United States
Environmental Protection
Agency
Environmental Sciences Researc
Laboratory
Research Triangle Park NC 27711
Research and Development
EPA-600/S4-81-069 Oct. 1981
Project Summary
Carbon Monoxide Commuter
Exposure Data Base: A 5-Day
Study in Los Angeles
William B. Petersen, Rodney H. Allen, Richard. A. Ziskind, and Michael B.
Rogozen
Recent concern about carbon
monoxide exposure to the commuter
population prompted the U.S. Envi-
ronmental Protection Agency to
conduct a five-day field project to
assess the carbon monoxide (CO)
exposure to Los Angeles commuters.
The purpose of this report is to docu-
ment the field project and to provide
the data collected during the project to
the public. The data collected include
measurements of interior CO, exterior
CO and vehicle speed for three
vehicles traveling typical commuter
routes during the morning and
evening peak traffic periods. In addi-
tion, hourly average CO measure-
ments were taken from eight South
Coastal Air Quality Mangement
District fixed-site monitoring stations
and six California Transportation
Agency vans in the proximity of the
commuter routes.
This Project Summary was develop-
ed by EPA's Environmental Sciences
Research Laboratory, Research Tri-
angle Park, NC, to announce key find-
ings of the research project that is fully
documented in a separate report of the
same title (see Project Report ordering
information at back).
Introduction
During October 1 through 5, 1979,
Science Applications Incorporated,
under contract with the U.S. Environ-
mental Protection Agency, conducted a
field study to monitor CO concentra-
tions both inside and outside three
vehicles traveling typical commuter
routes in Los Angeles County. The
vehicles traveled the typical commuter
routes during the morning and the
evening peak traffic periods. Two Inter-
scan continuous CO ajialyzers were
installed in each vehicle to monitor CO
levels simultaneously inside and
outside the vehicles. The outside samp-
ling probe was located near the fresh air
intake, while the inside probe was
located near the driver's breathing zone.
The instrumentation, route selection,
monitoring conditions, and observed
data are presented.
The data collected included recorder
time traces of interior CO (COiNj),
exterior CO (COExr), and vehicle speed.
Accompanying these were the
technician log sheets describing condi-
tions present as data were taken.
Conditions included location, roadway
description, degree of traffic congestion,
and vehicle comfort state. In addition,
hourly average CO measurements were
taken from eight South Coastal Air
Quality Management District fixed-site
monitoring stations and six California
Transportation Agency vans in the
proximity of the commuter routes
chosen.
The full EPA report describes the
instrumentation used in the study, the.
route selection and experimental
design, and the development of the data
-------
base. Appendices A and B in the report
present the exposure and fixed site data.
Appendix C describes the methodology
used to estimate the one-minute aver-
ages and Appendix D presents a graphi-
cal display of the exposure data.
Procedure
The monitoring periods and routes
were chosen to correspond to repre-
sentative commuter trips throughout
the Los Angeles area. Although no
specific available "typical" commuter
routes have been published, general
knowledge of the traffic patterns, along
with other factors such astraffic counts,
was used to select vehicle routes. Each
vehicle essentially simulated two com-
muter travel patterns. The mileage
driven was partitioned so that freeway
and arterial driving accounted for
roughly 80 to 20 percent, respectively.
Furthermore, the routes all traveled
some portion of the "42-mile loop."This
loop is instrumented by CALTRANS to
provide reaJ-time traffic volume and
speed data. A final consideration was
the proximity of routes to air quality
monitoring stations. Since the latter are
placed throughout the area, there was
no problem in locating routes near fixed
site stations.
The three Plymouth Valiants used
traveled morning and afternoon com-
muter routes. The three vehicles
followed the prescribed commuter
routes as nearl.y as possible during the
five-day study, and traveled over the
routes as many times as possible during
each three-hour period. Each half-hour
during a commuter run, a new comfort
state was established in the vehicle,
according to a predetermined schedule.
In order to provide an adequate descrip-
tion of the measurement conditions a
detailed recording of real time informa-
tion was made. An unambiguous
correspondence among CO levels,
vehicle speed, and recorder observa-
tions was made by assigning an alpha-
betical code to each notation and
simultaneously marking the log and
chart papers by check marks in the
progressive code letter.
Carbon monoxide was measured
using two InterScan 1146 portable
continuous analyzers in each vehicle.
The InterScan device is a direct reading,
battery operated unit with integral
sample pumps and battery charger. The
detection element is an electrochemical
voltametric sensor. The unit is designed
for over eight hours of continuous field
operation between recharges. The
detection ranges are 0 to 50 and 0 to
100 ppm. The electrical output is con-
nected to a Soltec VP-6723S 2-pen
portable strip chart recorder. This device
has a built-in battery charger and a
glitch marker push button feature,
which is useful for correlating recorder
trace location with technicians' log
comments.
Instrumentation for vehicle speed
measurements consisted of a magnetic
transducer pickup, pulse analyzer and
converter circuitry, and a Soltec
recorder. The pickup was attached to
the front right disc brake' caliper. Its
output was a pulse train with rate
proportional to the number of ventilator
rotor disc slots passing in a unit time.
This pulse output was converted to a
linear analog direct current voltage
which provided the Soltec recorder
input.
Conclusions
The full EPA report does not provide
any data analysis or conclusions, but it
does provide a description of the experi-
ment and a hard copy of the data
collected during the project. These data,
along with other data bases, will provide
researchers with the necessary tools to
characterize commuter exposures to
automotive pollutants.
The EPA authors William B. Peterson (also the EPA Project Officer, see below),
Rodney H. Allen, Richard A. Ziskind, and Michael B. Rogozen are with the
Environmental Sciences Research Laboratory, Research Triangle Park, NC
27711.
The complete report, entitled "Carbon Monoxide Commuter Exposure Data
Base: A 5-Day Study in Los Angeles," (Order No. PB 82-103 607; Cost: $9.50,
subject to change) will be available only from:
National Technical Information Service
5285 Port Royal Road
Springfield, VA 22161
Telephone: 703-487-4650
The EPA Project Officer can be contacted at:
Environmental Sciences Research Laboratory
U.S. Environmental Protection Agency
Research Triangle Park. NC 27711
United States
Environmental Protection
Agency
Center for Environmental Research
Information
Cincinnati OH 45268
Postage and
Fees Paid
Environmental
Protection
Agency
EPA 335
Official Business
Penalty for Private Use $300
RETURN POSTAGE GUARANTEED
PS 0000329
U S ENVJK PCOTECriUN
REGION 5 LIBRARY
230 S DEARBORN STREE1
CHICAGU IL 60604
U S. GOVERNMENT PRINTING OFFICE; 1981 — 559-017/7416
------- |