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Basic Information

This site provides information about a research study that the U.S. Environmental Protection Agency recently conducted in Detroit, Michigan. The study, named the Detroit Exposure and Aerosol Research Study (DEARS), will help develop data that improves our understanding of human exposure to various air pollutants in our environment. The primary objective of DEARS was to compare air pollutant concentrations and their sources measured at central or community air-monitoring stations with those measured in various neighborhoods in the Detroit, Michigan area.

What is the Detroit Exposure and Aerosol Research Study?

The Detroit Exposure and Aerosol Research Study was a three-year study conducted by the U.S. Environmental Protection Agency (EPA). Its primary objective was to investigate the relationship of select air pollutant concentrations and their sources measured at community air monitoring stations in comparison to those measured in various neighborhoods in Wayne County, Michigan. Data collections for the study have been completed. Data analyses will continue during the 2007-2008 calendar years. Preliminary data findings are expected to be reported in 2008 with additional findings reported in later years.

Why is DEARS important?

The study will contribute to our understanding of how well air quality information collected at community monitors accurately reflects what neighborhoods and the individuals living in these neighborhoods are exposed to every day. Likewise, it will provide needed information on defining what factors affect an individual's exposure to various particulate matter and air toxic sources.

Who conducted the study?

The Detroit Exposure and Aerosol Research Study was conducted by the EPA, assistance was provided by the Research Triangle Institute International, and the Michigan Department of Environmental Quality among others. This study is part of EPA's ongoing research on how people are exposed to particulate matter and air toxics and the conditions that affect their exposures.

How was the study conducted?

The Detroit Exposure and Aerosol Research Study can be divided into four main parts: personal monitoring, residential indoor monitoring, residential outdoor monitoring (all involving participants) and monitoring performed at a central community site (Allen Park). The personal and residential monitoring involved 120 participants over its three-year period of data collection. 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 and how they operate their homes. Participation for each individual during their year of involvement included 5 days of summertime monitoring and 5 days of wintertime monitoring (a total of 10 days).

Adults over the age of 18 who lived in detached, single-family residences were involved. These individuals had to be: ambulatory, nonsmokers, capable of providing informed consent concerning their participation, allow air monitoring inside and outside of their home, and have plans to live in the same home for a nine-month period. The study had no exclusion factors regarding the race, sex, occupation, religious affiliation or socio-economic status of participants. Participants who meet the qualifications above were then selected based upon where they lived in the Detroit area within various census areas. The study involved the EPA selecting various households and then asking individuals in these selected homes to participate. Survey and questionnaires used in the DEARS are available.

What was the schedule for the study?

In 2004, EPA scientists began to recruit participants for the first year of the study. The first winter monitoring period was completed in March 2005. Similar summer/winter schedules were used for the second and third year of the study. All field measurements were completed by March 2007. Due to the complex nature of the analyses supporting the study, a complete data set containing fully validated data will not be obtained until the 2008-2009 time frame. Preliminary data analyses on select pollutants from the first two years of the study are being performed. A select number of data summaries of early findings are provided.

How may individuals get more information on the Detroit Exposure and Aerosol Research Study?

Members of the general public may request further information on the Detroit Exposure and Aerosol Research Study from the U.S. EPA, Mr. Ron Williams, 919-541-2957 or toll-free at 1-866-EPA-DEAR. Additional information can be obtained at www.epa.gov/dears. Information about other EPA studies being conducted in the Detroit area may be obtained by contacting Dr. Lucas Neas at 919-966-9961 and Dr. Shaibal Mukerjee at 919-541-1865 (Detroit Children's Health Study) or Dr. Jane Gallagher (Mechanistic Indicator of Childhood Asthma) at 919-966-0638.

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 had a population density that allowed recruitment of participants into the study living near various types of pollutant sources. Also, the Detroit area has distinct summer and winter climates that may affect how individuals were exposed to various air pollutants. Finally, there existed a broad scope of support and interest from Detroit's local community action groups, state air quality agencies and local university researchers. In summary, the Detroit metro area had everything needed for a study contributing to our understanding of air quality characteristics.

