Sprawl and Health

Kelly-Schwartz 2004 - "Is Sprawl Unhealthy?"

Kelly-Schwartz, Alexia; Stockard, Jean, et al
"Is Sprawl Unhealthy? A Multilevel Analysis of the Relationship of Metropolitan Sprawl to the Health of Individuals"
Journal of Planning Education and Research
December 2004; v.24, n2; pp.184-196
On the Web
Relevance: high

The authors replicated and extended Ewing et al's work on the effect of sprawl on health. They compared self- and physican-rated health as well as a variety of chronic conditions across metropolitan areas while controlling for income, education, sex, etc. They found that sprawl does affect health somewhat, but in a complex way that is difficult to track.  It appears that a highly gridded street network is associated with better health while more density is associated with poorer health.  While sprawl was not significantly associated with a higher prevalence of chronic conditions, among those with those conditions, the gridded street network was associated with better health.

Ewing 2005 - "Can the Physical Environment Determine Physical Activity Levels?"

Ewing, Reid
"Can the Physical Environment Determine Physical Activity Levels?"
Exercise and Sport Sciences Reviews
April 2005; v.33, n.2; pp.69-75
On the Web (pdf)
Relevance: medium high

Ewing seems to be primarily reviewing and re-presenting earlier work, but does so in a concise, easy-to-grasp way. Although he doesn't show any of the data or analysis, Ewing offers elasticity estimates for the effect of the physical environment on physical activity and its mediators. The effects are greatest for the mode share of walking and public transportation. CAVEAT: Ewing shows no statistical tests or analysis, so the accuracy of these estimates is unknown.

Bauman 2002 - "Toward a Better Understanding of the Influences on Physical Activity: The Role of Determinants, Correlates, Causal Variables, Mediators, Moderators, and Confounders"

Bauman, Adrian E; Sallis, James F; et al
"Toward a Better Understanding of the Influences on Physical Activity: The Role of Determinants, Correlates, Causal Variables, Mediators, Moderators, and Confounders"
American Journal of Preventive Medicine
August 2002; v.23, n.2 (supplement); pp.5-14
On the Web (pdf)
Relevance: very low

The authors discuss and define the terms mentioned in the title. They show how complex are the influences on physical activity and demonstrate how they require careful thinking and vocabulary.

Handy 2002 - "How the Built Environment Affects Physical Activity: Views from Urban Planning"

Handy, Susan L.; Boarnet, Marlon G. et al
"How the Built Environment Affects Physical Activity: Views from Urban Planning"
American Journal of Preventive Medicine
August 2002; v.23, n.2 (supplement)
On the Web (pdf)
Relevance: low

The authors give a good overview of how urban planners think about how the built environment impacts physical activity, namely walking and biking.  They cover how to measure the built environment and travel behavior, how the built environment affects travel by foot differently from travel by car, and some tips on how empirically to connect the built environment to physical activity.

Giles-Corti 2005 - "How Important is Distance To, Attractiveness, and Size of Public Open Space?"

Giles-Corti, Billie; Broomhall, Melissa; et al
"How Important is Distance To, Attractiveness, and Size of Public Open Space?"
American Journal of Preventive Medicine
February 2005; vol.28, n.2 (supplement 2); pp.169-176
On the Web
Relevance: low

The authors surveyed Australian adults in Perth and used some sort of GIS to conclude that people walk more if they have more access to large, attractive public open space with facilities for multiple types of users. While access alone to open space was not significantly associated with achieving recommended levels of physical activity, access to large, attractive open space increased the likelihood of walking at least 6 times per week totaling >180 minutes by 50%.

Humpel 2004 - "Perceived Environment Attributes, Residential Location, and Walking for Particular Purposes"

Humpel, Nancy; Owen, Neville; et al.
"Perceived Environment Attributes, Residential Location, and Walking for Particular Purposes"
American Journal of Preventive Medicine
February 2004; vol.26, n.2; pp.119-125
On the Web
Relevance: medium-low

The authors conducted a survey of 400 Australian adults (mean age 60) on their walking habits and environmental perceptions. "Aesthetics, convenience of facilities, and access to services were positively associated with the neighborhood walking for men; convenience was associated with neighborhood walking for women."  People who walked more were more likely to say that weather did not influence their decision to walk.  Women were also more likely to walk if they lived near the coast.

