Mixtures of long-term exposure to ambient air pollution, built environment and temperature and stroke incidence across Europe

INTRODUCTION

The complex interplay of multiple environmental factors and cardiovascular has scarcely been studied. Within the EXPANSE project, we evaluated the association between long-term exposure to multiple environmental indices and stroke incidence across Europe.

METHODS

Participants from three traditional adult cohorts (Germany, Netherlands and Sweden) and four administrative cohorts (Catalonia [region Spain], Rome [city-wide], Greece and Sweden [nationwide]) were followed until incident stroke, death, migration, loss of follow-up or study end. We estimated exposures at residential addresses from different exposure domains: air pollution (nitrogen dioxide (NO2), particulate matter < 2.5 μm (PM2.5), black carbon (BC), ozone), built environment (green/blue spaces, impervious surfaces) and meteorology (seasonal mean and standard deviation of temperatures). Associations between environmental exposures and stroke were estimated in single and multiple-exposure Cox proportional hazard models, and Principal Component (PC) Analyses derived prototypes for specific exposures domains. We carried out random effects meta-analyses by cohort type.

RESULTS

In over 15 million participants, increased levels of NO2 and BC were associated with increased higher stroke incidence in both cohort types. Increased Normalized Difference Vegetation Index (NDVI) was associated with a lower stroke incidence in both cohort types, whereas an increase in impervious surface was associated with an increase in stroke incidence. The first PC of the air pollution domain (PM2.5, NO2 and BC) was associated with an increase in stroke incidence. For the built environment, higher levels of NDVI and lower levels of impervious surfaces were associated with a protective effect [%change in HR per 1 unit = -2.0 (95 %CI, -5.9;2.0) and -1.1(95 %CI, -2.0; -0.3) for traditional adult and administrative cohorts, respectively]. No clear patterns were observed for distance to blue spaces or temperature parameters.

CONCLUSIONS

We observed increased HRs for stroke with exposure to PM2.5, NO2 and BC, lower levels of greenness and higher impervious surface in single and combined exposure models.

Effect of residential relocation on environmental exposures in European cohorts: An exposome-wide approach

Residential relocation is increasingly used as a natural experiment in epidemiological studies to assess the health impact of changes in environmental exposures. Since the likelihood of relocation can be influenced by individual characteristics that also influence health, studies may be biased if the predictors of relocation are not appropriately accounted for. Using data from Swedish and Dutch adults (SDPP, AMIGO), and birth cohorts (BAMSE, PIAMA), we investigated factors associated with relocation and changes in multiple environmental exposures across life stages. We used logistic regression to identify baseline predictors of moving, including sociodemographic and household characteristics, health behaviors and health. We identified exposure clusters reflecting three domains of the urban exposome (air pollution, grey surface, and socioeconomic deprivation) and conducted multinomial logistic regression to identify predictors of exposome trajectories among movers. On average, 7 % of the participants relocated each year. Before relocating, movers were consistently exposed to higher levels of air pollution than non-movers. Predictors of moving differed between the adult and birth cohorts, highlighting the importance of life stages. In the adult cohorts, moving was associated with younger age, smoking, and lower education and was independent of cardio-respiratory health indicators (hypertension, BMI, asthma, COPD). Contrary to adult cohorts, higher parental education and household socioeconomic position were associated with a higher probability of relocation in birth cohorts, alongside being the first child and living in a multi-unit dwelling. Among movers in all cohorts, those with a higher socioeconomic position at baseline were more likely to move towards healthier levels of the urban exposome. We provide new insights into predictors of relocation and subsequent changes in multiple aspects of the urban exposome in four cohorts covering different life stages in Sweden and the Netherlands. These results inform strategies to limit bias due to residential self-selection in epidemiological studies using relocation as a natural experiment.

Ambient air pollution and cardiovascular diseases: An umbrella review of systematic reviews and meta-analyses

