Smart Growth Reduces Air Pollution and Promotes Health

The last two decades of environmental protection have yielded significant progress. Our cars and industry are less polluting, previously declining wildlife is on the rise and our ability to identify and mitigate hazardous waste sites is better than it's ever been. These successes have motivated some to claim that our environment is in great shape and is just getting better. As desirable as such a prognosis is, reality is somewhat bleaker.

Despite progress, environmental problems persist – air and water pollution, global warming, habitat fragmentation and conversion – threaten the health, welfare and sustainability of our communities. The prevalence of many of these concerns is in part due to the way in which we have built our neighborhoods, communities and metropolitan areas during the past half-century – dispersed, inaccessible, and automobile oriented – in a word sprawling.

Urban Sprawl Impacts Air Quality

The farther we have to travel between home and work, work and play, the more likely it is that we will drive. So it should not be surprising that as the distances between trip origins and destinations has increased, so has the amount of driving we have done. Between 1950 and 1990, passenger vehicle miles grew at an astonishing rate of 4.2 percent a year.

In California, vehicle use grew more than four times faster than population growth from 1970 to 1990. The end result of all this driving is that our air quality has suffered. If present rates of automobile use continue, the Environmental Protection Agency predicts that air quality gains made through technological improvements, such as catalytic converters, and regulation will be eroded within the next eight years.

Urban Sprawl and Health

The rise in air pollution due to more driving is creating a serious public health threat. Air pollution is a major contributor to lung diseases such as asthma and emphysema. More than 4 million Californians have lung disease, which is a leading cause of death in America and growing faster than almost any other leading killer.

What is Smart Growth?

The Smart Growth movement has grown out of these concerns. The American Lung Association has joined forces with the Local Government Commission and a variety of groups interested in transportation, land use, and air quality issues. These groups are working together to ensure that communities grow smartly instead of sprawling, with the least impact on the environment.

Research has shown that compact, pedestrian and transit-friendly communities have a positive impact on air quality by improving travel alternatives. According to the 1990 nationwide Personal Transportation Survey, households living in city centers take 18 percent fewer trips, make on average 18 percent shorter trips, and travel 36 percent fewer miles. City center residents not only reduce "cold starts" (starting the car when it hasn't been used for the past few hours), a major source of ozone pollution, but also cut vehicle miles traveled, further reducing smog-forming emissions.

Smart Growth and Diesel

Communities that offer viable transportation alternatives are part of the Smart Growth plan. Buses are an important part of a community’s transportation system. However, transit agencies need to start phasing out the use of diesel and replace old buses with new ones that are powered by alternative fuels such as natural gas, fuel cells or electricity. Diesel exhaust is a serious public health risk and has been listed as a known human carcinogen since 1990. In 1998, the California Air Resources Board (CARB) formally listed diesel particulate as a toxic air contaminant. In fact, diesel particulates are the most significant source of air toxics in California and account for 70 percent of the cancer risk from toxic air contaminants statewide, according to CARB. Diesel exhaust also exacerbates lung diseases such as asthma and emphysema.