| 1. |
- Raza, Wasif, 1971-
(författare)
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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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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)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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| 2. |
- Andersson, Martin, 1979-
(författare)
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Asthma in school age : prevalence, incidence and remission in relation to environmental determinants
- 2013
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Background In the past half-century, the prevalence of asthma among children and adolescents has risen and asthma has become an important public health challenge in Sweden as well as in many other countries, necessitating further studies on this complex disease and its risk factor pattern. The studies included in this thesis aimed to investigate the clinical expression of childhood asthma over time, to describe the determinants of new-onset and remission of asthma, and to evaluate possible environmental risk factors in northern Sweden.Methods As the result of a repeated questionnaire survey among primary school children aged 7-8 years in three municipalities in the north of Sweden, two pediatric cohorts were formed, one in 1996 (n=3430) and one in 2006 (n=2585). The cohort created in 1996 was followed annually until the age of 19 years. Skin prick testing was performed on children in both cohorts. Lung function and bronchial hyperreactivity testing were carried out in children with asthma in the first cohort. The study participation and retention rates were very high in both cohorts. Among children in the second cohort living in Luleå, the home addresses were assigned to coordinates in a geographical information system (GIS) to evaluate the impact on respiratory health of living near roads with much traffic, which was measured as the number of vehicles daily. We used a validated reported diagnosis of asthma and International Study of Asthma and Allergies in Childhood (ISAAC) questions were incorporated into the questionnaire. A cross-sectional study of children of the same age ten years apart, longitudinal studies on asthma incidence and remission as well as a cross-sectional study on vehicle traffic were performed.Results While children aged 7-8 years in 2006 more often had a physician-diagnosed asthma compared to children of the same age in 1996 (7.4% vs 5.7%, p<0.001), they had less asthma symptoms, especially severe symptoms. In parallel, a more beneficial environment and a more intense treatment with inhaled corticosteroids (ICS) were observed. The explanation for this change in clinical expression probably includes also an increased awareness and diagnosing of asthma. From age 12 years to age 19 years, the cumulative incidence of physician-diagnosed asthma was 7.2% and of current wheeze 22.0%. The risk of new-onset asthma in adolescence was increased among girls, sensitized and those with heredity for asthma. Smoking and home dampness increased the risk for incident wheeze. The risk for both incident asthma and wheeze was inversely related to number of siblings. Among children with current asthma at age 7-8 years, 21% were in remission, 38% had periodic asthma and 41% had persistent asthma at a follow-up at age 19 years. Subjects in remission and with periodic asthma had significantly less airway obstruction and showed less bronchial hyperreactivity compared to subjects with persistent asthma. The probability of asthma remission from childhood to early adulthood was significantly increased by absence of allergic sensitization, male gender and a low asthma severity scoring at age 7-8 years. Sensitization to furred animals was more important as a determinant of both incidence and remission than sensitization to pollen. Living close to roads with high traffic flows, especially with heavy vehicles, was associated with an increased risk for current wheeze. Stratified analyses showed that the effect of traffic on asthma and wheeze was restricted to non-sensitized subjects.Conclusion Asthma onset in adolescence was more common among girls and remission was more common among boys. Children sensitized to furred animals and children with a more severe asthma were risk groups for persistence of asthma. Environmental factors such as smoking and dampness were associated to onset of asthma symptoms during adolescence, and vehicle traffic was associated with asthma symptoms among children also in a small city with relatively low traffic flows. Preventive measures like smoking reduction programs, improvement of damp housing conditions and separation of areas where many children live from heavily trafficked roads could prove to be beneficial.
