The Study Of Ocular UV Exposure Intensity On Water Surface Background

Objective:Excessive exposure to ultraviolet can lead to many diseases,and the eye is an important target organ of ultraviolet exposure,its damage to the eye has become an important public health problem.There are many factors that affect the intensity of ultraviolet radiation into the eye,such as SEA,latitude,clouds and aerosols,and so on.In addition,the surface albedo is also an important factor,the degree of eye injury varies from the ground albedo.The surface of the water is a common ground background in people’s daily life,and the main exposed people are divided into two categories.One is occupational exposure.Typically,fishermen need to be exposed to strong sunlight for a long time due to their survival and occupation needs,except for fishermen and seafarers.The same is true for many occupations,such as sailing athletes,maritime patrols and maritime search and rescue teams;Second,entertainment exposure,tourism is one of the vital economic activities,and coastal tourism in the global scope of popularity,gradually become a holiday resort.The other research team has carried out eye ultraviolet monitoring in snow,grassland and beach.In order to further improve the integrity of the system of ground background exposure to eye ultraviolet radiation,this paper focuses on the study of ultraviolet eye damage in the water surface background.The aim is to provide reference for eye protection under the background of public water surface.Method:In this study,a self-made rotating ocular ultraviolet exposure model was used to monitor the water surface of Wulihe River Park in Shenyang during August 2017,and two different ground backgrounds were used to carry out continuous daytime monitoring at the same time.Taking the positive position of the sun as the starting point,the rotating disk rotates at a constant speed for one week,collecting a numerical value every 6°,60data are collected at each time point,and the data are collected once every 15 min.The monitored data were measured in units(μW/cm~2/nm)of eye ultraviolet exposure at different solar elevation angles.The physical intensity of ultraviolet exposure was obtained by using avasoft 7.6 for usb 2 software to convert the data into excel format and process.The biologically effective exposure intensity of cornea,conjunctiva and lens was calculated by weighted physical intensity and the effective spectrum of UV induced corneal,conjunctival and lens injury;The physical intensity was weighted to the spectrum of eye injury provided by ICNIRP,and the cumulative UV bioeffective dose per hour was calculated by multiplying the exposure time.Then the originpro 9 software was used to make the analysis.Results:1.Diurnal variation of maximum intensity and average intensity of ultraviolet exposure to eye UVA under the background of water surface showed a bimodal distribution and were higher than those in the background of wood,and reached the peak at 9:15(SEA=43°)and 14:32(SEA=41°),which was 2752μW/cm~2,2666μW/cm~2respectively.Under the background of water surface,the maximum intensity and average intensity of eye UVB ultraviolet exposure were higher than those of wood background,but there were no obvious double peaks in daytime change.2.Under the background of water surface,the intensity of eye UVA,UVB exposure was higher than that of wood background in different positions.The azimuth of the maximum exposure intensity of eye UVA,UVB was approaching 180°with the elevation of the sun rising in the surface of water and wood.3.The radiation intensity ratio of UVA and UVB eye to environment in the background of water surface is higher than that in the background of wood,and the distribution trend is high,middle and low on both sides.4.According to UVBE distribution of corneal,conjunctiva and lens injury on water surface and wood background with time and solar elevation angle,when SEA was in the range of 30°-57°,the biologically effective ultraviolet radiation intensity of corneal injury and lens injury under water surface were higher than those of wood background.The biologically effective ultraviolet radiation intensity of conjunctival injury under wood background was higher than that of water surface.5.Difference comparison of physical intensity and intensity of biological effective UV between water surface and wood background in the range of different Solar elevation Angles reveal that the difference of UVA in the range of 30°-45°was the largest,about 444.0445μW/cm~2 and the difference of UVB,corneal injury,conjunctival injury,lens injury increased gradually with the increase of the SEA 6.The diurnal variation of cumulative biological effective dose of ultraviolet exposure per hour under the water surface background showed unimodal distribution,the value were above 70 J/m~2 at 8:30–14:30(SEA=36.13°-57°),and its peak of 77.74 J/m~2 appeared at9:30-10:30 in the morning(SEA=45.12°-52.85°).Conclusion:The moniter was done beside River Park in Shenyang during August 2017,the following conclusions are drawn:1.The maximum exposure intensity,average exposure intensity,exposure intensity in different azimuths,and eye-to-environmental radiation exposure ratio of ocular UV exposure on water surface was higher than that on wood background.2.Compared with the intensity of biological effective UV in the background of wood,the intensity of biological effective UV of corneal and lens damage in the water surface background were higher,and the damage to the eyes was serious.3.The cumulative biological effective dose of ultraviolet exposure per hour under the water surface background were above 70 J/m~2 at 8:30–14:30(SEA=36.13°-57°),and its peak value up to 77.74J/m~2.