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Abstract Seasonal variations of events are apparently playing an important part in various psychiatric conditions. To study the seasonal variation of a condition appears to be one useful approach to clarify the aetiology of a mental disorder and phenomena to which mental disorders are associated. In the present study the seasonal variations of suicides during the period of 1980-95 (n=21279) and homicides during the years 1957-95 (n=4553) in Finland were analysed. In addition, the use of statistical techniques for seasonality and some important characteristics of study samples were evaluated from 44 original suicide seasonality studies published between 1970-97. Special attention was paid to statistical methods for seasonality and these were reviewed in the summary part of this dissertation. A statistically significant spring peak of suicides was found in both genders, in all age groups (aged 39 years or below, 40-64 years, and 65 years or more) and in violent (hanging, drowning, shooting, wrist-cutting, jumping from a height) and non-violent suicides (poisoning, gas, other methods). A secondary autumn peak of suicides was present in females and also associated with non-violent methods. The rate of violent suicides had increased significantly during 1980-90 and decreased thereafter, while the non-violent suicides had kept steadily increasing over the whole 16-year study period. The seasonal variation of violent suicides had remained stable and statistically significant over the whole study period, but the seasonality in non-violent suicides has diminished over time. The seasonal pattern of homicides showed a statistically significant peak in summer and a trough in winter. The observed rate of homicides was about 6% higher in summer and 6% lower in winter than expected under the null hypothesis of a uniform distribution. Both the crude numbers of homicide and the rate of homicides per 100 000 population increased significantly over the 39-year study period. The increasing rate of homicides in Finland was accompanied by decreasing homicide seasonality. The seasonal trends in homicides correlated significantly (positive correlation) with the seasonal trends in the violent suicides over the period of 1980-95. The use of particular statistical techniques was specified in the majority of the 44 reviewed suicide seasonality articles. This was considered as satisfactory, although in subgroup analyses and in comparisons of the seasonal pattern of suicides with phenomena other than suicides, researchers tended to interpret their study findings without a statistical significance test. In those 37 articles, which had actually examined the seasonal pattern of suicides with a statistical test, statistical methods varied from simple standard tests like the chi-square test (14 articles, 38%) to sophisticated time series analyses such as a spectral analysis (4 articles, 11%). The calendar effect (i.e. effect due to the unequal lengths of months and leap years) was reported to have been taken into account in only 10 out of 44 (22%) reviewed studies. The lack of reporting the size of a sample (12 articles, 27%) or monthly values of suicides (17 articles, 54%) was found to be a major deficit in the reviewed studies. On the basis of these findings it is recommended to carry out further surveys, which evaluate statistical content and use of statistical methods in published medical articles. These kinds of surveys remind researchers to consider more thoroughly methodological and statistical issues in their investigations.

The general aim of this thesis was to study symptoms, prehospital delay and time trends in long-term survival in men and women with myocardial infarction (MI). The study was based on quantitative and qualitative data collections. Study I was based on The Northern Sweden MONICA Myocardial Infarction Registry, 1989-2003, including 5072 men and 1470 women with a confirmed MI. Symptoms and prehospital delay were described and trends over time according to sex and age were studied. Typical pain was present in 86% of the men and 81% of the women and typical symptoms were more common among younger persons than older persons. Up to the age of 65 no gender differences were seen in the prehospital delay. In the oldest age group (65–74 years) time to hospital was longer than among the younger group, especially among women. Study II was based on individual interviews with 20 men with a first confirmed MI, representing the age range 65-80 years, about their experiences during the prehospital phase. The interviews were analyzed using qualitative content analysis. The interviewed older men described how the symptoms developed from diffuse ill-being, to a cluster of severe symptoms. The men had difficulties to relate to the experienced symptoms, which did not correspond to their expectations about an MI, and about whether they should seek medical care. By using different