Informal Workshop on Pollution Impacts of Secondary Roadways and Their Mitigation

1
Informal Workshop on Pollution Impacts of
Secondary Roadways and Their Mitigation
University of California at Davis, CA Traffic,
Air Pollution and Health Seeking
Connections William E. Wilson
Disclaimer The materials in this Proceedings
document, and the presentation on which they are
based, have been reviewed by the U.S.
Environmental Protection Agency and cleared for
presentation and release to the public. However,
the views expressed in this presentation are
those of the author and do not necessarily
reflect the views or policies of the EPA.
Office of Research and Development National
Center for Environmental Assessment, Office of
Research and Development, U. S. Environmental
Protection Agency
January 24, 2008
2
Workshop on Pollution Impacts of Secondary
Roadways and their Mitigation , January 24, 2008
at the University of California at Davis,
CATraffic, Air Pollution and Health - Seeking
ConnectionsWilliam E. Wilson, National Center
for Environmental Assessment, U. S.
Environmental Protection Agency, Research
Triangle Park, NC 27711

• Abstract The finding of associations between
  proximity to traffic and various health effects
  and associations of daily traffic source
  contributions to PM and daily mortality has led
  to increasing interest in traffic-air pollution-
  health connections. Early studies showed that
  traffic generated ultrafine and thoracic coarse
  particles but not accumulation mode particles.
  However, when the wind is parallel to the road,
  the ultrafine particles have time to grow into
  the accumulation mode before they affect nearby
  residents and commuters. ICRP and MPPD models of
  particle deposition in the respiratory system
  show that the fractional deposition of ultrafine
  and coarse particles is greater than that of
  accumulation mode particles. Toxicologic studies
  suggest the surface area of poorly soluble
  particles may be a better index of particle
  toxicity than number or volume or mass.
  Epidemiological studies associating health
  effects with proximity to traffic indicate that
  the effects of traffic fall off rapidly, being
  found only for people living a few hundred meters
  from traffic sources. Therefore, the toxic agent
  must also fall off rapidly with distance from
  traffic. Recent studies have shown how particle
  number, N, surface, S, and volume, V (and
  deposition of particle number, Nd, surface, Sd,
  and volume, Vd, in the lung) fall off with
  distance from the roadway. With wind
  perpendicular to the roadway, N and Nd fall off
  rapidly and smoothly. S and Sd and V and Vd,
  however, after a drop between 30 and 60 meters,
  remain about the same between 60 and 150 meters,
  only to drop to near background levels at 300
  meters. Potentially toxic gases emitted by
  vehicles (CO, NO, NO2, and a variety of organic
  compounds), dust from brake linings, and thoracic
  coarse particles (suspended by traffic-generated
  turbulence) would also be expected to decrease
  rapidly with distance from roadways. More
  information is needed on the relative toxicity of
  traffic-generated particles vs. gases and if
  particles are toxic, which size and chemical
  compositions are most toxic.
• Disclaimer The materials in this Proceedings
  document, and the presentation on which they are
  based, have been reviewed by the U.S.
  Environmental Protection Agency and cleared for
  presentation and release to the public. However,
  the views expressed in this presentation are
  those of the author and do not necessarily
  reflect the views or policies of the EPA

3
Notes for Slides for Proceedings of the Workshop

• 1. Title
• 2. Abstract
• 3. Notes
• 4. Many different types of health
  effects have been associated with proximity to
  traffic.
• 5,6,7,8. References and abstracts for Slide 4.
• 9. Traffic generates ultrafine
  particles (lt0.1 µm diameter) and coarse mode
  particles (gt1.0 µm diameter) but not accumulation
  mode particles (0.1 to 1.0 µm diameter).
• 10. However, when the wind is parallel
  to the roadway, there is time for the ultrafine
  particles to grow into the accumulation mode and
  the concentration of ultrafine and accumulation
  mode particles are much higher than when the wind
  is perpendicular to the roadway.
• 11. This figure shows the three major
  regions of the respiratory tract where inhaled
  particles can deposit.
• 12. Results from a dosimetric model show
  that the fraction of ultrafine particles
  deposited in the Alveolar and Tracheobronchial
  regions of the lung is greater than that for
  accumulation mode particles.
• 13. This figure shows that accumulation
  and coarse mode particles are scavenged by
  alveolar macrophages but that ultrafine particles
  can penetrate into cells and across cells into
  the blood stream.
• 14. Fine and ultrafine TiO2 particles
  behave differently when their toxicity is plotted
  versus number or mass.
• 15. However, they behave similarly when
  the toxicity is plotted versus surface area.
• 16. Toxicity of carbon particles also
  scales better with surface area than mass or
  number. The previous slides suggest that surface
  area of insoluble particles may be an important
  parameter for understanding toxicity.
• 17. Two epidemiological studies have found
  associations between health effects and particle
  surface area.
• 18. References for Slide 17
• 19. Changes in the number size
  distribution as a function of distance downwind
  of a freeway. Changes in size distribution and
  concentration with distance are thought to be due
  mostly to dilution and condensation.
• 20. Fall off of several concentration
  and deposition variables, normalized to 1 at 300
  meters.
• 21. Fall off of several concentration
  and deposition variables, normalized to 1 at 30
  meters. Note leveling off of surface and volume
  concentrations and in the amount of surface and
  volume deposited in the lung of at distances
  between 60 and 150 meters.

