北京地区臭氧层损耗、气溶胶污染与紫外辐射的变化

Ozone Layer Depletion, Aerosol Pollution and Solar UV-B Radiation at the Ground

对北京地区臭氧层损耗和气溶胶污染对紫外辐射量变化的影响进行了计算。结果表明，当臭氧总量减少１％－３０％时，ＵＶ－Ｂ对ＤＮＡ危害效应的辐射放大因子（ＲＡＦ）从２．３增加到４．２。城区和乡村环境的气溶胶污染使ＵＶ－Ｂ日辐射总量分别降低４５％和１０％。如果仅考虑臭氧总量的变化，１９８０—１９８９年间ＵＶ－Ｂ辐射量年变化率为１．４％，当考虑气溶胶因素的变化后，ＵＶ－Ｂ辐射量年变化率为－０．７％，这与实际观测的结果相符合。

Ozone layer depletion and aerosol pollution have aninfluence on the solar ultraviolet radistion reachingthe ground. A compunction indianaes that theradiation amplification factor (RAF) for a DNAdamage varies from 2. 3 to 4. 2 when a reduction incolumn ozone goes from 1% to 30%. Since theindustrial revolution, the daily UV-B radiation inurban and rural areas has decreaSed by about 45%and 10%, respeCtively, that Can be attributed toaerosol pollution. The computed UV-B radiation dueto the ozone reduction in Beijing shows an increasingtrend at an average annual rate of 1.4% during thePeriod of from 1980 to 1989. By taking thevariations in atmospheric aerosol concentration intoaccount,the computed UV-B radiation shows a trendof negstive shift at an annual rate of 0.7%. Thesevariations in UV-B radiation are found to be close tothose measured in the Alpine regions(47°N) and theUnited States (30-50°N).