Sprawl and Health

Washington Dept. of Ecology 2004 - "The Economic Benefits of Clean Air

Washington Dept. of Ecology
"The Economic Benefits of Clean Air"
Created Sept 2002, updated June 2004
Publication number 02-02-011
On the Web
Relevance: medium

The Washington State Department of Ecology says that

• “Washington citizens save over $2 billion per year in health costs because the air is cleaner now than it was in 1990.”
• “Washington businesses save at least $17 million per year because cleaner air means fewer lost workdays or lost productivity due to illness caused by air pollution, according to EPA.”
• “Based on EPA estimates of cancer risks and measured pollution levels in Washington, [levels] of 11 high risk Hazardous Air Pollutants (HAPs) […] may result in as many as 30 cancer cased per year in Washington that would not otherwise have occurred. The cost of medical treatment alone for these is about $3,000,000.” 

It also estimates that if central Puget Sound and Clark county returned to ozone non-attainment, it would cost businesses $253 million for required cleaner gasoline and additional pollution controls.  In central Puget Sound it would also cost consumers about $10 million a year (1 penny per gallon) for required cleaner gasoline. In addition, we would lose local control over clean air strategies.

(Note that these estimates cover all air pollution, including industrial emissions and agricultural burning.)

Brauer 2000 - "Evaluation of Ambient Air Pollution in the Lower Mainland of British Columbia"

Brauer, Michael; Brumm, Jochen; Ebelt, Stefanie
"Evaluation of Ambient Air Pollution in the Lower Mainland of British Columbia: Public Health Impacts, Spatial Variability, and Temporal Patterns"
Submitted to the Administrative Council of Lower Mainland Medical Health Officers
On the Web
Relevance: high

This study estimates that 0 to 600 excess deaths annually in the BC Lower Mainland each year can be attributed to anthropogenic outdoor air pollution. However, most of these deaths are for individuals age 65 and older and associated with cardiovascular disease.

This study modeled where certain air pollutants are concentrated, finding that Vancouver's air is not always dirtiest: "CO and NO2 concentrations were higher in Vancouver relative to locations in the eastern part of the region. In contrast, O3 concentrations were significantly higher in the Fraser Valley relative to Vancouver/Burnaby. PM10 did not exhibit much spatial variability, with concentrations being relatively homogeneously distributed within the region." See maps in the study.

The study also compared Vancouver's average concentrations to other cities including Seattle and Portland. For annual averages, Vancouver ranks best on PM10, CO, and ozone, while Seattle and Portland rank better on NO2.

BC Lung Assoc 2005 - "Health and Air Quality 2005 - Phase 2: Valuation of Health Impacts from Air Quality in the Lower Fraser Valley Airshed"

RWDI AIR Inc (for British Columbia Lung Association)
"Health and Air Quality 2005 - Phase 2: Valuation of Health Impacts from Air Quality in the Lower Fraser Valley Airshed"
July 15, 2005
On the Web
Relevance: high

This study estimates that a 10% reduction in fine particulate matter and ozone pollution in the Lower Fraser Valley (LFV) could produce $195+/- $122 million annually in 2010 (2003$ discounted) in health benefits. (I think these are not only direct health costs, but also use some other valuation method.)

• The study uses a linear model and assumes no thresholds, so the estimates are scalable to 1%, 20%, etc. The authors say that a 1% improvement would save $29 million (undiscounted) in 2010.
• They also note that the benefits from a given improvement in PM2.5 are about 10 times greater than the benefits from a similar improvement in ozone.

British Columbia 2003 - Air Quality in British Columbia, a Public Health Perspective

British Columbia Provincial Health Officer, Ministry of Health Services.
Every Breath You Take…Provincial Health Officer’s Annual Report 2003.
Air Quality in British Columbia, a Public Health Perspective.
2004 Victoria, BC
On the Web
Relevance: high

This report covers the sources, distribution, and health effects and costs of air pollution.