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Health Effects Associated with Proximity to
Traffic

• Mortality
• Dutch - living near roadways doubled risk of
  death from heart or lung disease (1)
• Canada - living near roadways increased the risk
  of death due to stroke and cardiovascular disease
  by 40 (2)
• Heart Attack
• Germany - the risk of a myocardial infarction was
  tripled by exposure to traffic in the previous
  hour (3)
• Prenatal Impacts
• Los Angles - women living near high traffic areas
  were at increased risk of premature delivery (4)
• Asthma Prevalence
• Southern California - prevalence of asthma among
  children was associated with several indicators
  of exposure to traffic including proximity of the
  home to a freeway (5)
• Respiratory Symptoms
• East Bay (San Francisco area) - children
  attending schools near freeways had more
  respiratory symptoms (5)
• Cardiovascular Effects
• North Carolina - PM exposure in cars was
  associated with cardiovascular effects in young
  men (6)

5
References for Slide, Health Effects Associated
with Proximity to Traffic

• (1) Hoek, G. Brunekreef, B. Goldbohm, S.
  Fischer, P. Van den Brandt, P. A. (2002)
  Association between mortality and indicators of
  traffic-related air pollution in the Netherlands
  a cohort study. Lancet 360 1203-1209.
  Abstract Background Long-term exposure to
  particulate matter air pollution has been
  associated with increased cardiopulmonary
  mortality in the USA. We aimed to assess the
  relation between traffic-related air pollution
  and mortality in participants of the Netherlands
  Cohort study on Diet and Cancer (NLCS), an
  ongoing study. Methods We investigated a random
  sample of 5000 people from the full cohort of the
  NLCS study (age 55-69 years) from 1986 to 1994.
  Long-term exposure to traffic-related air
  pollutants (black smoke and nitrogen dioxide) was
  estimated for the 1986 home address. Exposure was
  characterized with the measured regional and
  urban background concentration and an indicator
  variable for living near major roads. The
  association between exposure to air pollution and
  (cause specific) mortality was assessed with
  Cox's proportional hazards models, with
  adjustment for potential confounders. Findings
  489 (11) of 4492 people with data died during
  the follow-up period. Cardiopulmonary mortality
  was associated with living near a major road
  (relative risk 1.95, 95 CI 1.09-3.52) and, less
  consistently, with the estimated ambient
  background concentration (1.34, 0.68-2.64). The
  relative risk for living near a major road was
  1.41 (0.94-2.12) for total deaths.
  Non-cardiopulmonary, non-lung cancer deaths were
  unrelated to air pollution (1.03, 0.54-1.96 for
  living near a major road). Interpretation
  Long-term exposure to traffic-related air
  pollution may shorten life expectancy.
• (2) Finkelstein, M. M. Jerrett, M. Sears, M.
  R. (2005) Environmental inequality and
  circulatory disease mortality gradients. J.
  Epidemiol. Comm. Health 59 481-487. Citations
  1557,CTD. Abstract Study objective Studies in
  Europe and North America have reported that
  living in a disadvantaged neighbourhood is
  associated with an increased incidence of
  coronary heart disease. The aim of this study was
  to test the hypotheses that exposure to traffic
  and air pollution might account for some of the
  socioeconomic differences in mortality rates in a
  city where residents are covered by universal
  health insurance. Design Cohort mortality
  study. Individual postal codes used to derive
  (1) socioeconomic status from census data (2)
  mean air pollution levels from interpolation
  between governmental monitoring stations (3)
  proximity to traffic from the geographical
  information system. Analysis conducted with Cox
  proportional hazards models. Setting Hamilton
  Census Metropolitan Area, Ontario, Canada, on the
  western tip of Lake Ontario (population about 480
  000). Participants 5228 people, aged 40 years
  or more, identified from register of lung
  function laboratory at an academic respirology
  clinic between 1985 and 1999. Main results
  Circulatory disease (cardiovascular and stroke)
  mortality rates were related to measures of
  neighbourhood deprivation. Circulatory disease
  mortality rates were also associated with indices
  of long term ambient pollution at the subjects
  residences (relative risk 1.06, 1.00 to 1.13) and
  with proximity to traffic (relative risk 1.40,
  1.08 to 1.81). Subjects in more deprived
  neighbourhoods had greater exposure to ambient
  particulate and gaseous pollutants and to
  traffic. Conclusions At least some of the
  observed social gradients in circulatory
  mortality arise from inequalities in
  environmental exposure to background and traffic
  air pollutants.

