Disasters resulting from natural hazards such as earthquakes, hurricanes, tsunamis and floods, are increasing in intensity, frequency and impact, in part due to climate change (1, 2). They can cause severe environmental and infrastructural disruption and significant economic losses. Disasters can directly affect human health through injuries, death and disease outbreaks, and longer-term impacts may include noncommunicable diseases, psychiatric morbidity and disabilities. The capacity of the health sector to respond to these effects is frequently impaired by damage to health facilities and disruption to health services (3).
A natural hazard can trigger a chemical release. When the release is the result of a technological accident it is called a ‘Natech’ (natural-hazard-triggered technological) event. Natech events can exacerbate the impact of a natural disaster on the environment and on human health because of the release of hazardous materials, fires and explosions (4–6).
The causes and consequences of Natech events are relatively recent areas of study by risk managers. It has been observed that, while there may be prevention and preparedness measures and response and recovery plans to deal with the risks from either technological or natural hazards, these are rarely integrated (4). Moreover, there is a lack of methods and tools for Natech risk analysis and mapping (4). In areas prone to natural hazards it is, therefore, important to develop plans that incorporate the possibility of dealing with natural and secondary technological disasters at the same time.
Purpose, Scope and Structure of this Document
This document aims to provide brief information to planners in the health sector and to public health authorities who wish to learn more about chemical releases resulting from natural hazard events. While the main theme of the document is Natech events, information is also provided about other sources of chemical release subsequent to a natural hazard event. The particular challenges with Natech events are described. The document then gives an overview of the role and activities of the health sector at all stages of the risk-management cycle. Hazardspecific annexes (Annexes A–C) provide information on the mechanisms of chemical release resulting from earthquakes, floods and cyclones and the subsequent health impacts, as well as brief information on response activities. The annexes are intended to be standalone documents; hence there is some repetition of information.
The two final annexes list other resources relevant to this topic and provide information on hazard pictograms.
A natural hazard can also cause the release of radioactive material, e.g. following damage to a nuclear power plant caused by an earthquake or flood. While these types of release are outside the scope of this document, similar principles of prevention, preparedness and response apply.