Participant Assisted Data Collection Methods in the California Healthy Homes Indoor Air Quality Study of 2011-13

From November 2011 to March 2013, air quality was measured over 6-day periods in 324 residences across California using a mail-out strategy. All interactions with study participants, from recruitment, to data collection, to communication of results, were conducted with remote communication methods including conventional mail, electronic mail, telephone and text messaging. Potential participants were reached primarily by sharing study information with community groups and organizations that directed interested individuals to complete an online screening survey. Pollutant concentrations were measured with sampling equipment that was mailed to participants' homes with deployment instructions. Residence and household characteristics and activity data were collected via two phone surveys and an activity log. A comparison of responses to survey questions completed online versus over the phone indicated that a substantial fraction of participants (roughly 20%) required a researcher's assistance to respond to basic questions about appliance characteristics. Using the printed instructions and telephone assistance from researchers, roughly 90% of participants successfully deployed and returned sampling materials accurately and on schedule. The mail-out strategy employed in this study was found to be a cost-effective means for collecting residential air quality data.