THE ENVIRONMENTAL AND MEDICAL GEOCHEMISTRY OF URBAN DISASTERS

History abounds with accounts of cities that were destroyed or significantly damaged by rapid-onset natural or anthropogenic disasters such as volcanic eruptions, earthquakes, wildland-urban wildfires, hurricanes, tsunamis, floods, urban firestorms, terrorist attacks, and armed conflict. Burgeoning megacities place ever more people in harm’s way from future disasters. In addition to the physical damages, casualties, and range of illnesses and injuries they may cause, such disasters can also release into the environment large volumes of potentially hazardous materials. These disaster materials can be geogenic (e.g. volcanic ash, landslides), geoanthropogenic (e.g., polluted flood sediments, smoke and ash from wildland-urban fires), and anthropogenic (e.g. industrial chemical releases, complex dusts or debris from building collapses, smoke from building fires). Emergency responders must promptly assess the types and amounts of hazardous materials produced by a disaster and whether these materials are present in levels that pose a significant threat to the environment or human health. However, these initial "first responder" assessments may not fully reveal 1) the range of potentially hazardous materials produced by these extreme events, 2) how these mixtures of materials change physically or chemically in response to environmental processes, and 3) how such changes may influence the materials’ toxicity and health impacts on exposed ecosystems and humans. This presentation will use several case studies to illustrate how environmental and medical geochemistry insights can reduce uncertainties in urban disaster response and preparedness, by helping: 1) elucidate sources and environmental behavior of disaster materials, 2) assess potential threats the materials pose to the urban environment and health of urban populations, 3) inform strategies for cleanup and disposal of disaster materials, and 4) anticipate and mitigate potential environmental and health effects from future urban disasters.