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In the Netherlands, until recently, public messages in case of a large chemical fire, routinely contained phrases such as: ‘no hazardous materials have been detected in the smoke’, ‘there is no danger to public health’, and ‘people are recommended to stay indoors and close doors and windows’. Such messages not only fail to adequately inform people about risk, they are also inherently inconsistent. That is, the advice to stay clear from the smoke makes little sense unless there is a potential danger of the smoke. To improve risk communication in case of major fires, we developed several alternative risk messages and tested them in a digital experiment. We found that participants who read alternative messages that included the phrase: ‘all smoke is harmful’ considered the message more credible and less inconsistent than those who read the routine message. However, they also perceived the risk as higher. Participants who read an alternative message in which a qualification of the extremely low chance of developing cancer by inhaling the smoke was added, considered the message just as credible but also more clear. Moreover, they had lower perceptions of risk than those who read the alternative message without a qualification of risk. Responses with respect to adherence to recommendations or expectations towards government actions did not differ depending on the message. Based on our findings, we conclude that a public warning in case of major fires should take the public perspective into account, fitting the content s to the needs of the final receivers, and conveying a clear, consistent and informative message to enhance a basic understanding of the risk involved and the rationale of recommendations. This will not only enhance trust and credibility it may also reduce concerns and promote adherence to recommendations.

Little attention has been devoted to the potential diversity in residents' health responses when exposed to an uncertain environmental health risk. The present study explores whether subgroups of residents respond differently to a new high-voltage power line (HVPL) being put into operation. We used a quasi-experimental prospective field study design with two pretests during the construction of a new HVPL, and two posttests after it was put into operation. Residents living nearby (0-300 m, n = 229) filled out questionnaires about their health and their perception of the environment. We applied latent class growth models to investigate heterogeneity in the belief that health complaints were caused by a power line. Classes were compared on a wide range of variables relating to negative-oriented personality traits, perceived physical and mental health, and perceptions of the environment. We identified five distinct classes of residents, of which the largest (49%) could be described as emotionally stable and healthy with weak responses to the introduction of a new power line. A considerable minority (9%) responded more strongly to the new line being activated. Residents in this class had heard more about the health effects of power lines beforehand, were more aware of the activation of the new line, and reported a decrease in perceived health afterwards. Based on our findings we can conclude that there is a considerable heterogeneity in health responses to a new HVPL. Health risk perceptions appear to play an important role in this typology, which has implications for risk management.

Large fires involving hazardous materials are often characterized by failing crisis communication. In this study, we compared opinions of experts regarding the risks of major fires to lay beliefs using a mental models approach. Amongst lay people this revealed relevant knowledge gaps and beliefs in opposition to those held by experts. While, experts considered the chance of getting cancer from inhaling smoke from a chemical fire extremely small, most lay people thought that even at a great distance, the chance of getting cancer to be large. To improve crisis communication about risk in a case of large chemical fires, and reduce the potential for messages to be misunderstood, distrusted or dismissed, we recommend a clarification of cancer risk in communications about public health emergencies such as chemical fires, for which lay people equate even small exposures to carcinogenic chemicals make one more likely to get cancer later in life.

Little attention has been devoted to the potential diversity in residents' health responses when exposed to an uncertain environmental health risk. The present study explores whether subgroups of residents respond differently to a new high-voltage power line (HVPL) being put into operation. We used a quasi-experimental prospective field study design with two pretests during the construction of a new HVPL, and two posttests after it was put into operation. Residents living nearby (0-300 m, n = 229) filled out questionnaires about their health and their perception of the environment. We applied latent class growth models to investigate heterogeneity in the belief that health complaints were caused by a power line. Classes were compared on a wide range of variables relating to negative-oriented personality traits, perceived physical and mental health, and perceptions of the environment. We identified five distinct classes of residents, of which the largest (49%) could be described as emotionally stable and healthy with weak responses to the introduction of a new power line. A considerable minority (9%) responded more strongly to the new line being activated. Residents in this class had heard more about the health effects of power lines beforehand, were more aware of the activation of the new line, and reported a decrease in perceived health afterwards. Based on our findings we can conclude that there is a considerable heterogeneity in health responses to a new HVPL. Health risk perceptions appear to play an important role in this typology, which has implications for risk management.

