| 1. |
- Carlsen, Hanne Krage, 1981-
(author)
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Health effects of air pollution in Iceland : respiratory health in volcanic environments
- 2014
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Doctoral thesis (other academic/artistic)abstract
- Air pollution has adverse effects on human health. The respiratory system is the most exposed and short-term changes in air pollution levels have been associated with worsening of asthma symptoms and increased rates of heart attacks and stroke. Air pollution in cities due to traffic is the major concern, as many people are exposed. However, natural sources of air pollution such as natural dust storms and ash from volcanic eruptions can also compromise human health. Exposure to volcanic eruptions and other natural hazards can also threaten mental health. Air pollution has not been extensively studied in Iceland, in spite of the presence of several natural pollution sources and a sizeable car fleet in the capital area.The aim of this thesis was to determine if there was a measurable effect on health which could be attributed to air pollution in Iceland. This aim was pursued along two paths; time series studies using register data aimed to determine the short-term association between daily variation in air pollution and on one hand daily dispensing of anti-asthma medication or the daily number of emergency room visits and emergency admissions for cardiopulmonary causes and stroke. The other method was to investigate if exposure to the Eyjafjallajökull volcanic eruption was associated with adverse health outcomes, either at the end of the eruption, or 6 months later.In paper I time series regression was used to investigate the association between the daily number of individuals who were dispensed anti-asthma medication and levels of the air pollutants particle matter with an aerodynamic diameter less than 10 μm (PM10), nitrogen dioxide (NO2), ozone (O3), and hydrogen sulfide (H2S) during the preceding days. For the study period 2006-9, there were significant associations between the daily mean of PM10 and H2S and the sales of anti-asthma medication 3 to 5 days later. Giving the exposure as the highest daily one-hour mean gave more significant results. Air pollution negatively affected the respiratory health of asthma medication users, prompting them to refill their prescriptions before they had originally intended to.In paper II the main outcome was the number of individuals seeking help at Landspitali University Hospital emergency room for cardiopulmonary disease or stroke. Time series regression was used to identify the lag that gave the best predictive power, and models were run for data for 2003-9 pollutants PM10, NO2, and O3. O3 was significantly associated with the number of emergency hospital visits the same day and two days later in all models, and both for men, women and the elderly. Only emergency hospital visits of the elderly were associated with NO2, and there were no associations with PM10.In paper III the aim was to investigate if the health effects of PM10 were affected by the addition of volcanic ash from the 2010 eruption of Eyjafjallajökull and 2011 eruption of Grímsvötn to PM10 in the capital area. Time series regression of emergency hospital visits and PM10 before and after the Eyjafjallajökull eruption showed that the effect tended to be higher after the eruption, but the results were not significant. Analysis with a binary indicator for high levels of PM10 from volcanic ash and other sources showed that volcanic ash was associated with increased emergency hospital visits. There were no associations with high levels of PM10 from other sources.In paper IV, the health of the population exposed to the ongoing eruption of Eyjafjallajökull in 2010 was investigated thoroughly. Lung function in adults was better than in a reference group from the capital area, though many reported sensory organ irritation symptoms and symptoms of stress and mental unhealth, especially those with underlying diseases.Paper V report the results from a questionnaire study which was carried out six months after the Eyjafjallajökull eruption. The study population comprised a cohort of south Icelanders exposed to the eruption to varying degrees and a reference group from north Iceland. Respiratory and eye symptoms were much more common in south Icelanders than in the reference group, after adjusting for demographic characteristics. Mental unhealth rates had declined considerably.In the studies, we found that urban air pollution and natural particles have short-term effects on anti-asthma medication dispensing and emergency room visits and hospital admissions. Exposure to natural particles in the form of volcanic dust was associated with increased respiratory symptoms in a very exposed population. There were indications that volcanic ash particles were associated with increased emergency hospital visits in the following days.
