Tuesday, 24 January 2012: 3:30 PM
Preventing Disasters: Disaster Risk Reduction for Environmental Health
Room 333 (New Orleans Convention Center )
In recent years, disasters triggered by natural hazards have killed an increasingly large number of people and have become increasingly expensive. In particular, climate-related (e.g., hydrological and meteorological) hazards affect this increasing number of people and cause these increasingly large economic losses. Between 1970 and 1999, ninety percent of all disaster-related fatalities were the result of climate-related hazards. And the Intergovernmental Panel on Climate Change (IPCC) predicts that these same climate-caused natural hazards are predicted to rise in frequency and severity well into the future. Disasters occur as a result of the combination of population exposure to a hazard; the conditions of human vulnerability that are present; and insufficient capacity or measures to reduce or cope with the potential negative consequences. Thus, a disaster is defined by the vulnerability of the population to a hazard event—not by the mere fact of its occurrence. For any given hazard, disaster risk is variable according to the particular vulnerability of the population (i.e., degree of population susceptibility, exposure, and resilience to the hazard). Throughout the world, the overall approach to emergencies and disasters has recently shifted from post-impact activities (i.e., ad hoc relief and reconstruction) to a more systematic and comprehensive process of risk management. Disaster risk reduction (DRR) has emerged as a core element of sustainable development. Risk reduction activities seek first to prevent public health disaster from ever occurring and then seek to prepare for and mitigate the disaster's health effects. Public health may not have the capability to influence the probability of a hazard occurrence (i.e., preventing the heat wave itself), but within public health lies a unique ability and opportunity to lessen human vulnerability to the hazard. Given that an environmental hazard is likely to occur, the risk of a public health disaster is lessened by 1) reducing human exposures to the hazard by a reduction of human vulnerability, 2) lessening human susceptibility to the hazard, and 3) building resilience to the impact of the hazard. Within this context, exposure is defined as subjection to the influence or effects of a disaster-related health hazard. In the case of natural disasters, the degree of exposure of a given population to the environmental hazard (e.g., extremes of wind, temperature, precipitation, seismicity, and volcanism) has a direct relationship to the incidence and severity of adverse health outcomes. For example, persons living in temperate climate zones may be at higher risk for exposure to hazardous extremes of temperature. Public health disasters are prevented when populations are protected from exposure to the hazard in the first instance. Exposures may be lessened by structural or non-structural mitigation measures. Mitigation measures ensure structural safety through enforcement of adequate building codes; promulgating legislation to relocate structures away from disaster prone areas; land use planning and regulation and managing high hazard zones. Public health may also contribute to non-structural mitigation measures that include hazard monitoring, early warning, policy and legislation, public awareness, and population protective measures, (e.g. evacuation and sheltering prior to hurricane storm surge) Within the context of disaster risk reduction, susceptibility is defined as the likelihood of suffering an adverse health effect when exposed to a given health hazard. Populations are not equally susceptible to the same health hazard. Differences among persons are due to such factors as sex, age, genetic predisposition, and health status. And with natural disasters, the degree of susceptibility to a given environmental hazard also has a direct relationship to the frequency and severity of adverse health outcomes. For example, elderly persons living in temperate climate zones are more susceptible to heat wave disasters than are young adults living in the same location. In general, healthy people are less susceptible to the adverse health effects of disasters. Healthy populations are also more capable of taking actions to mitigate their own risk of illness and injury in the case of disaster. Resilience is defined, with reference to natural hazards, as the capacity of a system, community or society to resist or to change in order that it may obtain an acceptable level in functioning and structure. Persons within a population are not equally resilient to the same disaster hazard. Differences among persons are typically due to social and economic factors such as socio-economic status, governmental/organizational structures (e.g., the public health and medical system), social capital, political influence, and behavioral determinants. For example, poor, socially-isolated or underprepared persons living in temperate climate zones, (e.g. those living in New Orleans, LA before Hurricane Katrina), are less resilient and therefore more prone to adverse effects than are affluent, well-connected persons who prepare and otherwise ensure their own readiness for such an event. Public health is, by definition, the science and practice of protecting and improving the health of a community. Community-based public health agencies routinely develop and implement interventions that lessen human vulnerability, very often targeting high-risk groups through a wide range of programs. By reducing the vulnerability of the at-risk population, community-based public health is uniquely positioned to match sustainable adaptation to the increasing risk of climate-related disasters. Community public health and medical institutions can play an active part in lessening human vulnerability to climate-related disasters through promotion of what has been characterized as healthy people, healthy homes and healthy communities. Healthy people are less likely to suffer disaster-related morbidity or mortality and are therefore more disaster-resilient. Healthy homes are disaster-resilient—they are designed and built to stay safe during extreme weather events. Healthy communities minimize exposure of people and property to natural disasters; in other words, sustainable communities are disaster-resilient communities. While humans may not always have the ability to prevent any climate-related hazards from occurring, the public health and medical sectors can play an important role in lessening or even preventing the human suffering of these disasters. Community-based risk reduction activities that integrate public health, disaster management, and meteorological science can lessen human vulnerability to the impacts of natural disasters.