Sprawl and Health

Leung 1998 - "Evaluation of Personal Exposure to Monoaromatic Hydrocarbons"

Leung, Pei-Ling; Harrison, Roy M
"Evaluation of Personal Exposure to Monoaromatic Hydrocarbons"
Occupational and Environmental Medicine
April 1998; v.55, n.4; pp. 249-257
On the Web
Relevance: high

The authors measured the exposure of 50 volunteers in the UK to various monoaromatic hydrocarbons (MAHs) over the course of 12 hour days. They found that urban volunteers were exposed to more MAHs than non-urban volunteers. Most of the total exposure is from the home, despite low concentrations, due to the vast amount of time spent there. Although little time is spent driving, the high concentration of MAHs in vehicles made it a noticeable contributor for office workers (5% of total exposure) 

Allen 2004 - "Estimated Hourly Personal Exposures to Ambient and Nonambient Particulate Matter Among Sensitive Populations in Seattle"

Allen, Ryan; Wallace, Lance; et al.
"Estimated Hourly Personal Exposures to Ambient and Nonambient Particulate Matter Among Sensitive Populations in Seattle"
Journal of Air and Waste Management
September 2004; v.54; n.9; pp.1197-1411
On the Web
Relevance: High

The authors measured the concentration of particulate matter in various mircoenvironments (home indoors, home outdoors, work, school, in transit, other outdoors, other indoors) and the average exposure for 38 subjects in Seattle. The subjects selected were "sensetive populations" with asthma, coronary heart disease, or advanced age. The major findings were:

• The best air was indoors at home; the worst air was at work, followed by outdoors and in transit.
• Because subjects spend so much time at home, most of their exposure (79%) occured there.
• There was a low correlation between ambient and personal exposures (0.43) compared to findings from other studies. This means that localized sources highly affect personal exposure (i.e. cooking fumes vs.general air quality)

Nasar 1995 - "The Psychological Sense of Community in the Neighborhood"

Nasar, Julian
"The Psychological Sense of Community in the Neighborhood"
Journal of the American Planning Association
Spring 1995; v61, n2; pp 178-184
Relevance: high

There is more social capital--at least as conceived as neighborhood social ties--in mixed-use (and presumably higher density) communities than in single use communities. From the abstract: This paper describes the development and testing of an 11-item Likert scale of the sense of neighborhood community, using responses from 54 residents in three suburbs in Columbus, Ohio. One test of the scale with 100 residents in single-use and mixed-use areas near one another found significantly more sense of community in the mixed-use neighborhood. More sense of community emerged among married persons and couples with children as compared to singles and childless couples.

Much of this paper is devoted to justifying its research methodologies. Of particular interest is a list of 15 questions on page 181 that researchers used to ascertain neighborhood social ties. This could be of use in future primary research on social capital.

Hawe 2000 - "Social capital and health promotion: a review"

Penelope Hawe, Alan Shiell
"Social capital and health promotion: a review"
Social Science & Medicine    
September 2000; v51, n6, pp 871-885
On the Web
Relevance: Medium-low

This is a somewhat interesting perspective on the history of social capital. Written from a social science perspective it provides a different and broader context for social capital theory than the other scientific studies reviewed here. It also treats the metaphorical and rhetorical dimensions of the language of social capital.

The authors also briefly review the scientific literature on the relationship between social capital (and income inequality) and health. While the review is not as comprehensive or detailed as other studies reviewed here, it is clearly written and pithy, making it a handy reference.

Kingham 1998 - "Assessment of Exposure to Traffic-Related Fumes During the Journey to Work"

Kingham, Simon; Meaton, Julia; et al.
"Assessment of Exposure to Traffic-Related Fumes During the Journey to Work"
Transportation Research, Part D
July 1998; v.3, n.4; pp.271-274
On the Web
Relevance: medium-low

In a pilot study, the authors measured commuter's exposure to benzene and particulates using different modes (car, bus, train, road cyclist, path cyclist) but along similar routes(?). Findings include:

• The car driver had the highest mean exposure to benzene (108.3 micrograms/m^3) a factor of at least 4 and also the highest mean exposure to particulates (7.6 absorbance), but by a much smaller margin.
• Train riders had the lowest benzene exposure (12.9) and path cyclists had the lowest particulate exposure (2.7).
• The bus was slightly better than the road bike
• The exposure ratios for the car driver to the road cyclist were 4.05 for benzene and 1.26 for particulates.
• The exposure ratios for the road cyclist to the path cyclist were 1.73 for benzene and 2.41 for particulates.

