Development of a communication intervention to facilitate adherence to initial decontamination procedures during a mass casualty chemical incident

Student thesis: Doctoral ThesisDoctor of Philosophy


Chemical contamination, whether from deliberate or accidental release of harmful chemicals, continues to pose a risk to public health. The 2018 Novichok release in Wiltshire, UK highlights the need to protect the UK civilian population from future chemical contamination incidents. Casualties of chemical contamination need to be decontaminated as soon as possible both to prevent or reduce the extent of adverse health outcomes for the casualties themselves and to reduce the risk that other people will be exposed to the chemical. 
In the UK, the Initial Operational Response (IOR) protocol was implemented to address the need for fast, early decontamination. It is essentially first aid for chemical contamination. IOR involves casualties evacuating from the area in which the chemical was released, removing contaminated clothing (disrobing), then applying either water or dry, absorbent materials, depending on whether the chemical is known to be caustic. IOR places a lot of responsibility on casualties. They are required to carry out their own decontamination within a short space of time. 
IOR also places a lot of responsibility on first responders who, in addition to all other aspects of the decontamination process, need to get casualties to adhere to this protocol. This is challenging for several reasons. First, people do not necessarily know that they are contaminated because not all hazardous chemicals result in immediate symptoms on contact. Second, even if people do know that they are contaminated, findings from this thesis and previous studies indicate that not all aspects of IOR are necessarily intuitive to casualties. Third, first responders are competing for casualties’ attention with other, potentially more intuitive courses of action, such as presenting at a hospital, which may result in contamination of hospital staff and patients. 
The aim of this PhD was to determine how first responders should communicate with casualties to ensure that casualties adhere to the IOR protocol, particularly when the risk of chemical exposure is ambiguous due to a delayed onset of symptoms. 
I based the development of a preliminary communication strategy on: a review of the crisis communication literature; a systematic review of the effect of communication on casualty behaviour in mass casualty emergencies; a qualitative study on how first responders currently communicate with casualties during incidents that require decontamination; and an assessment of lay public perspectives on chemical contamination and decontamination. Findings from these studies indicated that, at a minimum, responders need to provide casualties with: practical instructions for undergoing IOR; contextual information about first responders’ expertise in decontamination; and updates about actions responders are taking to treat casualties. I drafted messages that contained this information but varied according to how the threat of contamination was conveyed and whether the effectiveness of IOR was made clear. Messages were tested in an experiment in which participants observed a chemical release scenario in the form of an immersive virtual reality video. The final communication intervention was based on the outcome of these studies. 
The main academic contribution of this PhD was the finding that explicitly addressing the threat facing casualties made study participants more likely to expect themselves to remove contaminated clothing in a real incident, whilst explicitly addressing the efficacy of dry decontamination made participants more likely to expect themselves to perform dry decontamination. This outcome serves as a useful addition to the wider behaviour change literature on the processing of fear-arousing information. 
In terms of practical impact, scripts based on the evidence gathered in this thesis will be finalised and disseminated to UK frontline responders and control room operators by the UK Home Office National Resilience Policy Team. The intention for the script is to serve as the basis for evidence-based communication training. 
Based on the studies within this thesis, the key finding to include in this training is that people responding to a chemical incident should not shy away from telling the truth. If people need to take action, they first need to know that they are in danger and that decontamination is the means to resolving that danger. This evidence-based principle should support the ongoing cultural shift from control to engagement in the relationship between emergency responders and the community in which they work.
Date of Award1 Nov 2019
Original languageEnglish
Awarding Institution
  • King's College London
SupervisorJames Rubin (Supervisor)

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