Grantee Research Project Results
2002 Progress Report: Behavioral Reactions to Ozone Alerts: What Do They Tell Us About Willingness-to-Pay for Children's Health?
EPA Grant Number: R829544Title: Behavioral Reactions to Ozone Alerts: What Do They Tell Us About Willingness-to-Pay for Children's Health?
Investigators: Mansfield, Carol , Van Houtven, George L. , Johnson, F. Reed , Crawford-Brown, Douglas , Pekar, Zachary
Current Investigators: Mansfield, Carol , Van Houtven, George L. , Johnson, F. Reed , Crawford-Brown, Douglas
Institution: Desert Research Institute , University of North Carolina at Chapel Hill
Current Institution: RTI International , University of North Carolina at Chapel Hill
EPA Project Officer: Hahn, Intaek
Project Period: February 18, 2002 through February 17, 2005
Project Period Covered by this Report: February 18, 2002 through February 17, 2003
Project Amount: $310,000
RFA: Valuation of Environmental Impacts on Children's Health (2001) RFA Text | Recipients Lists
Research Category: Environmental Justice , Children's Health , Human Health
Objective:
The objective of this research project is to investigate the averting behavioral responses to high-ozone concentrations by parents of young children, comparing children who have asthma with those who do not. Information from these parents about the daily activities of their children under high- and low-ozone conditions will be used to estimate lost activity time spent outdoors for the children using either standard regression techniques and/or a random utility model. We then will derive monetary values for the lost outdoor playtime using a stated preference conjoint survey. The data also will be used to estimate averted health endpoints using an exposure-response model. The risk assessment will help evaluate whether the defensive activities taken by parents are effective in actually reducing the asthma symptoms experienced by children.
The U.S. Environmental Protection Agency (EPA) developed the Air Quality Index (AQI) in part to convey information to the public about the level of ozone and other pollutants that might affect health. Currently, local governments use the AQI to issue air quality alerts during the summer on days when pollution is forecast to be high. Children, as well as those with respiratory diseases, are considered especially susceptible to ozone-related health concerns. Very little is known, however, about public awareness of the AQI and responses to warnings about high ozone, particularly changes in behavior.
Progress Summary:
Background
Even at relatively low levels, ground-level ozone is known to cause a number of acute respiratory health effects. According to the EPA, active children and asthmatics are among the most highly susceptible subpopulations. Physically active children are vulnerable because they tend to spend more time outdoors and to breathe faster and deeper. Asthma sufferers—particularly children with asthma—are at high risk because their lungs generally are more sensitive to environmental conditions and ozone is known to trigger asthma-related symptoms.
To protect children from ozone-related health effects, EPA and organizations such as the American Lung Association recommend that parents have their children spend more time indoors and engage in less strenuous activities on relatively high ozone days. These same recommendations apply to active adults and adults with asthma or other conditions that make them particularly susceptible to ozone.
The AQI, developed in part to assist parents and other individuals concerned about ozone condition, combines information about ozone levels (and other pollutants) to produce five categories of air quality, ranging from good to very unhealthy. To more easily and effectively communicate these conditions to the general public, the five categories also are color coded, ranging from green to purple. Using some versions of this air quality categorization scheme, forecasted and actual conditions typically are reported to the public on a daily basis (particularly during the summer) through local media outlets.
The combination of widely publicized air quality conditions and explicit recommendations for avoiding adverse health effects suggests that averting behaviors, such as spending more time indoors and less time in strenuous activities, should be relatively common on days with poor air quality. Thus far, however, evidence of these types of averting behaviors is somewhat limited, particularly regarding parental behaviors to protect their children’s health. Evidence of averting behaviors is not only useful for understanding how individuals protect themselves from potentially harmful exposures and reduce their health risks, but also reveals potentially important information regarding individuals’ preferences and willingness-to-pay for improved environmental conditions. Although the averting behavior method often is cited as one of the primary revealed preference approaches for nonmarket valuation, the number of empirical applications for valuing air quality improvements also is relatively limited. To our knowledge, averting behavior approaches have not been used previously to assess parents’ values for protecting their children from ozone-related health effects.
