Magnetic field - Wikipedia
A short questionnaire was constructed to assess risk perception, trust in government to Avoiding exposure to Electric and Magnetic Fields (EMF) is almost or exaggerated fear, in connection with exposure to ELF electromagnetic fields. Nov 3, Is it possible for the human body to create an electromagnetic field? Trust me, it 'll help make this description much more fun! Every atom has its own electric field, and when you put two atoms close together, they can mess. Oct 31, The sources of magnetic fields are electrical currents, caused by moving The relationship between electricity and magnetism was written .. I trust that if this script is sold that Cosmicopia will be given an on-screen credit?.
You're right about the properties, but the fields don't cause or influence each other in so direct away as a first glimpse of Maxwell's equations might suggest. Special Relativity is "hidden" in Maxwell's equations. An understanding of their relationship might be useful. We can check against Maxwell's equations. The Poynting Vector representing the direction of energy flux of the EM field is: So Maxwell's equations demonstrate certain properties of electro magnetic radiation without making any explicit reference to special relativity.
Some questions arise though. In the wave equation, the coefficient of the second time derivative is the reciprocal square of the velocity of the wave. So Maxwell's equations imply that electro magnetic waves travel at the speed of light.
But with respect to what frame of reference? The LISS enables the assessment of both cognitive and somatic stress symptoms in terms of the four stress phases. The respondent is asked whether he or she has had a stress symptom as specified in each chart in the past day, week, or month. Each of the first two sets alert and resistance contains 15 items.
The third chart, which assesses stress in the exhaustion phase, contains 23 items. Assessment is made in terms of the percentage tables of the test. Four Master's-level clinical psychologists conducted the interviews under the guidance of the first author. Opportunity samples were selected from adults attending churches, clubs or other group activity centers and residing in the target area. As highlighted by Bostrom, Morgan, Adams and Nairthe use of such opportunity samples is quite common practice in studies of risk perception and makes it feasible to interview a large sample for the study.
After establishing contact with a local collaborator, such as the directors of fitness academies, hair salon owners, coordinators of adult education classes, neighborhood associations and shopping center administrators, who helped the interviewers gain access to the potential participants, the four interviewers went to the target cities and talked to the people present, either individually or in groups, and explained the objective of the study and requested their participation.
The criteria for inclusion were: In exchange for participation, respondents received a brochure containing simple suggestions on stress management. The terms of free prior informed consent was signed by each participant.
It contained a brief explanation of the study, advised the respondents that they could terminate the interview at any time they wished and that their names would be kept totally confidential, as approved by the Ethics Committee.
Acceptance was greater in the small towns, where people were eager to express themselves.
In the larger cities, some people were hesitant and did not want to give their names or ID numbers or simply refused to participate due to lack of time to answer the questions. Data analysis The Chisquare test was used to compare the categorical variables between the groups, with Fisher's exact test used for values below five. The Mann-Whitney test was used to compare the numerical variables between the groups and the Kruskal-Wallis analysis of variance was performed with more than two variables, followed by the Dunn's multiple comparison test.
To assess the relationships between the main variables and risk perception, the study used logistic regression analysis univariate and multivariate models with stepwise selection of variables. To assess the joint relationship between the main variables and profile formation, a cluster analysis was used.
For the multiple regression analyses of risk perception, data was adjusted for age, gender, education and the size of the city where the data was collected.
Analyses were performed on the association of stress, educational level, marital status, age, gender, and the size of the city according to risk perception.
Perception of risk from electric and magnetic fields: Stress effects and psychological aspects
Typically, when the stress develops into the resistance stage, the person feels tired and needs to make a special effort to deal with the cumulative stressors present in life. This leads to self-centered decisions and attitudes due to the need to direct energy towards dealing with the challenges involved.
Analysis of the percentages of participants with stress according to the stage of the stress process and gender reveled that there were more women This data is compatible with other research in Brazil showing that, in a given group, typically more women are found to have symptoms of stress Lipp, This is usually attributed to the responsibilities women have as professionals and homemakers.
This result confirms previous research Lipp, that shows that, regardless of the city size, stress can manifest itself, even though it may originate from different types of stressors in each location. Risk perception To assess the relationships between the main variables and risk perception, the study used logistic regression analysis univariate and multivariate models with stepwise selection of variables.
Values of 1 to 5 were assigned to possible answers to the first seven items in the questionnaire, ranging from 1, the option "I completely disagree" to 5, where the answer was "I totally agree". The answers to the negative items 4, 5 and 6 were inverted to permit analysis. The other two items included in the questionnaire were open questions and were analyzed in categories.
