January 31, 2001 Numerous high-rise HUD residential buildings are being demolished by implosion in cities across the United States because of a new Department of Housing and Urban Development (HUD) initiative that encourages the building of mixed?income housing instead of high?rise tenements. Now, a group of researchers from the Johns Hopkins Schools of Public Health and Medicine warn that the dust from these implosions, which settles over nearby neighborhoods, infiltrating indoors and remaining for months, may pose a health risk. Researcher Timothy Buckley, PhD, assistant professor, Environmental Health Sciences, the Johns Hopkins School of Public Health, said, "The demolition projects undertaken by many urban centers over the past few years have increasingly been considered by many as a spectator sport. Local media too have fueled people's desire to watch buildings come down by focusing on parking, traffic, and what vantage points will provide the best views. We believe that this reporting needs to be balanced with information about possible health risks associated with the air pollution generated by these events." Last summer, the Hopkins researchers studied the quality of the air within a four-block radius immediately after an August 19 implosion of a 22-story housing project in Baltimore, Md. Immediately following the implosion, they found that outdoor street-level concentrations of airborne particles were as much as one hundred times higher than they had been just moments before. This dust cloud dissipated within 20 minutes but, for that short time, average particle levels in the immediate vicinity and downwind of the imploded building were two to ten times higher than the standard for outdoor air set by the U.S. Environmental Protection Agency (EPA). The wind blew the dust cloud to the southeast, so that neighborhoods to the north or west of the site were unaffected. Measurements made inside neighborhood houses showed indoor air to be unaffected by the implosion, suggesting that staying indoors offers protection from the high outdoor concentrations. The researchers found that the huge dust cloud contained high concentrations of very small particles that can irritate or damage tissues deep within the lung. "These airborne particles, depending on their size, concentration, and chemical composition, have been shown to be harmful to health," said Peyton Eggleston, MD, professor, Pediatrics and Immunology, the Johns Hopkins School of Medicine, and director of the Johns Hopkins Center for Childhood Asthma in the Urban Environment, "especially for vulnerable populations such as the very young, the elderly, those with immune systems weakened by HIV or other causes, and those with underlying heart or lung disease." The dust cloud may also contain toxic metals such as lead from the soil or fungal spores that may trigger allergic asthma or cause infection among individuals with compromised immune function. Based on their findings, as well as the work of other investigators, the scientists offered the following advice to those wanting to watch the implosion or those living in the vicinity. Watch building implosions on TV rather than in person, especially if you are very young, elderly, have a weakened immune system, or have lung or heart disease. If you are determined to watch the implosion in person, do so from at least two blocks away and from a position that is upwind. If you live near and downwind of the implosion, stay indoors with your doors and windows closed for at least an hour after the building has fallen. If you are among one or more of the vulnerable groups described above, leave the area if possible and stay away for at least one hour after the implosion. Some of the dust from the implosion will get indoors and settle on surfaces. Use a damp cloth or mop to clean these surfaces. Vacuuming is not as effective since it sometimes merely stirs up the dust. Support for this study was provided by the U.S. Environmental Protection Agency (EPA) and the National Institute for Environmental Health Sciences.
Public Affairs Media Contacts:
Tim Parsons @ 410.955.6878 or paffairs@jhsph.edu | 
