versus chronic concerns. These health risks need to be determined in multiple media, including the air, water, and food supplies.
Biological health risk assessment in contaminated areas needs to include viruses and protozoa in addition to bacteria. Because many viruses and protozoa can persist in the environment for much longer periods of time than bacteria, they can contribute to morbidity and mortality in humans, noted Schwab. He noted that routine biological monitoring does not usually include viruses and protozoa and that this would need to be addressed in the future.
For chemical exposures, such as volatile and semivolatile organic compounds, total metals, pesticides, herbicides, total petroleum hydrocarbons, and polychlorinated biphenyls, researchers need to include other specific exposure routes, such as dermal and airborne exposure routes, in addition to ingestion via drinking water.
Multiple pitfalls prevented assessment success after Hurricane Katrina, said Schwab. One of the major issues was damage to the telecommunication infrastructure, which limited the ability to communicate within the region. Land lines and the cell phone towers were damaged, and satellite phones were not working reliably. In addition, roads and bridges were impassable in some areas, and the shortage of gas supplies limited people’s ability to travel in order to perform rapid assessments (Figure 5-1). In addition to infrastructure damage limiting access, there were governance and training barriers. Multiple jurisdictions may have meant that assessors could not enter all places of interest (e.g., shelters), which slowed down health assessments. The lack of trained personnel who could rapidly adapt hindered the successful response as well, said Schwab.
Targeted health surveys applicable to the situation, using field-tested methods versus laboratory prototypes for agent identification during the assessments, were challenging in the very rapid response mode. For example, delay in sample analysis and ineffective dissemination of findings were problematic for rapid assessments. During the unfolding disaster, multiple contaminants—both microbes and chemicals—originating from multiple sources—municipal, industrial, and small businesses—and multiple media, including air, water, and sediment, were constantly changing, creating overlaying scenarios that had to be addressed during the assessments, noted Schwab. For the field of environmental health, this area suggests the need for further discussion.
Despite the many challenges to conducting health risk assessment, there were some positive outcomes, said Schwab. For example, Harvard University and Johns Hopkins University, teaming up with the Centers for Disease Control and Prevention, set up a toll-free hotline in Mississippi to provide the public with direct access to public health professionals who could provide information on