in winter, and higher endosulfan levels in summer. Those variations are neither related to temperature fluctuation nor seasonal hydrological events, and are therefore more likely caused by pesticide usage pattern. Very low levels of OCPs were found in the warm, dry, low organic matter soils of Botswana, including in soils from historical use areas. Such soils appear to have a low long-term storage capacity for pesticides allowing for rapid volatilization. They are thus not long-term sources of pesticides to the atmosphere. Endosulfan sulfate levels were observed to increase in tropical soils with increasing elevation. Water samples from high altitude cloud forests in Costa Rica contained very low concentrations of CUPs and it is unlikely that that those levels pose a threat to amphibians in cloud forests. Laboratory experiments and literature analysis showed that the inert gas stripping method for the determination of air-water partitioning equilibria is susceptible to surface sorption artifacts for chemicals with a interface-air partition coefficient log (KIA/m) > -3. Using larger bubbles reduces the surface-to-volume ratio and produces accurate air-water partition coefficients for chemicals with log (KIA/m) < -1.2.

Passive air samplers (PAS) using XAD-resin were deployed at a wide variety of sites around the world for four years to asses the spatial and temporal trends of legacy organochlorine pesticides (OCPs) and current use pesticides (CUPs) in the global atmosphere. Legacy OCPs are prevalent in developing countries, whereas certain CUPs dominate in North America and Europe. OCP levels are declining world wide. Concentrations from the XAD-based PAS agreed with those from polyurethane foam (PUF) disk PAS within a factor of 4 for most sites. The comparison revealed that the sampling rate of the PUF-based PAS is more dependent on wind speed, whereas that of the XAD-PAS has a higher dependence on temperature. Analysis of PAS deployed across arid, subtropical Botswana showed that recent use has more impact on present day air concentrations than historical use. Year-long measurements by high volume air sampling in Botswana yielded higher HCB levels in winter, and higher endosulfan levels in summer. Those variations are neither related to temperature fluctuation nor seasonal hydrological events, and are therefore more likely caused by pesticide usage pattern. Very low levels of OCPs were found in the warm, dry, low organic matter soils of Botswana, including in soils from historical use areas. Such soils appear to have a low long-term storage capacity for pesticides allowing for rapid volatilization. They are thus not long-term sources of pesticides to the atmosphere. Endosulfan sulfate levels were observed to increase in tropical soils with increasing elevation. Water samples from high altitude cloud forests in Costa Rica contained very low concentrations of CUPs and it is unlikely that that those levels pose a threat to amphibians in cloud forests. Laboratory experiments and literature analysis showed that the inert gas stripping method for the determination of air-water partitioning equilibria is susceptible to surface sorption artifacts for chemicals with a interface-air partition coefficient log (KIA/m) > -3. Using larger bubbles reduces the surface-to-volume ratio and produces accurate air-water partition coefficients for chemicals with log (KIA/m) < -1.2.