The way health risks of electromagnetic fields are portrayed in the media may shape public concerns that the growing exposure to electromagnetic fields in daily life constitutes a health hazard. We analysed the content of information on electromagnetic fields and health in Dutch media to identify aspects that might be linked to the public perception of electromagnetic fields. A systematic search was performed on archives of five major Dutch newspapers (from March 2008 to March 2010) and on the internet (in April 2010). Content analyses included the identification of main characteristics and the context or frame in which the information can be clearly understood. We identified 155 newspaper articles and 23 relevant websites. Analyses showed that the media content often suggested a negative relationship between electromagnetic field exposure and health but lacked detailed information about research, technical aspects, possible biological mechanisms and regulation policy. Regional media predominantly feature...

Om de ziektelast veroorzaakt door milieufactoren verder terug te dringen en de gezondheid te bevorderen, is het nodig om in de Omgevingswet gezondheidskundige advieswaarden op te nemen die strenger zijn dan bestaande normen en over meer onderwerpen gaan. Dat is de belangrijkste conclusie van de Gezondheidsraad in zijn advies Meewegen van gezondheid in omgevingsbeleid1aan de staatssecretaris van Infrastructuur & Milieu.

Background: There is public concern about the potential health effects of exposure to extremely low frequency electromagnetic fields (ELF-EMF) of high-voltage power lines (HVPLs). Some residents living near HVPLs believe ELF-EMF might cause non-specific health complaints. Objectives: The present study is the first to prospectively investigate whether self-reported health complaints and causal beliefs increase after the construction of a new power line. Methods: We used a quasi-experimental design with two pretests before and two posttests after a new HVPL was put into operation. Residents living near (0-300. m, n=229; 300-500. m, n=489) and farther away (500-2000. m, n=536) participated in the study. Linear mixed models were fitted to test whether symptom reports and beliefs that power lines caused health complaints increased more in residents living close to the new line compared to residents living farther away. Results: A significantly (. p

Public health services often have to deal with reported clusters of adverse health events. An important characteristic of disease clusters is that the involved community often is concerned about environmental factors influencing health. To facilitate cluster investigations, a stepwise protocol was developed in the Netherlands, based on international literature. Essential is the two-way approach, consisting of a disease-track and an environment-track. Attention to potential environmental exposures is as important as attention to the reported diseases, not only because environmental pollution often is the reason of public concern and thus relevant for risk communication, but also for deciding about the boundaries of the population at risk. Moreover, environmental information is necessary for judgement of the plausibility of a causal relation and for advising measures to prevent exposure. Within this two-way approach, three stages are distinguished: orientation stage, verification stage and quantification stage. Only if an increased risk as well as an elevated exposure is verified, under certain conditions a case-control study may be useful to study causality between exposure and adverse health events. During all stages of the investigation, good risk communication strategies have to be taken into account. However, even then it might be difficult to prevent conflicts, because of the differing interests between experts and the community involved. One of the most important aspects that determine judgements about risks by threatened people, is controllability; that is why community participation is essential. Therefore it can be concluded that cluster management is a mutual endeavour for experts, public and media, where experts are judged on three characteristics: expertise, credibility and empathy.

The literature concerning quantitative applications of the Delphi method is reviewed. No evidence was found to support the view that Delphi is more accurate than other judgment methods or that consensus in a Delphi is achieved by dissemination of information to all participants. Existing data suggest that consensus is achieved mainly by group pressure to conformity, mediated by the statistical group response that is fed back to all participants.

Rats were trained to discriminate flumazenil (15 mg/kg i.p.) from vehicle in a two-lever, food-reinforced, operant conditioning procedure. Substitution tests were performed with a wide dose range of flumazenil and of several benzodiazepines and non-benzodiazepine compounds possessing behavioural effects similar to or opposite to those of benzodiazepine agonists. The results indicate that low doses of flumazenil have behavioural effects, that the flumazenil cue has a low degree of specificity and is most strongly related to the stimulus properties of benzodiazepines.

Discriminative stimulus effects have been studied extensively with the two-response, food-reinforced operant procedure and more recently also with discriminated taste aversion (DTA) procedures. DTA procedures have the advantage of a more rapid discrimination training. However, the test phase, i.e., drug substitution, of the DTA procedure is more time consuming (1 test per 4 days) than the test phase of the two-response procedure (2 tests per 5 days). The present study investigated whether a DTA procedure with 2 tests per 5 days could be implemented. In addition, the specificity of the DTA procedure was investigated. Rats were trained to discriminate chlordiazepoxide (CDP, 20 mg/kg, IP) from vehicle using a discriminated taste aversion procedure. Selective suppression of saccharin consumption after CDP injections was maximal after seven CDP-LiCl pairings. In subsequent substitution tests, with 2 tests per 5 days, CDP-mimicking effects were found only for another benzodiazepine, diazepam, and for a barbiturate, pentobarbital. The results indicate that rats can be rapidly trained to discriminate CDP from vehicle in the discriminated taste aversion procedure and that the CDP-cue so produced has the same specificity as in a two-response, food-reinforced operant procedure. However, the DTA procedure has a number of drawbacks that make its advantage over the two-response procedure questionable.