Sources and distribution: Air pollution is neither evenly distributed around BC nor concentrated in Vancouver. For example, Vancouver has relatively low levels of particulate matter (excluding road dust) and ozone but relatively high levels of NO2, SO2, and CO. In the Lower Fraser Valley air shed (including Whatcom County, WA):

• mobile sources (excluding marine vehicles) account for 41% of smog-forming pollutants. according to an inventory in 2000. 
• 83% of CO comes from light-duty and off-road vehicles
• light-duty vehicles are responsible for 23% of NOx, 23% of VOCs, 3% of PM2.5

Health effects. The report estimates that 712 hospital admissions and 944 emergency room visits are due to outdoor air pollution. It also very informally estimates that the health burden from outdoor air pollution costs CAN$85 million annually. Estimates of annual deaths from outdoor air pollution range widely.

• Low estimate: 82
• Low intermediate estimate: 25-250
• High intermediate estimate: 115-402
• High estimate: 644
• Estimate of delayed mortality for PM2.5: 71-110

Handy 2005 - "Correlation or Causality Between the Built Environment and Travel Behavior? Evidence from Northern California"

Handy, Susan; Cao, Xinyu; Mokhtarian, Patricia
"Correlation or Causality Between the Built Environment and Travel Behavior? Evidence from Northern California"
Transportation Research Part D
November 2005; v.10, n.6; pp.427-444
On the Web
Relevance: medium

Handy et al surveyed residents of traditional and suburban neighborhoods on their travel habits, travel attitudes, perceived neighborhood attributes, and socio-economic status. They found that while residents of traditional neighborhoods drove 18% fewer miles than suburban residents, the variation in this cross-section could be better explained by differences in attitudes and SES factors than in the built environment.

When the authors separated out those who had moved in the past year for a quasi-longitudinal study, differences in the built environment (mainly in accessibility) appeared significant. The built environment seemed to affect increased walking more than decreased driving.

I'm a bit wary of the quasi-longitudinal part of this study. Why would the built environment be significant there but not in the cross-sectional analysis?

Riediker 2004 - "Particulate Matter Exposure in Cars is Associated with Cardiovascular Effects in Healthy Young Men"

Riediker, Michael; Cascio, Wayne; et al.
"Particulate Matter Exposure in Cars is Associated with Cardiovascular Effects in Healthy Young Men"
American Journal of Respiratory and Critical Care Medicine
April 15, 2004; v.168, n.8; pp.934-940
On the Web
Relevance: medium-low

Part of a larger research project measuring air quality in cars, the authors measured the effects of exposure to PM2.5 on the cardiovascular functions of nine young, healthy patrol officers in North Carolina. They concluded that in-vehicle PM2.5 negatively affected inflammation, coagulation, and cardiac rhythm in slight but significant amounts. However, they also measured PM2.5 concentrations to be lower in the vehicles than on the side of the road or at the ambient location.

This study suggests to me that even a small amount of PM2.5 from vehicles is bad.

Ebelt 2005 - "Exposure to Ambient and Nonambient Components of Particulate Matter"

Ebelt, Stefanie T; Wilson, William E; Brauer, Michael.
"Exposure to Ambient and Nonambient Components of Particulate Matter: A Comparison of Health Effects"
Epidemiology
May 2005; v.16, n.3; pp.396-405
On the Web
Relevance: medium

Intro: Using a small sample of pulmonary patients in Vancouver, the authors measured exposure to particulate matter and health effects, trying to separate out influence of ambient and nonambient particles on lung function, heart rate, and blood pressure.

Findings: They found that ambient exposure was not correlated with nonambient or personal exposure. They also found that ambient exposure was a better predictor of health effects. In contrast nonambient and personal exposures were not associated with health effects, except in the wrong direction for lung function. The authors caution that this is a small study and the results are not conclusive.