The sagebrush shrub steppe ecosystem is of great concern to researchers, conservationists, and the general public because of the documented declines associated with it. Monitoring in the past has generally been point-based and lacking in long-term data. To overcome these deficiencies, an automated method of monitoring was developed using GIS and remote sensing. Geospatial layers of vegetation, soils, fire history, roads, streams, and springs were acquired and processed to characterize selected monitoring locations. A temporal set of Landsat satellite imagery for the past 30 years was normalized to reduce the effects of sun angle, haze, and sensor change. After normalization, a Tasseled Cap Transformation was adapted with local coefficients to provide a landscape metric which was sensitive to actual ground conditions and meaningful at management level. The Tasseled Cap outputs of brightness and greenness are a relative measure of bare ground and plant productivity, respectively. When measured over time, brightness and greenness provided diagnostic trends and condition of treated big sagebrush communities

<p> Coliform bacterial pollution was studied in the Spencer Creek in Hamilton, Ontario. Data, derived from the Ontario Ministry of the Environment files in Hamilton, were used in the determination of whether distinctive temporal patterns of coliform bacterial counts and loads exist in Spencer Creek at Cootes Drive in Dundas. An initial investigation of the general streamflow trends showed that the peak flow period is during the spring snowmelt (March) and a secondary peak flow occurs in late fall due to frontal storms passing through the area. This coincides with the minimums of coliform counts and loads which consistently occur during these times of high flow, particularly March and April. Peak coliform counts and loads occur 70% of the time in late summer with varying starting times in June, July, August and September. This is attributed to the low flow and high temperature of the water in the summer. The average coliform count is 334,154 coliform bacteria per 100 mL water, well above the water quality objectives set by the Ontario Water Resources Commission for Ontario Ministry of the Environment. Approximately 80% of the coliform counts, measured in Spencer Creek in this study, were well above this water quality objective. Therefore, in terms of coliform bacteria, Spencer Creek is polluted, particularly in the summer months. This study simply points out the necessity for further study and continued water quality testing in Spencer Creek.</p> / Thesis / Candidate in Philosophy

Apesar da crescente prevalência da obesidade em países desenvolvidos e em desenvolvimento, há pouca evidência da associação com fatores ambientais. Objetivos: Investigar a evolução temporal do IMC em jovens alistados do sexo masculino de 18 anos no Brasil entre 1980 e 2005; identificar pontos específicos de maior variância na série temporal e comparar pontos específicos no tempo, a evolução temporal do IMC com as mudanças socioeconômicas no Brasil. Métodos: O presente estudo explorou uma série temporal de 26 anos em homens brasileiros que se alistaram no período de 1980 a 2005. A amostra compreendeu cerca de 35-40% de todos os jovens brasileiros de 18 anos de idade. O peso corporal e a estatura foram obtidos no momento do exame médico durante o alistamento militar. Todas as mensurações antropométricas foram realizadas por pessoal especializado e treinado. As prevalências do sobrepeso e da obesidade foram calculadas com intervalos de confiança de 95%. Com a finalidade de testar a presença de heterocedasticidade na série do IMC, realizou-se o teste de Multiplicador de Lagrange (LM). Para os pontos no tempo, com oscilações acima da média do IMC, variáveis dummies foram testadas utilizando-se o modelo ARCH (Autoregressivo de Heterocedasticidade Condicionada), com um nível de significância de p <0,05. Para aqueles pontos no tempo com oscilações acima da média do IMC (anos de 1985, 1994 e 2000), variáveis dummy foram incluídos sob a hipótese foi de que a taxa de crescimento do IMC não fosse a mesma ao longo da série temporal. Para as possíveis explicações para os aumentos bruscos na curva do IMC, foram consideradas as alterações nos principais indicadores econômicos do Brasil (Instituto Brasileiro de Geografia e Estatística e Instituto de Pesquisa Econômica Aplicada). Os fatores econômicos analisados foram: taxa de inflação anual, produção de alimentos, pobreza (%), o consumo de refrigerantes e o rendimento médio anual. Resultados: A prevalência de sobrepeso também passou de 4,5%, em 1980, para 12,5%, em 2005, um aumento de 2,6 vezes, enquanto a prevalência de obesidade aumentou de 0,5%, em 1980, para 1,9%, em 2005, um aumento de quase 300%, mas por comparação internacional estão abaixo da média. Particularmente em 1985-6 e 1994-5, houve um aumento acentuado e significativo do IMC. Em 1985-6, a média do IMC aumentou de 21,4 kg/m2 para 21,5 kg/m2 e, em 1994-5, a média do IMC médio aumentou de 21,7 kg/m2 para 21,9 kg/m2. Nesses dois pontos (1985-1986 e 1994-1995) ocorreram logo após duas grandes mudanças políticas econômicas que aumentaram o poder de compra da população. Em 1985-6, as mudanças foram principalmente relacionadas