The available evidence on the effects of ambient air pollution on cardiovascular diseases (CVDs) has increased substantially. In this umbrella review, we summarized the current epidemiological evidence from systematic reviews and meta-analyses linking ambient air pollution and CVDs, with a focus on geographical differences and vulnerable subpopulations. We performed a search strategy through multiple databases including articles between 2010 and 31 January 2021. We performed a quality assessment and evaluated the strength of evidence. Of the 56 included reviews, the most studied outcomes were stroke (22 reviews), all-cause CVD mortality, and morbidity (19). The strongest evidence was found between higher short- and long-term ambient air pollution exposure and all-cause CVD mortality and morbidity, stroke, blood pressure, and ischemic heart diseases (IHD). Short-term exposures to particulate matter <2.5 μm (PM_2.5 ), <10 μm (PM₁₀ ), and nitrogen oxides (NO_x ) were consistently associated with increased risks of hypertension and triggering of myocardial infarction (MI), and stroke (fatal and nonfatal). Long-term exposures of PM_2.5 were largely associated with increased risk of atherosclerosis, incident MI, hypertension, and incident stroke and stroke mortality. Few reviews evaluated other CVD outcomes including arrhythmias, atrial fibrillation, or heart failure but they generally reported positive statistical associations. Stronger associations were found in Asian countries and vulnerable subpopulations, especially among the elderly, cardiac patients, and people with higher weight status. Consistent with experimental data, this comprehensive umbrella review found strong evidence that higher levels of ambient air pollution increase the risk of CVDs, especially all-cause CVD mortality, stroke, and IHD. These results emphasize the importance of reducing the alarming levels of air pollution across the globe, especially in Asia, and among vulnerable subpopulations.

Air pollution exposure impairs lung function in infants

Aim

To assess associations between air pollution exposure and infant lung function.

Methods

Healthy infants from Stockholm were recruited to two cohorts (n = 99 and n = 78). Infant spirometry included plethysmography and raised volume forced expiratory flows. In pooled analyses, lung function at ~6 months of age was related to time‐weighted average air pollution levels at residential addresses from birth until the lung function test. The pollutants included particulate matter with an aerodynamic diameter < 10 μm (PM₁₀) or <2.5 μm and nitrogen dioxide.

Results

There were significant inverse relations between air pollution exposure during infancy and forced expiratory volume at 0.5 s (FEV_0.5) as well as forced vital capacity (FVC) for all pollutants. For example, the decline was 10.1 ml (95% confidence interval 1.3–18.8) and 10.3 ml (0.5–20.1) in FEV_0.5 and FVC, respectively, for an interquartile increment of 5.3 μg/m³ in PM₁₀. Corresponding associations for minute ventilation and functional residual capacity were 43.3 ml/min (−9.75–96.3) and 0.84 ml (−4.14–5.82).

Conclusions

Air pollution exposure was associated with impaired infant lung function measures related to airway calibre and lung volume, suggesting that comparatively low levels of air pollution negatively affect lung function in early life.

Living with a Severe Allergy: Lived Perspectives from Swedish Adolescents and their Parents

BACKGROUND

During adolescence, the young person should gradually develop independence from his or her parents. However, having a chronic disease like a severe allergy may add stress and challenges beyond normal development and involves a struggle between adapting socially, feeling healthy, and managing the disease.

OBJECTIVE

To describe experiences of living with a severe allergy from the perspective of adolescents and their parents.

METHOD

A qualitative study with six focus group interviews were performed, two with adolescents and four with their parents (10 adolescents, 10-16 years old and 21 parents). The transcribed data were analyzed using systematic text condensation.

RESULT

Four themes emerged: Feeling different (adolescents and parents), shift in responsibility (adolescents and parents), the importance of parents (only adolescents) and the importance of healthcare providers (only parents). The adolescents relied on their parents, while also taking responsibility for managing their disease. The parents expressed a need to protect their children; but they did not seem to be aware of the responsibility their children took. The parents highlighted the importance of support from healthcare providers but this was not mentioned by the adolescents.

CONCLUSION

This study showed that both the adolescents and their parents stated that they took responsibility for managing the disease, but in different ways. For healthcare providers, this needs to be taken into account in order to support both adolescents and parents for self-management and shift in responsibilities which begins during adolescents.

Is moving to a greener or less green area followed by changes in physical activity?

