Communication Challenges in CBRN Terrorism Crises: Expert Perceptions

The aim of this paper was to investigate experts' perceptions on communication in chemical, biological, radiological and nuclear (CBRN) terrorism crises, including challenges and good practices. This is pursued by means of a qualitative online questionnaire aimed at international crisis communication and crisis management experts. The challenges of communication concerning CBRN terrorism arise from the complexity of such incidents, having to do with the nature of the threat, leading to problematic public perceptions and response. Critical areas that need to be taken into consideration include resources, competences, and cooperation in preparedness communication and when providing information during a crisis. The findings and conclusions of this study will serve the development of an audit instrument for communication preparedness towards CBRN terrorism.


Introduction
S everal authors have described factors that make chemical, biological, radiological and nuclear (CBRN) terrorist events unique and demanding. These factors relate to terrorism and the hazardous -CBRN -materials involved (Ruggiero & Vos, 2013), including, for example, the element of surprise, unseen agents, lethal devices, risk of repetition, and new kinds of risks (Covello, Peters, Wojtecki, & Hyde, 2001;Sheppard, 2011;Slovic, 2002). These factors may create intense reactions among the public (Rubin, Amlôt, & Page, 2011) that have to do with risk perception factors such as involuntariness, uncontrollability, unfamiliarity, unfairness, lack of understanding, uncertainty and ethical/moral violations (e.g., Covello et al., 2001;Gray & Ropeik, 2002). Combined with urgency and a need for quick action should such an event take place, the importance of effective crisis communication, including identification of challenges and possible pitfalls before crises occur, goes without saying.
The aim of this study is to investigate experts' perceptions on communication in CBRN terrorist crises, including challenges and constraints as well as some good practices.This is pursued with the help of a qualitative online questionnaire aimed at international crisis communication and crisis management experts. The purpose was to identify areas that need attention when planning, implementing and evaluating communication in the case of CBRN terrorism incidents.The findings and conclusions will serve the development of an audit instrument to facilitate and improve communication preparedness towards CBRN terrorism along the lines of previous research on crisis communication measurement and scorecard construction (Palttala & Vos, 2011, people may not always be high, fear may also spread to non-exposed populations (Rogers, Amlôt, Rubin, Wessely, & Krieger, 2007). Moreover, terrorism may also affect the way people view the world or themselves (Rubin, Brewin, Greenberg, Hughes, Simpson, & Wessely, 2007), touching core values in the society (Griffin-Padgett et al., 2010;Ulmer & Sellnow, 2002), and indicating a heightened need for emotional support and affective communication (MacGeorge, Samter, Feng, Gillihan, & Graves, 2007).
In fact, the challenges related to the indirect consequences of terrorist attacks -anxiety, health concerns and various psychological reactions -may pose a greater threat than the acts themselves (Hyams, Murphy, & Wessely, 2002).When combined with a lack of knowledge and understanding, people could, in the case of an event, engage in unsafe behaviour, including acts of omission, e.g., becoming passive and ignoring instructions, and acts of commission, i.e., going against the advice of authorities (Rubin, Amlot, Page, & Wessely, 2008;Sheppard, 2011;Sheppard, Rubin, Wardman, & Wessely, 2006). Hence, although ensuring the safety of those who are directly affected is of primary importance, taking into account and addressing the information needs, concerns and feelings of indirectly affected wider audiences is important, too. As Fischhoff (2011) has pointed out, while the direct effects of terrorist attacks depend on operational factors, the indirect effects depend primarily on communication, thereby also determining whether terrorists succeed in achieving their primary objectives, i.e., getting public attention for their cause by spreading anxiety (Rubin et al., 2008).
By interacting with various psychological, social, institutional and cultural processes, risk communicators help mitigate how events unfold (Wray et al., 2004), as explained also in the Social Amplification of Risk Model (Kasperson, Renn, Slovic, Brown, Emel, Goble, Kasperson, & Ratick, 1988). Moreover, the environment is dynamic, consisting of numerous, sometimes competing issue arenas (Luoma-aho, Tirkkonen, & Vos, 2013), which in the case of terrorism comprise diffuse and complex processes (Falkheimer, 2014). Monitoring and analysing public response and perceptions before, during and after CBRN terrorist events is of central importance, including traditional media monitoring, opinion polling (Wray et al., 2004) and social media monitoring (Ruggiero & Vos, 2014). Through risk communication, actions can be taken to moderate risk perceptions, including the establishment of trust, increasing familiarity of terrorism risks and facilitating a sense of control by giving citizens a voice already in the preparedness phase (Covello et al., 2001). Addressing preparedness and facilitating informed-decision making is also part of an ethical approach to terrorism crisis communication (Wray et al., 2004). This paper consists of four parts.The introduction is followed by an explanation of the method including data collection and analysis. The next section presents the findings of the questionnaire study, and chapter four concludes the paper with a discussion of the main results in the light of the existing theory and empirical literature.

