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The U.S. Environmental Protection Agency (EPA) has initiated a program to develop and operate a monitoring network to measure ultraviolet (UV) radiation flux at the earth’s surface and to provide for public awareness of exposure to UV radiation through adaptation and publication of a predictive UV “exposure Index.” This Index, similar to the one developed and publicized by Canada in 1992, is being developed in conjunction with the National Weather Service for possible public distribution this year. Current plans call for a fifteen-site monitoring network to measure UV intensities on a spectrally-resolved basis, together with other parameters (e.g., total column ozone, cloud cover, interfering tropospheric pollutants, etc.) that affect UV flux. Eleven urban sites will provide data to validate the Index predictions in proximity to ~25% of the U.S. population. The combination of urban (polluted) and four rural (less polluted) sites will enable EPA to improve the algorithms upon which the Index predictions are based. A series of instrumental intercomparisons with other agencies are also planned to ensure comparability of data and good quality assurance/quality control. EPA’s intent is to coordinate its efforts with other federal agencies and with the international community. |
