Sprawl and Health

Rank 2001 - "Differences in Cyclists and Car Drivers Exposure to Air Pollution from Traffic in the City of Copenhagen"

Rank, Jette; Folke, Jens; Jespersen, Per Homann
"Differences in Cyclists and Car Drivers Exposure to Air Pollution from Traffic in the City of Copenhagen"
The Science of the Total Environment
2001; v.279; pp.131-136.
On the Web
Relevance: medium-high

The authors equipt two cyclists and two car drivers with air samplers for 4 hours at a time on 2 days. They found "The concentrations of particles and BTEX in the cabin of the cars were 2-4 times greater than in the cyclists' breathing zone, the greatest difference being for BTEX. Therefore, even after taking the increased respiration rate of cyclists into consideration, car drivers seem tot be more exposed to airborne pollution than cyclists.

Car/bicycle ratio

• Benzene: 2.8
• Toluene: 3.4
• Thylbenzene and Xylenes: 3.7
• Hydrocarbons: 3.7
• Particles (total dust):1.7.

Lopez n/a - "Urban Sprawl and the Risk of Physical Inactivity"

Lopez, Russ
"Urban Sprawl and the Risk of Physical Inactivity"
Unpublished
Not on the web (received from author)
Relevance: high

The author combines his sprawl index with 2001 BRFSS data on physical inactivity to estimate the sprawl connection. From the abstract

"For each one point increase in sprawl, the risk of being physically inactive [defined as no physical activity] increased by .04% ... Physical inactivity is associated with urban sprawl and other factors of the metropolitan social/physical environment, but the effect is small and minor changes in the overall metropolitan environment may not result in large changes in levels of physical activity."

Also see his published article on obesity.

Lopez 200? - "Thirty Years of Urban Sprawl in Metropolitan America: 1970-2000"

Lopez, Russ
"Thirty Years of Urban Sprawl in Metropolitan America: 1970-2000"
A report to the Fannie Mae Foundation
publication date unknown
Not on the web (received from author)
Relevance: high

The author constructed a sprawl index primarily measuring density for 330 metropolitan areas. The index ranged from 0-100 with the score roughly correlating to the percentage of residents who live in low-density census tracts, so a higher score means more sprawl. In this report the author lists his sprawl scores, compares his index to Ewing's index, and discusses changes in sprawl from 1970 to 2000. Lopez's index correlates roughly 50% to Ewing's index, and 92% to Ewing's density factor. Also see Lopez's sprawl-obesity article using this index.

Ewing 2002 - "Measuring Sprawl and Its Impact"

Ewing, Reid; Pendall, Rolf; Chen, Don
"Measuring Sprawl and Its Impact"
Smart Growth America
2002
On the Web
Relevance: high

Ewing et al. created a sprawl index for ~83 metropolitan areas, incorporating density, land use mix, centeredness, and street accessibility. The authors also estimated the impact of sprawl on various transportation-related outcomes. They found that a higher degree of sprawl is associated with higher average vehicle ownership, daily VMT per capita, annual traffic fatality rate, and maximum ozone level; more sprawl was associated with a lower share of work trips by transit and walking. Note that, as with most sprawl studies, we can't assume a causal relationship.

Guest 1999 - "Social ties at the neighborhood level: Two decades of GSS evidence"

Guest, Wierzbicki
"Social ties at the neighborhood level: Two decades of GSS evidence"
Urban Affairs Review   
September 1, 1999; v35, n1, pp 92-111
On the Web
Relevance: Medium-low

This article is mostly a by-the-book summary of the General Social Survey's findings on social capital from 1972 to the 1990s. It appears to question many of Putnam's findings about the seriousness and quality of the decline of US social capital. It also examines many of the theories about why social capital is eroding--urban form/highways, women in the workforce, structural social changes, etc. There's not much that's terribly relevant to our work, but two things bear mentioning.

The headline: "The data show a relatively continuous, albeit slow, decline in the importance of social ties on the basis of neighborhood and, in turn, an even smaller upward growth in the importance of nonneighborhood social ties."