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References for Slide, Health Effects Associated
with Proximity to Traffic (cont)

• (3) Peters, A. Von Klot, S. Heier, M.
  Trentinaglia, I. Hormann, A. Wichmann, H. E.
  Lowel, H. (2004) Exposure to traffic and the
  onset of myocardial infarction. N. Engl. J. Med.
  351 1721-1730. Abstract Background An
  association between exposure to vehicular traffic
  in urban areas and the exacerbation of
  cardiovascular disease has been suggested in
  previous studies. This study was designed to
  assess whether exposure to traffic can trigger
  myocardial infarction. Methods We conducted a
  case-crossover study in which cases of myocardial
  infarction were identified with the use of data
  from the Cooperative Health Research in the
  Region of Augsburg Myocardial Infarction Registry
  in Augsburg, in southern Germany, for the period
  from February 1999 to July 2001. There were 691
  subjects for whom the date and time of the
  myocardial infarction were known who had survived
  for at least 24 hours after the event, completed
  the registry's standardized interview, and
  provided information on factors that may have
  triggered the myocardial infarction. Data on
  subjects' activities during the four days
  preceding the onset of symptoms were collected
  with the use of patient diaries. Results An
  association was found between exposure to traffic
  and the onset of a myocardial infarction within
  one hour afterward (odds ratio, 2.92 95 percent
  confidence interval, 2.22 to 3.83 Plt0.001). The
  time the subjects spent in cars, on public
  transportation, or on motorcycles or bicycles was
  consistently linked with an increase in the risk
  of myocardial infarction. Adjusting for the level
  of exercise on a bicycle or for getting up in the
  morning changed the estimated effect of exposure
  to traffic only slightly (odds ratio for
  myocardial infarction, 2.73 95 percent
  confidence interval, 2.06 to 3.61 Plt0.001). The
  subject's use of a car was the most common source
  of exposure to traffic nevertheless, there was
  also an association between time spent on public
  transportation and the onset of a myocardial
  infarction one hour later. Conclusions
  Transient exposure to traffic may increase the
  risk of myocardial infarction in susceptible
  persons.
• (4) Wilhelm, M. Ritz, B. (2003) Residential
  proximity to traffic and adverse birth outcomes
  in Los Angeles County, California, 1994-1996.
  Environ. Health Perspect. 111 207-216.
  Abstract We reported previously that increases
  in ambient air pollution in the Los Angeles basin
  increased the risk of low weight and premature
  birth. However, ambient concentrations measured
  at monitoring stations may not take into account
  differential exposure to pollutants found in
  elevated concentrations near heavy-traffic
  roadways. Therefore, we used an epidemiologic
  case-control study design to examine whether
  residential proximity to heavy-traffic roadways
  influenced the occurrence of low birth weight
  (LBW) and/or preterm birth in Los Angeles County
  between 1994 and 1996. We mapped subject home
  locations at birth and estimated exposure to
  traffic-related air pollution using a
  distance-weighted traffic density (DWTD) measure.
  This measure takes into account residential
  proximity to and level of traffic on roadways
  surrounding homes. We calculated odds ratios
  (ORs) and risk ratios (RRs) for being LBW and/or
  preterm per quintile of DWTD. The clearest
  exposure-response pattern was observed for
  preterm birth, with an RR of 1.08 95 confidence
  interval (CI), 1.01-1.15 for infants in the
  highest DWTD quintile. Although higher risks were
  observed for LBW infants, exposure-response
  relations were less consistent. Examining the
  influence of season, we found elevated risks
  primarily for women whose third trimester fell
  during fall/winter months (ORterm LBW 1.39 95
  CI, 1.16-1.67 ORpreterm and LBW 1.24 95 CI
  1.03-1.48 RRall preterm 1.15 95 CI,
  1.05-1.26), and exposure-response relations were
  stronger for all outcomes. This result is
  consistent with elevated pollution in proximity
  to sources during more stagnant air conditions
  present in winter months. Our previous research
  and these latest results suggest exposure to
  traffic-related pollutants may be important.

