Project Number:10-07

Research Project:
Measurement and Toxicological Assessment of
Population Exposures to Airborne Particulate Matter (PM)
in Subways and Light Rail Trains

P.I. Name & Address:
Constantinos Sioutas
University of Southern California
Civil & Environmental Engineering Department
Kaprelian Hall, Room 210
Los Angeles, CA 90089-2531
Email: [email protected]
Website: http://www.usc.edu/dept/civil_eng/Earthquake_eng/
Phone: (213) 740-6134
Fax: (213) 744-1426

Co-P.I.
Zhi Ning
University of Southern California
Civil & Environmental Engineering Department
Kaprelian Hall, Room 210
Los Angeles, CA 90089-2531
Email: [email protected]
Website: http://www.usc.edu/dept/civil_eng/aerosol/ning1.html
Phone: (213) 321-1047
Fax: (213) 744-1426

Project Objective:
Expansion and increased use of urban public mass transit systems in the future are often portrayed as an unalloyed good with multiple personal, societal and environmental benefits. However, there is increasing evidence that respirable particulate matter (PM) in public mass transit systems is different from urban ambient PM concentrations. PM mass concentrations in urban subway systems have been reported to be up to an order of magnitude higher than at above?ground companion sites. Further, concentrations of metals ? particularly iron, and other transition metals such as manganese, chromium and nickel ? can be present in concentrations up to 100 times greater than typically observed in urban air dominated by motor vehicle emissions.

Not only may these species be toxic by themselves, but chemical interactions may increase oxidative stress within the cell. The association between elevated PM concentrations and adverse human health effects is well-established. While all of the specific mechanisms of impact remain to be determined, there is substantial evidence that induced oxidative stress is the principal factor in some health outcomes.

The primary objective of this project is to make measurements in the Los Angeles Metro system in order to quantify the chemical composition and physical and toxicological properties of respirable PM concentrations in its subway and light rail system. Observations in other systems may or may not be directly extrapolated to Los Angeles, although they do provide guidance. No systematic observations have previously been made in the Los Angeles transport system whose ridership has increased over 15% in the last two years and is expected to increase further in the future.

Task Descriptions
(1) Coordination with the Los Angeles County Metropolitan Transportation Authority for sampling campaign including fixed site identification.

(2) Prepare for and conduct sampling campaign.

(3) Perform analyses and investigate relationships between toxicity and chemical/physical properties of the collected particulate matter.

(4) Preparation of manuscripts for submission to the peer- reviewed technical literature, prepare final report.

Milestones, Dates:
(1) Month 1-3

(2) Months 3-4

(3) Months 4-10

(4) Months 9-12

Total Budget:
$90,000

Student Involvement:
One graduate student at 50% effort, 12 months

Relationship to Other Research Projects:
Related to 09-07; part of safety, security, and vulnerability focus area

Technology Transfer Activities:
Project report will be posted soon

Potential Benefits of the Project:
Developing an improved understanding of the factors affecting the toxicology of particulate exhaust emissions

TRB Keywords:
Light rail emissions, subway emissions, oxidative stress, particulate matter health effects, exposure assessment, transition metals and elements

Primary Subject:
2p.1 To make measurements in the Los Angeles Metro system in order to quantify the chemical composition and physical and toxicological properties of respirable PM concentrations in its subway and light rail system