As a hard working student you decide that you need to relax at the world renowned Ferguson Day Spa. After your massage you decide to use one of their ``therapeutic'' hot tubs. After some investigating, you find that the aqueous concentration of chloroform and trichloroethylene (TCE) in the hot tub water is 50 μg/L and 5 μg/L, respectively.
Chloroform and other trihalomethanes (THMs) are formed in water that is disinfected with chlorine. THMs are suspected carcinogens. Human exposure occurs when the water is ingested either directly or in a food or beverage product. Human exposure also occurs when THMs volatilize out of the water into the air and are inhaled, and when the skin is in contact with water or air containing THMs, especially during bathing. Wallace (1997) provides a recent summary of studies investigating chloroform intake.
Answer the following questions using the three-zone indoor air quality model tutorial.
What layout in a real home might be realistically represented by three zones?
Adjust the volumes and air flows for the three zones to represent a layout you have in mind. How much exposure might a person in one of the adjacent rooms to a smoker receive in the layout you have chosen?
Using the two-zone mass balance model interactive tutorial, answer the following questions about particle dynamics in two rooms that are connected by an open or closed doorway.
Under what conditions can concentrations in Room #2 exceed those in Room #1?
What parameters affect the distance in time between the concentration peaks in each room?
How realistic do you think this model in describing air pollutant levels in two separate rooms of a real home due to smoking or some other pollution source? What added features would make it more realistic?
There are many models available on the internet to estimate dietary exposure. This exercise guides you in using the U.S. EPA Dietary Exposure Potential Model.
Use the Excel version of the SHEDS (Zartarian et al., 2000) model and the included activity pattern (right hand of a university student) to estimate the incremental dermal exposure to chlorpyrifos. Also use the data included in Zartarian et al., (2000).
List your group's macroactivities and durations for each macroactivity. Compose tables (e.g., Excel PivotTables) summarizing the microactivities (duration in microenvironments, average duration of contact with each object, and frequency of contact with each object) within each macroactivity. Do this for each member of your group. Describe differences or similarities in microactivity statistics and potential reasons for these attributes.
Based on your analysis of activity patterns, state your opinion (with justification) on utilizing macroactivities for modeling dermal
Please describe briefly the context in which ConsExpo can be used to model inhalation exposure (e.g., What sorts of chemicals does the model estimate exposure from? Can the model be used for indoor or outdoor exposure? etc.). Discuss the major features and differences of the different exposure and uptake models.
Discuss the major features and differences of the different exposure and uptake models for dermal exposure and uptake.
Discuss the major features and differences of the different exposure and uptake models for oral exposure and uptake.
The book "Exposure Analysis" (533p), edited by Wayne R. Ott, Anne C. Steinemann, and Lance A. Wallace, was published in 2007 by CRC Press, Boca Raton (Taylor & Francis Group). It is the first complete resource in the emerging scientific discipline of exposure analysis.