Owen 2000 - "Environmental Determinants of Physical Activity and Sedentary Behavior"

Owen, Neville; Leslie, Eva; et al.
"Environmental Determinants of Physical Activity and Sedentary Behavior"
Exercise and Sport Sciences Review
October 2000; vol.28, n.4; pp153-158
On the Web
Relevance: low

The authors describe a basic model for describing the environmental determinants of physical activity and sedentary behavior. They cite the limited research that had been done so far. One interesting nugget is that one study showed that even among those who are highly physically active, those who watched 4+ hours of TV per day were twice as likely to be overweight as were those who watched less than 1 hour of TV per day.

King 2003 - "The Relationship Between Convenience of Destinations and Walking Levels in Older Women"

King, Wendy C.; Brach, Jennifer S.; et al.
"The Relationship Between Convenience of Destinations and Walking Levels in Older Women"
American Journal of Health Promotion
Sept-Oct 2003; vol.18, n.1; pp.74-82
On the Web
Relevance: medium-high

Using a small sample (149) of older women, the authors found that living within a 20 minute walk of a park; biking or walking trail; or a department, discount, or hardware store was significantly related to walking more, as objectively measured by pedometer readings.  Walking was also associated with living near more destinations and with a better neighborhood rating for walking.

Humpel 2002 - "Environmental Factors Associated with Adults' Participation in Physical Activity: A Review"

Humpel, Nancy; Owen, Neville; Leslie, Eva.
"Environmental Factors Associated with Adults' Participation in Physical Activity: A Review"
American Journal of Preventive Medicine
May 2002; vol.22, n.3; pp.188-199
On the Web
Relevance: medium-low

The authors reviewed 19 studies, finding that "accessibility, opportunities, and aesthetic attributes had significant associations with physical activities. Weather and safety showed less-strong relationships." Several of the studies focused on excercise facilities and equipments, but others looked at neighborhood attributes.

Owen 2004 - "Understanding the Environmental Influences on Walking: Review and Research Agenda"

Owen, Neville; Humpel, Nancy; et al.
"Understanding the Environmental Influences on Walking: Review and Research Agenda"
American Journal of Preventive Medicine
July 2004; vol.27, n.1; pp.67-76.
On the Web
Relevance: medium

The authors review eighteen studies and conclude that the early evidence is promising.  The studies show that aesthetic attributes, convenience of walking facilities (sidewalks, trails), accessibility of destinations, and perceptions about traffic are associated with utilitarian walking.  However, better theoretical models and more studies, especially ones that examine a causal relationship, are needed.

Ewing 2003 - "Relationship Between Urban Sprawl and Physical Activity, Obesity, and Mortality"

Ewing, Reid; Schmid, Tom, et al
"Relationship Between Urban Sprawl and Physical Activity, Obesity, and Mortality"
American Journal of Health Promotion
September/October 2003; vol.18, n.1; pp.47-57
On the Web
Relevance: high

The authors estimated the impact of a county and metropolitan area sprawl index on obesity, physical activity, and related diseases. They found that the county  index significantly influenced the number of minutes spent in leisure-time walking, average BMI, obesity status, and prevalence of hypertension.

WA Dept. of Health 2004 - "The Economic Cost of Physical Inactivity Among Washington State Adults"

Chenoweth & Associates, Inc.
"The Economic Cost of Physical Inactivity Among Washington State Adults"
Washington State Department of Health
February 2004
On the Web (pdf)
Relevance: high

Chenoweth and Associates estimate the direct costs of physical inactivity in Washington to be $4.8 billion in 2002:

• $197.8 million for direct medical care
• $9.2 million for worker's compensation
• $4600 million for lost productivity

They also calculate the indirect costs at $593 million for medical care and $36.8 million for worker's compensation, bringing the total cost (direct + indirect) to $5.46 billion. Per Washington resident, this total cost of physical inactivity was $899 in 2002; per Washington adult, the cost was $1,232.