Stress desensitization is observed as a decrease in the disruptive effects of a stressor on behavior when the organism is repeatedly exposed to the stressor. For instrumental behavior, stress desensitization was also reported for rats preexposed to anxiogenic drugs; stress sensitization was reported for rats preexposed to an anxiolytic compound. The present study investigated whether similar effects are found in a noninstrumental task situation. First, rats received 12 daily injections of pentylenetetrazol (PTZ, 20 mg/kg, IP), diazepam (DZP, 5 mg/kg, IP) or saline. After each injection the effect of the drugs on the acoustic startle reflex was measured. No drugs were given during the remainder of the experiment. Eight days later rats were given 5 days of Pavlovian fear conditioning to establish a light as a shock signal. During the next 3 days, potentiation of the startle response by the light was measured. None of the drug treatments had an effect on startle potentiation, indicating that stress sensitivity is not affected by previous administration of PTZ and DZP in a noninstrumental task. An explanation for the different effects found for instrumental and noninstrumental tasks is suggested.

Rats (N = 12) were trained to discriminate midazolam (1 mg/kg, IP) from vehicle in a food reinforced operant conditioning procedure. Midazolam, flunitrazepam, diazepam, chlordiazepoxide and pentobarbital showed dose-dependent substitution for midazolam. Buspirone and Ro 15-1788 did not substitute for midazolam. The midazolam cue was dose-dependently antagonized by Ro 15-1788. In rats (N = 12) trained to discriminate chlordiazepoxide (3 mg/kg, IP) from vehicle midazolam, flunitrazepam, diazepam and chlordiazepoxide substituted completely and dose dependently for chlordiazepoxide. The relative potency of chlordiazepoxide and diazepam was three times less in the midazolam-trained animals than in the chlordiazepoxide-trained animals. Response rate and latency data further support the main finding that the midazolam cue is similar, but not identical to the cue of classical benzodiazepines.

Rats (N = 14) were trained to respond under a five seconds differential reinforcement of low rate (DRL 5″) schedule and under a fixed ratio 10 (FR10) schedule of reinforcement. Ro 15-1788 did not influence the number of responses in the DRL 5″ schedule, but increased responding in the FR10 schedule. Ethanol (ETOH, 1250 mg/kg) and CGS 8216 (5 mg/kg) suppressed responding in both schedules and these effects were not antagonized by Ro 15-1788. The response suppressing effects of ETOH in both schedules were not influenced by CGS 8216. These results indicate that the response suppressing effects of ETOH and CGS 8216 are not mediated by the BDZ receptor. Ro 15-4513 suppressed responding strongly in the FR10 schedule. The response suppressing effects of Ro 15-4513 were additive with the response suppressing effects of ETOH. In rats (N=11) trained to respond under a variable interval 40 seconds-fixed ratio 10 (VI 40″-FR10) schedule Ro 15-4513 dose-dependently suppressed responding. These results indicate that Ro 15-4513 has sedative effects and is not able to antagonize all the behavioral actions of ETOH.

Background: New high-voltage power transmission lines will be introduced due to increasing demand for reliable and renewable energy supplies. Some residents associate non-specific health complaints with exposure to electromagnetic fields from nearby power lines. This study protocol describes the design and rationale of a prospective study investigating whether the introduction of a new power line triggers health responses in residents living nearby. Methods/Design. The study is designed as a quasi-experimental field study with two pretests during the construction of a new power line route, and two posttests after it has been put into operation. Key outcomes are self-reported non-specific somatic and cognitive health complaints, and attribution of these health complaints to a power line. The main determinant is proximity to the new power line route. One member of every household (n = 2379) residing in close proximity (0-500 meters) to the overhead parts of a new power line route in the Netherlands is invited to participate, as well as a sample of household members (n = 2382) residing farther away (500-2000 meters). Multilevel analysis will be employed to test whether an increase in key outcome measures is related to proximity to the line. Longitudinal structural equation models will be applied to test to what extent health responses are mediated by psychosocial health mechanisms and moderated by negative oriented personality traits. Discussion. This is the first study to investigate health responses to a new power line route in a prospective manner. The results will provide theoretical insight into psychosocial mechanisms operating during the introduction of an environmental health risk, and may offer suggestions to policymakers and other stakeholders for minimizing adverse health responses when introducing new high-voltage power lines. © 2014 Porsius et al.; licensee BioMed Central Ltd.