Journal of Photochemistry and Photobiology B: Biology 140 (2014) 14–19
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Knowledge, attitude and practice regarding solar ultraviolet exposure among medical university students in Northeast China q Qian Gao, Guangcong Liu, Yang Liu ⇑ Department of Environmental Health, School of Public Health, China Medical University, Shenyang, China
a r t i c l e
i n f o
Article history: Received 7 May 2014 Received in revised form 28 June 2014 Accepted 1 July 2014 Available online 9 July 2014 Keywords: Ultraviolet rays Sun protection Knowledge Attitude Practice
a b s t r a c t To assess the knowledge, attitudes and practices regarding the health effects of ultraviolet radiation (UVR) and sun exposure among medical university students in Northeast China, 385 subjects were investigated on October 2013 using a self-administered multiple-choice questionnaire. Most of the subjects knew the effects of UVR on skin cancer (95.6%) and sunburn (92.2%), but fewer knew of the eye damage that can result from UVR (27.8% cataract and 3.1% pterygium). Correspondingly, the main purpose of adopting sun protection was considered to be ‘preventing sunburn’ (55.4%), but ‘preventing eye damage’ was the least (1.8%). In actual behaviour, the eyes received the least protection as well. Although knowing the effects of UVR on vitamin D synthesis (87.3%), 66.8% of participants never or seldom increased sun exposure. Compared to men, women were more likely to reduce sun exposure (P < 0.001). Only a small fraction of subjects (6.6%) thought that tanning was attractive. Considering the response variability to UVR in people with different skin colours, different sun protection programs should be provided. In China, especially in the North, the public should be educated to moderately increase sun exposure to maintain adequate vitamin D status while also protecting against eye damage from UVR. Ó 2014 Elsevier B.V. All rights reserved.
1. Introduction Solar ultraviolet radiation (UVR) is an important environmental factor that affects human health, and we are exposed to it more or less almost every day. Every coin has two sides, and UVR is no exception. Exposure to UVR can have negative and positive effects. On the negative side, excessive UVR exposure may lead to skin cancer, eye damage, immune suppression, skin photo-ageing and other ailments . On the positive side, exposure of the skin to ultraviolet radiation B (UVB) is the main source of vitamin D synthesis, which prevents skeletal diseases and is positively associated with reduced risk of a number of other diseases [2,3]. Information from knowledge, attitude and practice (KAP) studies could help develop tailored strategies appropriate to the social and cultural contexts of different populations. Proper knowledge and positive attitudes can inﬂuence one’s sun exposure behaviour
q This research was supported by Scientiﬁc Research Fund of Liaoning Provincial Education Department (Grant No. L2013307). The funding bodies had no involvement in the study design, analysis and interpretation of data, writing of the report, and in the decision to submit the article for publication. ⇑ Corresponding author. Address: Department of Environmental Health, School of Public Health, China Medical University, 92 North 2nd Road, Heping District, Shenyang 110001, China. Tel.: +86 24 2325 6666x5407; fax: +86 24 2326 9025. E-mail address: [email protected]
http://dx.doi.org/10.1016/j.jphotobiol.2014.07.002 1011-1344/Ó 2014 Elsevier B.V. All rights reserved.