Green areas might provide an inviting setting and thereby promote physical activity. The objective of this study was to determine whether moving to different green area surroundings was followed by changes of physical activity. Data from a large population-based cohort of adults in Stockholm County responding to surveys in 2010 and 2014 were analysed (n = 42611). Information about walking/cycling and exercise were self-reported and living area greenness data were satellite-derived (NDVI, Normalized Difference Vegetation Index). Multinomial logistic regression analyses were performed separately for changes in levels of walking/cycling and exercise (decrease, stable, increase). Greenness was defined as a change in NDVI quartile to less green, same, or greener. Odds ratio's (OR) with 95% confidence intervals (CI) were presented adjusted for gender, age, education and area-based income. Contrary to what we hypothesized, those moving to a greener area were more likely to decrease their levels of walking/cycling (OR = 1.42, CI = 1.28-1.58), whereas those moving to a less green area were more likely to increase their walking/cycling (OR = 1.26, CI = 1.13-1.41). Exercise behaviour showed another pattern, with people being more likely to decrease exercise both when moving to a greener (OR = 1.25, CI = 1.22-1.38) and to a less green area (OR = 1.22, CI = 1.09-1.36). Studying subpopulations based on sociodemographic characteristics did not aid to clarify our results. This cohort study with repeated measurements did not support the currently available cross-sectional studies showing a strong positive relation between greenness and physical activity. Nevertheless, our findings have shown spatial patterns related to green areas and physical activity which imply a need for place-specific health policies.

Urban residential greenness and adiposity: A cohort study in Stockholm County

BACKGROUND

Increasing evidence suggests that exposure to residential greenness is associated with positive health outcomes among urban populations. However, few studies have considered effects on adiposity development in a longitudinal setting.

OBJECTIVES

This study aimed to explore the association between long-term exposure to urban residential greenness and markers of adiposity.

METHODS

A cohort of 5126 adults from five municipalities in Stockholm County was examined clinically at baseline (1992-1998) and follow-up (2002-2006) after on average nine years. Time-weighted average exposure to urban greenness was estimated by Normalized Difference Vegetation Index (NDVI) within 100 m, 250 m, and 500 m buffers around the residential addresses of each participant. Multiple linear and Poisson regression models were used to estimate associations between greenness and change in weight and waist circumference as well as risk of overweight, obesity and central obesity. Co-exposures to air pollution, traffic noise and distance to water were also examined.

RESULTS

In women, higher levels of residential greenness were associated with a reduced increase in waist circumference during follow-up (β = -0.11 cm/year, 95% CI -0.14; -0.08 per one interquartile range increase in NDVI) and decreased risk for central obesity (IRR = 0.88: 95% CI 0.79; 0.99) in the 500 m buffer. No associations were observed for men or with regard to weight development or the risk of developing overweight or obesity. Exposure to low NDVI levels in combination with high NO_x from road traffic and transportation noise as well as long distance to water rendered statistically significant increases in waist circumference in both sexes.

CONCLUSION

Higher long-term exposure to greenness was associated with a reduced increase in waist circumference and lower risk of central adiposity in women but not in men. In both sexes, low NDVI exposure in combination with other environmental risk factors appeared particularly harmful.

Global climate adaptation governance: Why is it not legally binding?

In the last decade, the United Nations Framework Convention on Climate Change has moved from a strong focus on mitigation to increasingly address adaptation. Climate change is no longer simply about reducing emissions, but also about enabling countries to deal with its impacts. Yet, most studies of the climate regime have focused on the evolution of mitigation governance and overlooked the increasing number of adaptation-related decisions and initiatives. In this article, we identify the body of rules and commitments on adaptation and suggest that there are more attempts to govern adaptation than many mitigation-focused accounts of the international climate regime would suggest. We then ask: to what degree are adaptation rules and commitments legalized in the United Nations Framework Convention on Climate Change? We examine the degree of precision and obligation of relevant decisions through an extensive analysis of primary United Nations Framework Convention on Climate Change documents, secondary literature on adaptation initiatives and institutions, interviews with climate change experts and negotiators, and participant observation at climate negotiations. Our analysis finds that adaptation governance is low in precision and obligation. We suggest that this is partly because adaptation is a contested global public good and because 'package deals' are made with mitigation commitments. This article makes a vital contribution to the global environmental politics literature given that adaptation governance is under-studied and poorly understood. It also contributes to the legalization literature by highlighting how contested global public goods may be governed globally, but with low obligation and precision.

"Healthcare seems to vary a lot": A focus group study among parents of children with severe allergy

BACKGROUND

Living with an allergic disease has consequences for both affected children and their families. The aim of this qualitative study was to gain deeper knowledge of what life is like for families of children with severe allergic disease, in order to improve care and thereby reduce the consequences of living with a chronic disease.

METHODS

Four focus group interviews were performed with Swedish parents of children, aged 6-11 and 12-16 years, with severe allergic disease (from one or more allergic conditions, such as food allergy/eczema/hay fever/asthma). The participants were attending a family support weekend. Interviews were analyzed with a qualitative method.

