Research Projects

Project at a Glance

Project Status: complete

Title: Activity patterns of California residents

Principal Investigator / Author(s): Wiley, James A.

Contractor: UC Berkeley

Contract Number: a6-177-33

Research Program Area: Health & Exposure

Topic Areas: Health Effects of Air Pollution, Indoor Air Quality


Retrospective time diaries were collected from a modified random sample of 1762 California residents aged 12 and over who were interviewed by telephone regarding all activities for the 24 hours of the previous day. Detailed information was also collected on the location of activities, on the presence of others smoking during the activity, and on socioeconomic and housing characteristics. Interviews were conducted with English speaking households between October 1987 and September 1988. On the average, adults and adolescents in California spent almost 15 hours per day inside their homes, and six hours in other indoor locations, for a total of 21 hours (87% of the day). About 2 hours per day were spent in transit, and just over 1 hour per day was spent in outdoor locations. The findings with respect to time spent in various activities were consistent with earlier national studies. Percentages of the sample using or near specific potential sources of pollution at any time during the diary day (derived from a set of ancillary direct questions developed especially for this survey) varied from 5% being proximate to oil-based paints to 78% taking a hot shower and 83% using soaps or detergents. In addition, some 25% of all California adults (and 13% of 12-17 year-olds) said their jobs involved working near dust particles, another 20% said they worked with gasoline or diesel vehicles or equipment, and 20% with solvents or chemicals. Among the demographic factors that were found to predict greater opportunities for potential exposure were employment, gender and age.


For questions regarding research reports, contact: Heather Choi at (916) 322-3893

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