science in ACTION

BUILDING A SCIENTIFIC FOUNDATION FOR SOUND ENVIRONMENTAL DECISIONS

FREQUENTLY ASKED QUESTIONS

GENERAL INFORMATION ABOUT THE
DETROIT EXPOSURE AND AEROSOL RESEARCH STUDY (DEARS)

What is the Detroit Exposure and Aerosol Research Study?

The Detroit Exposure and Aerosol Research Study (DEARS) was a three-year field study conducted
by the U.S. Environmental Protection Agency (EPA) from 2004 through 2007. Its purpose is to
develop scientific information that helps EPA understand how air pollutant concentrations measured
at outdoor community air monitoring stations compare to those measured in various neighborhoods
and in some residences. This study, which was conducted in Wayne County, Michigan, is part of
EPA's ongoing research on how people are exposed to fine particles and air toxics and the conditions
that affect their exposures.

Why is the DEARS important to understanding air quality?

The study is contributing to our understanding of how air quality information collected at the
community level compares to information collected in a neighborhood and in and around
individual homes. Additionally, by completing questionnaires and surveys, the DEARS
participants provided EPA scientists with a better understanding of the activities that affect
individuals' exposures to air pollutants. Ultimately what scientists learn from the DEARS will
help EPA, and others protect human health and the environment.

Why was Detroit selected as the study location?

Detroit has a variety of neighborhoods that might have air characteristics that are different from
one another. Wayne County's population enabled us to recruit participants for the study who might
live near different types of pollutant sources. Also, the Detroit area has distinct summer and winter
climates that may affect how individuals are exposed to various air pollutants. Finally, the study
received support and interest from Detroit's local community action groups, State air quality
agency and nearby university researchers when it was undergoing development in 2004.

When was the study conducted?

Participant recruitment and field data collections began during the summer of 2004. Collection of
all of the field measurements and information was completed by March 2007.

Who conducted this study?

The DEARS was conducted by scientists in the EPA's National Exposure Research Laboratory in
the Office of Research and Development. The Michigan Department of Environmental Quality
(MDEQ), an EPA contractor, and others provided valuable assistance.

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Which neighborhoods in Wayne County participated in the study?

Homes involved in the air monitoring were randomly selected from neighborhoods associated with
Southwest Detroit, the Ambassador Bridge, East Detroit, Northeast Dearborn, West Detroit and
Belleville. These neighborhoods were selected due to a variety of factors including their distance
to potential pollution sources, the number of homes available for successful recruitment, along with
the average age and construction type of the home.

How was the DEARS conducted?

The DEARS can be divided into four main parts: personal monitoring, residential indoor
monitoring, residential outdoor monitoring, and monitoring performed at a central community site
(Allen Park). The personal and residential monitoring involved a total of approximately 130
participants over the three-year period. During each year, approximately 40 new individuals were
involved. Their involvement included participating in personal monitoring, allowing indoor and
outdoor air monitoring at their residence, and providing information about their daily activities as
collected in questionnaires developed for the study. Participation for each individual during their
year of involvement included 5 days of summertime monitoring and 5 days of wintertime
monitoring. Their information will be compared to air quality information collected from the
community-level monitors for the same periods.

Who at the local level was involved in the study?

EPA scientists worked alongside local State of Michigan air quality scientists, university
researchers, community organizations, and the participants themselves to ensure local knowledge
or involvement in conducting of the study. Organizations that have been involved in the study
include the Michigan Department of the Environment (MDEQ), the University of Michigan, the
Community Action Against Asthma, and the Arab Community Center for Economic and Social
Services. In addition, EPA's contractor employed a large number of local research staff to assist
them with collection of the field data. Of course, the DEARS would not have been possible
without the vital cooperation and assistance from the people who participated with us in the study.
About 130 households volunteered to participate over the three years the study was conducted.

Which air pollutants were included in the study and why?

EPA air monitoring included the collection of information on pollutants such as particulate matter
(airborne dust), volatile organic compounds (benzene), metals (iron), select gases (ozone) and
certain air toxics (formaldehyde). This list is not all inclusive and simply represents examples of
the pollutants studied. Detailed information on the pollutants monitored in the study can be
obtained from the DEARS web site at http://www.epa.gov/dears/images/studv-design.pdf.