Using a series of Web-based surveys with parents of young children in relatively high ozone metropolitan areas, this study is intended to address these research gaps. Some of the key research questions to be addressed by the study are:
1. To what extent are parents aware of ozone alert systems?
2. To what extent do parents change their behavior and their children’s behavior in response to ozone alert systems?
3. How does the presence of asthmatic children in the household affect awareness and behaviors?
4. What costs (direct and indirect) are incurred by parents and children as a result of behaviors to avert ozone exposures?
5. To what extent are children's risks from exposure to high ozone levels offset by defensive/averting behaviors?
6. How much do parents value reductions in potentially harmful ozone exposures to their children?
Progress
We have almost completed the data collection stage of the project. A panel of 970 families was recruited through Harris Interactive, one-half with asthmatic children and one-half with children free of chronic disease, all under the age of 12. The households were located in the 35 metropolitan statistical areas with the highest ozone as of 2001. In each case, a parent was staying at home with the child during the summer. Harris Interactive maintains an Internet panel. The panel is self-selected. Panel members are recruited through advertisements on major Internet sites and receive incentives to complete surveys. All 970 households completed a baseline survey that included information about the family, the child, the child's health, the child's schedule, and information for the asthmatic children about actions the family had taken to deal with the child's asthma, the severity and characteristics of the child's asthma, and medications. After the baseline survey, each household received six time and activity diaries during the summer. The diaries were sent on selected days when ozone was forecast to be high (red and purple) or low (green and yellow). We attempted to get 3 days in each category (high and low) for each city; however, some cities did not have enough of one kind of day during the summer to achieve this objective.
In June 2003, we will administer the final debriefing survey. The debriefing survey contains questions about the parent's awareness of ozone alerts, knowledge of the possible health effects of ozone, information on when the child started school in the fall, and updates on the status of the child's health and asthma. The final survey also contains two stated preference conjoint experiments (each household only answered one set of conjoint questions). The first is designed to estimate a value for outdoor time for children using different types of medicine that had different restrictions on the number of minutes the child could be outdoors each day. The second is designed to elicit a willingness-to-pay for living in a city with fewer high ozone days.
Future Activities:
We will focus on completing the debriefing survey and analyzing the data. Three analyses are planned, with the hope of integrating the models in the future. First, we will use an economic model of behavior estimating the child's time outdoors and factors that might affect the amount of time outdoors (including high ozone levels). We anticipate using both linear regression techniques and random utility modeling. Second, we will analyze the conjoint data using both conditional and mixed logic. Third, we will conduct an exposure analysis for a portion of the sample to estimate the child's exposure to ozone and the expected health effects. We also will be presenting preliminary results at a U.S. EPA Valuation conference in October 2003, and at the Allied Social Science Association meetings in January 2004.
Journal Articles:
No journal articles submitted with this report: View all 9 publications for this projectSupplemental Keywords:
internet survey, altruism, air pollution, geographic information system, GIS, urban airshed model, information programs, economics research, social science research, behavioral science research, health, children's health, economics and decisionmaking, health risk assessment, social science, adult valuation of children's health, air toxics, behavior reactions, behavioral assessment, behavioral effects, children's environmental health, contingent valuation, decision analysis, economic objectives, economic valuation, environmental health hazard, environmental values, incentives, ozone, preference formation, psychological attitudes, random utility model, social impact analysis, social psychology, stated preference, survey, surveys, valuation, willingness-to-pay, ambient air, risk assessment, children, public policy, nonmarket valuation., RFA, Scientific Discipline, Economic, Social, & Behavioral Science Research Program, Health, Health Risk Assessment, Economics, Environmental Monitoring, Ecology and Ecosystems, decision-making, Children's Health, Economics & Decision Making, Social Science, social psychology, surveys, contingent valuation, behavioral effects, social impact analysis, valuation, random utility model, air toxics, economic valuation, internet survey, incentives, ozone, decision analysis, behavioral assessment, preference formation, air pollution, environmental values, survey, adult valuation of children's health, willingness to pay (WTP), psychological attitudes, children's environmental health, environmental health hazard, stated preference, willingness to pay, economic objectivesProgress and Final Reports:
Original AbstractThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.