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

EPA has a broad program of related research as described on the Particulate Matter Research Web site at https://www.epa.gov/pmresearch/.

During the last decade, EPA and its collaborators have conducted a series of human exposure studies investigating particulate matter and selected air toxics. These studies were performed in Baltimore, Maryland; Fresno, California; Research Triangle Park, North Carolina; Atlanta, Georgia; Boston, Massachusetts; New York City, New York; Seattle, Washington; Tampa, Florida; and Los Angeles, California. These studies investigated the magnitude and variability of individual's personal exposures and the resulting health effects. These studies were somewhat limited in their scope and did not attempt to identify fully the pollutant sources impacting participants.

Data from these studies indicate that numerous factors may be responsible for the degree and variability of how air pollutants from local, regional and national sources affect the air individuals breathe. These factors include the age and health state of the individual, their home and how it is operated, and the types and frequency of activities individuals are personally involved with everyday. Findings indicated that pollutant exposures may vary greatly among individuals living in the same area. Data from these studies have also shown that certain unwanted cardiovascular health effects would appear to be associated with changes in daily particulate matter concentrations for some individuals. It would appear that this was especially true for those having an underlying cardiovascular disease.

Are there other studies in Detroit about air quality?

An associated multi-year health effects study involving children, the Detroit Children's Health Study, is being performed by EPA and will use data collected in the DEARS exposure study. This particular EPA health study started during the summer of 2005 and will continue into 2006. Information about EPA Detroit Children's Health Study may be obtained from Dr. Lucas Neas at 919-966-9961. More information about other Detroit Studies.

EPA has also been meeting with scientists from Canada on research involving cross-border issues. Bilateral research is expected to begin using data from air quality studies performed in the region in the years to come.

Was there local involvement in the design, conduct, and analysis of the study?

EPA scientists have been meeting with Detroit area researchers, community organizations, and local officials. EPA scientists are genuinely interested in involving the local community in the design, conduct, and analysis of this study. Organizations formerly or currently involved in the study include the Michigan Department of the Environment, the University of Michigan, and the Community Action Against Asthma and the Arab Community Center for Economic and Social Services. EPA has also been meeting with scientists from Canada on research involving cross-border issues. EPA is also very grateful for the assistance of many other local agencies and non-governmental organizations. In addition, EPA's contractor, Research Triangle Institute International, employed a number of local researchers to assist them with data collection during the study.

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

The Detroit Exposure and Aerosol Research Study was primarily designed to help clarify the relationships between community-based air pollutants and their source with those measured at the residential level in various areas of Wayne County. The study was not designed to identify or provide a remedy for any single environmental issue in the Detroit area. It will however, attempt to identify the contribution of various pollutant sources at the community and neighborhood level. Data from the study will be made available at the earliest possible time to all interested national, international, state, public and private institutions having an interest in the data can obtain them for their own investigations. EPA hopes to be able to make DEARS data available by the end of 2010. No single study, however, can address all issues of local concern related to air quality.

What were the limitations of this study design?

The Detroit Exposure and Aerosol Research Study was limited in the number of participants (120) and the seasonal periods monitored (summer/winter). Not every neighborhood in the Wayne County area was selected for inclusion. It was not designed to be a population-based study that attempted to develop statistics such as those being established for a particular sub-population. Therefore, data from the study is not fully transferable to all citizens or neighborhoods in Wayne County.

Further background information

Below are links to supporting documentation concerning the study. Please note that some of these documents are technical in nature and quite long but do provide a compressive background for the purpose, scope and scientific justification of the study.

You will need Adobe Acrobat Reader, available as a free download, to view some of the files on this page. See EPA's PDF page to learn more about PDF, and for a link to the free Acrobat Reader.

DEARS Home | Human Exposure & Atmospheric Sciences | Exposure Research

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