Thorpe 2004 - "The Impact of Obesity on Rising Medical Spending"

Thorpe, Kenneth E; Florence, Curtis S; et al
"The Impact of Obesity on Rising Medical Spending"
Health Affairs
October 2004, Web Exclusive W4-480
On the Web
Relevance: high

Comparing data from the 1987 National Medical Expenditure Survey and the 2001 Medical Expenditure Panel Survey, the authors estimate the impact of obesity on inflation-adjusted medical spending. They estimate that 27% of the increase was due to obesity, and that 12% was due to the increased obesity rate alone, exclusive of medical advances. In 2001, medical costs for an obese person were 37% higher than for a comparable normal weight person. The authors also calculate the effect of obesity on the increase in spending on diabetes (38%), hyperlipidemia (22%), and heart disease (41%).

Frank 2001 - "The Built Environment and Human Activity Patterns"

Frank, Lawrence D; Englke, Peter O
"The Built Environment and Human Activity Patterns: Exploring the Impacts of Urban Form on Public Health"
Journal of Planning Literature
November 2001; v.17, n.2; pp.202-218
On the Web
Relevance: low

Frank and Engelke reviews current literature to explore how physical activity affects public health and how urban form affects physical activity. The article is a good introduction to the subject with references to many useful studies (also reviewed in this  lit review), but a few of which are outdated.

Berrigan 1998 - "The Association Between Urban Form and Physical Activity in US Adults"

Berrigan, David; Troiano, Richard
"The Association Between Urban Form and Physical Activity in US Adults"
American Journal of Preventive Medicine
2002; v.23, n.2S; pp.74-79
On the Web
Relevance: medium

Using data from NHANES III, the authors found that people who lived in houses built before 1946 or between 1946 and 1973 were more likely to walk regularly than were people who lived in houses built after 1973. Those living in homes built before 1946 were 1.43 times more likely and those in homes built 1946-1973 were 1.36 times more likely to walk at least a mile at least 20 times a month than were those living in homes built after 1973.

B.C Health Planning 2004 - "The Cost of Physical Inactivity in British Columbia"

Colman, Ronald; Walker, Sally
"The Cost of Physical Inactivity in British Columbia"
B.C. Ministry of Health Planning
November 2004
On the Web (pdf)
Relevance: high

The authors use data from the Canadian Community Health Survey, the Economic Burden of Illness in Canada, and the literature to calculate the cost of physical inactivity in BC.  They estimate that physical inactivity costs the British Columbian health care system $211 million (2001CAN$) (1.8% of provincial health spendig) a year in direct costs.  They also estimate that indirect costs of productivity losses add up to $362 million a year due to premature death and disability, leading to a total cost of $573 million.  5% (1400) of all premature deaths are due to physical inactivity. This results in more than 4,380 potential years of life lost annually.

Birmingham 1999 - "The Cost of Obesity in Canada"

Birmingham, C. Laird; Muller, Jennifer L; et al
"The Cost of Obesity in Canada"
Canadian Medical Association Journal
February 23, 1999; v.160, n.4; pp.483-488
On the Web
Relevance: high

The authors reviewed the literature to calculate the direct medical cost of obesity in Canada.  They estimate that obesity cost over $1.8 billion, or 2.4% of the total health care expenditures, in Canada in 1997. The three top contributors were hypertension ($656.6 million), type 2 diabetes ($423.2 million), and coronary artery disease ($346.0 million).

Katzmarzyk 2000 - "The Economic Burden of Physical Inactivity in Canada"

Katzmarzyk, Peter T; Gledhill, Norman; Shephard, Roy J.
"The Economic Burden of Physical Inactivity in Canada"
Canadian Medical Association Journal
November 28, 2002; v.163, n.11; 1435-1440
On the Web
Relevance: high

The authors reviewed the literature to calculate the burden of physical inactivity in Canada. They conclude that physical inactivity costs Canada about $2.1 billion, or 2.5% of total direct health costs.  The also calculate the about 21,000 lives were lost prematurely in 1995 and that a 10% reduction in inactivity could save Canada $150 million a year.

