Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Researchers discover links between city walkability and air pollution exposure

Study reveals the role of neighborhood design in reducing pollution and improving physical activity

A new study compares neighborhoods' walkability (degree of ease for walking) with local levels of air pollution and finds that some neighborhoods might be good for walking, but have poor air quality.

Researchers involved in the study include University of Minnesota faculty member Julian Marshall and University of British Columbia faculty Michael Brauer and Lawrence Frank.

The findings highlight the need for urban design to consider both walkability and air pollution, recognizing that neighborhoods with high levels of one pollutant may have low levels of another pollutant.

The study, done for the city of Vancouver, British Columbia, is the first of its kind to compare the two environmental attributes, and suggests potential environmental health effects of neighborhood location, layout and design for cities around the globe.

The research study is published in the November 2009 issue of Environmental Health Perspectives, the peer-reviewed journal of the United States' National Institute of Environmental Health Sciences, part of the U.S. Department of Health and Human Services.

The research team found that, on average, neighborhoods downtown are more walkable and have high levels of some pollutants, while suburban locations are less walkable and have high levels of different pollutants. Neighborhoods that fare well for pollution and walkability tend to be a few miles away from the downtown area. These "win-win" urban residential neighborhoods--which avoid the downtown and the suburban air pollution plus exhibit good walkability--are rare, containing only about two percent of the population studied. Census data indicate that these neighborhoods are relatively high-income, suggesting that they are desirable places to live. Neighborhoods that fare poorly for both pollution and walkability tend to be in the suburbs and are generally middle-income.

"Research has shown that exposure to air pollution adversely affects human health by triggering or exacerbating a number of health issues such as asthma and heart disease," said Marshall, a civil engineering faculty member in the University of Minnesota's Institute of Technology. "Likewise, physical inactivity is linked to an array of negative health effects including heart disease and diabetes. Neighborhood design can influence air pollution and walkability; more walkable neighborhoods may encourage higher daily activity levels."

In the study, researchers evaluated concentrations of nitric oxide, a marker of motor vehicle exhaust, and ozone, a pollutant formed when vehicle exhaust and other pollutants react, for 49,702 postal codes (89 percent of all postal codes) in Vancouver. The researchers assigned a walkability score by analyzing four common attributes of neighborhood design: land-use mixing, intersection density, population density and for retail areas, the relative amount of land area for shopping versus for parking.

More walkable neighborhoods tend to have mixed land uses, with destinations such as stores and shops within walking distance of people's houses. A conventional street grid and other more walkable road networks tend to have a higher intersection density, while less walkable neighborhoods often have circuitous road networks and low intersection density, thereby increasing average travel distances and reducing the likelihood that people will walk. More walkable areas generally have higher population density. Finally, in less walkable areas, stores devote a greater fraction of their land to parking.

"The finding that nitric oxide concentrations are highest downtown, while ozone concentrations are highest in the suburbs, is not surprising," said Marshall. "Motor vehicle exhaust is most concentrated downtown, leading to the high nitric oxide concentrations downtown. In contrast, ozone takes time to form. Air masses have moved away from downtown--often, to suburban areas--by the time ozone concentrations reach their highest levels. Thus, reductions in vehicle emissions can benefit people who live near high-traffic areas and also people living in less dense areas."

Creating neighborhoods that are more walkable and that allow for alternative travel modes such as walking, biking or public transportation is one approach to reducing motor vehicle emissions, the study suggests. Another approach is reducing emissions per vehicle, for example through mandated emission standards. The research did not study conditions for individual people, but points out that high-rise buildings may allow people to live in walkable neighborhoods while being somewhat removed from street-level vehicle emissions.

The study's new findings indicate that neighborhood design is an important consideration for improving pollution levels and providing opportunities for daily physical activity. The study identified neighborhoods that are walkable yet have low levels of pollution, but those neighborhoods encompass a very small percentage of the population. Researchers hope that future investigation of those "win-win" neighborhoods will suggest urban design features that could usefully be applied elsewhere.

In the future, the researchers hope to investigate changes over time in pollution and walkability, and also study other urban areas to see how spatial patterns may differ elsewhere.

To read the current research study in its entirety, visit the Environmental Health Perspectives Web site at

Patty Mattern | EurekAlert!
Further information:

More articles from Studies and Analyses:

nachricht Diagnoses: When Are Several Opinions Better Than One?
19.07.2016 | Max-Planck-Institut für Bildungsforschung

nachricht High in calories and low in nutrients when adolescents share pictures of food online
07.04.2016 | University of Gothenburg

All articles from Studies and Analyses >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Novel light sources made of 2D materials

Physicists from the University of Würzburg have designed a light source that emits photon pairs. Two-photon sources are particularly well suited for tap-proof data encryption. The experiment's key ingredients: a semiconductor crystal and some sticky tape.

So-called monolayers are at the heart of the research activities. These "super materials" (as the prestigious science magazine "Nature" puts it) have been...

Im Focus: Etching Microstructures with Lasers

Ultrafast lasers have introduced new possibilities in engraving ultrafine structures, and scientists are now also investigating how to use them to etch microstructures into thin glass. There are possible applications in analytics (lab on a chip) and especially in electronics and the consumer sector, where great interest has been shown.

This new method was born of a surprising phenomenon: irradiating glass in a particular way with an ultrafast laser has the effect of making the glass up to a...

Im Focus: Light-driven atomic rotations excite magnetic waves

Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion

Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Steering a fusion plasma toward stability

28.10.2016 | Power and Electrical Engineering

Bioluminescent sensor causes brain cells to glow in the dark

28.10.2016 | Life Sciences

Activation of 2 genes linked to development of atherosclerosis

28.10.2016 | Life Sciences

More VideoLinks >>>