Using the items from Chart 1 as a basis, which provides a translation for the questionnaire used in the research, and after inverting the values given to the negative items 4, 5 and 6, a measure of risk perception was created by calculating the mean of values given by the respondents to items 2 and 6. A score for the level of trust in the regulatory agencies was obtained from the means of the values given to items 1 and 5; and a score, for the level of emotional comfort the respondents felt with regard to EMF exposure, was obtained from the means of items 3 and 4.
The value given to item 7 was considered to be the score for trust in Government.
Table 1 shows the percentages of respondents who gave each type of answer to the first seven questions included in the questionnaire. It can be seen that When analyzing trust in the risk regulatory agencies and in the Government, care must be taken not to confuse lack of trust in the authorities in general and the lack of trust with regard to risk exposure in particular.
It is possible that the high level of mistrust Table 2 shows the descriptive analyses of the answers given and the scores for risk perception, trust in regulatory agencies, emotional comfort with regard to EMF, and trust in Government to enforce the necessary measures to protect people from unnecessary risk, calculated on the basis of the answers given by the respondents.
The mean risk perception score, for the entire group, was 3. The mean risk perception score was 3. To search for possible variables influencing risk perception, Spearman's correlation coefficient was calculated for all relevant variables. Table 3 shows the results of the multiple regression analyses for risk perception, adjusted for age, gender, education and the size of the city where the data was collected.
It can be seen that, after data adjustments, the variables emotional comfort, stress stage, and trust in the regulatory agencies were, together, found to be significant as associated factors related to risk perception.
Participants with higher risk perception scores were the ones with less emotional comfort, no stress and with lower scores in trust in the regulatory agencies. Cluster 1 was composed primarily of college educated males, from small towns, without stress, with lower score in the questions related to risk perception, higher score in the question related to trust in regulatory agencies and the government, and with more emotional comfort.
Cluster 2 included high school educated females, from large towns, with stress symptoms, higher risk perception, lower trust in regulatory agencies and the government, and with less emotional comfort. Women, in general, did not differ significantly from men in risk perception, as mentioned earlier in this article, however when the level of educational and the size of the city they reside in were taken into consideration, differences were detected, showing that women with low formal education, living in large cities, tended to have less trust in risk control by government and agencies, feel less emotional comfort, and have a higher risk perception.
Educational campaigns about EMF should target this population in a more direct way. The questionnaire also included two open-questions as shown in Chart 1. The answers to question 8, regarding what needs to be done so that people could feel comfortable in relation to power lines and electric and magnetic fields near houses and constructions, were mostly distributed into four categories, namely: If there is no trust, then it would be expected that more control would be a desired and designated measure.
Answers to question 9 If wires or transmission lines were no longer installed, how would people's daily lives be affected? The simplicity of the answers obtained revealed that most of the sample's participants had not thought carefully about the possible consequences the world would face without the installation of transmission lines; some of the answers were very much focused on personal situations and losses and not on society as a whole. This indicates that any educational campaigns in this area should consider this tendency.
Taken together, our findings indicate that the majority of the participants in this study did not trust the Government to take protective measures, some did not trust the regulatory agencies, a great number felt that there is no adequate risk control and thought about it frequently, and some felt that power lines were being installed unnecessarily.
Even though a consensus society is neither possible nor desirable, results endorse the need for risk education to be implemented and indicate that risk perception and feelings should be considered before starting new line installations.
Risk communication should incorporate knowledge about social cognition since the large proportion of people concerned about EMF may cause social conflict given the ubiquity of EMF in our everyday lives.
Study limitations As with any research, there are limitations that need to be discussed. One limitation is that the data came from opportunity samples selected from adults attending churches, clubs or other group activity centers and residing in the target area.
Although the use of such opportunity samples is a common practice in studies of risk perception and its use made it feasible to interview a large sample for the study, there was no uniformity in the subjects' characteristics which should be taken into consideration in the analysis of the results.
Conclusion Data from this study indicate that risk perception depends on many factors that determine how a person will process the danger that might exist.
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Among these factors it was concluded that emotional stress has a significant impact in risk perception. When the person is under stress, the attention is focused on the stressors that need to be faced, and little attention is given to other stimuli that are present at that time.
Another relevant factor to be considered is the amount of information that a person has about a particular technical situation, the less is known, the more probable it will be that the individual fills the blank with socially desirable beliefs.
To avoid unnecessary worries, it is concluded that public education is essential when new transmission lines are installed in a neighborhood. References Albuquerque Navarro, M. Risk perception, risk communication, and stakeholder involvement for biosolids management and research.
Journal of Environmental Quality, 34 1 Preferences for exposure control of power-frequency fields among lay opinion leaders. Residential magnetic fields and the risk of breast cancer.