Method
This study on communication in CBRN terrorism crises was conducted as part of a larger questionnaire study aimed at emergency management and communication specialists.The purpose of the part on CBRN terrorism was to investigate experts' perceptions on communication with the aim of answering the following research questions.

Data collection
The questionnaire comprised mainly open-ended questions accompanied by some multiple-choice questions. With regard to the latter, the respondents were asked to give some general background information on their organization, expertise and the state of preparedness in their organization for communication in terrorism-related CBRN crises. The open questions related to descriptions of organizations' preparedness for communication in terrorism-related CBRN crises, what the respondents saw as especially challenging for communication in CBRN terrorism crises, what kind of communication would be most effective when interacting with citizens, and ethical issues regarding communication in CBRN terrorism crises. Following strict ethical guidelines, an informed consent form was used and participants were told they could withdraw from the study at any point or leave any of the questions unanswered. In order to enable participants to respond to the long questionnaire in stages, respondents were asked to log in to the questionnaire using their email address as authentication information.
A pilot study was conducted in May 2012. The data were collected between June and September 2012. The sample consisted of emergency management and communication specialists working in Europe and was drawn from the database of the yearly International Disaster and Risk Conference in Davos of the Global Risk Forum. Four hundred ninety-three experts received an email invitation to participate in the ques-tionnaire, of whom 82 responded. The section on CBRN terrorism crises, the focus of the present paper, was answered by 28 respondents. Respondents could choose which questions to answer. It seems that only experts who felt confident that they could contribute to this topic chose to fill in this part. Although the number of respondents was not very high, their expert perceptions provide useful qualitative insights into the challenges facing communication in CBRN terrorism crises that can complement existing knowledge.

Data analysis
The analysis of the questionnaire data was conducted using version 7, by ATLAS.ti Scientific Software Development GmbH, a qualitative data analysis software.The analysis was implemented using data-driven thematic coding (Riessman & Quinney, 2005).Thematic analysis is commonly used with qualitative data (e.g., Schwandt, 2007). The aim was to reduce the data by segmenting, grouping and categorizing, and then to summarize and reconstruct them so as to capture important patterns and concepts (Ayres, 2008;Elo & Kyngäs, 2008).
In this manner, the data from the questionnaire sheets were read through and sections of text were coded based on whether they contributed to emerging themes (following e.g., Schwandt, 2007). The main themes included preparedness of organizations for communication in CBRN terrorist crises, challenges encountered in communication with citizens, what were considered possible solutions, and views on ethical issues. These themes were further divided into subthemes. Finally, the themes and subthemes were brought together in table overviews and described in a report, illustrated by quotes of the respondents. The main findings follow in the next section.

Results
In this section, we report the main findings of this study, including the state of preparedness of respondents' organizations for communication in terrorism-related CBRN crises, the main communication challenges, good practices for effective communication with citizens, and solutions provided to overcome ethical issues. First, the background information on the respondents is described.