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| 2. |
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| 3. |
- Hedman, Linnea, 1979-
(author)
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Epidemiological studies of asthma and allergic diseases in teenagers : methodological aspects and tobacco use
- 2010
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Doctoral thesis (other academic/artistic)abstract
- Parental reports are often used in studies of asthma and allergic diseases in children. A change in respondent from parent to index subject usually occurs during adolescence. Little is known about the effects this change in method might have on the outcomes of a longitudinal study. Smoking is a major cause of respiratory symptoms among adults and environmental tobacco smoke (ETS) is a risk factor for asthma among children. Less is known about these associations among teenagers. In order to improve prevention of smoking, it is important to identify populations at risk of becoming smokers. The aim of this thesis were to 1) evaluate the methodological change from parental to self-completion of a questionnaire about asthma and allergic diseases, and 2) to study determinants for, and respiratory health effects of ETS and personal smoking in teenagers.In 1996, a longitudinal study of asthma and allergic diseases among schoolchildren started within the Obstructive Lung Disease in Northern Sweden (OLIN) studies. All children in first and second grades (aged 7-8 years) in three municipalities, Luleå, Kiruna and Piteå (n=3,525) were invited and 97% participated by parental completion of a questionnaire. The cohort has been followed with annual questionnaires until age 16-17 years and with high participation rates (>91%). From age 12-13 years, the teenagers were the respondents and questions about their tobacco use were included. In addition to the questionnaire completed by the teenagers at age 13-14 years, a questionnaire was also distributed to a random sample of 10% of the parents and 294 participated (84%). The parents and the teenagers reported a similar prevalence of asthma, respiratory symptoms, rhinitis, eczema and environmental factors. Two statistically significant differences were found: the teenagers reported a higher prevalence of wheezing during or after exercise (14% vs 8%, p<0.05), and having a dog in the home in the last 12 months (42% vs 29%, p<0.001). Answer agreement between parents and teenagers on questions about asthma was almost perfect with kappa values of 0.8-0.9. Corresponding kappa values for questions about respiratory symptoms and rhinitis were 0.3-0.6 and for eczema 0.5-0.6. Agreement about environmental factors varied from 0.2-0.9. Kappa values for parental smoking were 0.8-0.9. The risk factor pattern for allergic diseases was similar regardless of respondent, ie parent or teenager.The prevalence of smoking increased from 3% at 12-13 years to 6% at 14-15 years. Smoking was more common among girls, while the use of snus was more common among boys. Significant risk factors related to smoking among teenagers were smoking family members, female sex and living in an apartment. Having physician-diagnosed asthma did not prevent the teenagers from becoming smokers. Factors related to using snus were a smoking mother and male sex. Daily smokers aged 16-17 years (9%) reported a significantly higher prevalence of wheezing and physician-diagnosed asthma compared to non-smokers. There was a significant dose-response association with higher prevalence of wheeze among those who smoked ≥11 cigarettes per day compared to those who smoked ≤10 per day. In multivariate analyses, maternal environmental tobacco smoke exposure was a significant risk factor for ever wheeze and physician-diagnosed asthma at age 16-17 years, while daily smoking was a risk factor for current wheeze.In conclusion, the methodological change of questionnaire respondent from parent to index subject did not substantially alter the findings of this longitudinal study. There were significant sex differences in the tobacco use: smoking was more common among girls and snus was more common among boys. The most important factor related to tobacco use was presence of family members who smoke. Both maternal ETS exposure and personal smoking was associated with asthma and wheeze in adolescence. ETS was associated with lifetime symptoms but daily smoking was more strongly associated with current symptoms.