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| 3. |
- Olstrup, Henrik, 1978-
(författare)
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Air pollution and health – Indicators, trends and impacts
- 2019
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis focuses on some of the limitations and difficulties that exist when it comes to quantifying the human health effects that arise as a result of air pollution exposure. The following four issues are particularly analysed and discussed: 1) The measurement techniques used for carbonaceous particles and their lack of consistency; 2) Do the health risks associated with exposure to PM10 depend on the content of elemental carbon in the aerosol?; 3) Trends in air pollutants and the health effects that arise as a result of changed exposure to the measured pollutants; 4) The associations between the measured concentrations of different air pollutants in Stockholm and the daily number deaths; 5) Air quality indicators and health outcomes as basis for an air quality health index (AQHI).The method that has been used is largely based on empirical data analysis, where further statistical processing has been used in order to clarify the scientific issues. The overall conclusions are the following: 1) The health impact assessments associated with exposure to carbonaceous particles would benefit from the introduction of a more uniform measurement technique in order to get more consistent and reliable results; 2) The health risks associated with exposure to PM10 are dependent on the content of elemental carbon; 3) The life expectancy increase associated with decreasing NOx trends during 1990–2015 in Stockholm, Gothenburg and Malmo make up as much as about 20 % of the total gain in life expectancy during this period, which clearly shows the beneficial effects related to decreased exposure; 4) The associations between daily mortality and the concentrations of O3 and PM2.5-10 in Stockholm are statistically significant, which does not apply to the exhaust-related pollutants, possibly reflecting behavioural factors affecting the degree of exposure; 5) In comparison with the currently used air quality index (AQI), the air quality health index (AQHI) is a more useful tool in order to address the short-term health effects associated with multi-pollutant exposure to NOx, O3, PM10 and birch pollen.We hope that these findings will be useful from a policy point of view. Introducing a more consistent measurement technique for soot particles would be beneficial in assessing the health effects related to exposure to these particles. The increase in life expectancy associated with decreasing NOx trends shows the benefits from a public health perspective when it comes to introducing emission-reducing measures from traffic. The AQHI would be beneficial to implement in legislation, as it is based on several pollutants, which means that the cumulative health effects associated exposure to several different air pollutants are accounted for.
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| 4. |
- Trygg, Kristina, 1979-
(författare)
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Arbetets geografi : Kunskapsarbetets organisation och utförande i tidrummet
- 2014
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This is a thesis about knowledge-intensive work and the organizational con-texts of such work. The specific objective is to analyze the geography of work. The geography of work may diverge from the geography of employ-ment when paid work is undertaken at the premises of client organizations, during commuting, on business trips, in external meetings, at home or in other places. The focus is on work practice and the perspective of everyday life. The study examines where knowledge workers are located and where knowledge work occurs. It is about what knowledge workers actually do. The everyday perspective is about the relationship between paid work and unpaid work. To understand the organization of knowledge-intensive work in a time–space context, different possibilities and constraints must be taken into con-sideration. This thesis has a time–geographical approach. The case study examines knowledge-intensive organizations located in central Stockholm. The organizations are in PR/communications, management consultancy, and research and development sectors. Both private and public sector organiza-tions are considered. The empirical study combines interviews, time diaries and questionnaires. The NVivo software program is employed to analyze the interview data. The main conclusion from the thesis is that in order to under-stand knowledge-intensive work, different factors such as relations, attitudes and norms need to be considered. These factors affect the organization of work, which in turn is affected by the choices, possibilities, constraints, ex-pectations and negotiations of different actors (i.e. employees, employers, family, clients and colleagues). The working time of the knowledge workers investigated in this study is mainly spent at the office of their employers. Social interaction with col-leagues and clients is an important part of their work. Work routines involve many meetings, both face-to-face and virtual. Face-to-face interactions play a crucial role in shaping the geography of work; teamwork is important. The knowledge workers in this study are “working long hours,” and the norm is to work more than what have been expected.
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| 5. |
- Åström, Christofer, 1983-
(författare)
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Health effects of heatwaves : short and long term predictions
- 2017
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)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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| 6. |
- Olsson, David, 1982-
(författare)
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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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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)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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| 7. |
- Silverforsen, D., et al.
(författare)
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Snoring and environmental exposure: results from the Swedish GA2LEN study
- 2021
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Ingår i: BMJ Open. - : BMJ. - 2044-6055. ; 11:6
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Tidskriftsartikel (refereegranskat)abstract
- ObjectiveHabitual snoring is associated with fatigue, headaches and low work performance. This cross-sectional study aimed to investigate if snoring is affected by environmental factors such as home dampness and exposure to air pollution.SettingGeneral population sample from four Swedish cities.Participants25 848 participants from the Swedish part of the epidemiological Global Asthma and Allergy and European network of excellence study carried out in 2008. The participants completed a postal questionnaire on snoring and, indoor and outdoor environmental exposure as well as potential confounders including smoking, weight, height and educational level.ResultsOf the participants, 4211 (16.3%) were habitual snorers. Habitual snorers reported water damage (8.3% vs 7.0% p<0.0001), floor dampness (4.6% vs 3.8% % p<0.0001) and visible mould (5.2% vs 3.8% p<0.0001) in their homes more often than non-snorers. Habitual snorers stated being annoyed by air pollution more often than non-snorers with habitual snorers reporting being irritated with the air in their residential area to a higher extent (sometimes 16.2% vs 13.9%, and daily 4.6% vs 3.1%) as well as annoyance from traffic fumes (somewhat 19% vs 18.5% and very 5% vs 3.6%) (p<0.0001). These results remained significant after adjustment for age, body mass index, smoking history and educational level.ConclusionSnoring is more prevalent in subjects reporting home dampness and air pollution. These association should be confirmed in further research using objective measurements and a longitudinal approach.
