A sincere thanks to Dave Heinlen,
Safety and Health Coordinator Bowling Green State University 102 College Park Office Building Bowling Green, Ohio 43403 for this video.
Mercury Vapor Experiment at Bowling Green State University
Phase 1. In this simulation, approximately 200 grams of mercury, as much as you'd find in a blood pressure measuring device, is poured into a dish at room temperature. As soon as it's exposed to air, mercury vapors leave the surface in wisps and plumes. Though heavier than air, and prone to collect in the lower levels of a room, the vapors are easily disturbed by air movement. In this case, people walking in the room during filming cause the vapors to change direction as they leave the dish. If the temperature of the room were elevated, the rate of vaporization would double for every eighteen degrees Fahrenheit increase.
Phase 2. A much smaller amount of mercury, about 1/200th of that shown in Phase I, is resting on the surface of a carpet. Some of the heavy beads are small enough to fall between the fibers, onto, and through the backing of the carpet. The vapor sources are more dispersed, and the plumes less dense. Smaller beads, and more of them, make for greater surface area and more rapid vaporization.
Phase 3. Mercury that is pushed below the surface of a porous material will continue to give off vapor. In Phase 3 you can no longer see the mercury beads, but in the ultraviolet light you can continue to see the shadows of the vapor.
Phase 4. This simulation demonstrates the results of trying to remove mercury from contaminated carpet. The technician is wearing the appropriate personal protective equipment and using a vacuum specifically designed for collecting mercury. Though some beads are extracted, those that remain give off more mercury vapor than before. Carpet and other porous materials cannot easily be decontaminated. They must be carefully removed and disposed of appropriately.
Phase 5. Most of us have played with mercury. A brief exposure for teens and adults is not a big health concern, but spills in areas where young children and pregnant women spend much of their day can cause severe health problems. Let's get mercury out of our lives!