sum of the noints from all knowledge questions was taken as a mefo each level ofunderstanding The of points obta question is presented in Table 1.To find out whether the level of understanding influenced respondents'attitudes and level of radiation fear,the respondents were divided into two groups:those who scored lower than median on the knowledge questions (the low-score group),and those wh thamedian (the hig-score group).The data were analysed using SPSSVersion 6.1 for Windows.A significance level of95%was applied Results and discussion Knowledge of the radiation process 10 A major aim in the survey was to get an overview of the respondents'understanding of and radiation phenomena From the answers to Question 3,it appeared that 89%of the respondents knew of the three radiation types (alpha,betaand gamma),whereas only 34%could correctly state what the radiation consisted of in each case.The definition of one becquerel(Question 5)was known to 25%.It should not be regarded as very alarming that most respondents were unable to define particular concepts such as the becquerel y radiation.These concise definitions are for expert use.More important,in view of the reasons for knowing stated in the introduction (the pragmatic,the democratic and the educational reason),is the lack of understanding of central features and processes related to radioactive decay and absorption of radiation 11 A prevalent tendency among the respondents was the lack of differentiation between the concept of radioactive material and that of radiation,most apparent in the answers to Question4: "Radiation from the ruined reactor in Chernobyl had gone into the lichen on which the sheep and reindeer grazed. It has previously been observed that laypeople have difficulties distinguishing the concept of radiation from that of radioactive material The difficulty isa serio obstacle to understanding the nature of radiation hazards and the appropriateness of countermeasures. 12 When asked about the concept of the half-life(Question6).%of the respondents gavea definition which might be called correct.However,some of the acceptable answers might conceal a misunderstanding: 5)统计产品与务解方款 6EAP1学术英语理工（第二版）
The answer betrays a lack of understanding that disintegration of a radioactive atom involves the creation of a new answers of the type"The amount of radioactive material is halvedmight conceal asimilar misunderstanding. 13 To find out if the respondents knew what was meant by"absorption of radiation,an example was used concerning the absorption of radiation in spice which is irradiated to kill bacteria(Question 7).The question appeared to be difficult-ony5%attempted an answe Ten percent of the respondentsanswered that the radiation is taken up by the spiceand some of these added that the radiation was"stored"in the spice,which gave reason to suspect that they really meant that the radiation made the spice radioactive.Twelve percent 14 The survey also dealt with the radiation sources to which we are exposed in our daily lives and the health consequences of exposure to ionising radiation.When asked whether they believed that there were radiation sources in their home (Question2).6%answered in the affirmative.It appeared from the answers that there was considerable confusion concerning what a source of radiation is.Many seemed to regard this as an expression for almost any undesirable agentin buildings:electric and magnetic fields",asbestos",toxic chemicals in building materials etc.confusion between sources of radiation and other environmental hazards hasalso been described in the literature.For instance,Durante al.found that almost 50%of the respondents in a survey of public understanding of science believed that nuclear power stations could cause acid rain. 1s The respondents had clear perceptions of the kinds of change that ionising radiatior can cause to the human body,and a wide variety of answers was given to the question concerning this(Question 8).The most frequent answer was cancer(mentioned by 75%),whereas mutations were mentioned by 49%and genetic damageby 36%.Other effects mentioned included birth defects,damage to cells and organs,death,sterilityor decreased reproductive capacity,skin damage,hair loss and burns.The results gave no information about the extent to which the respondents imagined these effects to appear(or after what kind of doses).It is worth mentioning that the most important effect,from an expert point of view,is cancer,presumed to be initiated by mutations.Genetic effects have so far been detectable in animal experiments,not in humans pacity生殖力 UNIT1 Choosing a Topic 7
16 No significant difference was found between women's and men's level of understanding as measured by the total score on the knowledge questions.This is in contrast to Lucas" finding that significantly more men than women were able to give acceptable answers to radiation questions in a survey of the British public.The contrast may be due to had completed secondary school and begun university studies in natural sciences,Lucas respondents were a sample of the general population where it may be assumed that women on the average had a lower level of education than men. 17 To sum up,the investigation revealed an incomplete understand g of some central concepts concerning radiation phenomena.However,knowledge of the biological effects of radiation was reasonably good. Radiation fear and attitudes Central aims in this survey were to detect whether investigate their attitudes to the applications of radiation.It appeared that whereas 62% believed that there were sources of radiation in their home(Question 2).only 16%were afraid of being exposed to radiation in their daily life(Question 1).Significantly more re afraid5.37;p=0.02),whereas no significant difference wa teiand low-coreup inthpopoio were afraid of radiation.Those who were afraid regarded nuclear power and nuclear submarines as the greatest hazards. n There was a small majority of antagonists to Swedish nuclear power among the respondents:When asked whether Sweden should continue its production of nuclear power(Question 9),36%answered"yes"and 43%"no,whereas 14%were uncertain and 7%failed to answer.A significantly higher proportion of women than men were negative to nuclear power17.00004).A small,but significant difference was found nuclear power,the high-scorers being the more positive(=4.76;p=0.03).Half of the protagonists(50%)gave as a reason that the control of plants in Sweden was so good that the risk of accidents was minimal,whereas 26%claimed that nuclear power was an environment friendly alternative.Of the tagonists,6%gave the risk for accident as a reason for their standpoint,whereas 21%mentioned problems concerning storage of nuclear wastes.The risk of leakages was also mentioned.It was evident that whereas Swedish nuclear power was regarded as relatively safe,the attitude to nuclear energy in general was sceptical,and it was often presented as a necessary evil. 20 Atomic energy"resistance in the Scandinavian population has been reported by Lofstedt and Ringius and by Skjak and Boyum,who showed that 50%of the Norwegian population regarded nuclear power as"extremely or very dangerous to themselves and 8EAP学术英语理工（第二版