What air samples were collected?

Daily air samples were collected inside and outside of the participants' homes as well as from a
vest they wore during the study days. Data collected through the vest will enable the EPA to better
understand what air pollutants participants were potentially exposed to, what factors influenced
how they were exposed, and possibly even the sources of these pollutants. Participants also
completed a questionnaire designed to help scientists understand the activities they were involved
in throughout the study periods. No biological samples (e.g., urine or blood) were collected from
the participants. In addition, daily air samples were also collected from a State of Michigan air
monitoring site in Allen Park to allow for a comparison between all of the measurement locations.
More information about the participants' involvement is available at
http ://www. epa. gov/dears/ survey. htm

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Were people participating in the study exposed to air pollutions because of their participation
in the DEARS?

This research study did not involve intentional or additional exposures of participants to air
pollutants other than those normally encountered in their everyday environments and during
everyday activities.

How were the people who participated in the DEARS monitoring selected?

Participant households were selected based primarily on where their residence was located.

Randomly selected homes had to be from one of the pre-selected neighborhoods which offered
scientists a wide range of environmental conditions to study. The study included adults 18 and older
who lived in single-family homes (e.g., not apartments), who were physically able to move around on
their own, nonsmokers, and capable of providing informed consent concerning their participation.
Selection criteria had no exclusion based on race, sex, occupation, religious affiliation or socio-
economic status of participants.

Were there any people exposed to high levels pollutants in there homes? What was done to help
them?

A few study participants were found to occasionally have higher than normal exposures to certain air
pollutants inside their homes. In all such cases, scientists provided the participants with a written
summary which included the type and potential sources of these pollutants. EPA scientists also
offered more information at local meetings in Detroit after each monitoring season and through
additional mailings to participants.

Can EPA tell me what sources of air pollution impacted my neighborhood?

EPA is in the process of developing the science that will help us understand how regional, local, and
potentially even homeowner sources of air pollutants might have impacted outdoor air in the
neighborhoods involved in the DEARS.

How is the monitoring information being provided to the participants and the public?

Participants have been provided with summary information following each season of monitoring.
Information has also been added to the internet site dedicated to the study

(http://www.epa.gov/dears/). Detailed information about the methods, models, measurements, and
findings will also be available to the research and regulatory communities through the publication of
manuscripts in technical journals and at scientific meetings throughout the U.S. and abroad. The local
air quality monitoring organization (the Michigan Department of Environmental Quality) has also
been receiving updates on early study findings.

Why is the EPA holding this community session now?

The EPA's primary commitment to the participants involved in the DEARS was to provide them with
information about their specific air monitoring. This has already been accomplished through
information sharing between scientists and participants throughout the DEARS. Even so, EPA wants
to provide the study participants, local community leaders, and other interested parties with an update
of early findings from some of the air monitoring analyses and at the completion of the field
monitoring.

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How can people get more information on the DEARS?

Any one can obtain information on the DEARS by contacting Mr. Ron Williams, the EPA Principal
Investigator, by calling toll-free at 1-866-EPA-DEAR or by visiting http://www.epa.gov/dears. You
may also email him at williams.ronald@epa.gov.

What has been learned about harmful gases like ozone and nitrogen dioxide observed in the
DEARS?

While the DEARS data were not typically collected in a manner in which they could be directly
compared to National Ambient Air Quality Standards (NAAQS), the data indicate that personal ozone
concentrations are often 10 times lower indoors than outdoors. This confirms the protective factor
people obtain by being indoors during days where the ozone concentrations are expected to be at
harmful levels outdoors. Data also reveals that some DEARS participants had much higher personal
exposures to nitrogen dioxide (a gaseous pollutant associated with smog and with certain combustion
processes) during the winter season in comparison to that observed outside their home. Review of
questionnaire data indicated that these individuals often had one or more gas appliances operating in
their home. Gas appliances not operating efficiently are known to sometimes create nitrogen dioxide
as a by-product of poor combustion. As needed, DEARS participants were provided written
summaries of these events and encouraged to have their gas appliances inspected by qualified
individuals of their choosing.

Some of the air pollution is from cars. Was that considered in the DEARS? Is that type of
pollution coming into my house? Am I exposed to more air pollution if I spend a lot of time near
a roadway?