Berkman 1995 - The Role of Social Relations in Health Promotion

Berkman, Lisa F.
"The Role of Social Relations in Health Promotion"
Psychosomatic Medicine - Special Issue: Superhighways for Disease
May/June 1995; v.57, n.3; pp.245-254
On the Web
Relevance: low/medium

Here's the nut of the article, from the abstract: "There is now a substantial body of evidence that indicates that the extent to which social relationships are strong and supportive is related to the health of individuals who live within such social contexts. A review of population-based research on mortality risk over the last 20 years indicates that people who are isolated are at increased mortality risk from a number of causes." According to Berkman, social isolation, "seemed to make people more vulnerable to a broad range of diseases and disabilities..." (This is in marked contrast to the standard medical etiological approach that specific causes for specific diseases.)

Must 1999 - "The Disease Burden Associated with Overweight and Obesity"

Must, Aviva; Spadano, Jennifer; et al
"The Disease Burden Associated with Overweight and Obesity"
Journal of the American Medical Association
October 27, 1999; v.282, n.16; pp.1523-1529
On the Web
Relevance: low/medium

Using NHANES III (1988-1994) the authors estimate the risk of having type 2 diabetes, gallbladder disease, coronary heart disease, high cholesterol, high blood pressure, or osteoarthritis for normal weight, overweight, obese groups.  Risk increased with BMI for all diseases except coronary hearth disease in men and cholesterol in both sexes.

Kannel 1996 - "Effect of Weight on Cardiovascular Disease"

Kannel, Wiliam B; Agostino, D; et al
"Effect of Weight on Cardiovascular Disease"
American Journal of Clinical Nutrition
March 1996; v.63, n.3; p.419S-422S
On the Web
Relevance: low

Using the Framingham Heart Study, the authors find that the optimal BMI to avoid cardiovascular disease is 22.6 for men and 21.1 for women.  Each SD (???) increment in relative weight increased risk of cardiovascular events by 15% for men and 22% for women.  The authors estimate that if everyone was their optimal BMI, there would be 1) 25% less coronary heart disease and 2) 35% fewer strokes or episodes of cardiac failure.

Xiang 2005 - "Obesity and Risk of Nonfatal Unintentional Injuries"

Xiang, Huiyun; Smith, Gary A; et al
"Obesity and Risk of Nonfatal Unintentional Injuries"
American Journal of Preventive Medicine
July 2005; v.29, n.1; pp.41-45
On the Web
Relevance: low

The authors used a survey of adults in 1999-2000 to estimate the likelihood of injuries for persons in different weight categories.  The found that injuries increase linearly with BMI category among women and that both men and women with BMI>35 had the highest likelihood of injury.

Pratt 2000 - "Higher Direct Medical Costs Associated with Physical Inactivity"

Pratt, Michael; Macera, Caroline A; Wang, Guijing
"Higher Direct Medical Costs Associated with Physical Inactivity"
The Physician and Sportsmedicine
October 2000; v.28, n.10; pp.63-70
On the Web
Relevance: medium

Using the 1987 National Medical Expenditures Survey, the authors estimate the costs of physical activity in the US. They conclude:

"The mean net annual benefit of physical activity [among people with no physical limitations] was $330 per person in 1987 dollars.  Our results suggest that increasing participation in regular moderate physical activity among the more than 88 million inactive Americans over the age of 15 might reduce annual national medical costs by as much as $29.2 billion in 1987 dollars--$76.6 billion in 2000 dollars."

Finkelstein 2004 - "State-Level Estimates of Annual Medical Expenditures Attributable to Obesity"

Finkelstein, Eric A; Fiebelkorn, Ian C; Wang, Guijing
"State-Level Estimates of Annual Medical Expenditures Attributable to Obesity"
Obesity Research
January 2004; v.12, n.1; pp.18-24
On the Web
Relevance: high

Beginning with their earlier estimates of the national medical expenditures on obesity, the authors use BRFSS data from 1998-2000 to estimate the state-level expenditures.  Idaho spent $227 million; Oregon, $781 million; and Washington, $1330 million.  In the first study, they found: "Annual U.S. obesity-attributable medical expenditures are estimated at $75 billion in 2003 dollars, and approximately one-half of these expenditures are financed by Medicare and Medicaid.

Finkelstein 2003 - "National Medical Spending Attributable to Overweight and Obesity: How Much, and Who's Paying?"