strategies the participants initially tried to understand, reduce, or treat the symptoms by themselves, with a desire to maintain an ordinary life. As the symptoms evolved to a persistent and alarming chest pain, the men realized the seriousness in the perceived symptoms, that all strategies were inefficacious and they came to the decision to seek medical care. Study III was based on individual interviews with 20 women with a first confirmed MI, representing the age range 65-80 years, about their experiences during the prehospital phase. The interviews were analyzed using qualitative content analysis. The interviewed older women described how the symptoms were perceived as a stepwise evolvement from intangible and bodily sensations to a more distinct, persistent and finally overwhelming chest pain. The women struggled against the symptoms and used different strategies, by downplaying and neglecting the symptoms in order to maintain control over their ordinary lives and maintain the social responsibilities. As the symptoms evolved to a persistent and overwhelming chest pain the women realized the seriousness in the perceived symptoms, they were not able to struggle against them anymore and they came to the decision to seek medical care. Study IV was based on The Northern Sweden MONICA Myocardial Infarction Registry which was linked to The Swedish National Cause of Death Registry for 6762 men and 1868 women, 25 to 64 years of age, with a first MI during 1985-2006. Also deaths before admission to hospital were included. Follow-up ended on August 30, 2008. Between 1985 and 2006 long-term survival after a first MI increased in both men and women. Over the whole 23-year period women showed a 9 percent higher survival then men. This slight difference was due to lower risk for women to die before reaching hospital, and during the last period similar rates of long time survival were noted in men and women. In conclusion there were no major differences between men and women in symptoms, prehospital delay or long-term survival. However, older patients had fewer typical symptoms and longer prehospital delay, especially among women. The prehospital phase was found to be multifaceted with experiences difficult to interpret in both men and women, with a dynamic development of symptoms, conceptions and expectations while the participants strove to maintain the ordinary and familiar life. The symptoms experienced presented a more heterogeneous and complex picture in both men and women than is usually described in the literature. Women under the age of 65 have a slightly higher age-adjusted long-term survival than men. Over a 23-year period long-term survival has improved similarly in both men and women. / Det övergripande syftet med avhandlingen var att beskriva symtom, prehospital fördröjning och långtidsöverlevnad hos män och kvinnor med hjärtinfarkt. Studien baserades på kvantitativa och kvalitativa datainsamlingar. Delstudie I baserades på data från hjärtinfarktregistret vid The Northern Sweden MONICA Study under åren 1989-2003, inkluderande 5072 män och 1470 kvinnor, med fastställd hjärtinfarkt. Symtom och tid från symtomstart till medicinsk vård beskrevs och tidstrender relaterades till kön och ålder. Resultatet visade att typisk smärta förelåg hos 86% av männen och 81% av kvinnorna och att typiska symtom var mer förekommande hos de yngre. Upp till 65 års ålder fanns inga könsskillnader mellan symtomstart och tid till medicinsk vård. I den äldsta åldersgruppen (65-74 år) var tiden till sjukvård längre, främst hos kvinnor. Delstudie II baserades på individuella intervjuer med 20 män, mellan 65 och 80 år som drabbats av sin första hjärtinfarkt, om hur de upplevde den prehospitala fasen. Intervjuerna analyserades med hjälp av kvalitativ innehållsanalys. Männen beskrev hur symtomen utvecklades från ett diffust illabefinnande, till ett kluster av  svåra symtom. De hade svårt att relatera till de upplevda symtomen som inte motsvarade deras föreställningar om hur symtom på hjärtinfarkt tar sig uttryck, och hade svårt att veta om de skulle söka vård. Deltagarna vidtog olika strategier för att försöka förstå, minska eller behandla symtomen på egen hand, i en strävan att få livet att fortgå som vanligt. När symtomen utvecklats till en alarmerande och ihållande bröstsmärta insåg männen  allvarlighetsgraden i symtombilden och att strategierna för att hantera symtomen var verkningslösa och beslutade att söka vård. Delstudie III baserades på individuella intervjuer med 20 kvinnor, med sin första hjärtinfarkt i åldern 65-80 år, för att få en djupare förståelse för hur de upplevde den prehospitala fasen. Intervjuerna analyserades med hjälp av kvalitativ innehållsanalys. De äldre kvinnorna beskrev hur symtomen stegvis utvecklades från ogripbara och kroppsliga förnimmelser, mot en mer distinkt, ihållande och slutligen överväldigande bröstsmärta. Kvinnorna kämpade mot symtomen och använde olika strategier, som att tona ner och negligera