Presentation on theme: "Time Use Research for Exposure and Risk Assessment"— Presentation transcript:
1 Time Use Research for Exposure and Risk Assessment Rosemary Zaleski, ExxonMobil Biomedical Sciences, Inc., andVirpi Tenhola, KTL National Public Health Institute, FinlandInternational Association for Time Use ReseachBrussels, Belgium, September 2003
2 Introduction Ultimate Goal: Ensuring protection of public health Risk = function of (hazard, exposure)Exposure data critical to estimate riskDevelop most realistic, complete estimates of exposure as possibleTime Use Information is critical to developing exposure estimates
3 Time Use Information and Exposure Assessment Media Concentration X Intake Rate X Contact Timee.g., Inhalation Exposure (mg/day) =Pollutant in air (mg/m3) X Breathing Rate (m3/hr) X Time (hrs/day)Occupational scenario: requires time at work in task areaIndoor residential scenario: requires time indoors at homeage-specific exposures require age-specific time indoorsmulti-chamber residence models require room-specific movement patterns
5 Examples of Time Use Parameters Relevant for Exposure Assessment Hours indoors/outdoorsTime in specific environments (home, work, school, driving)Time in specific microenvironments (kitchen, bedroom, garage)Time in specific tasks (gardening, recreation, bathing)Time using or in presence of certain products (paints, adhesives, cigarettes)Residence time, employment tenure
6 Ideal Level of Information for Time Use Parameters for Exposure Assessment Distributionsby ageby genderby time of yearby region or populationby activity levelby other significant factorssignificant factors may differ across time parametersex. Day of week, employment status, education statusSequentially (preserve potential correlations)
7 Why Does Time Use Information Matter? A few of the many applications of time use information in exposure and risk assessment include:Occupational exposure and safety assessmentConsumer product safety assessmentChildren’s exposure assessmentAmbient air pollutant risk assessmentEnvironmental emissions exposure and risk assessment
8 Examples of Time Use Data in Exposure Assessment US National Human Activity Pattern Survey:distributional data by environments (e.g., work) and activities (e.g., bathing)Summary data in USEPA Exposure Factors Handbook:US Consolidated Human Activity Database:includes activity level estimates for each task
9 Examples of Time Use Data in Exposure Assessment (cont’d) ECETOC European Exposure Factors Sourcebook, with Focus on UK Data:OECD: years with employer for multiple countriesGershuny 1995: estimated weekly work hours for multiple countries
10 Multinational Time Use Data: Relevance for Exposure Estimates Differences: weekly work hours & employer tenure
11 Summary So FarTime use data for exposure assessment is nowadays mostly from the U.S.For other countries, data are still (largely) missingAlways looking for most current, representative dataPossible ways to leverage social science and exposure science studies:EPA/ ACC RfA announcement:ExpoFacts:
13 Do you have data for ExpoFacts? Do you want to use the ExpoFacts? The database will be free to useThe database will be available on the InternetUsers can search and combine data tables to best suit their needsThe database will be published in 2004Do you have data for ExpoFacts?Do you want to use the ExpoFacts?
14 Conclusions Ultimate Goal: Ensuring protection of public health Risk = fn (hazard, exposure)Exposure data critical to estimate riskDevelop most realistic, complete estimates of exposure as possibleTime Use InformationCritical to developing exposure estimatesUtilize all sources of relevant dataInterdisciplinary studies - a good use of time!