a fatores econômicos, tais como: a redução do nível de desigualdade social; aumento da renda familiar; redução da pobreza; o controle da inflação; aumento do tempo assistindo televisão e aumento do consumo de alimentos. Em 1994-5, além das mudanças no poder de compra, houve uma modificação na atividade física obrigatória nas escolas. Conclusão: O presente estudo mostrou um aumento abrupto da obesidade na população de homens jovens no Brasil em duas ocasiões durante esta série temporal (anos de 1985-6 e 1994-5), quando uma possível redução no gasto calórico e aumento do consumo de alimentos da população foram observados. / Background: Despite the increasing prevalence of obesity in developed and developing countries, there is little evidence for association between obesity and environmental factors. Objective: To investigate the temporal evolution of BMI in young enlisted men of 18 years in Brazil between 1980 and 2005 to identify specific points of greatest variance in time series and compare specific points in time, the temporal evolution of BMI with socioeconomic changes in Brazil. Methods: The present study explores a temporal series of twenty-six national surveys of Brazilian men who enlisted between 1980 and 2005. Each survey comprises a 35-40% of all Brazilian men aged 18 years at the time of examination. Body weight and height were obtained at the time of medical examination. All measurements were performed by previously trained examiners. Prevalence of overweight and obese men was calculated with 95% confidence intervals. Heteroscedasticity in BMI time series was tested using Engles Lagrange-multiplier (LM) test, and analyses were performed using the ARCH (1) model with a level of significance set at p < 0.05. For those points in time with higher oscillations of the mean of BMI (1985, 1994 and 2000), dummy variables were included under the assumption that the growth rate of mean BMI was not the same throughout the period. As possible explanations for these increases in mean BMI, changes in economic indicators were considered (Brazilian Institute of Geography and Statistics; and Institute of Applied Economic Research). The economics factors which have been analyzed were: annual inflation rate, food production, poverty (%), soft drinks consumption and average annual real income. Results: The prevalence of overweight men changed from 4.5% in 1980 to 12.5% in 2005 (2.6 times larger) and the prevalence of obesity increased from 0.5% in 1980 to 1.9% in 2005, an increase of almost 300% during the period, but by international comparison they are below average. Particularly in 1985-6 and 1994-5, there was a sharp and significant increase in BMI. In 1985-6, the BMI mean increased from21.4 kg/m2 to 21.5 kg/m2 and in 1994-5, the BMI mean increased from 21.7 kg/m2 to 21.9 kg/m2. These two points (1985-1986 and 1994-1995) occurred after two major economic policy changes that increased the purchasing power of the population. In 1985-6, the changes were mainly related to economic factors such as: reducing the level of social inequality, increased family income, poverty reduction, inflation control, increased time watching television and increased consumption of foods. In 1994-5, in addition to changes in purchasing power, there was a change in the physical activity mandatory in schools. Conclusion: The present study showed a sharp increase of obesity in the population of young men in Brazil on two occasions during this series (years 1985-6 and 1994-5), when a possible reduction in caloric expenditure and increased food consumption population were observed.

Natural fluctuations in the state of the environment can long conceal or distort important trends in the human impact on our ecosystems. Accordingly, there is increasing interest in statistical normalisation techniques that can clarify the anthropogenic effects by removing meteorologically driven fluctuations and other natural variation in time series of environmental quality data. This thesis shows that semi- and nonparametric regression methods can provide effective tools for applying such normalisation to collected data. In particular, it is demonstrated how monotonic regression can be utilised in this context. A new numerical algorithm for this type of regression can accommodate two or more discrete or continuous explanatory variables, which enables simultaneous estimation of a monotonic temporal trend and correction for one or more covariates that have a monotonic relationship with the response variable under consideration. To illustrate the method, a case study of mercury levels in fish is presented, using body length and weight as covariates. Semiparametric regression techniques enable trend analyses in which a nonparametric representation of temporal trends is combined with parametrically modelled corrections for covariates. Here, it is described how such models can be employed to extract trends from data collected over several seasons, and this procedure is exemplified by discussing how temporal trends in the load of nutrients carried by the Elbe River can be detected while adjusting for water discharge and other factors. In addition, it is shown how semiparametric models can be used for joint normalisation of several time series of data.

