A Pilot Study to Identify Factors Affecting UV-B Radiation Exposure in Selected Microenvironments

摘要

A pilot study was conducted to test a protocol for collecting data useful for identifying local factors affecting exposure to ultraviolet-B radiation (UV-B). A trained technician followed a prepared script through a series of microenvironments representing varying conditions of overhead shielding and ground cover while collecting UV-B irradiance and related data on days selected to represent varying conditions of solar radiation, cloud cover, groundlevel ozone concentration, and fine particulate matter (PM2.5) concentration. The resulting data were combined with air pollution, UV-B, and meteorological data obtained from local fixed-site monitoring stations and analyzed to identify the principal factors affecting (1) UVI (UV Index) measured by the Safe Sun monitor and (2) fixed-site UV-B. Results of these analyses indicated that the best predictors of UVI were degree of shielding, solar angle, fixed-site UV-B, cloud cover, wind speed, time of day, and season. Although cloud cover was an important predictor of UVI, the clearest days did not correspond to the highest UVI values. Variations in cloud parameters can cause intraday UVI variations not reflected in a daily forecast. Residential outdoor microenvironments tended to have lower mean UVI values than outdoor recreation microenvironments (e.g., athletic field, pool), which may have implications for estimating total personal exposure to UV-B.