7
References for Slide, Health Effects Associated
with Proximity to Traffic (cont)

• (5) Gauderman WJ, Avol E, Lurmann, F, Kuenzli N,
  Gilliland F, Peters J, McConnell R. (2005)
  Childhood asthma and exposure to traffic and
  nitrogen dioxide. Epidemiology 16(6)737-743.
• Abstract Background Evidence for a causal
  relationship between traffic-related air
  pollution and asthma has not been consistent
  across studies, and comparisons among studies
  have been difficult because of the use of
  different indicators of exposure. Methods We
  examined the association between traffic-related
  pollution and childhood asthma in 208 children
  from 10 southern California communities using
  multiple indicators of exposure. Study subjects
  were randomly selected from participants in the
  Children's Health Study. Outdoor nitrogen dioxide
  (NO2) was measured in summer and winter outside
  the home of each child. We also determined
  residential distance to the nearest freeway,
  traffic volumes on roadways within 150 meters,
  and model-based estimates of pollution from
  nearby roadways. Results Lifetime history of
  doctor-diagnosed asthma was associated with
  outdoor NO2 the odds ratio (OR) was 1.83 (95
  confidence interval 1.04-3.22) per increase of
  1 interquartile range (IQR 5.7 ppb) in
  exposure. We also observed increased asthma
  associated with closer residential distance to a
  freeway (1.89 per IQR 1.19-3.02) and with
  model-based estimates of outdoor pollution from a
  freeway (2.22 per IQR 1.36-3.63). These 2
  indicators of freeway exposure and measured NO2
  concentrations were also associated with wheezing
  and use of asthma medication. Asthma was not
  associated with traffic volumes on roadways
  within 150 meters of homes or with model-based
  estimates of pollution from nonfreeway roads.
  Conclusions These results indicate that
  respiratory health in children is adversely
  affected by local exposures to outdoor NO2 or
  other freeway-related pollutants.
• (6) Kim JJ, Smorodinsky S, Lipsett M, Singer BC,
  Hogdson AT, Ostro B. (2004) Traffic-related air
  pollution near busy roads the East Bay
  Childrens Respiratory Health Study. American
  Journal of Respiratory Critical Care Medicine. Am
  J Respir Crit Care Med 170520-526.
• Abstract Recent studies, primarily in Europe,
  have reported associations between respiratory
  symptoms and residential proximity to traffic
  however, few have measured traffic pollutants or
  provided information about local air quality. We
  conducted a school-based, cross-sectional study
  in the San Francisco Bay Area in 2001.
  Information on current bronchitis symptoms and
  asthma, home environment, and demographics was
  obtained by parental questionnaire (n 1,109).
  Concentrations of traffic pollutants (particulate
  matter, black carbon, total nitrogen oxides
  NOX, and nitrogen dioxide NO2) were measured
  at 10 school sites during several seasons.
  Although pollutant concentrations were relatively
  low, we observed differences in concentrations
  between schools nearby versus those more distant
  (or upwind) from major roads. Using a two-stage
  multiple-logistic regression model, we found
  associations between respiratory symptoms and
  traffic-related pollutants. Among those living at
  their current residence for at least 1 year, the
  adjusted odds ratio for asthma in relationship to
  an interquartile difference in NOX was 1.07 (95
  confidence interval, 1.00-1.14). Thus, we found
  spatial variability in traffic pollutants and
  associated differences in respiratory symptoms in
  a region with good air quality. Our findings
  support the hypothesis that traffic-related
  pollution is associated with respiratory symptoms
  in children.