and protection practices. For the purpose of preventing skin cancer through sun protection, many KAP studies on sun protection have been carried out among Caucasian populations. KAP studies regarding vitamin D deﬁciency have also been carried out by some researchers. However, the important impact of UVR on Asian people, such as Chinese, is different from that on Caucasian people. People of colour are less likely to develop skin cancer , but cataracts are the major effect of excessive exposure to UVR [5,6]. In addition, due to darker skin pigmentation, the effect of UVR on vitamin D synthesis in people of colour is reduced . Currently, China has more than 60 million patients with cataracts, and more than 7 million of them have a visual disability . Vitamin D deﬁciency is a major global public health problem  and also found to be widely prevalent in the Chinese population in almost all age groups and areas , especially in women [11,12] and children . Furthermore, chronic diseases related to UVB or vitamin D is an increasing concern in China [14–16]. However, as far as we know, few studies have focused on the KAP of Chinese people on solar UVR and its effects. Therefore, it is signiﬁcant to understand the KAP of Chinese people. University students are considered as the most highly educated young people in China, and medical university students should have more health knowledge than others. Hence, we conducted a population survey of medical university students in Northeast China to assess their KAP of UVR and sun exposure protection. By characterising their KAP and analysing
Q. Gao et al. / Journal of Photochemistry and Photobiology B: Biology 140 (2014) 14–19
its differences compared to the Caucasian population, we offer a suggestion regarding sun protection for Chinese people. 2. Materials and methods This survey was conducted among 385 medical undergraduate students in Shenyang (41°N, 123°E), a city situated in Northeast China with the noon Solar Elevation Angle ranging from 25° to 72°. At China Medical University, we randomly selected 10 junior classes and 3 senior classes in October 2013. All students present on the day of the study were included. Data were collected using a self-report questionnaire that comprised 20 questions including demographic information, the subject’s general knowledge of UVR, their attitudes towards UVR exposure and their behaviour regarding sun protection. This study was approved by the ethics committee of China Medical University. 2.1. Measuring knowledge The general knowledge about UVR was assessed by eight questions. First, we asked whether participants knew that UVR was harmful (question 1) or beneﬁcial (question 2) to human health. ‘Yes’, ‘no’ and ‘not sure’ were the answer options. In question 3, participants were asked about the health effects of UVR in humans. In question 4, participants were asked which of the answers to question 3 were most important to Chinese. For question 3, the correct answers included sterilisation, skin cancer, skin ageing, sunburn, suntan, cataract, pterygium, protection against rickets, protection against osteoporosis, and effect on immune function. Five distractor options, such as glaucoma, were also used in the two above multiple-choice questions. Question 5 was ‘‘Do you know the meaning of ultraviolet index (UVI)?’’ The answers were ‘yes’, ‘no’ or ‘I have heard of it, but I do not know the exact meaning’. If the answer was ‘yes’, participants were further asked to provide the number of levels into which the UVI is divided. Question 6 asked which vitamin (Vitamin A, Vitamin B, Vitamin C, Vitamin D and Vitamin E) is synthesised by exposure to UVR. Question 7 asked which element (iron, calcium, magnesium, zinc, copper and tin) is affected by the vitamin synthesised by exposure to sunlight. In question 8, participants were asked where they obtained information about health effects of UVR. The answers included ‘family members’, ‘school’, ‘books’, ‘newspaper’, ‘Internet’, ‘TV’, ‘radio’, ‘friends’, and ‘doctors’. For questions 3, 4 and 8, participants could choose more than one answer.
reduced (question 1) or increased (question 2) exposure to the sun when considering the health effect of UV?’’ Question 3 asked about participants’ sun protection behaviour and consisted of six parts, wearing long-sleeve clothes, applying sunscreen, wearing a sun hat or cap, wearing sunglasses, holding a sun umbrella and reducing outdoor activities. Responses to question 3 were further measured using a ﬁve-level scale. A score of one was given if the response was ‘never’ and 5 if the response was ‘always’. For participants who answered all six parts of this question, the score values of ‘wearing long-sleeve clothes’ and ‘applying sunscreen’ were summed to evaluate the protection against skin damage. The score values of ‘wearing sun hat or cap’ and ‘wearing sunglasses’ were summed to evaluate the protection against eye damage. The score values of ‘holding a sun umbrella’ and ‘reducing outdoor activity’ were summed to evaluate the full protection against sunlight. In question 4, participants were asked whether they paid attention to the weather forecast. Question 5 asked whether participants paid attention to UVI when reading the weather forecast. The answers to the 5 above questions all ranged from ‘never’, ‘seldom’, ‘sometimes’, ‘often’, and ‘always’. Question 6 was ‘‘Would you reduce or increase sun exposure due to the UVI forecast?’’ Question 7 was ‘‘Would you reduce or increase the amount of sunscreen you applied due to the UVI forecast?’’ The answers to the two above questions were either ‘yes, I would’ or ‘no, I would not’. 2.4. Statistical analysis All statistical analyses were performed using SPSS for Windows 12.0 (SPSS, Chicago, IL, USA). Categorical variables were compared using the v2 test and Fisher’s exact test when appropriate. Ordinal categorical variables were compared using ridit analysis. The difference among the mean scores of sun protection behaviour by gender was compared using the Wilcoxon test. A P value less than 0.05 was considered statistically signiﬁcant.
3. Results 3.1. Characteristics A total of 385 subjects were included in this study. Men comprised 40.5% of the participants, and 59.5% were women. The average age of the subjects was 21.25 years, with a range of 19–25 years.