Adams 2002 - "Assessment of Road Users' Elemental Carbon Personal Exposure Levels, London, UK"

Adams, HS; Nieuwenhuijsen, MJ; Colvile, RN.
"Assessment of Road Users' Elemental Carbon Personal Exposure Levels, London, UK"
Atmospheric Environment
November 2002; v.36, n.34; pp.5335-5342
On the Web
Relevance: low

The authors measured exposure to elemental carbon (EC) a component of diesel exhaust, along various routes, using different modes, and in summer vs. winter.  They found that exposure levels were higher:

• for cars, followed by buses and bicycles (cyclists may have lower exposure because they don't get stuck in traffic and keep "away from the central road 'tunnel of pollution'.";
• along the most congested central route, perhaps due to higher traffic density and a street canyon effect;
• in winter, perhaps due to colder engines and more stable meteorological conditions.

Fruin 2004 - "Black Carbon Concentrations in California Vehicles and Estimation of In-Vehicle Diesel Exhaust Particulate Matter Exposures"

Fruin, Scott A; Winer, Arthur M; Rodes, Charles E.
"Black Carbon Concentrations in California Vehicles and Estimation of In-Vehicle Diesel Exhaust Particulate Matter Exposures"
Atmospheric Environment
August 2004; v.38, n.25; pp.4123-4133
On the Web
Relevance: low

The authors measured black carbon (BC) concentrations inside vehicles driven around LA and Sacramento. BC is typically associated with diesel emissions. The authors found that the most important predictor of in-vehicles BC concentrations was the type of vehicle followed, with diesel buses and delivery trucks that had ground-level exhaust pipes being the worst. Following a gasoline powered car did not increase BC concentrations.

The authors also estimate daily exposure to diesel particulate matter (DPM), concluding that compared to earlier models, "in-vehicle DPM exposures appear to make very significant contributions to overall DPM exposures, randing from approximately 30-55% of total DPM exposure on a statewide, population basis.  Thus the in-vehicle microenvironment may be the most important route of overall DPM exposure, though only 1.5h day-1 is spend there, on average."

Friedman 2001 - "Impact of Changes in Transportation and Commuting Behaviors During the 1996 Summer Olympic Games in Atlanta on Air Quality and Childhood Asthma"

Friedman, Michael S; Powell, Kenneth E; et al.
"Impact of Changes in Transportation and Commuting Behaviors During the 1996 Summer Olympic Games in Atlanta on Air Quality and Childhood Asthma"
Journal of the American Medical Association
February 21, 2001; vol.285, n.7; pp.897-905.
On the Web
Relevance: low

The authors compared the level of air pollution and asthma events during the Atlanta Olympics to levels just before and after. They found that ozone levels and asthma events were lower during the Oympics, likely due to changes in traffic patterns. The number of asthma acute care events decreased 41.6% in the Georgia Medicaid claims file.  Organizers increased public transportation, closed the downtown to cars, encouraged workers to change work hours, and made other adjustments. There are several caveats to this study, so we may not want to quote it alone, but it could be one building block of the case.

Adams 2001 - "Determinants of Fine Particle (PM2.5) Personal Exposure Levels in Transport Microenvironments, London, UK"

Adams, HS; Nieuwenhuijsen, MJ; Colvile, RN
"Determinants of Fine Particle (PM2.5) Personal Exposure Levels in Transport Microenvironments, London, UK"
Atmospheric Environment
September 2001 v.35, n.27; pp.4557-4566
On the Web
Relevance: medium-low

The authors measured concentrations of fine PM on fixed routes using different modes (car, bus, bicycle) in London. They found that route was a significant factor, explaining 20% of the variation, but mode was not. Wind speed explained 18% of the variation. "Personal exposure levels were reasonable correlated with urban background FSM [fixed site monitor] concentrations."