8
References for Slide, Health Effects Associated
with Proximity to Traffic (cont)

• (7) Riediker M, Cascio WE, Griggs TR, Herbst MC,
  Bromber PA, Neas L, Williams R, Devlin RB. (2004)
  Particulate matter exposure in cars is associated
  with cardiovascular effects in healthy, young
  men. Am J Respir Crit Care Med 169934-940.
  Exposure to fine airborne particulate matter
  (PM2.5) is associated with cardiovascular events
  and mortality in older and cardiac patients.
  Potential physiologic effects of in-vehicle,
  roadside, and ambient PM2.5 were investigated in
  young, healthy, nonsmoking, male North Carolina
  Highway Patrol troopers. Nine troopers (age 23 to
  30) were monitored on 4 successive days while
  working a 3 P.M. to midnight shift. Each patrol
  car was equipped with air-quality monitors. Blood
  was drawn 14 hours after each shift, and
  ambulatory monitors recorded the
  electrocardiogram throughout the shift and until
  the next morning. Data were analyzed using mixed
  models. In-vehicle PM2.5 (average of 24 Ág/m3)
  was associated with decreased lymphocytes (û11
  per 10 Ág/m3) and increased red blood cell
  indices (1 mean corpuscular volume), neutrophils
  (6), C-reactive protein (32), von Willebrand
  factor (12), next-morning heart beat cycle
  length (6), next-morning heart rate variability
  parameters, and ectopic beats throughout the
  recording (20). Controlling for potential
  confounders had little impact on the effect
  estimates. The associations of these health
  endpoints with ambient and roadside PM2.5 were
  smaller and less significant. The observations in
  these healthy young men suggest that in-vehicle
  exposure to PM2.5 may cause pathophysiologic
  changes that involve inflammation, coagulation,
  and cardiac rhythm.

9
Particle Concentrations 20m Downwind from Roadway
Source Wilson et al. (1977)
10
Contributions of Vehicle Emissions to In-Car
Concentrations
Source Wilson et al. (1977)
11
Fractional Deposition of Inhaled Particles in the
Human Respiratory Tract (ICRP Model, 1994
Nose-breathing)
Oberdörster et al, 2005 Drawing courtesy of
J.Harkema
12
Alveolar
TB
13
Ultrastructure of Pulmonary Alveoli and
Capillaries Fate of deposited Particles
Large particle
Chemotaxis
Surfactant layer Phospholipids, proteins
ultrafine particles
TranscellularTranslocation
Endocytosis
Tight junction (paracellular) Translocation
Largely unknown Translocation rates
14
? Fine TiO2 (250nm) Ultrafine TiO2 (20nm)
? Saline
15
Particle Surface Area Instilled, cm2
16
Inflammatory Effects of Ultrafine Carbon
ParticlesInstilled into the Lungs of Mice
17
Health Effects Associated with Surface Area in
Epidemiologic Studies

• Asthma and respiratory symptoms
• The geometric surface area of particles between
  10 and 100 nm, calculated from size distribution
  measurements, was associated with doctor visits
  by adults in Atlanta, GA. (1)
• Lung Function and respiratory symptoms
• The signal from a diffusion charging sensor
  (LQ1-DC), measuring the active surface area of
  suspended particles, was found to be associated
  with decrements in lung function and respiratory
  symptoms for a group of elementary school
  children in Linz, Austria (2)

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• References for Slide
• Epidemiologic Studies Using Surface-related
  Variables
• Associations and Lags Between Air Pollution and
  Acute Respiratory Visits in an Ambulatory Care
  Setting 25-month Results From the Aerosol
  Research and Inhalation Epidemiological Study.
  Amber Hughes Sinclair and Dennis Tolsma, J. Air
  Waste Management Association, 2004, 54,
  1212-1218.
• The geometric surface area of particles between
  10 and 100 nm, calculated from size distribution
  measurements, was associated with doctor visits
  for adult asthma, upper and lower respiratory
  symptoms in Atlanta, GA. Although only about one
  year of data was available, compared to 1½ to 2
  years for other variables, the association of
  particle surface area with adult asthma visits
  was by far the most significant relationship
  found.
• (2) The Active Surface of Suspended Particles as
  a Predictor of Lung Function and Pulmonary
  Symptoms in Austrian School Children. Hanns
  Moshammer and Manfred Neuberger, Atmospheric
  Environment 2003, 37, 1737-1744.
• The daily means of the signal from a diffusion
  charging sensor (LQ1-DC), measuring the active
  surface area of suspended particles, was found to
  be associated with decrements in lung function
  for a group of elementary school children in
  Linz, Austria and with respiratory symptoms in a
  sensitive subgroup (p 0.001 to 0.041).

19
Traffic Pollution Particle Number Distributions
at Various Distance Downwind of Freeway 405 in
Los Angeles
Zhu et al.(2002)
20
(No Transcript)
21
(No Transcript)
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Proximity to Traffic Is Associated with Many
Types of Health Effects

• What is the toxic or causal pollutant?
• Apparently it must fall off rapidly with
  distance. Is this due to dilution or a change in
  composition or size distribution?
• We should not forget that commuters in cars and
  buses and workers in trucks may receive even
  higher peak exposures than people living near
  roadways.

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Possible Toxic Agents