On June 17, 2005 Brendan Boyle of the Michigan Department of Community Health (MDCH) arrived on site to conduct screening at the World Medical Relief (WMR) building located at 11745 Rosa Parks Blvd, Detroit, Wayne County, Michigan. WMR is a non-profit organization that collects medical supplies and equipment to send to developing countries and helps local low-income citizens with prescriptions. The room on the second floor was used to store medical devices including mercury thermometers and sphygmomanometers. According to anecdotal information, this room was the location of several historical mercury spills. Monitoring results showed concentrations above 30 micrograms per cubic meter (μg/m3) in the breathing zone. Mr. Boyle then contacted U.S. EPA requesting additional air monitoring support. U.S. EPA tasked TTEMI START with providing additional air monitoring and site documentation. START conducted additional mercury vapor monitoring and found mercury vapor concentrations ranging from 20 to 200 μg/m3.
OSC Brian Kelly determined based on the large amount of elemental mercury present in the warehouse, coupled with the fact that the mercury has the potential to be tracked out of the building, a human health threat existed. A response was approved by management and initiated on June 20th.
Mercury is a silvery liquid at room temperature, but becomes an odorless colorless vapor at temperatures above 70 degrees Fahrenheit. Mercury vapor is highly toxic when inhaled, especially for sensitive populations such as infants, children, and the elderly. At high levels, mercury exposure can result in damage to the brain and kidneys.
June 20, U.S. EPA, START, and Environmental Restorations (ER) mobilized to the site to commence cleanup activities. ER initiated cleanup by bagging items from the room. If levels found within the bag were above 20 μg/m3, the bag was staged for disposal. Crews used a mercury vacuum to collect mercury beads from within the room, and initiated ventilation within the room to minimize mercury vapor concentrations. Clean up work was conducted using level-C personal protective equipment. The room was allowed to ventilate overnight.
June 21, mercury-containing devices were removed from the room. Additional mercury beads were found along and underneath the north wall. A roll-off was delivered to the site and used for disposal of contaminate items. Those items found to have free mercury were drummed. Ventilation continued overnight.
June 22, mercury contaminated work benches were disassembled, bagged and disposed of in the roll-off box. Crews removed the east drywall board that separated the equipment room from a storage area. A poly partition was put in place to separate the two rooms. Additional monitoring showed mercury vapor and visible beads had migrated from the equipment room to the adjoining storage area. Caution tape was put up to prevent access. Vacuuming and mopping the floor with Mercsorb took place in the storage area and in the equipment room.
June 23, visible mercury beads the size of nickels were discovered under shelving in the storage area. Crews bagged one shelving unit and disposed of it in the roll-off, vacuumed the visible beads, and mopped the floor with Mercsorb. The cleanup in the equipment room continued with a final vacuuming and mopping with Mercsorb. The equipment room and storage area were ventilated overnight.
June 24, START conducted final air monitoring with the Lumex throughout the equipment room and storage area. Breathing zone concentrations ranged from 1.4 to 3.2 ug/m3 in the equipment room, and from 1.8 to 2.4 ug/m3 in the storage area. U.S. EPA demobilized the site.
July 22, finalize disposal of waste was completed.
U.S. EPA has completed removal of free mercury and secured the room. U.S. EPA has recommended WMR hire a contractor to complete cleanup of contaminated items before reusing the room and contact the health agency to screen the room next winter.
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