Listen to the episode:

Check out the shownotes through this link.

---

 Are you interested in how to enhance urban air quality and active transportation?

---

Our summary today works with the article titled Transforming our cities: Best practices towards clean air and active transportation from 2019 by Andrew Glazener and Haneen Khreis, published in the Current Environmental Health Reports journal. This is a great preparation for our next interviewee, Oliver Stoltz in episode 194 talking about urban mobility changes. Since we are investigating the future of cities, I thought it would be interesting to see how urban transportation and clean air are connected. This article explores effective strategies for enhancing urban air quality and encouraging active transportation like walking and cycling, highlighting the significant overlap between these two areas and the positive impacts of integrated policy approaches.

[intro music]

---

Welcome to today’s What is The Future For Cities podcast and its Research episode; my name is Fanni, and today I will introduce a research paper by summarising it. The episode really is just a short summary of the original paper, and, in case it is interesting enough, I would encourage everyone to check out the whole paper. Stay tuned until because I will give you the 3 most important things and some questions which would be interesting to discuss.

---

[music]

In 2015, ambient air pollution, especially fine particulate matter (PM2.5), was the fifth-leading cause of death globally, causing 4.2 million premature deaths, mainly in low- and middle-income countries in Asia, Africa, and the Eastern Mediterranean, with older adults most vulnerable. This pollution costs $5.7 trillion in health burdens, 4.4% of global GDP. Motor vehicle reliance worsens air pollution and physical inactivity, linked to 3.2 million deaths yearly. Encouraging active transportation like walking and cycling could mitigate these risks. However, most research is centred on Western countries, with less data from the fastest-growing urban areas facing the greatest risks.

In 2017, more than 80% of urban dwellers worldwide were exposed to air pollution levels surpassing WHO guidelines, with the highest pollution found in cities across the U.S., Poland, and India. This issue is particularly acute in middle- and low-income countries. Road transportation is a significant contributor, releasing pollutants like PM2.5 and nitrogen oxide, linked to a range of health problems including cardiovascular and respiratory diseases. Despite efforts like Europe’s Euro Standards and the U.S. Clean Air Act, many urban populations still face pollution levels above recommended limits. Studies highlight the need for more targeted research on the health impacts of traffic-related air pollution to inform effective policy decisions.

Walking, cycling, and public transportation, crucial for active transportation, are shaped by the built environment. Features like dedicated paths for non-motorized transport and accessible parks encourage active transit, while urban sprawl increases dependency on private vehicles by spreading out destinations. The WHO suggests a minimum of 150 minutes of moderate-intensity physical activity weekly, but adherence varies worldwide. Transportation choices are greatly influenced by the built environment and infrastructure. Enhancing active transportation requires multi-level policy interventions, including societal initiatives like speed limit reductions and city or route-level adjustments to boost density and walking/cycling infrastructure. These interventions must be comprehensive to effectively shift behaviours.

Clean air and active transportation, essential elements of urban mobility, are interlinked. Shifting to active transportation not only improves air quality but also boosts physical activity, enhancing urban health. While active transportation can lead to increased individual exposure to pollutants, the health benefits from physical activity generally outweigh these risks. In high-pollution cities like Delhi, the advantages of activities like cycling are significant. Motorists typically encounter more pollutants than cyclists and pedestrians, though this varies based on the specific urban environment. Factors such as route choice and proximity to traffic influence pollutant exposure for those using active transportation, with routes further from traffic showing lower pollution levels. Ultimately, the health gains from active transportation, despite increased pollutant inhalation, are considerable.

Recent best practices for achieving clean air and active transportation include car-free policies, advanced vehicle technologies, urban design changes, green space enhancements, and improved public transportation. These practices are more effective when used together. Car-free policies, such as motor vehicle restrictions, road pricing, and taxation, aim to reduce pollution and promote active transportation. Examples include Oslo’s plan for a car-free city center and GHG reduction, and diesel bans in Paris and Madrid. Events like Bogota’s Ciclovia and U.S. open streets have boosted physical activity and cut pollution, but are limited by their infrequency. Meanwhile, environmental zones in Germany and road pricing in London have effectively lowered air pollution.

Electric and autonomous vehicles offer potential for reducing urban air pollution, though their impact depends on adoption rates and energy sources, with electric vehicles possibly shifting the greenhouse gas (GHG) burden to the energy sector. Urban design changes, like denser layouts, safer roads, and green spaces, have promoted active transportation; initiatives like Barcelona’s superblocks and U.S. complete streets have proven successful. Public transportation not only reduces pollution but also boosts physical activity, as evidenced in the UK and U.S. studies showing public transport users are more active and emit less pollution than car commuters. Integrated approaches combining these strategies have yielded notable emission reductions and increased active transportation in places like California and Copenhagen.

Cities combatting air pollution and physical inactivity face challenges from growing road networks and car ownership. To counter this, many are enhancing active transportation, reshaping environments for walking and cycling, and enforcing vehicle and fuel restrictions. These integrated strategies aim to diminish car reliance and foster healthier, active lifestyles, though their full effects may emerge slowly. Future research, particularly in rapidly urbanizing low- and middle-income countries, needs to focus on creating active transportation guidelines, measuring the influence of green spaces and complete streets on air quality and active transportation, identifying pollution sources, and understanding the health effects of low-level pollution.

[music]

---

What was the most interesting part for you? What questions did arise for you? Do you have any follow up question? Let me know on Twitter at WTF4Cities or on the wtf4cities.com website where the transcripts and show notes are available! Additionally, I will highly appreciate if you consider subscribing to the podcast or on the website. I hope this was an interesting paper for you as well, and thanks for tuning in!

---

[music]

Finally, as the most important things, I would like to highlight 3 aspects:

1. In 2015, ambient air pollution, especially fine particulate matter (PM2.5), was the fifth-leading cause of death globally, causing 4.2 million premature deaths, mainly in low- and middle-income countries in Asia, Africa, and the Eastern Mediterranean, with older adults most vulnerable.
2. Motor vehicle reliance worsens air pollution and physical inactivity, linked to 3.2 million deaths yearly. Encouraging active transportation like walking and cycling could mitigate these risks.
3. Clean air and active transportation are interlinked, with shifting to active transportation not only improving air quality but also boosting physical activity, enhancing urban health.

Additionally, it would be great to talk about the following questions:

1. How is the air in your city influencing your well-being?
2. How can you influence local leaders to prioritize clean air and active transport in your area?
3. Which car-free or urban design ideas inspire you for cleaner, active living in your city?
4. What steps can you take to reduce your contribution to urban air pollution and support green initiatives?

[outro music]

---