Canada 2004 - "Estimated Number of Excess Deaths in Canada Due to Air Pollution"

Judek, Stan; Jessiman, Barry; et al.
"Estimated Number of Excess Deaths in Canada Due to Air Pollution"
Health Canada & Environment Canada
August 30, 2004
On the Web
Relevance: medium

This study estimates the number of annual excess deaths due to current air pollutions levels in 8 major cities. They estimate that, in the Greater Vancouver Regional District, 230 deaths are due to short-term air pollution and 440 deaths are due to long-term air pollution, for a total of 680 (sic). They also estimate that this is 5% (range 3%-7%) of deaths from all causes.

For the eight cities across Canada, the study estimates that 1,800 (+/-700) deaths are due to short-term air pollution; 4,200 (+/-2,000), due to long-term; for a total of 5,900 (+/-2,100), or 8% (range 5%-11%) of all preventable deaths in those cities in Canada.

Note that short-term and long-term deaths may not be additive, but may rather overlap, making the total less than the sum of its parts.

Lund 2002 - "Pedstrian Environments and Sense of Community"

Lund, Hollie
"Pedestrian Environments and Sense of Community"
Journal of Planning Education and Research   
2002 Associate of Collegiate Schools of Planning
On the Web
Relevance: medium-high

Lund's study is intended to gauge the community effects of New Urbanism-style architecture and neighborhood design. The study is conducted in two Portland neighborhoods, an inner-city neighborhood with traditional design and a modern-style suburban neighborhood (post-WWII). Researchers distributed questionaires door-to-door in the two neighborhoods using questions similar to the Nasar study. They got 57 responses (22 percent) in the traditional neighborhood and 49 (18.8 percent) in the suburban neighborhood.

The study found more sense of community in the traditional neighborhood than in the modern suburb. The most powerful subjective explanatory variable was "perception of walking"--the better that people felt about walking in the neighborhood, the higher their sense of community. Interestingly, there is one big counterpoint to this: the study found a negative correlation between destination trips (walking to the store or for other errands) and sense of community. That is, the more likely people are to walk to destinations, the lower their sense of community. Strolling trips--walking for pleasure--are positively associated with community, but destination trips are negatively associated.

One failing of this research is that the respondents are self-selected and many not be statistically accurate representations of their communities. Also, the number of respondents is relatively low and it may be difficult to obtain statistically valid results when using controls or regressions. Finally, we cannot be sure whether people's behavior and attitudes are determined by their urban environment, or whether people self-select into neighborhoods that reflect their values and preferences.

Frank 2005 - "A Study of Land Use, Transportation, Air Quality, and Health (LUTAQH) in King County, WA: Executive Summary"

Frank, Lawrence (Lawrence Frank & Company, Inc.)
"A Study of Land Use, Transportation, Air Quality, and Health (LUTAQH) in King County, WA: Executive Summary"
September 27, 2005, Submitted to King County officials.
Relevance: high
On the Web (big pdf)

NOTE: The following summary includes only the sections of this report that deal with air quality and vehicle emissions.

The study examined per capita VOC and NOx emissions from both automobile and transit trips. It uses a variety of measures to classify urban, suburban and other land uses. Urban land uses are responsible for much lower air pollution, on a per capita basis, than suburban land uses. Interestingly, the strongest correlate to lower per capita emissions is “street connectivity.”

• “Significantly lower estimates for NOx were generated by respondents living in areas with higher levels of retail floor area ratio, intersection density, and land use mix and residential density. Increased street connectivity where people live appeared to be the most closely associated with NOx. Mean emissions of NOx declined from 29 to 23 grams per person per day, a 26 percent reduction, between residents of the most to the least connected environments.”
• “Significantly lower levels of VOC’s were found for respondents in areas with higher levels of floor area ratio and intersection density and residential density. Improvements to street connectivity where people lived appeared to be the most effective tool to reduce VOC’s as well. Mean emissions of VOC’s declined from 14 to 12 grams per person per day, a 7 percent reduction, for residents of the most to least connected environments.”