their families"Radiation and radioactivity are,for many people,associated with danger and fear,and surveys have shown that atomic energy and radioactive contamination rank high among people's conceptions of risks This is probably closely connected to earlier observations that it is the aspects of,catastrophic potentia and involuntary exposure which give radiation its aura of dread.These characteristics of radiation are especially prevalent in connection with nuclear power 21Another matter of interest was the respondents attitudes to radioactive wastes,exemplified 10).The respondents were asked whether they personally believed the sub to be a threat to the environment in the northern seas;57%answered"yes"and 17%"no,whereas 13%were uncertain and 13%failed to answer.There were significantly more women than men who found between the high-and low-score groups.Of those who answered"no some stated that the amount of radioactive material was too small to be a real threat:others thought that the contamination around the sub would be very localised,making a very small contribution to the overall state of the area.Of those who did judge the sub to be a threat,34%stated that was a danger to the marine flora and faunain the area."Contamination/Irradia of the environment"was given by 27%as a reason for fearing Komsomolets,whereas 15% thought the radioactivity would contaminate fish and thereby constitute a health hazard to people and said simply that the fish would become radioactive. 22 In the present investigation of attitudes to radiation and its applications,women tended to be more worried about radiation and more sceptical about nuclear power than were men. This tendency has also been demonstrated in similar studies,and seems to represent a general difference in women's and men's cautiousness towards a range of perceived risks such aselectromagnetic fieldscar exhaustand chemicals used in food production Implications for improving public understanding of radioactivity and radiation 23 It is evident from the above discussion that the lay model of radiation phenomena differs significantly from the expert model.How has the lay model of radioactivity and radiation arisen?Lucas has reviewed literature indicating that the informal mass media are important sources of scientific knowledge for the public.A comparison betweer the mass media's treatment of radiation phenomena after the Chernobyl accident and pupils'conceptions about such phenomena seemed to indicate that the press played a considerable role in forming non-experts'understanding of such phenomena) Indications of the role of the media were found also in the present study,for instance in press treatment of the sales limits for contaminated meat after the Chernobyl accident) UNIT 1 Choosing a Topic 9
Also,typical wording from newspaper headlines,such as'the threat from the East" (referring to nuclear reactors in Russia),appeared in the respondents'answers. 24 In the constructivist approach to learning.the learner's ideas and conceptions prior to instruction are seen as important prerequisites for learning.A typical example from mechanics is the notion that an object will come to rest unless it is kept in motion by a force.This is contrary to Newton's first law and the scientific view of motion-but it works in daily life!With reference to this theory of"everyday conceptions"Liinse et al.after studying lay conceptions of radiation,claimed that in areas where satisfactoryveryday conceptions"exist(ofen conveyed through the mass media)people do not feel the need to apply "school knowledge"to phenomena they encounter in real life.Thus,formal knowledge about radiation phenomena,acquired in a classroom context,will not be applied in order to understand the situations arising in the"real worldas for example after the Chernobyl acciden 25 This tendency could also be observed in the answers given in the present survey.For instance,one of the respondents was able to give excellent"classroom"definitions of after the Chernobyl disaster"because the animals ate food which had been irradiated thereby betraying that the confusion between radiation sources and radiation was still present.Thus,the answers to the questions concerning real-life situations which had been treated in the media might not measure what the school education had taught the students,but rather what the media had taught them.The gap between the"real world and the realm of school knowledge could also be identified in answers to the questions regarding the sources of radiation exposure in everyday life.When asked which sources of radiation the respondents feared,they mostly mentioned sources that are frequently highlighted in mass media and by env onmentalists and that have a threatening ring in most people's ears:nuclear power plants,nuclear submarines,radiation through a depleted ozone layer"and so forth. How can the gap be bridged between the lay and the expert models of radioactivity radiation and risk?How can the desired level of knowledge in the population (refer to the reasons for knowing stated in the introduction)be attained?As already mentioned,lay ideas are amazingly persistent,even after formal instruction.Thus,Eijkelhof reported that a number of lay ideas concerning radiation were maintained by secondary school pupils in the Netherlands after a course unit on radioactivity.The lack of success of school and information campaigns in the past may have been partly due to lack of consideration fo the preconceptions of the learners.Millar et al developed a teaching unit on radioactivit and ionising radiation that explicitly took into account the pupils preconceptions in the field.Hopefully,this and similar programmes may in the future contribute to improving the public understanding of such phenomena 10EAP1学术英语理工（第二版