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| 8. |
- Sundström, Johan, Professor, 1971-, et al.
(författare)
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Risk factors for subarachnoid haemorrhage : a nationwide cohort of 950 000 adults
- 2019
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Ingår i: International Journal of Epidemiology. - : Oxford University Press. - 0300-5771 .- 1464-3685. ; 48:6, s. 2018-2025
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Subarachnoid haemorrhage (SAH) is a devastating disease, with high mortality rate and substantial disability among survivors. Its causes are poorly understood. We aimed to investigate risk factors for SAH using a novel nationwide cohort consortium.METHODS: We obtained individual participant data of 949 683 persons (330 334 women) between 25 and 90 years old, with no history of SAH at baseline, from 21 population-based cohorts. Outcomes were obtained from the Swedish Patient and Causes of Death Registries.RESULTS: During 13 704 959 person-years of follow-up, 2659 cases of first-ever fatal or non-fatal SAH occurred, with an age-standardized incidence rate of 9.0 [95% confidence interval (CI) (7.4-10.6)/100 000 person-years] in men and 13.8 [(11.4-16.2)/100 000 person-years] in women. The incidence rate increased exponentially with higher age. In multivariable-adjusted Poisson models, marked sex interactions for current smoking and body mass index (BMI) were observed. Current smoking conferred a rate ratio (RR) of 2.24 (95% CI 1.95-2.57) in women and 1.62 (1.47-1.79) in men. One standard deviation higher BMI was associated with an RR of 0.86 (0.81-0.92) in women and 1.02 (0.96-1.08) in men. Higher blood pressure and lower education level were also associated with higher risk of SAH.CONCLUSIONS: The risk of SAH is 45% higher in women than in men, with substantial sex differences in risk factor strengths. In particular, a markedly stronger adverse effect of smoking in women may motivate targeted public health initiatives.
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| 9. |
- Tornevi, Andreas, 1975-
(författare)
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Precipitation, Raw Water Quality, Drinking Water Treatment and Gastrointestinal Illness
- 2015
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)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. |
- Accordini, S., et al.
(författare)
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Prenatal and prepubertal exposures to tobacco smoke in men may cause lower lung function in future offspring: a three-generation study using a causal modelling approach
- 2021
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Ingår i: European Respiratory Journal. - : European Respiratory Society (ERS). - 0903-1936 .- 1399-3003. ; 58:4
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Tidskriftsartikel (refereegranskat)abstract
- Mechanistic research suggests that lifestyle and environmental factors impact respiratory health across generations by epigenetic changes transmitted through male germ cells. Evidence from studies on humans is very limited. We investigated multigeneration causal associations to estimate the causal effects of tobacco smoking on lung function within the paternal line. We analysed data from 383 adult offspring (age 18-47 years; 52.0% female) and their 274 fathers, who had participated in the European Community Respiratory Health Survey (ECRHS)/Respiratory Health in Northern Europe, Spain and Australia (RHINESSA) generation study and had provided valid measures of pre-bronchodilator lung function. Two counterfactual-based, multilevel mediation models were developed with: paternal grandmothers' smoking in pregnancy and fathers' smoking initiation in prepuberty as exposures; fathers' forced expiratory volume in 1 s (FEV1) and forced vital capacity (FVC), or FEV1/FVC z-scores as potential mediators (proxies of unobserved biological mechanisms that are true mediators); and offspring's FEV1 and FVC, or FEV1/FVC z-scores as outcomes. All effects were summarised as differences (Delta) in expected z-scores related to fathers' and grandmothers' smoking history. Fathers' smoking initiation in prepuberty had a negative direct effect on both offspring's FEV1 (Delta z-score -0.36, 95% CI -0.63--0.10) and FVC (-0.50, 95% CI -0.80--0.20) compared with fathers' never smoking. Paternal grandmothers' smoking in pregnancy had a negative direct effect on fathers' FEV1/FVC -0.57, 95% CI -1.09--0.05) and a negative indirect effect on offspring's FEV1/FVC (-0.12, 95% CI -0.21--0.03) compared with grandmothers' not smoking before fathers' birth nor during fathers' childhood. Fathers' smoking in prepuberty and paternal grandmothers' smoking in pregnancy may cause lower lung function in offspring. Our results support the concept that lifestyle-related exposures during these susceptibility periods influence the health of future generations.
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