Mobile Monitoring Research Project

This page last reviewed May 23, 2012

Several Toyota RAV 4 Electric Vehicles (EV) hav ebeen outfitted with an array of air monitoring instruments to measure greenhouse gases (GHG) and toxic air pollutants important to exposure and community health. Projects are currently underway to investigate pollutant levels near and on several freeways in the L.A. area, greenhouse gas emissions from poorly characterized sources, the effect of high emitting vehicles on short-term exposure, and community health monitoring.

  Much of the monitoring equipment has never been used in a mobile manner prior to these projects. Among the equipment in the RAV 4 EVs are NOx and CO analyzers, N2O and CO2 analyzer, a nephelometer, an aethalometer, PM10 and PM2.5 monitors, an ultrafine particle counter, and an ultrafine particle size classifier. The electric RAV 4 was selected for this project since it has an adequate interior volume for the monitoring equipment and has no emissions of its own to contaminate the samples being collected.   



The RAV 4 is modified to be an air sampling platform.




The RAV 4 gets the sampling equipment installed.




The RAV 4, charging and and calibrating at the "LA Supersite".

  ARB researchers prepare for a greenhouse gas field campaign.

Plot showing how the concentration of ultrafine particles changes
as a function of distance from a freeway in Santa Monica.

Links to projects involving the mobile platform include:
Harbor Communities Monitoring Study (HCMS)
ARB Board Hearing Presentation - Presented on August 14, 2003

Publications related to this research include:

Hu et al., Observation of elevated air pollutant concentrations in a residential neighborhood of Los Angeles California using a mobile platform, Atmospheric Environment, 2012.

Park et al., Emissions Factors for High-Emitting Vehicles Based on On-Road Measurements of Individual Vehicle Exhaust with a Mobile Measurement Platform. Journal of the Air and Waste Management Associations, 2011

Ning et al., Impact of roadside noise barriers on particle size distributions and pollutants concentrations near freeways, Atmospheric Environment, 2010.

Kozawa et al., Near-road air pollution impacts of goods movement in communities
adjacent to the Ports of Los Angeles and Long Beach, Atmospheric Environment, 2009.

Hu et al., Aircraft Emission Impacts in a Neighborhood Adjacent to a General Aviation Airport in Southern California, Environmental Science and Technology, 2009.

Hu et al., A wide area of air pollutant impact downwind of a freeway during pre-sunrise hours, Atmospheric Environment, 2009.

Fruin et al., Measurements and predictors of on-road ultrafine particle concentrations and associated pollutants in Los Angeles, Atmospheric Environment, 2008.

Westerdahl et al.  Mobile platform measurements of ultrafine particles and associated pollutant concentrations on freeways and residential streets in Los Angeles, Atmospheric Environment, 2005

For more information on this study please contact 

Walter Ham at or call 916-327-0599.

Research Activities