2.2. Measuring attitude 3.2. Knowledge of UVR Three questions were used to measure participants’ attitude towards sun protection. The ﬁrst question was ‘‘Considering the effects of UVR, what times of day do you think would be appropriate for outdoor activities in the summer, or spring and autumn, or winter?’’ The answers ranged from ‘6:00–8:00’, ‘8:00–11:00’, ‘11:00–13:00’, ‘13:00–16:00’ and ‘16:00–18:00’. The second question was about the reason why participants adopt sun protection. The answers included ‘preventing skin cancer’, ‘preventing skin ageing’, ‘preventing sunburn’, ‘preventing suntan’ and ‘preventing eye damage’. The third question asked about individuals’ opinions on tanning, and the answers included ‘tanning makes people look healthier’, ‘tanning makes people look more attractive’, ‘tanning makes people look older’ and ‘I do not care’. For questions 1 and 3, participants could choose more than one answer. 2.3. Measuring practice There were seven questions regarding participants’ practice of sun protection. Firstly, participants were asked ‘‘Have you ever
A partial compilation of participants’ knowledge about UVR is shown in Table 1. Approximately 93.8% of participants believed that UVR was both harmful and beneﬁcial to human health. Only 1.9% of them believed that UVR is only harmful to human health, and 4.3% of them thought UVR is only beneﬁcial. Few participants (19 from 385) stated that they knew the meaning of UV index. However, only 5 of them gave the correct number of levels in the UVI. No one correctly choose all of the health effects of UVR from the 15 answer options of question 3. Among the 10 correct answer options, the least chosen correct options were pterygium (3.1%, 12 from 385) and cataract (27.8%, 107 from 385). The most chosen were skin cancer (95.6%), sterilisation (94.0%), and sunburn (92.2%). For question 4, 71 students responded to this multiplechoice question with the same response given for question 3. The effects chosen for questions 4, which asked about effects that were important to Chinese people, were skin cancer (72.5%), sterilisation (70.7%) and sunburn (66.5%).
Q. Gao et al. / Journal of Photochemistry and Photobiology B: Biology 140 (2014) 14–19
Table 1 Participants’ general knowledge about UVR.a
Q1: UVR was harmful to human health Yes No Not sure
146(93.6) 6(3.8) 4(2.6)
217(94.8) 10(4.4) 2(0.9)
363(94.3) 16(4.2) 6(1.6)
Q2: UVR was beneﬁcial to human health Yes No Not sure
147(94.2) 3(1.9) 6(3.9)
219(95.6) 4(1.8) 6(2.6)
366(95.1) 7(1.8) 12(3.1)
Q5: Do you know the meaning of UVI? Yes No I have heard of it, but I do not know the exact meaning
9(5.8) 81(51.9) 66(42.3)
10(4.4) 99(43.2) 120(52.4)
19(4.9) 180(46.8) 186(48.3)
Q6: Which vitamin is synthesised by exposure to UVR? Vitamin D Others
Q7: Which element is affected by the vitamin synthesised by exposure to solar UV? Calcium 148(94.9) Others 8(5.1)
Q8: Information sourcesb Family members School Books Newspaper Internet TV Radio Friends Doctors
97(42.4) 181(79.0) 167(72.9) 107(46.7) 179(78.2) 171(74.7) 24(10.5) 120(52.4) 62(27.1)
149(38.7) 285(74.0) 276(71.7) 166(43.1) 287(74.5) 276(71.7) 48(12.5) 179(46.5) 102(26.5)
0.074 0.007 0.514 0.083 0.048 0.115 0.153 0.005 0.754
52(33.3) 104(66.7) 109(69.9) 59(37.8) 108(69.2) 105(67.3) 24(15.4) 59(37.8) 40(25.6)
Data are expressed as n (%) of participants. Percentages are rounded and may not sum to 100% because multiple answers were allowed.
3.3. Attitude towards sun protection
The participants’ attitudes towards sun protection are shown in Table 2. Most participants believed that it was more appropriate to have outdoor activity between 6:00–8:00 and between 16:00– 18:00 in the summer, and in spring and autumn. In winter, they chose 8:00–11:00. The main purpose of adopting sun protection was ‘preventing sunburn’, followed by ‘preventing suntan’ and ‘preventing skin cancer’. However, ‘preventing eye damage’ was the least considered item when adopting sun protection. There was a signiﬁcant difference in attitudes towards tanning between genders. Men were more inclined to believe that tanning makes people look healthier and attractive, but women were more inclined to believe that tanning makes people look older.