Finkelstein, Eric A; Fiebelkorn, Ian C; Wang, Guijing
"National Medical Spending Attributable to Overweight and Obesity: How Much, and Who's Paying?"
Health Affairs - web exclusive
May 2003; web published
On the Web
Relevance: high

Using the 1998 Medical Expenditure Panel Survey (MEPS) and the 1996 and 1997 National Health Interview Survey, the authors estimate that aggregate medical expenditures for obesity and overweight in 1998 were 9.1% of total US medical expenditures: $78.5 billion ($92.6 billion in 2002 dollars).  The also found that Medicare and Medicaid paid for about half of these costs.

Fontaine 2003 - "Years of Life Lost Due to Obesity"

Fontaine, Kevin R; Redden, David T; et al
"Years of Life Lost Due to Obesity"
Journal of the American Medical Association
January 8, 2003; v.289, n.2; pp.187-193
On the Web
Relevance: medium

Using data from NHANES I, II, and III, the authors calculated that a BMI of 23-25 for whites and 23-30 for black was associated with the longest life.  The estimated that years of life lost (YLL) increases with BMI in a J or U shaped curved among whites. Overweight and obesity cut more years off life for younger adults than for older adults.   Overweight had less effect on blacks, especially black women and elderly blacks.

Hu 2004 - "Adiposity as Compared with Physical Activity in Predicting Mortality among Women"

Hu, Frank B; Willet, Walter C; et al
"Adiposity as Compared with Physical Activity in Predictiong Mortality among Women"
New England Journal of Medicine
December 23, 2004; v.351, n.26' pp.2694-2703
On the Web
Relevance: high

Using the Nurse's Health Study (1976-1998?), the authors studied how both adiposity (obesity) and physical activity affect mortality risk. They found that obesity predicted a higher risk of death regardless of physical activity level, and physical inactivity predicted a higher risk of death regardless of BMI.

Gregg 2005 - "Secular Trends in Cardiovascular Disease Risk Factors According to Body Mass Index in US Adults"

Gregg, Edward W.; Cheng, Yiling J; et al
"Secular Trends in Cardiovascular Disease Risk Factors According to Body Mass Index in US Adults"
Journal of the American Medical Association
April 20, 2005; v.293, n.15; pp.1868-1875
On the Web
Relevance: high

Using data from NHES (1960-1962), NHANES I (1971-1975), II (1976-1980), and II (1988-1994) and NHANES 1999-2000, the authors looked at trends in high cholesterol, high blood pressure, and diabetes. They found that the prevalence of high cholesterol and high blood pressure have declined, and that they declined most in overweight and obese groups; however, the decline was smaller when the authors looked at the prevalence of both the conditions and treatments for the conditions. The prevalence of diabetes increased in all groups, most dramatically among the overweight and obese.

• "The net result of these phenomena may be a population that is, paradoxically, more obese, diabetic, arthritic, disabled, and medicated, but with lower overall CVD risk."

Manson 1995 - "Body Weight and Mortality Among Women"

Manson, Joann E; Willett, Walter C; Stampfer, Meir J; et al
"Body Weight and Mortality Among Women"
New England Journal of Medicine
September 14, 1995; v.333, n.11; pp.677-685
On the Web
Relevance: medium

Using data from the Nurses Health Study (1976-1992), the authors calculated the risk of mortality at various BMI levels for women of smoking and non-smoking status.  They found that among non-smoking women, mortality increases with BMI at all levels of BMI.  Smoking affects the association by raising the mortality risk for the leanest group (lowest BMI).

Stevens 1998 - "The Effect of Age on the Association Between Body-Mass Index and Mortality"

Stevens, June; Cai, Jianwen; et al
"The Effect of Age on the Association Between Body-Mass Index and Mortality"
New England Journal of Medicine
January 1, 1998; v.338, n.1; pp.1-7
On the Web
Relevance: medium

Using data from the American Cancer Society's Cancer Prevention Study I (1960-1972), the authors found that: "Excess body weight increases the risk of death from any cause and from cardiovascular disease in adults between 30 and 74 years of age.  The relative risk associated with greater body weight is higher among younger subjects."  In short, the older you are, the less detrimental obesity and overweight are for mortality.