symtomen för att behålla kontrollen över livssituationen och upprätthålla det sociala ansvarstagandet. När symtomen utvecklades till en ihållande och överväldigande bröstsmärta insåg kvinnorna allvarlighets­graden i symtombilden, att de inte kunde kämpa mot symtomen längre och beslutade att söka vård. Delstudie IV inkluderade patienter med en första hjärtinfarkt mellan åren 1985 och 2006 validerade i hjärtinfarktregistret vid The Northern Sweden MONICA Study i Norr- och Västerbotten som följdes upp i dödsorsaksregistret tom 30 augusti, 2008. Totalt 6762 män och 1868 kvinnor i åldern 25-64 studerades. Även patienter som avled före sjukhusvård inkluderades. Resultatet visade att mellan 1985 och 2006 förbättrades långtidsöverlevnaden efter en första hjärtinfarkt hos både män och kvinnor. Över hela 23-års perioden hade kvinnor 9 procents högre åldersjusterad överlevnad jämfört med män. Denna skillnad berodde på lägre risk för kvinnor att avlida innan de nådde sjukhuset. Under den sista tidsperioden var långtidsöverlevnad lika hos både män och kvinnor. Sammanfattningsvis visar denna studie inga stora skillnader mellan män och kvinnors symtom, prehospitala fördröjning eller långtidsöverlevnad. Dock hade äldre patienter färre typiska symtom och längre prehospital fördröjning, särskilt hos kvinnor. Den prehospitala fasen var en mångfasetterad och svårtolkad upplevelse hos både män och kvinnor, med en dynamisk utveckling av symtom, föreställningar och förväntningar, samtidigt som deltagarna strävade efter att upprätthålla det vardagliga och välbekanta livet.  Symtomen vid hjärtinfarkten  var en mer heterogen och komplex upplevelse hos både män och kvinnor än vad som vanligtvis beskrivs i litteraturen. Över en 23-års period har långtidsöverlevnaden efter en första hjärtinfarkt förbättrats hos både män och kvinnor. Kvinnor under 65 år har en något högre långtidsöverlevnad jämfört med män.

Measurement of chemical composition of precipitation is important both to understand acidification of terrestrial and aquatic ecosystems and neutralization process in the atmosphere. Such data are scarce in the Mediterranean region. In this study, chemical composition of daily, wet-only, 387 number of rain water samples collected between 1991 and 1999 were investigated to determine levels, temporal variation and long-term trends in concentrations of major ions and trace elements between 1991 and 1999. Samples had already been collected and some of the analysis had been completed. The anions SO42-, NO3- and Cl- were analyzed by HPLC coupled with UV-VIS detector, NH4+ was analyzed by colorimetry and H+ ion was analyzed by pH meter. The major ions and trace metals were analyzed by using Atomic Absorption Spectrometry (AAS) and Graphite Furnace Atomic Absorption Spectrometry (GFAAS). In this study complete data set were generated by analyzing samples that had not been previously analyzed for major ions and trace elements with Inductively Coupled Plasma with Optical Emission Spectrometry (ICP-OES). Statistical tools were used to determine the distribution of the pollutants. The rain water data tends to be log-normally distributed since data show large variations due to meteorological conditions, physical and chemical transformations and air mass transport patterns. The median pH of the rain water was found to be 5.29, which indicates that the rain water is not strongly acidic. This case is not a result of lacking of acidic compounds but rather indicates extended neutralization process in rain water. Eastern Mediterranean atmosphere is under the influence of three general source types: (1) anthropogenic sources, which are located to the north and northwest of the basin brings low pH values to the region (SO42-, NO3- ions) / (2) a strong crustal source, which is dried and suspended local soil and air masses transported from North Africa transport which have high pH values (Ca2+, Al, Fe ions) and (3) a marine source, which is the Mediterranean Sea itself (Na+, Cl- ions). In the region, the main acid forming compounds are H2SO4 and HNO3 whereas / CaCO3 and NH3 are responsible for the neutralization process. To describe the level of pollutant concentrations and the factors that affect their variations in rain water / ion compositions, neutralization of acidity, short and long-term variability of ions and elements, their time trend analysis and wet deposition fluxes were investigated briefly. Positive matrix factorization (PMF) was used to determine components of ionic mass in the precipitation. In Antalya Station the rain water has five factors: free acidity factor, crustal factor, marine factor, NO3- factor and SO42- factor. Potential Source Contribution Function (PSCF) and trajectory statistics were used to determine source regions generating these components. NO3- has potential source regions of Western Mediterranean countries and North Africa, whereas SO42- has additional southeasterly trajectory components of Israel and south east of Turkey.