Apesar da crescente prevalência da obesidade em países desenvolvidos e em desenvolvimento, há pouca evidência da associação com fatores ambientais. Objetivos: Investigar a evolução temporal do IMC em jovens alistados do sexo masculino de 18 anos no Brasil entre 1980 e 2005; identificar pontos específicos de maior variância na série temporal e comparar pontos específicos no tempo, a evolução temporal do IMC com as mudanças socioeconômicas no Brasil. Métodos: O presente estudo explorou uma série temporal de 26 anos em homens brasileiros que se alistaram no período de 1980 a 2005. A amostra compreendeu cerca de 35-40% de todos os jovens brasileiros de 18 anos de idade. O peso corporal e a estatura foram obtidos no momento do exame médico durante o alistamento militar. Todas as mensurações antropométricas foram realizadas por pessoal especializado e treinado. As prevalências do sobrepeso e da obesidade foram calculadas com intervalos de confiança de 95%. Com a finalidade de testar a presença de heterocedasticidade na série do IMC, realizou-se o teste de Multiplicador de Lagrange (LM). Para os pontos no tempo, com oscilações acima da média do IMC, variáveis dummies foram testadas utilizando-se o modelo ARCH (Autoregressivo de Heterocedasticidade Condicionada), com um nível de significância de p <0,05. Para aqueles pontos no tempo com oscilações acima da média do IMC (anos de 1985, 1994 e 2000), variáveis dummy foram incluídos sob a hipótese foi de que a taxa de crescimento do IMC não fosse a mesma ao longo da série temporal. Para as possíveis explicações para os aumentos bruscos na curva do IMC, foram consideradas as alterações nos principais indicadores econômicos do Brasil (Instituto Brasileiro de Geografia e Estatística e Instituto de Pesquisa Econômica Aplicada). Os fatores econômicos analisados foram: taxa de inflação anual, produção de alimentos, pobreza (%), o consumo de refrigerantes e o rendimento médio anual. Resultados: A prevalência de sobrepeso também passou de 4,5%, em 1980, para 12,5%, em 2005, um aumento de 2,6 vezes, enquanto a prevalência de obesidade aumentou de 0,5%, em 1980, para 1,9%, em 2005, um aumento de quase 300%, mas por comparação internacional estão abaixo da média. Particularmente em 1985-6 e 1994-5, houve um aumento acentuado e significativo do IMC. Em 1985-6, a média do IMC aumentou de 21,4 kg/m2 para 21,5 kg/m2 e, em 1994-5, a média do IMC médio aumentou de 21,7 kg/m2 para 21,9 kg/m2. Nesses dois pontos (1985-1986 e 1994-1995) ocorreram logo após duas grandes mudanças políticas econômicas que aumentaram o poder de compra da população. Em 1985-6, as mudanças foram principalmente relacionadas a fatores econômicos, tais como: a redução do nível de desigualdade social; aumento da renda familiar; redução da pobreza; o controle da inflação; aumento do tempo assistindo televisão e aumento do consumo de alimentos. Em 1994-5, além das mudanças no poder de compra, houve uma modificação na atividade física obrigatória nas escolas. Conclusão: O presente estudo mostrou um aumento abrupto da obesidade na população de homens jovens no Brasil em duas ocasiões durante esta série temporal (anos de 1985-6 e 1994-5), quando uma possível redução no gasto calórico e aumento do consumo de alimentos da população foram observados. / Background: Despite the increasing prevalence of obesity in developed and developing countries, there is little evidence for association between obesity and environmental factors. Objective: To investigate the temporal evolution of BMI in young enlisted men of 18 years in Brazil between 1980 and 2005 to identify specific points of greatest variance in time series and compare specific points in time, the temporal evolution of BMI with socioeconomic changes in Brazil. Methods: The present study explores a temporal series of twenty-six national surveys of Brazilian men who enlisted between 1980 and 2005. Each survey comprises a 35-40% of all Brazilian men aged 18 years at the time of examination. Body weight and height were obtained at the time of medical examination. All measurements were performed by previously trained examiners. Prevalence of overweight and obese men was calculated with 95% confidence intervals. Heteroscedasticity in BMI time series was tested using Engles Lagrange-multiplier (LM) test, and analyses were performed using the ARCH (1) model with a level of significance set at p < 0.05. For those points in time with higher oscillations of the mean of BMI (1985, 1994 and 2000), dummy variables were included under the assumption that the growth rate of mean BMI was not the same throughout the period. As possible explanations for these increases in mean BMI, changes in economic indicators were considered (Brazilian Institute of Geography and Statistics; and Institute of Applied Economic Research). The economics factors which have been analyzed were: annual inflation rate, food production, poverty (%), soft drinks consumption and average annual real income. Results: The prevalence of overweight men changed from 4.5% in 1980 to 12.5% in 2005 (2.6 times larger) and the prevalence of obesity increased from 0.5% in 1980 to 1.9% in 2005, an increase of almost 300% during the period, but by international comparison they are below average. Particularly in 1985-6 and 1994-5, there was a sharp and significant increase