Project at a Glance

Title: Allergens in paved road dust and airborne particles.

Principal Investigator / Author(s): Cass, Glen

Contractor: California Institute of Technology

Contract Number: 95-312

Research Program Area: Health & Exposure

Topic Areas: Health Effects of Air Pollution, Toxic Air Contaminants


The purpose of the research reported here is to quantify the allergen content of paved road dust and to estimate the magnitude of the road dust contribution to airborne allergen concentrations. Paved road dust present on the surface of streets in Southern California consists of a complex mixture of soil dust, deposited motor vehicle exhaust particles, tire dust, brake lining wear dust, plant fragments and other biological materials. The research presented here shows that allergens from at least 20 different source materials are found in the paved road dust. These include pollens and pollen fragments, animal dander and maids. Natural rubber latex allergens were not detected in the present work but have been measured in previous studies. When paved road dust is resuspended into the atmosphere by passing vehicle traffic, allergen concentrations in the air are increased above the levels that would prevail without the vehicle traffic. Using immunological essays which measure the proteins extracted from environmental samples that bind to antibodies present in the blood serum of allergenic patients, it is possible to measure the allergen concentrations present in paved road dust and in airborne particle samples. Results show that 5% to 13% of the allergenicity of atmospheric totaI suspended particulate matter samples at Long Beach and Rubidoux, California is attributable to paved road dust emissions. In an industrial area of urban central Los Angeles where there is less proximity to vegetation and domestic activities, the paved road dust contribution to airborne allergen concentrations is lower, accounting for approximately 0.5% of the total allergenic activity of the atmospheric particle samples.

For questions regarding this research project, including available data and progress status, contact: Research Division staff at (916) 445-0753

Stay involved, sign up with CARB's Research Email Distribution List