The amount of uncertainty surrounding the Gulf oil disaster underscores a need to fill gaps in the current state of knowledge. Additional data can provide raw material for scientific discovery, observation, and theory, as well as desired information and answers most needed by at-risk populations, said Savitz. Within the context of surveillance, additional data can help identify high-risk hazards, identify the most at-risk populations, evaluate service needs and current capacities, and drive actions to better prevent or mitigate adverse health effects from future disasters. Moreover, as Nicole Lurie noted (see Chapter 1) surveillance systems and related research may have the potential to generate knowledge that could influence general public health responses and the overall delivery of health care services.
Assessing the effects of the Gulf of Mexico oil spill on human health is complex, and many questions remain about the hazards and risks posed to different populations. As elaborated throughout the workshop, there are many unanswered questions about at-risk populations, potential hazards (including exposures) to human health, the potential effects of these hazards, and how best to minimize hazards. Some of the uncertainty stems from the enormity and unprecedented magnitude and scope of the disaster. For example, as John Howard and Scott Barnhart discussed (see Chapter 2), proximity to the oil spill and response activities is a major risk factor for exposure by inhalation, ingestion, or dermal contact (see Figure 2-1), and everyone in the Gulf region, arguably even outside the region, is potentially vulnerable to feelings of anxiety and other negative psychological symptoms, conditions, or disorders.
But much of the uncertainty stems from the scarcity of scientific evidence about the types of risks to human health associated with various hazards. As Kenneth Olden remarked, “We are living in a state of toxic ignorance.” Establishing a cause-effect relationship between a specific exposure and any given outcome is rarely straightforward, and the ongoing nature of the Gulf oil spill makes surveillance design and analysis more challenging. Edward Overton explained that very few of the thou-