CARB 1998 - "Measuring Concentrations of Selected Air Pollutants Inside California Vehicles"

California Air Resources Board (CARB)
"Measuring Concentrations of Selected Air Pollutants Inside California Vehicles"
December 1998, Contract No. 95-339, Final Report
On the Web
Relevance: medium-low

CARB measured concentrations of various air pollutants inside vehicles as a range-finding experiment. They studied the effect of freeway conditions (rush vs. non-rush), roadway types, vehicle types, air vent settings, time of day, and roadside/ambient air quality.

CARB found that pollutant concentrations were higher:

• in the regular vs. carpool lane
• during rush hour
• when following diesel or other high-emitting vehicles

Other findings include:

• Vent settings and vehicle type did not seem to make a big difference
• "Most pollutants levels, especially the VOC's, were elevated inside and outside the vehicles relative to either the roadside or ambient station concentrations"
• "Particle concentrations were typically significantly higher outside the vehicles than inside, presumably due to losses in the vehicle ventilation systems (and other factors) - while significant differences were not observed between inside and outside levels of gas phase pollutants for the same vehicle."

CAVEAT: this was a preliminary, range-finding study, so we should look at other studies for confirmation and hard numbers.

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.

Hirdes 1992 - "The importance of social relationships, socioeconomic status and health practices with respect to mortality among healthy Ontario males"

Hirdes, Forbes
"The importance of social relationships, socioeconomic status and health practices with respect to mortality among healthy Ontario males"
Journal of Clinical Epidemiology
February 1992; v45, n2; pp 175-182
On the Web
Relevance: Medium

The authors examined 2000 men in Ontario and found that social relationships had "a strong association with mortality." Unfortunately, their social relationships index was comprised of marital status, number of children, family contact, and participation in voluntary associations -- only the last of these is conceivably affected by sprawl. Also, the strong association of social capital to mortality is in the comparison between the highest scoring 10% in social capital and the lowest scoring 10%. It's not clear whether sprawl is affect social capital in these extremes or in the middle 80% (where, in turn, the effects on mortality are less pronounced).

Interestingly, the effect of income was greater than the effect of social capital (adjusted relative risk of 0.41 versus 0.30). The effect of income is even greater because the risk factors for income include the top 20% versus the bottom 20% (not just top and bottom deciles, as for social capital).

Veenstra 2002 - "Social capital and health (plus wealth, income inequality, and regional health governance)"

Veenstra
"Social capital and health (plus wealth, income inequality and regional health governance)"
Social Science and Medicine
March 2002; v54, n6; pp 849-868
On the Web
Relevance: Medium-high

Describes a study of 30 health districts in Saskatchewan, comparing population health with social capital, income inequality, wealth, and governance. Social capital meant associational and civic participation. Two findings stand out:

• The author found no evidence of a relationship between social capital and good governance in the health districts.
• Low social capital was correlated to high mortality; high income inequality was also correlated to high mortality. The author writes, "the two may be co-mingled somehow when it comes to population health, although they were not significantly related to one another."

Veenstra's findings are promising because his use of social capital--associational and civic participation--is the same kind that may be affected by sprawl. And while the effects of social capital on mortality are "co-mingled" with income inequality, there is a relationship.

McCann 2003 - "Measuring the Health Effects of Sprawl"

McCann, Barbara; Ewing, Reid
"Measuring the Health Effects of Sprawl: A National Analysis of Physical Activity, Obesity, and Chronic Disease."
Smart Growth America and Surface Transportation Policy Project
September 2003
On the Web
Relevance: high

This report is based on Ewing et al's earlier article (2003) and is longer with more details and sidebars. The conclusions, of course, are the same, but the report includes sprawl scores for all 448 counties and the web page has fact sheets for counties in most states.