| Objective:Sustained solar ultraviolet exposure is a prerequisite for the occurrence of cataract disease.Previous researches of solar ultraviolet quantity mainly focus on outdoor exposure irradiance,but ignore indoor ultraviolet exposure with longer exposure time.Hence,in the current study,we study the potential risk of indoor ultraviolet exposure,and explore whether the continuous process of indoor and outdoor ultraviolet exposure contributes to cataract occurrence.Combining the time and intensity of indoor and outdoor ultraviolet exposures can provide support to the study of the ultraviolet exposure of human eyes throughout the day.Methods:Measurements were carried out in the town of Sanya city?18.4°N,109.7°E,18m above sea level?in the province of Hainan,China and the town of Lhasa city?29.7°N,91.14°E,3650 m above sea level?in the province of Xizang,China.We use a rotary body model,monitoring by micro fiber spectrometer eye study ocular UV exposure.Outdoor solar UV irradiance was measured on the rooftop of five-storey building.Indoor irradiance was measured in the room which were eastward,westward,northward and southward orientation.Results:1.The outdoor environmental exposure representative wavelengths at the two monitoring sites in Sanya and Lhasa increased with the angle of the sun's elevation and showed a bell-shaped distribution.However,the ocular exposure representative wavelength shows a bimodal distribution with the variation of the sun's elevation angle.Different wavelength intensity values at the same solar elevation angle become larger as the wavelength increases.2.The wavelength UV radiation intensity of the ocular exposure in north and south room in the morning and afternoon sub-sections generally increase with the sun's elevation angle,whose curve is gentle.The indoor east direction of both places peaks in the morning SEA 0-90°segment.Sanya ocular representative wavelength ultraviolet spectral radiation peaks at a sun's elevation angle of 31.79 degrees.The intensity peaks of the representative wavelengths of Lhasa appears in the solar elevation angle of 36.98-53.25 degrees.The west ocular exposed representative wavelengths of Sanya and Lhasa slowly increased with decreasing solar elevation angle in the afternoon SEA90-0°segment,and peaks at 45.70 and 56.25 degrees respectively.3.The maximum UV radiation exposure intensity of unweighted single-nano-UVB in the interior of Sanya and Lhasa appear at320nm in the east orientation room.However,the bio-effective wavelengths of ultraviolet light in the indoor eye lens are mainly observed near the 307 nm.4.The maximum of bio-effective ultraviolet radiation dose for intraocular lens damage in different orientations in Sanya indoor occurs in the southern indoor solar elevation angle of 90-55°,and the dose value was 20.14 J m-22 nm-1.However,the maximum dose value of Lhasa occurs at the east indoor solar elevation angle of 10-50°,and the dose value is 39.73 J m-22 nm-1.5.Maximum UVB exposure dose ratio between the indoor eye and the outdoor environment in the solar angular range throughout the day is 0.17.Conclusion:1.The UV exposure of indoor eyes in Sanya and Lhasa is the highest in the eastward room.2.Maximum UVB exposure dose ratio between the ocular and the ambient exposure in the solar angular range throughout the day is 0.17.Provide support for the evaluation of UV exposure in indoor and outdoor eyes. |
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