Calle 1999 - "Body-Mass Index and Mortality in a Prospective Cohort of U.S. Adults"

Calle, Eugenia E; Thun, Michael J; Petrelli, Jennifer M; et al
"Body-Mass Index and Mortality in a Prospective Cohort of U.S. Adults"
New England Journal of Medicine
October 7, 1999; v.341, n.15; pp.1097-1105
On the Web
Relevance: medium

Using data from the Cancer Prevention Study (1982-1996), the authors calculated the relative risks of mortality for different categories of BMI at baseline, adjusting for sex, age and other risk factors. They found the usual J-shaped BMI-mortality curve with the lowest risk at a normal BMI. Smoking and disease change the curve by making leanness more risky.

Mokdad 2004 - "Actual Causes of Death in the United States, 2000"

Mokdad, Ali H; Marks, James S; Stroup, Donna F; Gerberding, Julie L
"Actual Causes of Death in the United States, 2000"
Journal of the American Medical Association
March 10, 2004; v.291, n.10
On the Web
Relevance: medium

Mokdad et al reviewed the literature for best estimates of the numbers of deaths attributable to various causes.  "The leading causes of death in 2000 were tobacco (435 000 deaths; 18.1% of total US deaths), poor diet and physical inactivity ([365 000 deaths; 15.2%]), and alcohol consumption (85 000 deaths; 3.5%).  Other actual causes of deaht were microbial agents (75 000), toxic agents (55 000), motor vehicle crashes (43 000), incidents involving firearms (29 000), sexual behaviors ( 20 000), and illicit use of drugs (17 000)."

Colditz 1999 - "Economic Costs of Obesity and Inactivity"

Colditz, Graham A
"Economic Costs of Obesity and Inactivity"
Medicine and Science in Sport and Exercise
November 1999; v.31, n.11 (supplement); pp.S663-S667
On the Web
Relevance: medium

Using similar methods to a previous study, Colditz estimates the direct costs of lack of physical exercise to be $24 billion per year (2.4% of national health care expenditures) and the direct costs for obesity, independent of lack of exercise, to be $70 billion (9.4%) for the year 1995.

Allison 1999 - "Annual Deaths Attributable to Obesity in the United States"

Allison, David B.; Fontaine, Kevin R.; Manson, JoAnne E.; Stevens, June; VanItallie, Theodore B.
"Annual Deaths Attributable to Obesity in the United States"
Journal of the American Medical Association
October 27, 1999; v.282, n.16; pp.1530-1538.
On the Web
Relevance: High

The authors used data from 5 cohort studies and 1991 national statistics to estimate that approximately 280,000 deaths annually are attributable to obesity, using all subjects.  When restricted to non-smokers the estimate rises to 325,000 deaths annually.

Wolf 1996 - "Social and Economic Effects of Body Weight in the United States"

Wolf, Anne M.; Colditz, Graham A.
"Social and Economic Effects of Body Weight in the United States"
The American Journal of Clinical Nutrition
March 1996; v.63, n.3 (supplement); pp.466S-469S
On the Web
Relevance: medium

Wolf and Colditz estimated the direct and indirect costs of obesity using risk estimates for various diseases from the Nurses' Health Study and estimates of lost productivity from the1988 National Health Interview Study.  The authors estimate that "if obesity were prevented, the United States could have saved $45.8 billion in 1990 (in 1993 dollars) or (6.8%) of health care expenditures for that year."

ICTA 2000 - “In-Car Air Pollution: The Hidden Threat to Automobile Drivers"

International Center for Technology Assessment,
“In-Car Air Pollution: The Hidden Threat to Automobile Drivers"
Report No. 4, An Assessment of the Air Quality Inside Automobile Passenger Compartments
Washington, DC: July 2000
On the Web
Relevance: high

This report reviews 23 studies from between 1982 and 1998 covering the main pollutants inside cars: particulate matter, volatile organic compounds, carbon monoxide, nitrogen oxides, and ozone.  For all exhaust pollutants except CO and the largest PM, concentrations are typically higher inside cars in heavy traffic than elsewhere.