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| 4. |
- Modig, Lars, 1976-
(author)
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Asthma, rhinitis, and asthma-related symptoms in relation to vehicle exhaust using different exposure metrics
- 2009
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Doctoral thesis (other academic/artistic)abstract
- Air pollution is a well known public health problem that involves both long-term and acute effects. An outcome associated with traffic-related air pollution is respiratory illness. Many studies have described the relationship between asthmatic symptoms and traffic-related air pollution; however, few have investigated the potential of air pollution to cause asthma itself, especially among adults. The overall aim of this thesis was to study the relationship between vehicle exhaust levels at home and the prevalence of self-reported annoyance and asthmatic symptoms, and the incidence of asthma and rhinitis. These relationships were evaluated using different indicators of exposure with a high spatial resolution. Three different data sets were used for the four papers included in this thesis. The first paper (paper I) is based on a questionnaire that was sent to a random selection of the adult population within three Swedish cities (Gothenburg, Uppsala, and Umeå) as part of the Swedish Environmental Protection Agency’s health-related environmental monitoring. The aim was to study the degree of self-reported annoyance and the prevalence of asthmatic symptoms in relation to the levels of vehicle exhaust outside the home. The level of exposure was described using modeled levels of nitrogen dioxide (NO2) as the exposure indicator. The second paper (paper II) is based on new asthma cases identified within the Obstructive Lung disease In Northern Sweden (OLIN) study, each with a matched referent. The aim of this study was to analyze if new cases of asthma had higher levels of vehicle exhaust outside the home compared to the population controls. Exposure was assessed using both measured levels of NO2 outside each home, and by summarizing the amount of traffic within a 200 metre buffer surrounding each participant’s home. Papers III and IV were based on the Respiratory Health in Northern Europe (RHINE) Cohort, a prospective cohort of adults included in 1990 and followed up with in 1999. The proportion of new cases of asthma (papers III and IV) and rhinitis (paper IV) were identified based on the answers from the initial and follow-up questionnaires. In paper III, exposure was assessed by using meteorological dispersion models to calculate the levels of NO2 outside each home as an indicator of the levels of vehicle exhaust. As an alternative indicator, the distance from each participant’s home to the nearest major road was calculated using geographical information system (GIS) tools. The exposure assessment in paper IV was also based on meteorological dispersion models, but expressed the levels of vehicle exhaust as particle mass concentration. The results show that the levels of vehicle exhaust outside the home are significantly correlated with the degree of self-reported annoyance and the prevalence of asthmatic symptoms, and also with the risk of developing asthma, but not rhinitis, among adults. The odds ratio (OR) for high annoyance to vehicle exhaust and reporting asthmatic symptoms was 1.14 (95% Confidence Interval, CI 1.11-1.18) and 1.04 (95% CI 1.01-1.07) per 1 µg/m3 increase in the NO2 level outside the home, respectively. Paper II showed there was a non-significant tendency for increased risk of developing asthma among those living with high levels of vehicle exhaust outside their home. This finding was then supported by papers III and IV, showing a significant relationship between the onset of asthma and the mean (winter) levels of NO2 outside the home (OR=1.46, 95% CI 1.07-1.99 per 10 µg/m3) and the levels of vehicle exhaust particles outside the home. In paper III, living close to a major road was significantly related to the risk of developing asthma. No significant results were shown between vehicle exhaust and rhinitis. In conclusion, vehicle exhaust outside the home is associated with the prevalence of annoyance and asthmatic symptoms, and with the risk of developing asthma, but not rhinitis, among adults.