Background information
Most of the 28 respondents were experts in crisis or emergency management (15), followed by crisis communication specialists (10) and experts in other related fields (9) such as risk analysis, disaster risk reduction or risk management.The majority of the respondents (12) had more than 10 years of experience in their respective fields, while 11 respondents had between 6 and 10 years of work experience, and five had less than 6 years of experience.
The types of organizations represented mostly comprised governmental organizations (e.g., municipality or ministry) or authorities, expertise centres or research organizations, and enterprises, while some worked for non-governmental organizations (NGOs), police or rescue services, and health care (see Table 1). Most of the respondents worked for organizations that operated nationally and/or internationally, while some were also active locally and/or regionally (see Table 1). Many had work experience in more than one country, by working for an international organization or providing assistance elsewhere. Many respondents (20) worked primarily in Europe (France, Greece, Romania, Belgium, Germany, Wales, Finland, Spain, Italy, Austria, Netherlands, Switzerland), while some (5) worked primarily outside Europe (Turkey, Sri Lanka, Georgia, Myanmar, Haiti, the Philippines, Myanmar, Indonesia, Cambodia, Zimbabwe, worldwide), or had (3) combined work experience in and outside Europe (Italy, Turkey, Germany, USA, Chile, New Zealand, Japan, global, worldwide). The majority of the respondents worked both in urban and rural areas (17), while some worked only in an urban area (8) and others only in rural areas (2).
Five of the respondents further specified their experience and mentioned concrete work experience in terrorism-related CBRN crises, participation in, or organization of specific training and exercises, communication planning for such scenarios, and work for the North Atlantic Treaty Organization and nuclear power plants.

Preparedness for CBRN terrorism crises
Many (10) of the respondents considered their organizations moderately prepared for communication in the event of terrorism-related CBRN crises. Moderate preparedness was described with reference to both positive matters and issues that could be further improved. Positive comments all indicated that some plans and preparedness were in place, as in the following.

Crisis communication channels in general are good. (R26)
However, positive matters were often accompanied by points for further improvement, centring on a lack of experience of real situations, and a lack of training or exercises: There are plans. But there hasn't been an exercise (yet). (R42) Besides moderate preparedness, many other respondents (8) considered their organizations poorly or very poorly prepared. Poor or very poor preparation was associated with a lack of plans, training, expertise, equipment and public education. One respondent working in an NGO/expert centre in the field of public education for disaster prevention described it thus: Almost no public education in what to expect. Do people really have radio and batteries for communications? Do they know when to evacuate and when to lock-down? Do they have supplies to shelter in place? Can schools shelter students for prolonged periods with parents trusting them to do so? (R11) Moreover, very poor preparedness was attributed to low perceptions of terrorism risk in the country. Some respondents, on the contrary, reported their organizations as well (n = 5) or very well (n = 1) prepared for communication in the event of a CBRN terrorism crisis. Good preparedness was linked to planning and exercises: Exercises covering CBRN scenarios are conducted regularly on the national level. (R8) One respondent described close cooperation and training in the response network: The governmental partners train and engage very close together. (R35) Another respondent, who perceived his or her organization as very well prepared, also reported experience of real events: Well documented, tested and faced real incidents as well as threats numerous times. (R2)

The nature of the threat poses a challenge
According to the respondents, the specific nature of the threat in question sets certain challenges for communication in a CBRN terrorism crisis. For example, a threat may not always be easy to perceive, as one respondent puts it.
You can't see or smell the danger. (R42) Moreover, it was pointed out that 'C, B, R, N issues are each very specific', comprising different threat types and involving different scenarios for crisis situations, which are also characterized by a lack of time. These risks were considered anxiety-inducing, for example, because they may be invisible and thus create uncertainty. Quick changes in the situation may be caused by, for example, changing weather conditions, which can further complicate, for example, evacuation.
[. . .] it might be challenging to react quickly to changing weather conditions that determine the spread of contamination.While potential evacuation area should be kept as small as possible, the weather uncertainty might require evacuation of very large areas. (R18) A further challenge related to the terrorism side of CBRN crises is the global nature and unpredictability of such crises, as described by one respondent.
It is a global threat, and it cannot be predicted. (R25)

Lack of resources, competences and cooperation in the response network
The respondents cited lack of resources as a factor challenging communication in a CBRN terrorism crisis. According to one respondent, there is 'a lack of everything'. This respondent mentioned that personnel and equipment for the analysis of CBRN materials are inadequate, and that an area-wide database for measurement results is also lacking. Moreover, it is hard to involve citizens in information gathering, unlike in other types of crises, such as floods. Another respondent pointed out that in such scenarios, 'excellent crisis communicators are required'. However, the lack of experts and competences in this field constitutes a big challenge, such that in the view of one respondent 'sometimes preparedness is jeopardized'. This problem also relates to a lack of experience and technical knowledge with regard to the terrorism aspect of such crises.
Arising out of the lack of resources and competences, the respondents stated that training in risk and crisis communication is needed. In the view of one respondent '[. . .] the most important issue [is] to improve our competence in this field, training people [. . .]' (R29).
According to this respondent, few communication experts and competences are available, and the authorities are not 'focused on enhancing preparedness and knowledge in this field'.The respondent further calls for 'a common national programme' to train and prepare all those involved in such emergencies -from physicians and security services to citizens. Research activities in this field also need to be increased.Another respondent stressed that CBRN terrorism crises are not priorities at national and local levels, and hence, it was 'a matter to put CBRN crises as a priority'.
Moreover, another respondent reflected on the need for realistic expectations. Moreover, another expert noted that, when the cooperation for crisis communication is not smooth, it may happen that too many organizations and 'so-called experts' will communicate and create confusion. Having too many players communicate without coordination may also evoke more fear in the population. Furthermore, one respondent mentioned that schools also need to be involved when planning crisis communication, 'so that they can act in loco parentis' in the event of a CBRN terrorism crisis, with parents trusting them to do so.