As they are not only the home of many threatened species, but also one of the main actors in the global carbon cycle, peatlands are highly valuable ecosystems. Human disturbance, in particular drainage for forestry and agriculture, has substantially changed the state of the world’s peatlands and will continue to do so. Lowering the water table by drainage has many hydrological and biological effects, including an increased growth of trees and shrubs as well as reduced growth of the key peat moss genus Sphagnum, leading to peat degradation and release of carbon dioxide. The effects of drainage are sometimes used as predictions for how peatlands will respond to climate change, and undrained mires are thus expected to become more like drained ones in the future. The accuracy of that assumption has, to my knowledge, not been tested on a large scale. Here, I use data from two Swedish national monitoring programs to analyze how the vegetation on drained and undrained mires has changed in recent decades. The results showed an increased tree growth but a decreased establishment of new trees on both drained and undrained mires, implying that contrary to common belief there is no current large-scale afforestation of open mires in Sweden. Sphagnum had, surprisingly, increased on both drained and undrained mires, while other functional groups showed varying results. The tree growth rate was faster on drained mires, but in most other analyses the response to time did not differ depending on drainage regime. Thereby, this study found limited support for the hypothesis that undrained mires are becoming more like drained mires with climate change.

Large and ever-increasing numbers of chemicals, including large quantities of a broad spectrum of organic compounds are used in modern society. More than 30 000 of the more than 100 000 chemical substances registered in the EU are estimated to be daily used, of which many will be discharged into the waste-streams handled by municipal sewage treatment plants (STPs). The main objective of the work underlying this thesis was to improve understanding of the relationships between the characteristics of sewage contaminants and their sewage treatment efficiency. Further objectives were to examine the relationships between socio-economic uses of chemicals and sludge quality, and the effects of regulatory actions on sludge quality. The quality of the sewage sludge and the levels and distribution patterns of the sludge contaminants, both within and between the STPs, seem to remain quite constant over time. The overall findings indicate that the levels of contaminants in sewage sludge seem to be largely independent of the location, size and treatment techniques applied at the STPs, and generally, of the types of human activity connected to them. The total and relative concentrations of the sludge contaminants were found to be fairly constant on a dry weight basis, with some exceptions, indicating that the pollutants originate from broad usage and diffuse dispersion rather than (industrial) point sources. The proportion of cyclic methylsiloxanes recovered in sludge seems to strongly depend on their vapour pressure, which decreases with the number of siloxane units. The higher water solubility and biodegradability of organophosphorus flame retardants and plasticizers than polybrominated diphenyl ethers (PBDEs) were also reflected in lower percentages (relative to their national use) found in sludge. Significant time-trends in levels of a-third of the sludge contaminants included in the annual national measurement program were detected over a period of seven years. The levels of compounds displaying significant time-trends generally decreased following declines in the quantities used nationally. However, a quarter of these compounds showed increasing trends, of which the linear methylsiloxanes followed the same trend as used quantities. The decaBDE was also found to be increasing in sludge, probably as a result of the phase-out of pentaBDE and octaBDE. The results indicate that the STP removal efficiency of anthropogenic substances, in Sweden, is generally good and that STPs, at least those in cold climates, do not efficiently remove certain polar contaminants. A non-targeted screening (by use of environmetrics and GCxGC-TOFMS) was performed and found to fulfil the objective to assess the STP removal efficiency, with emphasis to systematically analyse which compound classes that are not efficiently removed using the current STP technology. Many polar aromatic compounds were identified to be poorly removed. The acquired data on levels, profiles and variations in sludge contaminants (sludge quality) extend both the available information and understanding of the degree and nature of sludge contamination, which should help attempts to track changes in its contaminants and revisions, if necessary, of guideline values. This thesis also contributes to improve the knowledge base for the development of future STP technologies, and that archived sewage sludge can be used in retrospective analysis of new and emerging pollutants.

