Cascading hazards and hazard mitigation plans: Preventing cascading events in the United States

The concentration of people and commerce in densely packed megacities has created interconnections between engineered and human-service systems that are susceptible to a single potentially hazardous event triggering others. We identify the interdependencies between engineered and human-service systems as well as the progression of hazardous cascading effects in the US context. The three purposes of this paper are (1) to determine how much attention is paid to cascading events in state and local hazard mitigation plans in the United States; (2) evaluate findings in the context of other environmental health programs in these places, noting that the paper is based on reviews of recent state and selected local hazard mitigation plans; and (3) offer suggestions for jump-starting focus on cascading events in hazard mitigation plans. Cascading events have not been a focus of US hazard mitigation plans, but we find a trend toward more attention, especially in states and cities that have a history of innovative environmental health and protection programs. Given a new administration in Washington, DC, we urge legislators and risk managers to be more aggressive about the challenge of cascading events.