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DEARS Frequently Asked Questions

What is the Detroit Exposure and Aerosol Research Study?

The Detroit Exposure and Aerosol Research Study (DEARS) was a three-year study conducted by the U.S. Environmental Protection Agency. 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, Mich. Data collections for the study have been completed. Data analyses conducted between 2007 and 2011 resulted in the publication of a number of papers detailing scientific findings. EPA researchers are continuing to analyze the data.

Why is DEARS important?

The study contributed to our understanding of how well air quality information collected at community monitors reflects what neighborhoods and the individuals living in them 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 EPA, with assistance from the Research Triangle Institute International and the Michigan Department of Environmental Quality, among others. The 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?

DEARS 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 136 participants over its three-year period of data collection. During each year, approximately 40 individuals were involved. Their involvement included participating in personal monitoring, allowing indoor and outdoor air monitoring at their residences, and providing information about their daily activities and how they operate their homes. Participation for each individual during their year of involvement included five days of summertime monitoring and five days of wintertime monitoring.

Adults over age 18 who lived in detached, single-family residences were involved. These individuals had to be: ambulatory, nonsmokers who were capable of providing informed consent concerning their participation. They also had to allow air monitoring to take place inside and outside their home, and have plans to live in the same residence for a nine-month period. The study had no exclusion factors regarding race, sex, occupation, religious affiliation or socio-economic status. Participants who met the qualifications were selected based on where they lived in the Detroit area. Participants were selected from several census areas. The study involved 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. In October 2007, researchers provided initial study findings to EPA Region 5 staff, the State of Michigan (MDEQ), Detroit and Wayne County officials, and regional and local community action groups. Since the completion of data collection in 2007, scientists from EPA and many other institutions have used the data compiled by DEARS in published peer-reviewed studies. EPA scientists continue to pursue new source-apportionment and modeling applications with the data.

Where can 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, Ron Williams, 919-541-2957 or toll-free at 1-866-EPA-DEAR. Information about other studies that used DEARS data and results can be found on the Related Studies web page.

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 living near various types of pollutant sources. The Detroit area also has distinct summer and winter climates that may affect how individuals are exposed to various air pollutants. Finally, there was a broad 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 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.

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 conducted in Baltimore; Fresno, Calif.; Research Triangle Park, N.C.; Atlanta; Boston; New York City; Seattle; Tampa, Fla.; and Los Angeles. These studies investigated the magnitude and variability of individuals’ personal exposures and the resulting health effects. These studies were somewhat limited in their scope and did not attempt to fully identify the pollutant sources impacting participants.

Data from these studies indicate that many different factors may affect the way air pollutants from local, regional and national sources affect the air individuals breathe. These factors include the age and health of the individual, conditions in their home, and the types and frequency of activities individuals are involved in 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 appear to be associated with changes in daily particulate matter concentrations for some individuals. It appeared that this was especially true for those with 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 — was conducted by EPA using data collected in the DEARS exposure study. This particular EPA health study started during summer 2005 and continued into 2006. More information about other Detroit Studies.

In collaboration with the University of Michigan, EPA conducted the Near-road Exposures to Urban Air Pollutants Study (NEXUS) in Detroit in 2010-2011 to examine the effects of traffic-related air pollution exposure on children suffering from persistent asthma. The study was designed to determine which measures of roadway-related pollutants are most closely-associated with aggravated asthma symptoms, whether children with asthma who live near major highways show more inflammation and other biological responses over those who live further from highways, and whether traffic exposure influences the likelihood of respiratory viral infections in children with asthma. More information on EPA’s near-roadway research.

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

EPA scientists met with Detroit area researchers, community organizations, and local officials. EPA scientists worked closely with the local community in the design, conduct, and analysis of the study. Organizations formerly or currently involved in the study include the Michigan Department of the Environment, the University of Michigan, Community Action Against Asthma and the Arab Community Center for Economic and Social Services. EPA has also met with scientists from Canada on research involving cross-border issues. EPA is 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. 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.

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