Vehicles that travel along busy roadways may release certain air pollutants as byproducts of the
gasoline combustion process or as a result of incomplete combustion. A comprehensive list of
compounds emitted by vehicles can be found at www.epa.gov/otaa/regs/toxics/420b06002.pdf. Some
of these pollutants are released more frequently and in higher concentrations than others. When a
large number of vehicles travel along a highway or interstate, their combined emissions (exhaust and
vapors) have the potential to contribute to higher outdoor concentrations of certain air pollutants in
areas close to the road. These increased concentrations often decrease quickly with increasing
distance from the roadway. Preliminary results in the DEARS and from other research suggests that
traffic-related increases in air pollutant levels drop significantly after certain distances are reached
(approximately 450 feet from the roadway) and that by approximately 900 feet the pollution levels are
almost the same as those found anywhere else in the area. The amount of traffic on a roadway, the
type of traffic (cars, buses, etc) as well as the wind direction, wind speed and the local roadway
elevation may also be important factors.

What will this study say about any particular local environmental problems?

The DEARS was not designed to identify or provide a remedy for any single environmental issue in
the Detroit area. Its purpose was to identify the contributions of various pollutant sources at the
community-scale and neighborhood-scale. The DEARS was limited to data collections for short
periods of time during the summers and winters of 2004-2007 and from a small number of households
in Detroit. As a result, the information gained through the DEARS cannot be generalized to all
neighborhoods in Wayne County or the U.S. The study will, however, contribute to our
understanding of how air quality information collected at the community level compares to
information collected in a neighborhood and in individual homes and how an individual's activities
affect their exposures to air pollutants. Ultimately what scientists learn from the DEARS will help

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EPA and state regulators develop strategies that reduce pollution and lessen the risks to people and the
environment.

When will all the results of the DEARS be available?

EPA scientists have provided this information during a series of participant debriefings held in Detroit
over the last three years. Preliminary data analyses are currently being performed on the data from
the earliest years of the study. Some of the summaries of these early findings are provided at
http://www.epa.gov/dears/abstracts.htm. In addition, each DEARS participant has already received a
personalized individual data packet summarizing some of the air pollutant monitoring associated with
their involvement. However, due to the complex nature of the analyses supporting the study, a
complete data set containing fully validated data is not anticipated to be available until sometime after
2010. EPA anticipates publishing data findings as they become available in scientific journals in
between 2009-2012.

What particulate matter and air toxics research has EPA already conducted?

During the last decade, EPA and its collaborators have conducted a series of similar studies in
Baltimore, MD; Fresno and Los Angeles, CA; Research Triangle Park, NC; Atlanta, GA; Boston,
MA; New York City, NY; Seattle, WA; and Tampa, FL. EPA has a broad program of related
research as described on the Particulate Matter Research Web site at http://www.epa.gov/pmresearch/.
Information about other EPA studies being conducted in the Detroit area is available at
http://www.epa.gov/dears/studies.htm

RELEVANT WEBSITES

•	DEARS homepage at http://www.epa.gov/dears/

•	DEARS homepage for participants at http://www.epa.gov/dears/participants.htm

•	EPA's Particulate Matter Research Strategy at http://www.epa.gov/pmresearch/

•	EPA AirNow at http://airnow.gov/index.cfm?action=airnow.outlook

•	Asthma Triggers (information for caregivers and health professionals) at
http://www.noattacks.org/.

•	Protecting children from environmental health risks at http://www.epa.gov/children or
http://yosemite.epa.gov/ochp/ochpweb.nsf/content/OCHP_CEH_Report_2007.htm/$file/OCH
P_CEH_Report_2007.pdf

•	Michigan State Government athttp://www.michigan. gov/

•	Michigan Department of Environmental Quality at http://www.michigan.gov/deq/

CONTACT US

Ronald Williams, Principal Investigator

Detroit Exposure and Aerosols Research Study (DEARS, http://www.epa.gov/dears/)

U.S. EPA, Office of Research and Development http://www.epa.gov/ord/

National Exposure Research Laboratory (http://www.epa.gov/nerl/)

Human Exposure and Atmospheric Sciences Division (http://www.epa.gov/heasd/)
williams.ronald@epa.gov or toll-free at 1-866-372-3327

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