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RECRUITMENT AND RETENTION ACTIVITIES UTILIZED DURING THE FIRST TWO SEASONS OF THE DEARS
Citation:
PHILLIPS, M., K. EDGREN, C. RODES, D. AHSAN, A. F. VETTE, AND R. W. WILLIAMS. RECRUITMENT AND RETENTION ACTIVITIES UTILIZED DURING THE FIRST TWO SEASONS OF THE DEARS. Presented at International Society of Exposure Analysis Conference, Tucson, AZ, October 30 - November 03, 2005.
Impact/Purpose:
Six objectives have been defined for this study.
(1) To determine the associations between concentrations measured at central site monitors and outdoor residential, indoor residential and personal exposures for selected air toxics, PM constituents, and PM from specific sources.
(2) To describe the physical and chemical factors that affect the relationship between central site monitors and outdoor residential and indoor residential concentrations, including those that affect ambient source impacts.
(3) To identify the human activity factors that influence personal exposures to selected PM constituents and air toxics.
(4) To improve and evaluate models used to characterize and estimate residential concentrations of and human exposures to selected air toxics, PM constituents, and PM from specific sources.
(5) To investigate and apply source apportionment models to evaluate the relationships for PM from specific sources and to determine the contribution of specific ambient sources to residential concentrations and personal exposures to PM constituents and air toxics.
(6) To determine the associations between ambient concentrations of criteria gases (O3, NO2, and SO2) and personal exposures for these gases as well as personal exposures to air toxics, PM constituents, and PM from specific sources.
Description:
Identification, recruitment, enrollment, and retention of participants in the Detroit Exposure and Aerosol Research Study (DEARS) presented many challenges. A population-based cohort was chosen to reduce participant selection bias. Contact information for nearly everyone who lived in the five selected Census Tracts in the Detroit area of Wayne County, Michigan was purchased from a marketing vendor. The geographic coordinates for each home on the list were obtained in order to identify the homes either closest or farthest away from exposure sources (e.g. roadways and industrial point sources). Next, these houses were flagged in the datafile and systematic samples were randomly chosen and provided to the recruiters from the Community Action Against Asthma (CAAA) Group. A letter and DEARS study brochure were mailed to everyone on each list. Recruiters from CAAA performed door-to-door recruitment activities in the selected areas. To increase the likelihood of success, recruiters were hired from the community, trained by staff from the Research Triangle Institute and CAAA, and supervised by CAAA staff. Challenges faced in recruitment included: finding non-smokers; addressing language differences in situations where English was not the primary language spoken at home; overcoming a lack of trust regarding research among the largely low-income, minority population; demanding work schedules and other responsibilities; and lacking phone service among some participants. Although recruitment was a challenge, a total of 70 potential study participants were recruited from five exposure areas. Recruitment goals were achieved as only 40 participants were needed in the study allowing for several alternates in each area. Some of the participants dropped out of the study immediately prior to or during their week of sampling because they changed their mind about participating or a family emergency occurred. Participant dropouts caused difficulties because there were times when alternates were not available on such short notice. In these situations, CAAA recruiters performed additional door-to-door recruitment in order to fill the sampling schedule. Some of the study participants attended a retention-related gathering where they received recognition for their participation. After each season of data collection, participants were thanked for their participation by CAAA and EPA staff either in person or on the telephone.
Although this work was reviewed by EPA and approved for publication, it may not necessarily reflect official Agency policy.