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.

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.

1. Under what conditions can concentrations in Room #2 exceed those in Room #1?
2. What parameters affect the distance in time between the concentration peaks in each room?
3. 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.

1. 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.
2. Based on your analysis of activity patterns, state your opinion (with justification) on utilizing macroactivities for modeling dermal