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| 5. |
- Olsson, David, 1982-
(author)
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Adverse effects of exposure to air pollutants during fetal development and early life : with focus on pre-eclampsia, preterm delivery, and childhood asthma
- 2014
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Doctoral thesis (other academic/artistic)abstract
- Background Air pollution exposure has been shown to have adverse effects on several health outcomes, and numerous studies have reported associations with cardiovascular morbidity, respiratory disease, and mortality. Over the last decade, an increasing number of studies have investigated possible associations with pregnancy outcomes, including preterm delivery. High levels of vehicle exhaust in residential neighborhoods have been associated with respiratory effects, including childhood asthma, and preterm birth is also associated with childhood asthma.The first aim of this thesis was to investigate possible associations between air pollution exposure and pregnancy outcomes – primarily preterm delivery but also small for gestational age (SGA) and pre-eclampsia – in a large Swedish population (Papers I–III). The second aim was to study any association between exposure to high levels of vehicle exhaust during pregnancy and infancy and prescribed asthma medication in childhood (Paper IV).Methods The study cohorts were constructed by matching other individual data to the Swedish Medical Birth Register. In the first two studies, air pollution data from monitoring stations were used, and in the third and fourth studies traffic intensity and dispersion model data were used.Preterm delivery was defined as giving birth before 37 weeks of gestation. SGA was defined as having a birth weight below the 10th percentile for a given duration of gestation. Pre-eclampsia was defined as having any of the ICD-10 diagnosis codes O11 (pre-existing hypertension with pre-eclampsia), O13 (gestational hypertension without significant proteinuria), O14 (gestational hypertension with significant proteinuria), or O15 (eclampsia). Childhood asthma medication was defined as having been prescribed asthma medication between the ages of five and six years.Results We observed an association between ozone exposure during the first trimester and preterm delivery. First trimester ozone exposure was also associated with pre-eclampsia. The modeled concentration of nitrogen oxides at the home address was associated with pre-eclampsia, but critical time windows were not possible to investigate due to high correlations between time windows. We did not observe any association between air pollution exposure and SGA. High levels of vehicle exhaust at the home address, estimated by nitrogen oxides and traffic intensity, were associated with a lower risk of asthma medication.Conclusion Air pollution exposure during pregnancy was associated with preterm delivery and pre-eclampsia. We did not observe any association between air pollution levels and intrauterine growth measured as SGA. No harmful effect of air pollution exposure during pregnancy or infancy on the risk of being prescribed asthma medication between five and six years of age was observed.
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| 6. |
- Orru, Hans, 1980-
(author)
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Exposure to particulate matter and the related health impacts in major Estonian cities
- 2009
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Doctoral thesis (other academic/artistic)abstract
- Particulate matter (PM) is one of the most studied and problematic pollutants due to its toxicity and relatively high concentrations. This thesis aims to clarify the main sources and exposures of PM in Tallinn and Tartu, study the associations with health effects, and estimate the extent of those effects with health impact assessment (HIA).It appeared that the main sources of particulate air pollution in Tallinn (the capital of Estonia) and Tartu (the second largest city of Estonia) are local heating and traffic, including road dust. In addition to local emissions, particulate levels are affected by transboundary pollution. If the transboundary air masses originated from the Eastern European areas, the concentration as well as the oxidative capacity of fine particles was significantly higher in urban background air in Tartu compared to air masses coming from Scandinavian areas (Paper I).During the last 15 years, traffic increase has been very fast in Tartu. However, due to the improvement in vehicle technology during this period, there has been only a slight increase in concentration of exhaust particles (Paper II). Nevertheless, a greater increase in road dust emissions was detected.A statistically significant relationship between long-term exposure to those traffic induced particles and cardiac disease in the RHINE (Respiratory Health in Northern Europe) Tartu cohort was shown (Paper III). However, no significant associations with respiratory health were found.The HIA in Tallinn demonstrated 296 (95% CI = 76–528) premature deaths annually, because of PM (Paper IV). The average decrease in life expectancy was predicted to be 0.64 (95% CI 0.17–1.10) years. However, among risk groups it can be higher. In addition, several cardiovascular hospitalizations are related. The costs to society because of health effects reach up to €150 million annually (95% CI = 40–260) from premature deaths and hospitalization constitute an additional €0.3 million (95% CI = 0.2–0.4).The special HIA scenario, when more pollution fuel peat will be used in boiler houses was analysed as well (Paper V). It indicated that peat burning would result in up to 55.5 YLL per year within the population of Tartu. However, the health effects of pollution from current traffic, local heating, and industry are at least 28 times bigger.In conclusion, exposure to PM cause considerable health effects in the form of cardiopulmonary diseases in main Estonian cities.
