# Presentation: 069623

## Rich Baldauf, U.S. EPA
2008 National Air Quality Conference
April 6-9, 2008
Portland, Oregon

***2008 National Air Quality Conference***
***April 6-9, 2008***
***Portland, Oregon***

**Methods and Considerations for Near-Road Air Quality Monitoring**** **

## Overview

- Why are we concerned with near road air quality?
- What do previous monitoring studies show?
- What are the key factors to consider for near-road monitoring?

## Why are we concerned?

- Estimate over 35 million people live within 100 meters of a major transportation system including 4+ lane highways

- More than 1,000 compounds have been identified in exhaust and evaporative emissions from mobile sources
- Regulated Pollutants
- Air Toxics
- Particulate Matter

- Air quality measurements have indicated elevated pollutant concentrations near roads
- CO and Pb the focus during the 70’s
- Recent studies indicate complex mixture of pollutants

## Why are we concerned?

- Living near major roadways has been associated with numerous adverse health endpoints
- Cardio-respiratory effects (e.g., asthma, bronchitis)
- Adverse birth outcomes/developmental effects
- Premature mortality
- Cardiovascular effects
- Childhood cancer
- Hundreds of studies published just since 2000
- Account for varying fleets, engine technologies, etc.
- Evidence not equally as strong for each of these health effects
- Most initial studies conducted in Europe, although similar results have been reported for all parts of the world including the U.S.

## Key Factors for Consideration

- Objectives for near road monitoring
- Measurement data needs
- Traffic activity
- Meteorology
- Air Quality
- Network Design
- Monitor number/placement
- Site location(s)

## Potential Monitoring Objectives

- Trends sites to evaluate control strategies and fuel changes
- Accountability of regulatory programs
- SIP evaluations
- Monitoring data to evaluate regulatory emissions and dispersion models used for local assessments
- Environmental Impact Assessments (e.g. NEPA)
- Inventory projections
- Urban and land use planning
- Community-scale monitoring
- Evaluate concentrations near transportation sources
- Support health studies/determine population exposures
- Evaluate mitigation measures

## Measurement Data Needs

- Traffic Activity
- Key parameters: Volume, fleet mix, speed
- Many DOTs collect this data, but require coordination for access
- Meteorology
- Key parameters: Wind direction, wind speed, temperature, humidity
- 3-D measurements can provide added parameters (e.g., standard deviation of the vertical fluctuation in wind – measure of turbulence)
- Vehicle induced turbulence may affect siting meteorological stations (horizontal distance from road and vertical height)
- Air Quality
- Pollutants of interest
- NAAQS pollutants: CO, NO/NO2/NOx, Pb, PM10, PM2.5
- Particulate Matter: size, number, carbon, organics, elements, ions
- Air Toxics: VOCs (e.g., benzene, 1,3-butadiene), carbonyls (acetaldehyde, formaldehyde, acrolein), etc.
- Measurement frequency
- Shortest averaging times generally most desirable to determine relationships among traffic, meteorology and air quality

## Traffic, Meteorology and Air Quality Relationships

- Traffic Volume

- CO

- BC

- Wind Direction

## Pollutant Mixtures

- NO

- CO

- Ammonia

- Benzene

- Naphthalene

- Traffic Volume

- Wind Dir.

## Near-Road PM Elemental Chemical Characteristics

**Near-Road PM Elemental Chemical Characteristics**

## Network Design Considerations

- Monitor number/placement
- Distance from the road (monitoring objectives)
- Upwind/background monitoring
- Horizontal/vertical spacing
- Site location:
- Type of road
- Highway
- Arterial
- Traffic volumes and activities supported
- Roadway design
- Topography: at-grade, depressed (vertical, sloped), elevated
- Roadside structures: noise barriers, vegetation, buildings

## Concentration Changes with Distance from Road

## Wind Tunnel Assessments:Roadway Design

## Wind Tunnel Assessments:Roadway Design

## Fluid Dynamics Modeling: 

**Fluid Dynamics Modeling: **
**Noise Barriers and Vegetation**

## Noise Barrier and Vegetation Effects

## Noise Barrier and Vegetation Effects

## Summary

- Growing interest in collecting near road air quality data
- A number of factors should be considered before initiating monitoring
- Objectives/needs
- Pollutants of interest
- Integration with traffic and meteorological data
- Network design
- Number and distance from road/background sites
- Site location
- Type of road
- Presence of structures, changing topography
- Representativeness of site for monitoring objectives

## Participants

- Brian Gullett, Cary Secrest, Dave Davies, David Heist, David Olson, David Proffitt, Eben Thoma, Eric Morris, Fu-Lin Chen, Gorge Bowker, Ian Gilmour, Jason Weinstein, John Kinsey, John McGee, Laurie Brixey, Mike Hays, Nealson Watkins, Patricia Rowley, Rich Baldauf, Richard Shores, Richard Snow, Robert Seila, Seung-Hyun Cho, Steve Perry, Sue Kimbrough, Tim Barzyk, Todd Krantz, Tom Long, Vlad Isakov, Andrey Khlystov, Chris Frey, John Bang
*Organizations:*
- U.S. Environmental Protection Agency
- Office of Research and Development, Research Triangle Park, North Carolina, USA
- National Risk Management Research Laboratory
- National Health and Environmental Effects Research Laboratory
- National Exposure Research Laboratory
- Office of Air and Radiation
- Office of Transportation and Air Quality
- Office of Air Quality Planning and Standards
- Office of Civil Enforcement
- National Oceanic & Atmospheric Admin, Atmospheric Sciences Modeling Division
- Arcadis Inc., Research Triangle Park, North Carolina, USA
- Alion, Research Triangle Park, North Carolina, USA
- Duke University, Department of Civil and Environmental Engineering
- North Carolina Central University, Department of Environmental Sciences
- North Carolina State University, Department of Civil and Environmental Engineering