There was no difference between central cities and suburbs (or other areas for that matter). The authors divided the GSS samples into four urban-form categories: central city of large metro area, suburbs of large metro area, other urban areas, and rural areas. "We examined the effect of locale over the three decades but found no significant interaction."

Kawachi 1997 - "Social capital, income inequality, and mortality"

Kawachi, Kennedy, Lochner, Prothrow-Stith
"Social capital, income inequality, and mortality"
American Journal of Public Health
September 1997; v87, n9, pp 1491
On the Web
Relevance: High

This is perhaps the single most compelling study that social capital--in the broad sense of civic engagement--affects health. The authors use the General Social Survey's result to perform "ecologic" analyses of 39 states' levels of social capital and income inequality compared to mortality. Still, there are some important short-comings.

The authors claim that "income inequality leads to increased mortality via disinvestment in social capital" though it is not clear to me that they actually demonstrate this. Instead, they demonstrate that income inequality is correlated to social capital and also show a correlation between social capital and mortality. (It's relatively well-documented that income inequality is associated with higher mortality).

House 1998 - "Social Relationships and Health"

House, Landis, Umberson
"Social Relationships and Health"
Science
July 29, 1988; v241 n4865, pp 540-545
Relevance: Medium

This is essentially a review of the primary studies relating social connections to health. Because the article is now 7 years old it fails to mention any of Kawachi's studies, which are arguably some of the most compelling pieces of evidence for believing that there is a link. Still, while the article is largely confined to summarizing the findings of studies that we are familiar with (Alameda County, CA; Evans County, GA; Tecumseh, MI; Gothenberg, Sweden; eastern Finland, etc), it does make at least two  interesting points that are worth attending to.

"Social relationships, or the relative lack thereof, constitute a major risk factor for health--rivaling the effects of well-established health risk factors such as cigarette smoking, blood pressure, blood lipids, obesity, and physical activity."

"In Tecumseh, Evans County, and eastern Finland, mortality is clearly elevated among the most socially isolated, but declines only modestly, if at all, between moderate and high levels of social integration."

Kawachi 1999 - "Social capital and community effects on population and individual health"

Kawachi
"Social capital and community effects on population and individual health"
Annals of New York Academy of Sciences
1999; v896; pp 120-130
On the Web
Relevance: High

This paper references what is probably the single most convincing piece of evidence we have for believing that social capital affects health--Kawachi et al's 1997 analysis of the GSS survey for 39 states, conducted between 1986 and 1990. In two reported analyses, he finds a close state-by-state correlation between social capital and health. In particular, trust was important: "the level of trust explained 58% of the variance in total mortality across states, including statistically significant associations with most major causes of death including heart disease, malignant neoplasms, stroke, homicide, and infant mortality."

Kawachi 1996 - "A prospective study of social networks in relation to total mortality and cardiovascular disease in men in the USA"

Kawachi, Colditz, Ascherio, Rimm, Giovannucci, Stampfer, Willet
"A prospective study of social networks in relation to total mortality and cardiovascular disease in men in the USA"
Journal of Epidemiology and Community Health
June 1996; v50, n3; pp 245-251
On the Web
Relevance: High

A longitudinal study of roughly 32,000 male health professionals in the US. According to the authors, "socially isolated men... were at increased risk for cardiovascular disease mortality... and deaths from accidents and suicides... [and] risk of stroke incidence." These results were most strongly seen comparing the 50% of most socially-connected men to the 6% of least socially-connected. The study defined social networks as marrital status, number of friends and relatives, and membership in church or community groups--some of these features are conceivably affected by sprawl.

Seeman 1996 - "Social ties and health: the benefits of social integration"

Seeman
"Social ties and health: the benefits of social integration"
Annals of Epidemiology
September 1996; v6, n5; pp 442-451
On the Web
Relevance: Medium-high

An overview of major findings on social ties and health published since the mid-1970s. The upshot is that "social integration does appear to have a highly beneficial effect on post-myocardial infarction prognosis (functioning and longevity)." That is, while social ties do not affect the incidence of heart disease, they do affect recovery from it. Following, I limn the major findings recapitulated by Seeman.