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| 7. |
- Raza, Wasif, 1971-
(author)
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Impacts of Active Transport on Health : with a focus on physical activity, air pollution, and cardiovascular disease
- 2021
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Doctoral thesis (other academic/artistic)abstract
- Background: There are increasing number of health impact assessment studies investigating the health effects by transferring trips made by motorised transport to active commuting; however, air pollution exposure during active commuting and its impact on health has been less thoroughly assessed. It is furthermore uncertain whether there is any interaction effect between air pollution and physical activity for the risk of cardiovascular diseases. The overall aim of the thesis was to improve the knowledge base for assessments of the total impact on health of a mode shift resulting in both increased physical activity and increased air pollution exposure, especially regarding combined effects on cardiovascular risks.Methods: The thesis is based on four studies. In Study I, methodological issues related to the assessment of air pollution in previous studies on the health impact of changes in transport mode were critically reviewed. In Study II, the effect of leisure time and active commuting physical activity, on chronic diseases was quantified by conducting a random-effect meta-analysis. In two prospective cohort studies, participants of the Västerbotten Intervention Programme living in the Umeå region were studied to assess the impact as well as interaction effect of physical activity and air pollution on the incidence (Study III) and recurrence (Study IV) of cardiovascular diseases.Results: In previous studies on the health impact of changes in transport mode, there was a large methodological discrepancy between studies due to different assumptions for air pollution exposure assessments in general populations and commuters as well as methods for estimation of impacts. Randomeffect meta-analyses showed a beneficial effect of leisure time physical activity and active commuting on morbidity among individuals performing these activities at the minimum level of physical activity recommended by WHO, equivalent to 11.25 MET-hours per week. Beneficial effects of exercise on firstincident ischemic heart disease (IHD) were observed among individuals with high residential PM10/PM2.5 concentrations, but not among individuals with low concentrations. Adverse effects associated with high residential PM10 and PM2.5 concentrations were only observed among the individuals whom less frequently exercised. A statistically significant interaction effect was found between air pollution and exercise in training clothes for first-incident IHD but not for recurrence of IHD/stroke.Conclusions: The results in this thesis strengthen the public health message that physical activity is beneficial for cardiovascular health, even in areas with air pollution. Therefore, public health and transport policies should be designed to improve population health through promotion of active transport and mitigation of air pollution.
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| 8. |
- Rocklöv, Joacim, 1979-
(author)
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Short-term effects of ambient temperature on daily deaths and hospital admissions
- 2010
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Doctoral thesis (other academic/artistic)abstract
- Background: Incidence of death and hospitalizations have been observed to depend on short-term changes in weather and to increase with extreme temperatures. This thesis aims to strengthen the scientific knowledge on the relationship between temperature and daily deaths, but also the relationship between temperature and daily hospital admissions. Methods: We constructed time series regression models using daily counts of death and daily weather from the Stockholm area incorporating adjustment for potential confounding factors, season, and long-term time trends. From these models, we established the short-term relationship with daily temperatures and the associated relative risks on daily deaths allowing for a delay between exposure and subsequent deaths. Daily hospital admissions and daily temperatures were analyzed correspondingly using data from Skåne. Results: Hot and cold temperatures significantly impact on mortality rates as well as rates of hospitalization in Sweden. We found an immediate heat effect on daily deaths, while the impacts of cold temperatures were delayed up to a week after exposure. Cold-related deaths are generally cardiovascular in nature, while deaths resulting from warm temperatures are cardiovascular, respiratory as well as non-cardiorespiratory in nature. The impacts following a heat wave appear to increase proportionally with the length of the extreme hot conditions. The results suggest that the population aged 45 years and older is the main group at elevated risk of death when exposed to high and low temperatures. Moreover, the results suggest that there are several factors of susceptibility on an individual basis that correspond to larger relative risk with high and/or low temperatures. Daily hospitalisations increased in particular among individuals with respiratory illnesses during extreme persistent heat, whereas high temperatures in general have little impact. In contrast, hospitalizations increased for up to two weeks following exposure to cold temperatures. Conclusions: The health impacts related to temperature are a serious concern and the attributed impacts are likely to increase to some extent in the future due to an ageing population. Public health preventive strategies should be developed to prevent health consequences related to heat waves and cold temperatures. Future studies should aim at identifying susceptible individuals with elevated death risk at hot and cold ambient temperature conditions.
