A of heavy damage where telephone communication was not possible. In hypothetical questions about a future natural disaster such as a purchase Astragaloside IV hurricane or flood, the researchers asked respondents if they would evacuate if told to do so by a government official and if not, why they would not leave. The survey found a large proportion (19-33 ) of respondents would not evacuate. Houston respondents were statistically significantly more likely not to evacuate (p < .05) than were respondents in Baton Rouge or Mississippi/Alabama. Respondents who said they would not leave gave these explanations: ?thought they would be safe at home (73-79 ) ?thought that the hurricane and its aftermath would not be too bad (42-51 ) ?need to protect property (20-31 ) ?not able to get gas (16-29 ) ?did not know where to go to be safe (11-21 ) ?could not afford to leave (8-23 ) ?tried but unable to leave (6-21 ) ?did not want to leave pets (10-22 ) ?physically could not leave (5-11 ) ?caring for someone who could not leave (8-16 ) A second article, Mulilis and Lippa examined if negative threat appeals caused behaviour change for a sample of California homeowners [34]. People who agreed to participate were randomly assigned to one of theFitzpatrick-Lewis et al. Environmental Health 2010, 9:67 http://www.ehjournal.net/content/9/1/Page 11 ofcells of a 2 ?2 ?2 ?2 factorial design or a control group. Baseline questionnaires were sent to 243 participants; 154 questionnaires were returned. Questionnaires consisted of the Mulilis-Lippa Earthquake Preparedness Scale (MLEPS), demographic and earthquake history information, an experimental manipulation essay and manipulation checks (used to measure the effects of the essay). The essay consisted of four paragraphs of information about earthquakes. The participants read the essay meant to manipulate their beliefs around four dimensions: probability of a large earthquake, expected severity of earthquake damage, perceived effectiveness of earthquake preparedness and perceived capability of preparedness. These four conditions represented the four factors in a 2 ?2 ?2 ?2 between-subject factorial design. The subjects read one of 16 different combinations of the same four paragraphs - each paragraph dealing with low or high conditions for each of the four dimensions. Approximately five weeks later, follow-up questionnaires were sent to 145 of the 154 participants (representing those who PubMed ID:http://www.ncbi.nlm.nih.gov/pubmed/20691029 could be located at home). Seventy nine percent 
(experimental group n = 87, control group n = 27) of the follow-up surveys were returned. The four manipulated variables all strongly influenced subjects’ beliefs at the time the essays were read (p < .05). There were no gender differences in findings. Participants subjected to the high effectiveness condition exhibited greater preparedness behaviour when they read the high probability essays than when they read the low probability essays (p = .04). Negative threat-inducing persuasive messages influenced preparedness over a five-week period after they were read. Further, this increase in preparedness did not appear to be the result of completing the earthquake preparedness scale. The increased preparedness appeared to result from the experimental manipulations. The direct effects of the negative threat appeals on respondents (which were significant at the time the communication was read) diminished in intensity when an increase in preparedness behaviour was measured. Natter and Berry's randomized controlled.