RESULTS

Based on parental experiences, the following themes were presented in the analysis: limitations, control, injustices, and fear and anxiety. It was evident that the families lived isolated lives and experienced different kinds of limitations. Parents felt a need to have control of their child's everyday life and described a feeling of constantly being on guard. They also suggested that understanding of the child's allergies was lacking in preschool/school and that healthcare did not provide adequate support. They felt that the same care should be offered to children and families, no matter where they lived.

CONCLUSIONS

Based on parental experiences, having a child with severe allergic disease implies a need to constantly be on guard. In order to improve the care of children with severe allergy and their families, a more person- and family-centered approach is needed.

Institutionalization or wither away? Twenty-five years of environmental policy integration under shifting governance models in Sweden

Snapshot views of environmental policy integration (EPI) practices fail to consider the stability of EPI over time – both as aspiration and performance. This paper reviews the evolution of EPI over more than two decades at the national level in the agriculture and energy sectors in Sweden – an EPI pioneer. We study how the extent of EPI stability can be explained partly by shifting political priorities by governments and partly by underlying governance models (actors and organizational landscape and policy instruments used). Comparing the two sectors, the institutionalization of EPI appears to be stronger in the energy sector. In the agricultural sector, the current reform of the Common Agricultural Policy seems to imply decreasing prominence of EPI – due to shrinking budgets for environmental targets along with greater policy goals complexity. Overall, observed shifts in governance have been mildly conducive to EPI by providing an infrastructure, but further enhancements require clear political priority awarded to the environment.

Radixin expression in microglia after cortical stroke lesion

Stroke induces extensive tissue remodeling, resulting in the activation of several cell types in the brain as well as recruitment of blood-borne leucocytes. Radixin is part of a cytoskeleton linker protein family with the ability to connect transmembrane proteins to the actin cytoskeleton, promoting cell functions involving a dynamic cytoskeleton such as morphological changes, cell division and migration which are common events of different cell types after stroke. In the healthy adult brain radixin is expressed in Olig2(+) cells throughout the brain and in neural progenitor cells in the subventricular zone. In the current study, we detected a 2.5 fold increase in the number of radixin positive cells in the peri-infarct cortex two weeks after the induction of cortical stroke by photothrombosis. Similarly, the number of Olig2(+) cells increased in the peri-infarct area after stroke; however, the number of radixin(+)/Olig2(+) cells was unchanged. Neural progenitor cells maintained radixin expression on their route to the infarct. More surprising however, was the expression of radixin in activated microglia in the peri-infarct cortex. Seventy percent of Iba1(+) cells expressed radixin after stroke, a population which was not present in the control brain. Furthermore, activation of radixin was predominantly detected in the peri-infarct region of oligodendrocyte progenitors and microglia. The specific location of radixin(+) cells in the peri-infarct region and in microglia suggests a role for radixin in microglial activation after stroke.

EGF-induced expansion of migratory cells in the rostral migratory stream

The presence of neural stem cells in the adult brain is currently widely accepted and efforts are made to harness the regenerative potential of these cells. The dentate gyrus of the hippocampal formation, and the subventricular zone (SVZ) of the anterior lateral ventricles, are considered the main loci of adult neurogenesis. The rostral migratory stream (RMS) is the structure funneling SVZ progenitor cells through the forebrain to their final destination in the olfactory bulb. Moreover, extensive proliferation occurs in the RMS. Some evidence suggest the presence of stem cells in the RMS, but these cells are few and possibly of limited differentiation potential. We have recently demonstrated the specific expression of the cytoskeleton linker protein radixin in neuroblasts in the RMS and in oligodendrocyte progenitors throughout the brain. These cell populations are greatly altered after intracerebroventricular infusion of epidermal growth factor (EGF). In the current study we investigate the effect of EGF infusion on the rat RMS. We describe a specific increase of radixin⁺/Olig2⁺ cells in the RMS. Negative for NG2 and CNPase, these radixin⁺/Olig2⁺ cells are distinct from typical oligodendrocyte progenitors. The expanded Olig2⁺ population responds rapidly to EGF and proliferates after only 24 hours along the entire RMS, suggesting local activation by EGF throughout the RMS rather than migration from the SVZ. In addition, the radixin⁺/Olig2⁺ progenitors assemble in chains in vivo and migrate in chains in explant cultures, suggesting that they possess migratory properties within the RMS. In summary, these results provide insight into the adaptive capacity of the RMS and point to an additional stem cell source for future brain repair strategies.