Public perception and response in CBRN terrorism crises
The public response to CBRN terrorism crises may set challenges for communication related to the psychological and behavioural reactions of people. According to the respondents, people's psychological reactions have to do with, for example, anxiety because of a lack of understanding and control regarding the handling of such a crisis.The respondents also mentioned problematic behavioural reactions of the public in CBRN terrorism crises caused by not following instructions or possible ignorance as such crises hardly occur. A further challenge, specific to terrorist situations, would be a fear of future attacks among the public and high levels of anxiety caused by exaggeration of the danger inherent in such situations. Several respondents mentioned challenges regarding the need to calm people.
[. . .] often the situation might be exaggerated and lead to panic -most CBRN attacks will only affect people in the direct vicinity (e.g., some km around the place of attack) [. . .] Therefore it is important to calm the population and to prevent a panic. (R8) One respondent mentioned 'panic from misinformation' as a potential challenge, indicating that anxiety may be caused by e.g., problems hampering information dissemination by response organizations. Moreover, according to the respondents, a limited understanding of the risks may cause problems for people.
People are highly emotional, mainly because they do not understand the risks, and have no clue what e.g., a 0.1% probability of an event means. Furthermore, acceptable limits are usually set at an extremely cautious level, and most people are not used to think in categories of risk to understand such limits. (R13)

Preparedness communication and providing information during a crisis
Because of the rareness of such crises, people are more concerned about more recurrent crisis scenarios. According to one expert: Usually people do not consider these risks within their living conditions. For them, their livelihoods systems are more disrupted by recurrent crises due to natural hazards, climate change or conflicts, provoking food insecurity [. . .] (R27) According to some respondents, concerning CBRN terrorism crises, preparedness communication and education are lacking.The public tends to delegate prepar-edness for unlikely threats to response organizations. Some respondents consider preparedness needed. It is a long-term challenge, according to one respondent, of how 'to avoid that the population enters the "it won't happen to me" mode, thus reducing their attention and preparedness'. In the words of another respondent: IF we continue to NOT TRAIN the public in what to expect, there will simply be too much to do, too much disinformation and noise, and it's too late to teach people after the crisis begins. (R11) One respondent suggested that discussion of the results of studies and lessons learnt from accidents and exercises could be used to help prepare the public and thus decrease anxiety in the event of a crisis. Another respondent stressed that terrorism preparedness should not be singled out, but embedded in preparedness for various threats.Terrorism adds a dimension of deliberation to e.g., industrial CBRN accidents, but that needs no emphasis as it calls for the same kind of preparedness for the consequences.
Don't communicate about terrorism/violence separately from all man-made hazards to settlements and environments. [It is] easier to communicate about industrial accidents, and fold deliberate acts into this (e.g., Bhopal explosion or Deepwater Oil Spill in the Gulf of Mexico or Exxon Valdez). (R11) Another approach, according to the respondents, is to focus on prior education. One respondent mentioned prior education with parents as a key challenge.
Most of the respondents' insights on the challenges for communication were related to communication and providing information. Deciding how much information could be provided to the public and providing accurate information to the people closest to the critical area were thus considered of paramount importance. Although the public may expect the government to act fast in terrorism-related CBRN crises, providing information fast enough was seen as challenging. One respondent mentioned public distrust of news media and official sources as a problem. Not following instructions may be the result, also caused by lack of understanding of such threats. Because of the high specificity of CBRN issues, distinct approaches need to be developed.
An overview of the respondents' insights on challenges of communication is provided in Table 2.

