【作者】 王阳；

【导师】 刘扬；

【作者基本信息】 中国医科大学 ， 劳动卫生与环境卫生学， 2005， 硕士

【摘要】 前言 紫外线是引起白内障的重要环境因素之一。有色人种白内障患病率要高于白种人。我国进入老龄化社会,亟待进行紫外线与白内障的危险性评价。 个体紫外线眼晶体暴露剂量的准确评价是建立紫外线与眼晶体损伤的量效关系研究的前提。生活在同一地区的不同个体由于生活工作方式和户外暴露时间的不同,接受的紫外线剂量千差万别,因此用环境紫外线辐射水平来评价个体暴露是十分不准确的。同时由于眼晶体的损伤是人群长期暴露于紫外线的结果,因此要选择一种能够反映人群在一般行为方式下眼晶体紫外线暴露的监测模式,并结合个体的一生各时期户外活动规律,推算个体一生眼紫外线暴露量。海南省纬度较低,太阳高度角大,日照时间长。夏季从3月中旬至11月上旬,全年没有冬季。且具有人口构成稳定,流动性小,生活史较单一的样本,适合进行紫外线与眼晶体效应关系的研究。 本研究选择海南省三亚市崖城地区人群进行了紫外线暴露史的问卷调查和眼晶体灰度值测定。采用旋转人体模型的监测方式,模拟眼晶体日间全程紫外线暴露状况,建立数学模型。根据个体一生主要生活阶段户外活动史的问卷调查,将其不同生活阶段户外活动主体时间及其在日间的分布带入数学模型中,推算出该个体一生眼紫外线暴露剂量。探讨了崖城地区人群紫外线暴露剂量与眼晶体灰度值量效关系。 对象与方法 在海南崖城及沈阳分别进行旋转人体模型监测。将紫外线个体监测仪放置旋转人体模型的眼部,并使个体监测仪的紫外线接收面在模特眼眶内更多还原

【Abstract】 IntroductionUltraviolet Radiation is one of important factors for cataract. The incidence of cataract in colored people is higher than white people. Now we are entering a society of more elder people, so it is urgent to develop the risk evaluation of cataract induced by Ultraviolet Radiation.To evaluate the individual UV exposure exactly is the necessary precondition for dose -effect relationship research of ultraviolet radiation and opacity of lens. UV exposure dose of different people may differ much because of different work and life style. So it is not appropriate to evaluate individual UV exposure using the ambient UV level. And the biological effects of ultraviolet radiation are results of exposure constantly, so we need to find a kind of recording method which can simulate ocular UV exposure realistically and combine the data from this method with lifetime outdoor time to calculate individual ocular UV exposure dose. In Hainan, the UV level is high and the latitude,sun latitude and sunshine time are all suitable to do dose - effect relationship research of ultraviolet and opacity of lens. And there also have population with stable composition and simple life history.We took questionnaire survey of UV exposure history and eye examination of population in Yacheng, Hainan and used a circling - model method to simulate individual ocular UV exposure during daytime. Then we constituted a formulation for calculating individual ocular UV exposure dose combing with outdoor time.Objects and MethodSpectral Sensitivity of Solar UV sensor was put in the eye position of circling - model. It faced vertical to the horizontal level nearly and was fixed by a piece of special - made wood. The model circled constantly at a speed of 10 rounds /min in the open air. We recorded the cumulated UV dose of the sensor in eyes every 15 minutes.We chose population in one village in Yacheng as our research objects by cluster sampling method. Then we took a questionnaire survey to get the outdoor time of people’s major stage of life and took examination including using eye chart to test visual acuity, cranny light to examine eyeground and EAS - 1000 to get opacity of eyes.We selected the means of data received by simulated - monitoring and made curve estimation to get two formulations calculating individual UV exposure time and dose. Then we worked out the individual UV exposure time and dose of population in Yacheng by taking the out door time into the formulations.ResultsThe monitoring results of circling - model in Shenyang showed that the daily distribution of individual ocular UV exposure dose presented different current in different seasons. The curve of daily distribution was campanulate in winter and trapeziform in spring, autumn. In summer there curve was sunken in noon. The curve of Yacheng is similar with the curve in spring and autumn in Shenyang.The results of Yacheng population showed high, low, high again and stable current feature of average UV exposure of every age. The average annual outdoor time of Yacheng population showed lowest at school age, highest at elder age, and kept stable at other ages.The opacity of lens related most with age, then with the UV exposure dose and related least with the UV exposure time.Cataract people received more UV exposure dose and time between 3 ~ 12years old than normal people (p = 0.03, p=0.022).The cumulated UV exposure dose and time of population in Hainan are much higher than population in Zhangwu (p <0.05). But there is no difference between the mean value of lens opacity of two groups (p=0. 223). And there is no difference between the mean value of len’s opacity in each age group expect 50 -60 group(p =0.021). Taking T - test of the opacity of lens after dividing the paired people by age, the results showed there was difference between people from two area after 45 years old( p=0.008).DiscussionExcessive UV exposure will increase damage to eyes. Either in developing or developed countries, cataract has become a critical problem. Report of WHO showed the number of cataract patient had reached to one billion and fifty - eight million. A lot of epidemiological evidence support that ultraviolet radiation is a factor for formation of cataract, but some epidemiological conclusion are contrary because of the loss of precise evaluation to cataract and individual UV exposure dose.We used circling - model to simulate the daily ocular UV exposure, then created formulations and combined them with outdoor time to calculate individual ocular UV exposure dose. And we also examined the opacity of lens with the EAS - 1000 supplied by Japan.Results from circling - model monitoring showed that the daily distribution of ocular UV exposure looked like trapeziform and this current is different from that of environmental UV exposure. The daily distribution current of simulated monitoring showed that reflecting UV light took a great part in all UV exposure received in lens and eye socket visibly keep UV light out of lens. Though the reflecting ratio of material used on sensor is different from human eyes, this finding exhibited important significance to future study in UV exposure of eyes.The average annual UV exposure, dose of every year (age3 - 85) in Hainan showed high, low, high again and stable; the average annual UV exposure time of every year showed lowest at school age, highest at elder age, and kept stable更多还原