in BMI. In 1985-6, the BMI mean increased from21.4 kg/m2 to 21.5 kg/m2 and in 1994-5, the BMI mean increased from 21.7 kg/m2 to 21.9 kg/m2. These two points (1985-1986 and 1994-1995) occurred after two major economic policy changes that increased the purchasing power of the population. In 1985-6, the changes were mainly related to economic factors such as: reducing the level of social inequality, increased family income, poverty reduction, inflation control, increased time watching television and increased consumption of foods. In 1994-5, in addition to changes in purchasing power, there was a change in the physical activity mandatory in schools. Conclusion: The present study showed a sharp increase of obesity in the population of young men in Brazil on two occasions during this series (years 1985-6 and 1994-5), when a possible reduction in caloric expenditure and increased food consumption population were observed.

No description available.

Doctor of Philosophy / Over the past decade, population-based cancer registry data have been used increasingly worldwide to evaluate and improve the quality of cancer care. The utility of the conclusions from such studies relies heavily on the data quality and the methods used to analyse the data. Interpretation of comparative survival from such data, examining either temporal trends or geographical differences, is generally not easy. The observed differences could be due to methodological and statistical approaches or to real effects. For example, geographical differences in cancer survival could be due to a number of real factors, including access to primary health care, the availability of diagnostic and treatment facilities and the treatment actually given, or to artefact, such as lead-time bias, stage migration, sampling error or measurement error. Likewise, a temporal increase in survival could be the result of earlier diagnosis and improved treatment of cancer; it could also be due to artefact after the introduction of screening programs (adding lead time), changes in the definition of cancer, stage migration or several of these factors, producing both real and artefactual trends. In this thesis, I report methods that I modified and applied, some technical issues in the use of such data, and an analysis of data from the State of New South Wales (NSW), Australia, illustrating their use in evaluating and potentially improving the quality of cancer care, showing how data quality might affect the conclusions of such analyses. This thesis describes studies of comparative survival based on population-based cancer registry data, with three published papers and one accepted manuscript (subject to minor revision). In the first paper, I describe a modified method for estimating spatial variation in cancer survival using empirical Bayes methods (which was published in Cancer Causes and Control 2004). I demonstrate in this paper that the empirical Bayes method is preferable to standard approaches and show how it can be used to identify cancer types where a focus on reducing area differentials in survival might lead to important gains in survival. In the second paper (published in the European Journal of Cancer 2005), I apply this method to a more complete analysis of spatial variation in survival from colorectal cancer in NSW and show that estimates of spatial variation in colorectal cancer can help to identify subgroups of patients for whom better application of treatment guidelines could improve outcome. I also show how estimates of the numbers of lives that could be extended might assist in setting priorities for treatment improvement. In the third paper, I examine time trends in survival from 28 cancers in NSW between 1980 and 1996 (published in the International Journal of Cancer 2006) and conclude that for many cancers, falls in excess deaths in NSW from 1980 to 1996 are unlikely to be attributable to earlier diagnosis or stage migration; thus, advances in cancer treatment have probably contributed to them. In the accepted manuscript, I described an extension of the work reported in the second paper, investigating the accuracy of staging information recorded in the registry database and assessing the impact of error in its measurement on estimates of spatial variation in survival from colorectal cancer. The results indicate that misclassified registry stage can have an important impact on estimates of spatial variation in stage-specific survival from colorectal cancer. Thus, if cancer registry data are to be used effectively in evaluating and improving cancer care, the quality of stage data might have to be improved. Taken together, the four papers show that creative, informed use of population-based cancer registry data, with appropriate statistical methods and acknowledgement of the limitations of the data, can be a valuable tool for evaluating and possibly improving cancer care. Use of these findings to stimulate evaluation of the quality of cancer care should enhance the value of the investment in cancer registries. They should also stimulate improvement in the quality of cancer registry data, particularly that on stage at diagnosis. The methods developed in this thesis may also be used to improve estimation of geographical variation in other count-based health measures when the available data are sparse.

