Communicating risk to the public after radiological incidents.

In this week's BMJ, Rubin and colleagues report a cross sectional survey and qualitative analysis of perceptions of risk and strategies to communicate risk in relation to the poisoning of Alexander Litvinenko with polonium-210 in London in 2006.1 The study breaks new ground, not only because it examines an important public health incident in a major metropolitan area, but because it is one of the first studies of behaviour and risk communication after an incident involving the intentional release of radioactive materials. As such, it offers valuable insights into emergency preparedness. Major incidents involving radioactive materials can pose many challenges for emergency services, hospitals, and health departments. These include identifying the presence, type, and extent of contamination; issuing guidance on protective actions; implementing decontamination procedures; arranging health screening for potentially affected people; providing necessary treatment (for example, for internal contamination); and organising long term follow-up of affected populations.2 The extent of difficulty in meeting these challenges depends on several factors—one of the most important of which is public reaction. Risk research has shown that radiation is one of the most feared of all hazards, and situations involving radioactive contamination produce a great deal of apprehension, alarm, and dread. Furthermore, as research and historical experience have shown, people's concerns have the potential to translate into behavioural responses that complicate the situation.3 4 5 This is often true when information is confusing or in short supply. Such an example occurred during the 1979 Three Mile Island nuclear accident in the United States, when people received inadequate and conflicting information. Ultimately, for each person advised to evacuate, nearly 45 actually did. In all, nearly 150 000 people fled the area.6 Radiological incidents can also cause chronic stress in unexposed people and can lead to healthcare facilities being overwhelmed by worried people. After a caesium-137 incident tragically took four lives in Brazil in 1987, around 112 000 people sought radiological monitoring in special facilities.7 8 Social stigma and discrimination against people and products from an affected area are also common after radiological incidents. These phenomena, which can complicate recovery efforts, were seen after the 1986 Chernobyl disaster and after incidents in Brazil in 1987, Japan in 1999, and Thailand in 2000.9 The above experience relates to accidents involving radioactive materials. But since the terrorist attacks in New York and London, many people involved in emergency preparedness are worried about how the public might react to a large scale intentional release of radioactive materials. This question is difficult to answer. Few malicious releases have ever been recorded, and opportunities for systematic study have been rare. Thus, researchers have relied largely on simulations, hypothetical scenarios, and extrapolations from experience with accidents to try to understand people's views and information needs. That is why the study by Rubin and colleagues is so important. The study uses extensive data gathered during the 2006 polonium incident and helps us to understand perceptions, reactions, and risk communication strategies during a real world incident involving the intentional release of radioactive materials. One of the study's most interesting findings is that only 11% of the 1000 Londoners surveyed perceived their health to be at risk from the incident. The authors suggest two explanations for this. Firstly, most of those surveyed did not view the incident as terrorism or a public health threat. Rather, it was seen as a criminal act or an act of espionage. Likewise, the act was seen as being targeted at one, or perhaps a few, specific people, rather than being targeted at the public. Secondly, nearly three quarters of respondents agreed with the statement that, “if you have not been in one of the areas known to be contaminated with polonium 210, then there is no risk to your health.” This was one of the key messages of the public information campaign undertaken by health agencies, and the findings suggest that those efforts were successful. In short, the relatively low levels of health concern about the incident seem to have resulted from the way that people categorised the incident and from effective risk communication. What are the broader implications for preparedness and response? As the authors rightly point out, things could have unfolded differently if more people had perceived the event as related to terrorism. According to the survey results, the minority of people who did perceive it in this way were more likely to believe their health was at risk. This suggests that in a large scale terrorist attack involving radioactive materials (for example, a “dirty bomb”), levels of public concern could be dramatically higher. This should only serve to emphasise what Rubin and colleagues conclude—that it is essential to give the public access to detailed, comprehensible, and relevant health information. Indeed, in a terrorist incident involving radioactive materials, effective risk communication may be the most important way to reduce morbidity and mortality, tackle people's concerns, avoid the impact on behaviour, and maintain public trust and confidence. As such, improved crisis and emergency risk communication needs to be at the heart of future planning and training.