Suffocating Cities

Earlier this month, we shared an article by Rachel Quednau about the impact of accessible transit on jobs, written using a new comprehensive mapping tool called mySidewalk. This week, we're pleased to publish a guest article by Stephen Hardy, CPO of mySidewalk as part of our article exchange.


Air pollution is a full-on, flashing-lights, health emergency. And to make matters worse, planners, city officials, and the rest of us aren’t doing much about it. That's what I learned after diving into mySidewalk’s new air quality data (EPA’s Respiratory Health Index).

According to a recent MIT study, air pollution can be directly attributed to 200,000 premature deaths in the U.S. every year. That is more than murders (16,100), automobile fatalities (32,700), and deaths from strokes (128,000) combined.

Another fascinating part of the research is that the leading contributor to this statistic is air pollution from road transportation (followed closely by pollution from electricity generation). The number of vehicles, traffic, speed, and the type of traffic (ex: heavy diesel) are all contributors to this “on-road” pollution.

This pollution is most concentrated within 600 feet of major roadways creating a corridor of bad air coursing through major metropolitan areas. According to the EPA, inside of these pollution zones, people who live, work, or attend school “have an increased incidence and severity of health problems associated with air pollution exposures related to roadway traffic including higher rates of asthma onset and aggravation, cardiovascular disease, impaired lung development in children, pre-term and low-birthweight infants, childhood leukemia, and premature death.” In 2009, the EPA estimated that 45 million people live or work within 300 feet of a major roadway.

Dense, auto-dependent metropolises are particularly at risk. Let’s look at Atlanta to see how this plays out:

On the map, the darker green shades denote where there are higher concentrations of air toxicity. You can see that everywhere in Atlanta has at least a respiratory index of 2 or higher - only index scores below 1 indicate no health threat (find out more about the index here). The purple dots are schools. You can see a nifty interactive version of the map from mySidewalk here.

It is clear from the data that many of Atlanta’s schools are located near major roadways putting young children at a higher risk of breathing unhealthy air. As an example, Dunbar Elementary is located near I-20 and well within its pollutive halo and has a respiratory health index score of 3.59 - one of the higher scores in the region. Unfortunately, Dunbar is just one example of tens of thousands of schools, daycares, and elder-care facilities that suffer from being located near high concentrations of on-road air pollutants. This is needless exposure.

What can be done

Fortunately, there are a host of ways to reduce the risk posed by on-road air pollution. New facilities that are designed for children and the elderly can be pushed a few hundred feet further from major roadways; roadway design elements like sound walls and cut sections have been shown to reduce the impact on neighboring communities; and existing buildings can be fitted with air-filtration systems to minimize exposure. Even better, moving schools and elder care facilities away from stroads and highways and into residential neighborhoods would reduce exposure to air pollution. Phytoremediation or the use of vegetative plantings is perhaps the most interesting and promising technique (especially in dense plantings of evergreen/coniferous trees). Encouraging cleaner transportation options like biking and walking would also directly benefit air quality. The EPA published a specific guide to help remediate air pollution for schools.

Improving the air we breath and the health of our communities will take significant work, but understanding the health emergency posed by on-road air pollutants and putting into place policies that limit exposure and remediate impacts are straight-forward. The data illustrates that this is a health threat with full emergency status. We know enough to start taking action now.

If you would like an interactive map revealing areas in your community where residents are struggling to breathe, request one here.

(All images courtesy of mySidewalk)


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About the Author

Stephen Hardy is the Chief Product Officer of mySidewalk. Stephen is responsible for providing the strategic vision for mySidewalk’s team of designers and developers working on their data insights platform for cities. Before joining mySidewalk, he used the platform as the Director of Planning with BNIM Architects. Stephen is certified by the American Institute of Certified Planners and holds a LEED AP credential.