In recent decades, to control the signiﬁcant increase in the incidence rates of cutaneous melanoma and non-melanoma skin cancers, many sun protection programs have been launched in Western countries. Some concepts and protection strategies have been introduced in China and accepted by the general public. However, Chinese people, as people of colour, have their own characteristics. People of colour have a lower incidence of skin cancer  and a higher incidence of cortical opacities [5,6], which are mainly caused by UVR, compared to Caucasians. Furthermore, Asian adults are at risk of vitamin D deﬁciency due to their dark skin pigmentation . Therefore, sun-protection strategies from Western countries should be adapted before being applied to the Chinese population. To develop appropriate protection and education strategies, it is necessary to know the KAP of Chinese regarding UVR and sun protection. As medical undergraduate students, the participants in this study had greater health knowledge than the general public. However, their knowledge of UVR health effects was not comprehensive. Most of them knew the effect of UVR on skin and skeletal health or even on sterilisation and immune function. Fewer knew the effect of UVR on the eyes. They did not know that the important health effects of UVR in the Chinese population are different from those in the Caucasian population, either. As a result, few participants in this study adopted sun protection measures to prevent eye damage. It was quite evident that eye damage from UVR had not received much attention. Participants’ attitudes towards outdoor activity timing showed that morning and late afternoon were thought to be appropriate times for outdoor activities in the summer, spring and autumn. People hold this opinion mainly based on the ambient UVR distribution or temperature distribution throughout the day. Avoiding the strongest sunlight at noon might be useful for preventing skin
3.4. Sun protection behaviours The participants’ sun protection behaviours are presented in Tables 3 and 4. Most participants seldom initiated increased or reduced sun exposure. A small number of participants (2.6%) only increased exposure to the sun instead of reducing it. However, more women (14.0%) than men (5.2%) had only reduced the exposure to the sun (P = 0.005). Women were more likely to adopt sun protection methods than men. For women, the most popular methods of sun protection were sun umbrella and sunscreen. For men, the main methods were covering skin with clothes and reducing outdoor activity. The preferred body protection regions were also different for women and men (P < 0.001) (Table 5). The eyes received the least protection for both genders. Women were more concerned about the weather forecast than men (P < 0.001). Among participants who were always or often concerned about the weather forecast (195 persons), few of them (11.9% for men and 6.6% for women) were always or often concerned about UVI forecast.
Q. Gao et al. / Journal of Photochemistry and Photobiology B: Biology 140 (2014) 14–19 Table 2 Participants’ attitudes regarding sun protection.a Men
Q1: More appropriate time to have outdoor activity In the summer 6:00–8:00 115(74.7) 8:00–11:00 38(24.7) 11:00–13:00 6(3.9) 13:00–16:00 9(5.8) 16:00–18:00 101(65.6)
171(78.1) 33(15.1) 7(3.2) 12(5.5) 147(67.1)
286(76.7) 71(19.0) 13(3.5) 21(5.6) 248(66.5)
0.444 0.020 0.717 0.880 0.757
In the spring and autumn 6:00–8:00 8:00–11:00 11:00–13:00 13:00–16:00 16:00–18:00
95(61.7) 86(55.8) 25(16.2) 43(27.9) 95(61.7)
155(68.6) 123(54.4) 23(10.2) 43(19.0) 155(68.6)
250(65.8) 209(55.0) 48(12.6) 86(22.6) 250(65.8)
0.164 0.785 0.081 0.042 0.164
In the winter 6:00–8:00 8:00–11:00 11:00–13:00 13:00–16:00 16:00–18:00
89(58.2) 94(61.4) 63(41.2) 62(40.5) 89(58.2)
124(56.1) 138(62.4) 78(35.3) 93(42.1) 139(62.9)
213(57.0) 232(62.0) 141(37.7) 155(41.4) 228(61.0)
0.692 0.844 0.249 0.764 0.357
Q2: The reason of adopting sun protection Preventing skin cancer Preventing skin ageing Preventing sunburn Preventing suntan Preventing eye damage
24(15.6) 4(2.6) 90(58.4) 33(21.4) 3(2.0)
33(14.5) 6(2.6) 121(53.3) 63(27.8) 4(1.8)
57(15.0) 10(2.6) 211(55.4) 96(25.2) 7(1.8)
Q3: Opinions on tanningb Look healthier Look more attractive Look older I don’t care
65(42.2) 16(10.4) 12(7.8) 72(46.8)
46(20.4) 9(4.0) 93(41.2) 90(39.8)
111(29.2) 25(6.6) 105(27.6) 162(42.6)