Chertok 2004 - “Comparison of Air Pollution Exposure for Five Commuting Modes in Sydney – Car, Train, Bus, Bicycle and Walking”

Chertok, Michael ; Voukelatos, Alexander ; Sheppeard, Vicky ; and Rissel, Chris
“Comparison of Air Pollution Exposure for Five Commuting Modes in Sydney – Car, Train, Bus, Bicycle and Walking”
Health Promotion Journal of Australia
April 2004; v.15,n.1; pp.63-67
On the Web (pdf)
Relevance: high

The study measured the BTEX pollutant and NO2 exposure of 44 subjects on their regular daily commutes, each lasting at least 30 minutes each way.  Car commuters were exposed to the highest levels of BTEX pollutants, while bus commuters were exposed to the highest levels of NO2.  Train (light and heavy rail) commuters were exposed to the lowest levels of all pollutants measured.  Walking and cycling commuters were exposed to significantly lower levels of BTEX than car commuters and of NO2 than bus commuters. 

Batterman 2002 - “Levels and Composition of Volatile Organic Compounds on Commuting Routes in Detroit, Michigan”

Batterman, Stuart A; Peng, Chung-Yu; and Braun, James.
“Levels and Composition of Volatile Organic Compounds on Commuting Routes in Detroit, Michigan”
Atmospheric Environment
December 2002; v.36,n.39-40; pp.6015-6030
On the Web
Relevance: high

Batterman et al measured VOCs in cars and buses during rush hour on commercial, industrial, and residential routes in Detroit, Michigan.  They found that:

• VOC concentrations along roadways and in buses were similar;
• route did not much affect differences in air quality; however, the buses all traveled on congested 4 lane roads during rush hour; and
• VOC concentration varied significantly over time, which the authors attribute to changes in weather, mainly inversions and wind speed and direction;
• vehicle sources dominate industrial sources in influencing urban VOC concentrations, corroborating earlier studies; and
• VOC concentrations on roadways were much higher than concentrations at the two fixed-site monitoring stations in Detroit.  For example, BTEX concentrations measured at the fixed sites were 2-4 times lower than levels measured in traffic.

Kim 2001 - “Concentrations and Sources of VOCs in Urban Domestic and Public Microenvironments”

Kim, Young Min; Harrad, Stuart; Harrison, Roy M.
“Concentrations and Sources of VOCs in Urban Domestic and Public Microenvironments”
Environmental Science and Technology
March 15, 2001; v.35, n.6; pp.997-1004
On the Web
Relevance: high

Concentrations of volatile organic compounds (VOCs) were measured in a wide range of urban microenvironments (including homes, offices, shops, roadsides, buses, trains, and cars) in Birmingham, UK.  Of transportation microenvironments, cars had the highest mean concentrations of most of the VOCs measured; however the automobiles in the study were over 10 years old and smoking occurred in 6 of them during sampling.

Kim 2002 - “Levels and Sources of Personal Inhalation Exposure to Volatile Organic Compounds”

Kim, Young Min; Harrad, Stuart; Harrison, Roy M.
“Levels and Sources of Personal Inhalation Exposure to Volatile Organic Compounds” Environmental Science and Technology
December 15, 2002; v.36,n.24; pp.5405-5410
On the Web
Relevance: medium

Personal exposures to VOCs of 12 urban dwellers (Birmingham, UK) were measured over 5-10 days.  Exposure in the home contributed 50-80% of overall individual exposure to 2 main VOCs, mostly due to the large amount of time spent at home.  Smoking, vehicle use, and heating also contributed noticeably to personal exposure to VOCs.

Pucher 2003 - “Promoting Safe Walking and Cycling to Improve Public Health: Lessons from The Netherlands and Germany”

Pucher, John; Dijkstra, Lewis.
“Promoting Safe Walking and Cycling to Improve Public Health: Lessons from The Netherlands and Germany.”
American Journal of Public Health
September 2003; v.93, n.9; pp.1509-1516
On the Web
Relevance: high

Pucher and Dijkstra used data from national travel and crash surveys to compute fatality trends fatality and injury rates for pedestrians and cyclists in The Netherlands, Germany, and the United States.  The authors found that Americans walked/biked far less than do Dutch and Germans but were much more likely to be killed or injured than were Dutch and German pedestrians and cyclists, both on a per-trip and per-kilometer basis.  Causes include urban design and traffic regulations.