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| 9. |
- Tornevi, Andreas, 1975-
(author)
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Precipitation, Raw Water Quality, Drinking Water Treatment and Gastrointestinal Illness
- 2015
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Doctoral thesis (other academic/artistic)abstract
- Background On numerous occasions, outbreaks of acute gastrointestinal illnesses (AGI) have been linked to municipal drinking water in the industrialised world. Many of the reported outbreaks were observed after heavy rainfall events, which suggests that such events could result in a deterioration in the quality of drinking water. The observed drinking water-related outbreaks are, however, probably just the tip of the iceberg, and the extent to which public drinking water also influences the endemic level of gastroenteritis during non-outbreak periods is largely unknown. With climate change projected to increase the frequency of extreme weather events, data for preventive actions are needed now, to ensure safe drinking water today and in the future. The primary aim of this thesis is to increase the knowledge of the extent to which rainfall can still be a risk for insufficient drinking water quality, even with modern drinking water production methods. We aim to study if the incidence of gastroenteritis during normal endemic levels can be associated with water quality and the efficacy of pathogen elimination in different treatment processes. The thesis focuses first on AGI in the Gothenburg population and how precipitation affects its main fresh water supply (papers I-III); this is followed by a broader comparison of AGI in 20 cities across Sweden (Paper IV).Methods Observational time series data was used for all papers to construct generalized additive regression models, using smooth functions to adjust for long-term trends. Delayed effects on the outcome were evaluated using distributed lag non-linear models. In Paper I, the raw water-quality data for the river Göta älv were analysed – this water is used to produce drinking water for the population living in the north part of City of Gothenburg. The short-term variation of daily mean turbidity measurements and samples of three different types of indicator bacteria were modelled with daily precipitation using seven years of data. In papers II and III, the analyses aimed to determine whether the daily incidence of AGI in the population which households received drinking water produced from the river water could be associated with precipitation. As a measure of AGI, we used four years of data on the daily number of phone calls to the nurse advice line about vomiting, diarrhoea or abdominal pain (Paper II), and six years of data of the daily number of visits to health care clinics, when individuals were diagnosed with gastrointestinal infections (Paper III). Paper III also evaluates the similarities and differences between the frequency of nurse advice calls and primary health care visits. Paper IV analyses and compares the occurrence and seasonal patterns of nurse advice calls in twenty cities in Sweden, using seven years of data. The water treatment technique used by the public drinking water plants was obtained, and the processes theoretical efficacy of pathogen elimination was determined. The extent of AGI calls in relation to the pathogen elimination efficacy was analysed using a binomial regression design, adjusting for population size, age distribution and geographical area.Results We observed a strong relation between precipitation and the water quality in the Göta älv. A heavy rainfall event was related to increased concentrations of E. coli bacteria for several days, with the peak increase two days after the event. Precipitation was found to affect raw water quality parameters across all seasons. Heavy precipitation was also associated with a significant increase in the daily number of nurse advice calls due to AGI symptoms, with the number of calls peaking five days later. Consecutive wet weather periods were associated with both an increased number of AGI calls, as well as visits to clinics that led to diagnoses of AGI. Finally, we observed in Paper IV that cities with a higher pathogen elimination efficacy in their drinking water utility had a lower amount of AGI calls. The relations applied both to surface water and groundwater utilities, although the protective effect of a more advanced drinking water treatment on AGI was observed to be most significant in cities with surface water plants during the winter season.Conclusions The results suggest it is possible to reduce the occurrence of endemic gastroenteritis with a more advanced treatment process for drinking water. The delay between a heavy rainfall event (and the resulting decrease in raw water quality) and the increased number of nurse advice calls suggests viruses are the main cause, as the timing is consistent with viral incubation times. A viral transmission was also proposed when comparing different cities, as a more advanced water treatment process seems to be most beneficial during seasons where viruses are acknowledged as the main cause of AGI. Our research suggests that upgrades to drinking water treatment techniques, especially those aiming to better eliminate viruses, are warranted