Doctor of Philosophy / Over the past decade, population-based cancer registry data have been used increasingly worldwide to evaluate and improve the quality of cancer care. The utility of the conclusions from such studies relies heavily on the data quality and the methods used to analyse the data. Interpretation of comparative survival from such data, examining either temporal trends or geographical differences, is generally not easy. The observed differences could be due to methodological and statistical approaches or to real effects. For example, geographical differences in cancer survival could be due to a number of real factors, including access to primary health care, the availability of diagnostic and treatment facilities and the treatment actually given, or to artefact, such as lead-time bias, stage migration, sampling error or measurement error. Likewise, a temporal increase in survival could be the result of earlier diagnosis and improved treatment of cancer; it could also be due to artefact after the introduction of screening programs (adding lead time), changes in the definition of cancer, stage migration or several of these factors, producing both real and artefactual trends. In this thesis, I report methods that I modified and applied, some technical issues in the use of such data, and an analysis of data from the State of New South Wales (NSW), Australia, illustrating their use in evaluating and potentially improving the quality of cancer care, showing how data quality might affect the conclusions of such analyses. This thesis describes studies of comparative survival based on population-based cancer registry data, with three published papers and one accepted manuscript (subject to minor revision). In the first paper, I describe a modified method for estimating spatial variation in cancer survival using empirical Bayes methods (which was published in Cancer Causes and Control 2004). I demonstrate in this paper that the empirical Bayes method is preferable to standard approaches and show how it can be used to identify cancer types where a focus on reducing area differentials in survival might lead to important gains in survival. In the second paper (published in the European Journal of Cancer 2005), I apply this method to a more complete analysis of spatial variation in survival from colorectal cancer in NSW and show that estimates of spatial variation in colorectal cancer can help to identify subgroups of patients for whom better application of treatment guidelines could improve outcome. I also show how estimates of the numbers of lives that could be extended might assist in setting priorities for treatment improvement. In the third paper, I examine time trends in survival from 28 cancers in NSW between 1980 and 1996 (published in the International Journal of Cancer 2006) and conclude that for many cancers, falls in excess deaths in NSW from 1980 to 1996 are unlikely to be attributable to earlier diagnosis or stage migration; thus, advances in cancer treatment have probably contributed to them. In the accepted manuscript, I described an extension of the work reported in the second paper, investigating the accuracy of staging information recorded in the registry database and assessing the impact of error in its measurement on estimates of spatial variation in survival from colorectal cancer. The results indicate that misclassified registry stage can have an important impact on estimates of spatial variation in stage-specific survival from colorectal cancer. Thus, if cancer registry data are to be used effectively in evaluating and improving cancer care, the quality of stage data might have to be improved. Taken together, the four papers show that creative, informed use of population-based cancer registry data, with appropriate statistical methods and acknowledgement of the limitations of the data, can be a valuable tool for evaluating and possibly improving cancer care. Use of these findings to stimulate evaluation of the quality of cancer care should enhance the value of the investment in cancer registries. They should also stimulate improvement in the quality of cancer registry data, particularly that on stage at diagnosis. The methods developed in this thesis may also be used to improve estimation of geographical variation in other count-based health measures when the available data are sparse.