Good practices in communicating with citizens
The respondents presented their views on what kinds of communication would be most effective in the event of terrorism-related CBRN crises when interacting with citizens. The responses included references to certain principles of communication that, in their eyes, CBRN terrorism crises call for. Transparency and openness about uncertainties were described in the following ways: 'dare to communicate about uncertainties'; 'communicate in a transparent way'; 'authorities have to accept uncertainties and risks'. Moreover, timely rather than comprehensive actions were emphasized:'a fast stickerlike spreading of information from officials' and 'fast update cycles'. The principle of consistency was described by one respondent as 'no contradictions', and reflected in the words of another respondent according to whom 'national authorities need to bring their agency experts together fast so they can talk with one voice'. Accuracy was also called for.
The tasks that the respondents assigned to communication with citizens included, for example, prevent, care and help combat. Moreover, 'trust should be won ahead of time, by straight talking'. Populations should be prepared for such crises, and creating fear and anxiety should be avoided. In the view of one respondent, effective communication with citizens requires 'analysing social media and responding asap'.
Communication means mentioned by the respondents to communicate with citizens included social media, such as Facebook or Twitter, but also traditional media channels, such as radio and TV. One respondent referred to 'using all the media'. Mobile phones and text messages were also emphasized. Related matters mentioned included e.g., websites, dedicated spokespeople, social influencers, and early alert systems.
The types of communication that the respondents perceived as most effective when communicating with citizens include, for example, personal communication, although 'this is rarely feasible' as one respondent added. Similar views were expressed by other respondents, who nominated interpersonal communication and group-related communication as the most effective types of communication with citizens. In the direct vicinity of an incident, information needs to be provided 'directly to affected people'. Moreover, open discussion and face-to-face communication were mentioned.
According to the respondents, information targeted at citizens should be illustrated with concrete examples, for example, comparing the level of radioactivity or concentration of chemical agents in the atmosphere to normal levels. In the view of one respondent: Most people are not able to think in theoretical terms, they only understand practical examples. (R13) Moreover, both best case and worst case scenarios should be described jointly. In the event of a crisis, citizens need to know what happened, where and what to do. One respondent referred to the need to provide additional information with 'links to secondary literature' so that citizens could find relevant background information.
In the view of one respondent, involving neutral actors, such as the UN or NGOs, is needed. Moreover, when VIPs (very important persons) visit an affected area without protective clothing, this is likely to suggest to the lay observer that the threat level is lower than expected. Similarly, the behaviour and outward appearance of the first responders may also be interpreted by the public. One respondent calls for 'a single trusted authority' to provide accurate information.The current players may not be adequately prepared for a CBRN terrorism situation, including the appropriate communication. In the view of one respondent: [. . .] our local fire departments have done the best at this, but they are not necessarily equipped or authorized for a terrorism-related CBRN role. (R11) The role of citizens was stressed by one respondent, who stated that 'citizens must be able to track activities as close as possible (measurements taken, risks, etc.)' to be able to create 'their own operational picture'. The latter may also be seen as an ethical point of view. Ethics, however, were addressed in a separate question.
An overview of the respondents' insights on good practices in communicating with citizens is presented in Table 3.

Ethical issues
The respondents were introduced to the topic of ethical constraints by explaining that communication about terrorism may,on the one hand,help citizens to be prepared for such situations, while on the other it may create fear and polarization in society, thereby posing an ethical problem. They were then asked how communication specialists can take such ethical dimensions into account when communicating about terrorism.
According to one respondent, 'ethical dilemmas are one of the crucial points of communication in this field'. Moreover, ethical dilemmas should be explained whenever the topic is discussed in public. In the view of another respondent, ethical issues need special consideration 'where terrorism isn't very present'.
In the respondents' points of view, ethical issues should be communicated avoiding generalizations, stereotypes and stigma based on e.g., religious, political, ethnic or national connotations. In the words of one respondent: We believe that the most important aspect is to isolate the terrorists from any religion, ethnic or political group they claim to represent. E.g., Islamic terrorists never represent in any way the Islamic people.This must be clearly repeated and communicated over and over by the crisis communication officers. (R3) Moreover, communication should take place keeping in mind human rights and with respect towards people's civil and religious feelings. One respondent pointed out that terrorism should be cast as a singular act and terrorists as insane people, no matter what the ideology claimed to be underlying their behaviour.
According to the respondents, people need an explanation of what can happen, including the potential threats and risks in the particular instance of terrorism. In the view of one respondent: Moreover, information about terrorism should be communicated 'referring as much as possible to the facts', combined with practical advice.
We have to explain what can happen in case of such events. And we have to give practical advices, what everybody can do in such a situation. (R4) In the view of some respondents, terrorism itself should not be emphasized, but explained in conjunction with man-made hazards and accidents.
The effects of terrorist attacks can also be created by accidents; therefore, the population can be In my opinion it is the right of the public to be informed about terrorism threats.This holds particularly true in case of concrete threats (concrete attack plan for specific city or even location). (R18) However, in other cases, when the threat is not concrete and may not materialize, people could also be protected from information.
However, in case [of] only vague threats (such as general findings that attacks are planned in a country, without evidence where exactly) it might be better to protect the civilians from such information as it would reduce their well-being. (R18) The insights of the respondents on ethical issues were related to the following sub-themes: general importance of ethical issues, content regarding how ethical issues should be taken into account in communication concerning terrorism and what should be the content of communication.

