Olena Gruzieva

Identifying the urban environment exposures related to asthma is the key to mitigate the disease burden of asthma in urban areas. We aim to adopt the exposome-wide approach to address the question: ‘Is there a single urban environment exposure or a combination of several exposures significantly associated with the risk of asthma from childhood to young adulthood?’ and the molecular mechanism behind these associations.We will use data from the prospective birth cohort BAMSE (Children, Allergy, Environment, Stockholm, Epidemiology). Asthma outcomes from childhood to young adulthood will be assessed based on questionnaire at specific follow-ups. Time-varying urban external exposome including ambient air pollution, noise, built environment, temperature, socioeconomic status from birth to the latest follow-up will be assessed. The internal exposome is represented by untargeted urine and serum metabolomics data. We will apply exposome-wide approach to investigate the associations of both urban external and internal exposome with the risk of asthma and link the urban exposome to asthma in a causal-inference framework.The output of this project may offer better understanding to the complex relationships of urban environment exposures with asthma and help addressing environmental inequality using a multifaceted approach, eventually improving health outcomes for all individuals living in urban areas.

Research problem and specific questionsUrban living environments challenge the individual’s capacity to maintain a good health throughout the course of life. In Sweden, current trends in housing and neighborhood conditions tend to further increase disparities in health. The rapid urbanization and densification of Stockholm County makes it an optimal setting for studying health effects of urban living, for example in relation to air quality, transportation noise, urban greenness, climate change and overcrowded housing. In this program, we aim to assess and develop strategies for building a sustainable city promoting equitable public health among inhabitants of urbanized areas.Data and methodsThe program will use a variety of different data materials and methods. To map environmental hazards in Stockholm County, a new GIS-based tool aimed at regional stakeholders will be developed. A new cohort, based on the National Environmental Health Survey 2023, will form the basis for analyses of environmental health associations and estimates of disease burden. Furthermore, the effects on children’s development, education and health from overcrowded housing will be investigated in a nation-wide cohort study and in an intervention setting. In a literature review, we will summarize evidence on environmental interventions which can guide stakeholders in implementing planning and mitigation measures.Relevance and utilizationThe national Commission for Equity in Health listed 7 key areas of life which determine health inequalities. Among these, the intended program has a focus on Housing and neighborhood conditions but is also of relevance for aspects of Early life development, Health behavior, and Control, influence and participation. By this program, we aim to establish a strong research infrastructure for monitoring and assessing the impact of the built environment on public health and for the promotion of environmental health equity. This is in line with several other initiatives and governing documents within Sweden, e.g. “Health as a driving force for the environmental goals and sustainable development”, initiated by Miljömålsrådet.Plan for program realizationThe program will be carried out at the Institute of Environmental Medicine, Karolinska Institutet, in collaboration with the Center for Occupational and Environmental medicine, Region Stockholm, and builds on six different work packages, each with its specific aims, activities, and deliverables. The researchers of the program represent many different disciplines, spanning from environmental medicine, public health and epidemiology to GIS, nursing and multicultural psychiatry, and will work closely together in the different work-packages. To ensure a good dialogue with end-users of our research, we will host, and take part in, an array of activities throughout the program progression, e.g. via reference groups, seminars, workshops, regional networks and other applied activities.

Cardiovascular and metabolic diseases (CMD) remain the leading cause of morbidity and mortality globally, including myocardial infarction, stroke and type 2 diabetes. Although young people are not typically affected by CMD, the risk factors for these conditions are present during the early years of life, affecting long-term disease risk and the disease burden in the adulthood. Air pollution, transportation noise, and greenness are among the modifiable risk factors that may influence cardiometabolic health. Previous research on causes of CVD often focuses on single risk factors while effects from multiple environmental exposures in young adults are understudied. This project aims to investigate how air pollution, transportation noise and neighborhood greenness contribute to the development of a wide range of early markers of CMD and to elucidate characteristics that may modify the relation between environmental exposures and CMD traits. The project will be based on the prospective population-based birth cohort BAMSE comprising 4000 individuals followed from birth up to young adulthood with repeated questionnaires and extensive clinical investigations. Exposure to environmental factors is estimated based on residential address history. The results of the project will serve as a basis for policy makers in decision making processes, particularly related to environmental policies and urban planning as well as for individual risk assessment and prevention in clinical practice.