Urban living may come with health risks far worse than most think. A major new study links asthma to city pollution and poor planning. Researchers from Karolinska Institutet found that city residents face a higher asthma risk tied to their environments.
Their research examined 350,000 people from 14 study groups in seven European countries. The study ran under the EU-funded EXPANSE project.
The goal: understand how air pollution, dense development, and green space loss affect asthma in both children and adults.
They used home addresses to link each person to satellite-based environmental data. The images identified buildings, vegetation, and water bodies.
MORE THAN ONE RISK AT A TIME: POLLUTION, DENSITY, AND GREY CITIES COLLIDE
Urban residents are rarely exposed to just one risk. This study analyzed how multiple environmental threats combine to fuel asthma. Most earlier research looked at single threats like air pollution or traffic. This new method looks at how they interact and overlap.
Lead author Zhebin Yu says the goal was to show how real-world exposure looks. Cities are ecosystems of risk, not single sources. By mapping air pollution, urban heat, and green space levels, they built a clearer picture of urban asthma triggers.
The results were alarming. Over 11% of asthma cases could be traced directly to these combined urban exposures.
In simpler terms: one in ten people who developed asthma might not have if they’d lived in healthier areas.
WHO’S MOST AT RISK? AND WHERE?
The study doesn’t stop at statistics. It offers geographical insights, showing how asthma risk varies across different parts of cities. The worst outcomes were in areas with high pollution, little greenery, and tight development. These places were also hotter year-round.
Small changes in location could mean big changes in health risk. Green areas showed a noticeable protective effect. Water bodies and open spaces also helped. But in high-density city zones, these were usually scarce. This means policymakers can use the data to flag problem zones and plan healthier cities in the future.
ASTHMA IN ADULTS AND CHILDREN: URBAN DAMAGE KNOWS NO AGE
The study didn’t limit its findings to children. Adults were just as likely to develop asthma from long-term environmental exposure. City planning has long focused on housing and infrastructure. Now, it needs to consider health exposure as part of the design.
Prof. Erik Melén, the study’s senior author, says cities must rethink how they use land. It’s about air, space, and shade, not just roads. This is especially urgent as cities grow denser and hotter from climate change and rising populations. Asthma is often treated with medicine. But what if it could be prevented by planting trees or rerouting traffic?
THE NEXT STEP: UNDERSTANDING HOW POLLUTION IMPACTS THE BODY
Researchers are now analyzing blood samples from thousands of participants to go deeper.
They will study each person’s metabolome—a chemical snapshot of how the body processes pollution and stress. By linking internal chemical changes to external exposures, scientists can uncover how asthma really starts in the body.
This could lead to better diagnostics and perhaps early-warning systems for people at risk. It might also explain how other diseases—like COPD, stroke, heart attacks, or diabetes—respond to urban environments.
CITY DESIGN CAN’T BE BLIND TO HEALTH ANYMORE
The researchers want city leaders to use this data proactively. The methods can identify risky zones, predict health impacts, and shape safer designs.
Concrete without green space is dangerous. Air pollution needs stricter controls. Urban heat islands must be cooled with shade and water. Public health isn’t just about hospitals. It’s about the streets people walk, the air they breathe, and the trees they don’t see.
This study adds to a growing call: healthy cities must be green, breathable, and human-focused. With urban populations rising fast, ignoring these risks means more chronic illness and higher healthcare costs.
WHAT URBAN PLANNERS CAN DO RIGHT NOW
This study provides tools—not just warnings. Planners can:
- Add green buffers to dense districts
- Protect existing parks and water areas
- Reduce urban heat through trees and building materials
- Lower emissions with better transport planning
- Design cities around well-being, not just convenience
Every green rooftop or pollution-free street is a step toward a lower asthma rate.
ASTHMA ISN’T JUST GENETIC—IT’S ENVIRONMENTAL
We often treat asthma as a personal condition. This study shows it’s also a systemic urban outcome.
City living exposes people to daily environmental stressors. Over time, these shape health risks just as much as family history. The concept of an “exposome”—your total environmental exposure—may become a new cornerstone of public health.
WHAT THIS MEANS FOR THE AVERAGE URBAN RESIDENT
If you live in a big city, your health may depend on how much greenery and clean air surround your home. While individual choices matter, city design can stack the odds for or against your well-being. This research arms residents with knowledge—and gives cities a blueprint for a healthier future.
Urban growth is inevitable. But its shape—and impact—can still be changed. This study is a reminder that health begins at street level, not just in hospitals. Cities built with nature and people in mind don’t just look better—they breathe better, live longer, and heal faster.
The findings from Karolinska Institutet and partners across Europe send a clear message:
If we want to lower asthma rates, we need to change how we build our cities.