Biologically effective radiation of solar ultraviolet radiation and the depletion of stratospheric ozone

Based on the biological action spectra and total UV-B radiation in the atmosphere,the effective UV-dose for DNA, erythema,and plant at different seasons in the last decade,and their future change in Beijing area were calculated.Computation results indicate that the maxi- mum of biologically effective radiation dose at noontime is in July and the minimum is in January. From 1980 to 1989 biologically effective radiation dose have increased with the average rates of about 0.6,0.7 and 1.1 mW/m2 per year for January, April and October,while in July the trend of radiation dose is not ln evidence. For 1% reduction of ozone concentration radiation amplification factor for DNA,erythema and plant are 2.3,2.3 and 1.4 and for 30% reduction of ozone concentration the RAF for DNA,erythema and plant are 4.2,4.0 and 2.1,respectively.