Discussion
While it is sometimes questioned whether the challenges facing communication in CBRN terrorism crises are not more or less similar to those in other severe crises, the combination of terrorism with largely unfamiliar hazardous substances clearly presents a high level of complexity. As the present respondents stated, this complexity emerges from the nature of the threat, including diverse scenarios and risks that evoke emotions, cause uncertainty and rapid changes, and are unpredictable with possibly global consequences, complicating communication with the public. With respect to the reasons explaining why CBRN terrorism risks are special and demanding, the present findings support those of previous research (e.g., Covello et al., 2001;Sheppard, 2011). Insights from subject matter specialists and risk analysts may be needed to support communication planning and preparedness (Fischhoff, 2011) in this risk context. Moreover, the challenges facing communication about CBRN terrorism include the sheer diversity of actors, and hence making sense of CBRN terrorist events necessitates cooperation, utilizing a stakeholder approach.
The challenging aspects of communication that are related to public groups arise from risk perceptions and public response. The respondents phrased this as 'people can be highly emotional' when they do not understand risks. The fact that the most challenging aspect about communicating with citizens reported by the present respondents is 'to calm the population and prevent panic' shows that the panic myth (Sheppard et al., 2006) still lives on in the minds of crisis managers and communication specialists.This observation should be addressed in crisis communication training, as previous studies show that although there may be gaps between actual and advised behaviours (Gray et al., 2002;Rogers et al., 2007;Rubin et al., 2008), panic is nevertheless rare among citizens. On the contrary, as the London polonium incident showed, underestimating people's ability to handle a situation and providing non-specific assurances can undermine successful communication (Rubin et al., 2011). The distinction between panic, and say, anxiety is more than an academic issue, as it relates to what decisions and consequences result from applying it. The assumption of panic is often used as a reason to reduce information to citizens, which hinders public empowerment and underestimates the fact that lack of information in itself creates anxiety.
A preparedness paradox exists. On the one hand, to prepare the public to be able to act in a real situation in a timely manner and to harness public initiative to compensate for the scarcity of resources by, e.g., using self-diagnosis kits to lessen the burden on hospitals, will require a high level of public empowerment (e.g., Becker, 2011). On the other hand, lack of trust in and underestimation of the abilities of the public to act in and handle stressful situations by authorities can hamper public involvement. In addition, complicated expert knowledge and the low probability of such crises may hinder motivation for preparedness activities among the public, resulting in e.g., a lack of understanding of the risks involved. A respondent suggested that the public tend to delegate preparedness for unlikely threats to response organizations. This may not be a problem, if there would at least be basic knowledge of hazardous substances and infectious diseases.
One way to tackle the challenges of communicating about high-impact, low-risk issues, including CBRN terrorism, is to embed preparedness activities in an allhazards approach.As pointed out by the respondents of this study, terrorist threats can be explained in conjunction with other man-made hazards and accidents. This integral approach is also in line with good ethical practices for communication about CBRN terrorism; terrorism threat is not emphasized and negative side effects of polarization are avoided.When people have a basic understanding of hazardous materials such as radiation or viruses, they are better prepared for possible accidents and other risks with similar negative consequences. By addressing preparedness and explaining background information, awareness with respect to potential risks is created, thus facilitating informed and voluntary decision making among citizens (Wray et al., 2004). Other ethical guidelines suggested by the respondents were the provision of facts and practical advice, caution to minimize false alarms in the case of threats, and avoiding generalizations and language that could be interpreted as stigmatizing others. This supports the views in the literature according to which negative reactions towards differing 'others' or minorities need to be prevented by, e.g., cautious framing of related messages (Stevens, Agho, Taylor, Barr, Raphael, & Jorm, 2009;Veil & Mitchell, 2010).