Made available in DSpace on 2011-05-04T12:36:30Z (GMT). No. of bitstreams: 0 Previous issue date: 2009 / O município de Monte Alegre, PA apresenta níveis aumentados de radiação natural devido à presença de ocorrências uraníferas na região. Os objetivos dessa dissertação foram: realizar uma análise da evolução da mortalidade na população residente de Monte Alegre e compará-la com aquela observada nos municípios controles (Alenquer e Prainha); e determinar a ocorrência de neoplasia maligna no município de Monte Alegre a partir da avaliação do excesso de risco de mortalidade e das estimativas da incidência. A dissertação foi dividida em dois artigos, cada um atendendo a um dos objetivos. No primeiro foi avaliada a tendência temporal da mortalidade por todas as causas, causas mal definidas e neoplasias entre 1981 e 2005. Os dados utilizados foram os disponíveis no Sistema de Informação sobre Mortalidade (SIM). No segundo foram estimadas as Razões Padronizadas de Mortalidade (SMR), as razões de risco através da razão das SMRs de Monte Alegre e municípios controles e razões de chances de mortalidade por câncer (CMOR) para o município de Monte Alegre e controles no período de 1981 a 2005, utilizando a população do estado do Pará como referência. Para estimar a incidência de câncer foram realizadas três diferentes abordagens: a partir dos dados obtidos nos centros de diagnósticos para câncer que atendem a população da área de estudo; através dos dados de Autorização de Internação Hospitalar; e dados primários obtidos no inquérito populacional realizado na região em 2007/2008. Ao longo do período, observou-se um decréscimo da taxa padronizada de mortalidade geral em Monte Alegre por todas as causas assim como por causas mal definidas para ambos os sexos. Embora a tendência da mortalidade por neoplasias em Monte Alegre se apresente estável, a qualidade da base de dados de mortalidade não permite análises conclusivas da real situação deste grupo de causa de morte nos municípios analisados. Os valores de SMR para mortalidade por todas as causas, encontrados para Monte Alegre, foram similares aos dos municípios controles, apresentando redução estatisticamente significativa: SMRMA= 72,9, IC 95 por cento 70,5-75,3 e SMRMC=75,2, IC 95 por cento 76,2-77,3, respectivamente. Não se observou excesso de mortes por câncer em Monte Alegre e nos municípios controles, e a análise da mortalidade segundo sexo não revelou um excesso de risco estatisticamente significativo nas diferentes localizações tumorais. As diferentes abordagens para estimar a incidência de câncer em Monte Alegre apesar da precária qualidade dos dados não mostraram padrão distinto dos municípios controles. A inexistência de um registro de câncer de base populacional, no município de Monte Alegre, constitui-se em uma limitação importante para se conhecer a real incidência de câncer. No momento, pode-se afirmar que não há evidência científica que assegure um aumento das ocorrências de óbitos por neoplasias no município, sendo precipitado e especulativo concluir que a utilização das rochas de urânio estaria ocasionando um aumento na mortalidade por câncer na população de Monte Alegre. / The municipality of Monte Alegre, located in the Amazonian State of Pará, Brazil, presents scattered areas with increased levels of natural radiation due to uranium rocks. The objectives of this dissertation were: to evaluate the mortality trend among Monte Alegre residents, and to compare it with that observed in neighbor municipalities (Alenquer and Prainha) without natural radiation sources; and to determine the impact of cancer distribution either in Monte Alegre or control counties population, taking into account their estimates of cancer incidence and mortality. The dissertation was organized in two papers. The first one aimed to evaluate the mortality trend for all causes of death, cancer, and unknown causes of death occurred between 1981-2005. Analyzed data was provided by the Brazilian National Mortality Information System (SIM), being the general population of the State of Para used as reference. In the second paper, cancer mortality risks at selected sites were ascertained using standardized mortality ratios (SMR) and mortality odds ratios (MOR). Additionally, cancer mortality risk ratios of Monte Alegre and control counties were obtained towards the ratio between SMRs of selected cancer sites in both areas. Three different sources of data were used to retrieve all cancer cases in the studied area, and therefore, to estimate cancer incidence in the studied populations: the diagnosed cancer cases at the regional reference centers for oncological care settled in Santarem, Belém and Manaus; the cancer-related hospitalization authorization records obtained at the Brazilian National Health System (SUS) registries; and primary data of cancer reported by local residents at a population-based health survey conducted by our research team in 2007-2008. A declining trend for all causes of death mortality in Monte Alegre general population, as well as for the unknown causes of death, was observed along the studied time series for both gender. Cancer mortality trend in Monte Alegre and at the control counties remained stable, but the high proportion of unascertained causes of death at the mortality database does not allow a conclusive ascertainment. SMR for all causes of death in Monte Alegre was similar to that observed at the control counties, respectively, SMR=72.9, 95% CI 70,5-75,3 and SMR=75.2 , 95% CI 76,2-77,3. No excess of cancer deaths was observed in Monte Alegre or at the control populations, and cancer mortality by gender also did not reveal statistically significant differences at the different tumor sites. Despite the use of three different approaches to estimate cancer incidence in Monte Alegre and the control counties, similar patterns were observed in the studied areas. To conclude, no evidence supporting an increase of cancer deaths in Monte Alegre was observed.

Increasing time trends in the recorded incidence of childhood cancer have been reported in many different settings. The extent to which these trends reflect real changes in incidence, rather than improvements in methods for diagnosis and registration, is controversial. Using data from the National Registry of Childhood Tumours (NRCT), this thesis investigates time trends in cancer diagnosed under age 15 in residents of Britain during 1966-2005 (54650 cases), and considers potential sources of artefact in detail. Several different methods are used to estimate completeness of NRCT registration. The history of methods for diagnosis and registration of childhood cancers in Britain is described, and predictions are made for effects on recorded incidence. For each of the 12 main diagnostic groups, Poisson regression is used to fit continuous time trends and ‘step’ models to the annual age-sex-standardised rates by year of birth and year of diagnosis. Age-specific rates by period, and quinquennial standardised rates for diagnostic subgroups, are shown graphically. For three broad groups (leukaemia, CNS tumours and other cancer), geographical variation is compared by period of diagnosis. The results of these analyses are discussed in relation to the predicted artefacts. The evidence for a positive association between affluence and recorded incidence of childhood leukaemia is briefly reviewed. A special form of diagnostic artefact, the ‘fatal infection’ hypothesis, is proposed as an explanation of both this association and the leukaemia time trend. This hypothesis is examined in a novel test based on clinical data. The recorded incidence of childhood cancer in Britain increased in each of 12 diagnostic groups during 1966-2005 (from 0.5% per year for bone cancer to 2.5% for hepatic cancer, with 0.7% for leukaemia). Evidence presented here suggests that these increases are probably artefacts of diagnosis and registration. The potential implications for epidemiological studies of childhood cancer should be considered.