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| 10. |
- Åström, Christofer, 1983-
(author)
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Health effects of heatwaves : short and long term predictions
- 2017
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Doctoral thesis (other academic/artistic)abstract
- Background: Climate change is defined by the Intergovernmental Panel on Climate Change as changes in the state of the climate associated with changes in the mean and/or the variability of its properties. Climate change will affect temperatures both as an increase in mean temperature as well as changes in the frequency of temperature extremes. Health effects associated with extreme heat, both mortality and morbidity, have been observed all over the globe. Groups that are often found to be more vulnerable are the elderly and people diagnosed with certain diseases and/or on taking some specific types of medication. The health effects from climate change in the future depend on a number of underlying sociodemographic and other factors. It is difficult to predict how the underlying societal factors that are likely to alter the health effects from high temperatures will change. The aim of this thesis is to investigate the influence of the underlying assumptions and factors that are key components when predicting and projecting heat-related illness, both in the short and long term. This work aims to identify and to some extent quantify different sources of uncertainty that will have effects on the outcome of health impact assessments.Methods: We wanted to evaluate if different statistical models would alter the ability to identify days with elevated heat-related risk. We used observations of temperatures and daily mortality for Greater Stockholm to model different exposure-response relationships (Paper I). Along the observed data, we collected temperature forecasts for the Stockholm area. We defined what constitutes a risk day and compared the model’s ability to identify these days using both observed and forecasted temperatures to evaluate the predictive performance of models based on the different statistical approaches. To estimate how climate change will alter the heat-related health impacts we used climate change projections from a range of climate change scenarios to be able to get stable estimates as well as a measure of the uncertainty in the climate projections (Paper II-III). We estimated the change in respiratory hospital admissions (Paper II) and the future need for adaptation to keep heat-related mortality at current levels (Paper III) in Europe. We also estimated the change in heat-related mortality due to changes in climate, demographics and health status of the population in Stockholm (Paper IV).Results: The models using a highly complex exposure-response relationship showed lower predictive performance, especially when looking at a longer time-scale. The more complex models did also estimate a lower mortality increase compared to the less complex ones. There was however high agreement of which days to be considered risk days. The estimated increase in heat-related illness from the three health impact assessment studies showed impacts on a similar order of magnitude when looking at changes in climate only. Respiratory hospital admissions were estimated to more than double in Europe and heat-related mortality in Stockholm was estimated to increase to around 257% of current levels. Therefore, adaptation needs to lower the vulnerability to heat by around 50% in the European countries. In study III and IV we take changes in demographics into account and find that the future health burden from heat will increase due to the growing elderly population.Conclusion: To be able to make predictions of future health burdens from heat, both in the long and short term, we need to consider the properties of the epidemiological models and how the choice of model might limit its use within a health impact assessment. Climate change seems to be the main driver of the future health burden from extreme temperatures, but our results suggests that changing demographics will add to the burden considerably unless relevant adaptation measures are implemented. Adding this on top of the challenges posed by climate change, we find that need for adaptation will increase substantially in the future.
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