Unhealthy Sprawl

IS SUBURBAN SPRAWL BAD FOR HEALTH?

This emerging public health issue was the subject of a recent meeting of the SSVMS Public and Environmental Health Committee.

The Greater Sacramento Region is one of the fastest growing areas in the state, predicted to grow by 1 million people over the next 30 years. A majority of the new housing planned for our region will be built far from the urban centers where most people work, and far from public transit centers.

The US Department of Transpor-tation reports that over the past 20 years, the average length of the commute to work has increased by 36 percent, and average time spent in traffic has increased over 200 percent. Children spend about an hour a day in cars, in addition to school bus time. Sprawling growth forces people to spend more time in their cars, with important effects on health: people walk less, traffic-related injuries increase, and motor vehicle exhaust contributes to air pollution.

The role of public health had traditionally been to improve sanitation. Now, research shows that the design of our built-up environment is a significant factor in the epidemic of obesity, traffic accidents, and respiratory disease.

The obesity epidemic
Obesity will soon be the number one cause of preventable death in the U.S., according to a recent JAMA article. We have all heard about how our poor diet causes obesity, but now a study of 200,000 people in the CDC's Behavioral Risk Factor Surveillance System has established a direct association between the amount of sprawl in a community and the health of the people who live there.

The results showed that people living in sprawling developments are likely to walk less, weigh more (up to 6 pounds) and have higher blood pressure than those living in more compact neighborhoods, even after controlling for factors such as age, education, gender, race, and ethnicity. When the researchers controlled for the amount of "exercise time" reported, they still found that people in sprawled areas were more obese.

This suggests that those in a sprawl area are missing out on the significant health benefits of walking or biking for the short trips and errands of everyday life. The CDC reports that the number of trips Americans take on foot has dropped by 42 percent in the last 20 years.

We are using cars for about 90 percent of all trips, even though one quarter of them are less than one mile. The CDC estimates that if all inactive Americans increased their physical activity by the equivalent of 20 minutes of walking per day, we could eliminate the obesity epidemic and save some $70 billion in annual medical costs.

Traffic injuries
Motor vehicle accidents are the number one cause of death of Americans from ages 1 to 34, approximately 41,000 deaths per year. Another 3 million are injured. A recent DMV study of traffic accidents in the Sacramento area showed that traffic accidents with injuries increased last year by 22 percent and 18 percent in rapidly growing Elk Grove and Folsom, while declining by 6 percent in slower growth Sacramento.

Walking has become more dangerous in our car-oriented communities. In Sacramento County, pedestrians account for about 25 percent of traffic fatalities, even though walking accounts for only 5 percent of trips by people here. Creating safer places to walk and bicycle could have a profound impact on health, and help reduce the costs associated with care in expensive trauma centers.

Air pollution
Over 113 million Americans live in cities with significant air pollution, with motor vehicles producing at least half of it. Communities requiring a car-centered life-style have contributed to this problem, as the number of miles driven per person in the U.S. has doubled in the past 40 years.

Several studies have shown a link between air pollution levels and exacerbation of asthma and chronic lung diseases. One of them was a CDC study during the summer Olympics in Atlanta, when the city encouraged use of car pooling and public transportation. Auto trips dropped 23 percent, air pollution ozone levels dropped 28 percent, and asthma-related emergency room visits fell by 42 percent during the same period. According to the American Lung Association, health problems from motor vehicle air pollution in the U.S. account for an estimated $40 billion in health care costs per year.

More research will be needed to completely understand the impact of sprawl on Public Health, but clearly the medical community should support efforts to reduce sprawl and to design communities that encourage walking and physical activity.

To learn more about local land use issues, see the Environmental Council of Sacramento website, www.ecosacramento.net. Learn about Walk Sacramento's efforts to create healthier communities through a partnership with Active Living by Design at: www.activelivingbydesign.org

tderiggi@msn.com