Abstract
The threshold exposure time for synthesis of vitamin D was simulated by using a radiative transfer model considering variations in total ozone, cloud, and surface conditions. The prediction of total ozone took the form of an empirical linear regression with the variables of meteorological parameters in the upper troposphere and lower stratosphere and the climatology value of total ozone. Additionally, to consider cloud extinction after the estimation of clear-sky UV radiation using a radiative transfer model simulation, a cloud modification factor was applied. The UV irradiance was estimated at one-hour intervals, and then, to improve the temporal resolution of the exposure time simulation, it was interpolated to a one-minute resolution. Exposure times from the simulation clearly followed seasonal and diurnal cycles. However, upon comparison with observations, biases with large variations were found, and the discrepancy in the exposure time between the observations and simulations was higher in low UV irradiance conditions. The large deviations in the prediction errors for total ozone and the simplified assumption for the cloud modification factor contributed to the large deviations in exposure time differences between the model estimation and observations. To improve the accuracy of the simulated exposure time, improved predictions of total ozone with a more detailed cloud treatment will be essential.
Highlights
Increases in surface UV irradiance resulting from stratospheric ozone depletion have had harmful effects on human health by inducing skin damage [1, 2]
UVEry irradiance generally varies with atmospheric conditions that include the quantity of ozone, which is an important factor in its accurate estimation. e widely used action spectrum for the erythemal dose is that of the Commission International on Illumination (CIE) [5]
The optimized exposure time for vitamin D synthesis is normally shorter than the time required to cause erythema [15]. erefore, the exposure time to solar UV radiation that results in sufficient vitamin D synthesis without damaging the skin can be determined
Summary
Increases in surface UV irradiance resulting from stratospheric ozone depletion have had harmful effects on human health by inducing skin damage [1, 2]. Erefore, the exposure time to solar UV radiation that results in sufficient vitamin D synthesis without damaging the skin can be determined. Erefore, exposure time calculations require accurate calculations of UVEry and the UV irradiance spectra weighted by the action spectrum of vitamin D synthesis (UVVitD hereafter). Focusing on studies that have calculated exposure time, the regional distribution of the levels of threshold of UV exposure for vitamin D synthesis have been determined by using the statistical relationship between UVVitD and several variables, such as global solar irradiance, total ozone, and dew point temperature [27, 29].
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
