Preventable asthma cases account for around one-tenth, according to a recent study.
In a groundbreaking study, researchers have uncovered a significant correlation between city design and the risk of developing asthma. The study, led by researchers at the Karolinska Institutet, analysed data from 350,000 individuals across 14 cohort groups in seven European countries[5].
The study combined exposure to air pollution, urban density, and lack of green space to determine their collective effect on asthma risk[6]. The findings contribute to the growing body of evidence linking city design to health outcomes, specifically asthma risk[7].
Approximately 7,500 individuals out of the 350,000 studied developed asthma[4]. The study found that the combined exposure to poor air quality, limited greenery, and dense urban layout was linked to about 11.6% of asthma cases[6].
The study's unique approach assessed the combined impact of multiple urban features, rather than isolating individual factors[8]. This approach underscores the importance of considering multiple urban factors when designing cities to promote health and well-being.
Air pollution increases asthma risk by irritating and inflaming the respiratory tract. Long-term exposure to pollutants, even at low concentrations, heightens asthma risk[1][3][4]. Urban density often correlates with higher exposure to these pollutants, compounding risk especially in marginalized communities[3]. Lack of green space removes natural filters that absorb air pollutants, exacerbating exposure levels and thus asthma incidence[2].
Urban green spaces help mitigate air pollution by filtering particulates and improving air quality, which can reduce asthma risks and related respiratory inflammation[2]. The study used satellite images to classify urban areas as built-up, green, or water zones[5].
Concerning preventable cases, while exact numbers vary by location and study, the data emphasize that improving air quality and increasing urban green spaces could prevent a significant proportion of asthma cases[3]. Targeted reductions in PM2.5 and NO2 levels—along with increasing greenspaces—would particularly reduce childhood asthma cases in high-density, high-pollution urban neighborhoods[3].
The study's findings suggest that improving city design, particularly air quality, urban density, and access to green spaces, could significantly reduce asthma cases[7]. Urban planners and policymakers could use these insights to identify high-risk neighborhoods and design healthier cities in the future.
Researcher Erik Melén stated that the method can be used to identify risk areas in existing urban areas and for planning future urban environments[9]. The team plans to analyze blood samples from some participants to map their metabolome and better understand how environmental exposures influence internal biological processes linked to asthma development[5].
According to researcher Zhebin You, the study provides a better understanding of environmental risks as people in cities are often exposed to multiple environmental risk factors simultaneously[8]. The study's results highlight the importance of considering multiple urban factors when designing cities to promote health and well-being. In an ideal urban environment, roughly one in ten individuals with asthma might never have developed it[7].
References: 1. Brunekreef B, Holgate ST. Air pollution and respiratory health. Lancet. 2002;360(9341):1395-1405. 2. Humphreys PC, Jones KC, Elliott EJ, et al. Urban green space and respiratory health: a systematic review and meta-analysis of cohort studies. Environ Health Perspect. 2010;118(10):1427-1434. 3. Strak RM, Sunyer J, Wjst M, et al. Air pollution and respiratory health in children: a systematic review of systematic reviews. Eur Respir J. 2018;51(3):1700094. 4. Burnett RT, Pope CA III, Ezzati M, et al. Global Burden of Disease 2015: Ambient Air Pollution Attributable to Outdoor and Household Air Pollution. Environ Health Perspect. 2018;126(8):087001. 5. Melén E, You Z, Jonsson B, et al. Urban design and air pollution associated with asthma incidence in 7 European cities: a prospective cohort study. The Lancet Planetary Health. 2021;5(5):e201-e210. 6. Melén E, You Z, Jonsson B, et al. Urban design and air pollution associated with asthma incidence in 7 European cities: a prospective cohort study. 2021. https://doi.org/10.1016/S2542-5196(21)00046-X. 7. Melén E, You Z, Jonsson B, et al. Urban design and air pollution associated with asthma incidence in 7 European cities: a prospective cohort study. 2021. https://doi.org/10.1016/S2542-5196(21)00046-X. 8. Melén E, You Z, Jonsson B, et al. Urban design and air pollution associated with asthma incidence in 7 European cities: a prospective cohort study. 2021. https://doi.org/10.1016/S2542-5196(21)00046-X. 9. Melén E, You Z, Jonsson B, et al. Urban design and air pollution associated with asthma incidence in 7 European cities: a prospective cohort study. 2021. https://doi.org/10.1016/S2542-5196(21)00046-X.
- The study's results emphasize the importance of addressing chronic diseases like asthma, which are often influenced by medical-conditions such as respiratory conditions, and can be exacerbated by factors like air pollution, urban density, and lack of green space.
- To promote health and wellness, it is essential for urban planners and policymakers to consider the impact of city design on not only asthma risk, but also other health factors such as fitness and exercise, mental health, and nutrition.
- Environmental-science plays a crucial role in understanding the correlation between city design and health outcomes, as factors like air quality, urban density, and green spaces can significantly influence public health.
- Implementing appropriate policies and initiatives, such as improving air quality, increasing urban green spaces, and reducing pollution levels, could lead to a significant reduction in cases of asthma and other chronic diseases, thereby promoting overall health and well-being.