Conclusions
The aim of this qualitative study was to investigate experts' perceptions on communication in CBRN terrorism crises, including challenges and good practices. This was pursued with the help of an online questionnaire, containing mostly open questions, aimed at international crisis communication and crisis management experts.The good practices mentioned by the respondents related to transparency and openness about uncertainties, using multiple communication media and personal communication involving trusted sources. Next to this, many challenges were discussed.The challenges and critical areas for communication are explained together with some implications for both research and practice.
The challenges of communication concerning CBRN terrorism, according to the results of this study, arise from the complexity of such incidents, which has to do with the nature of the threat, including diverse scenarios and risks, which cannot always be detected by the human senses, lack of time in crisis situations, high levels of uncertainty, rapid changes and unpredictable global consequences. This complexity in the case of CBRN terrorism threats is manifested in problematic public perceptions and response, including inadequate understanding of the risks and substances that may be involved, delegation of preparedness activities by public groups, and action or non-action that may go against health instructions.
Areas that are critical and need attention when planning, implementing and evaluating communication concerning CBRN terrorism, based on the findings of this study, include resources, competences and cooperation, which can be improved through training and other network-wide preparedness activities. Moreover, preparedness communication is needed, embedded in an allhazards approach that addresses various kinds of risks (Reynolds & Seeger, 2012) and takes ethical views into account (Wray et al., 2004).
Communication and providing information during a crisis, when the situation is at its peak, include instructing those in direct danger, calming people and dealing with possibly high levels of anxiety. As the findings of this study point out, although ensuring the safety of the directly affected is of paramount importance, responding to the needs of the wider audiences in CBRN terrorism cases is also critical. Different teams can respond to the inquiries of the worried well and the directly affected. Moreover, training should be provided to ensure that personnel are adequately prepared to deal with psychological turmoil and anxiety, including a contact person for very distressed people (Rubin et al., 2011).
In responding to the needs of the indirectly affected, social media monitoring may become critical. In a situation where people would be advised to shelter in a place for long periods of time, given that electricity would be available, social media fora may become meeting places and arenas for interaction, asking for help and information. In communication preparedness, attention needs to be paid to ensure that means for social media monitoring and online communication including enough competent personnel as well as tools and solutions are in place (Ruggiero et al., 2014). As CBRN terrorism comprises various types of risks and scenarios, including C, B, R and N materials with different kinds of consequences, preparations also need to be made for different communication approaches.
A topic for future research could be to delve more profoundly into how all these challenges affect the choice of particular communication actions and strategies. Moreover, as this study did not account for possible differences among C, B, R and N risks, a future study could focus on what implications and specific challenges these distinct scenarios would bring into the communicational picture by interviewing experts with specific expertise and knowledge on each of the risk categories. The fact that the question regarding ethical constraints was the least answered indicates that the familiarity with ethical issues of crisis management and communication specialists may be low. In the light of the multiple ethical issues that terrorist risks trigger, this may also be a gap that warrants further investigation. These insights on communication challenges and good practices complement results from previous studies and will be used in the development of an audit instrument for communication concerning CBRN terrorism. Although the number of respondents to this study was not high, their profile shows experience in crisis management and crisis communication over a number of years, with a reasonable spread over, e.g., countries and types of organizations involved. However, while the responses generated important qualitative insights and provide a fruitful starting point for future studies, the lower response rate for the part on CBRN terrorism crises is a cause for concern. Namely, it may indicate that the community of experts who are knowledgeable in this area is rather a small one, which also accords with the remarks of some respondents. In light of the severity and complexity of CBRN terrorism crises, the question of preparedness is paramount. As one respondent concluded, on the topic of public preparedness, the same goes for organizations as well ' [. . .] there will simply be too much to do, too much disinformation and noise, and it's too late to teach people after the crisis begins'.