It is not as sunny as it used to be over China and pollution is probably to blame, Chinese researchers reported on Friday. They found a significant decrease in daily surface solar radiation and less sunshine per month compared with 1961 -- especially over the eastern part of the country where most people live and most factories are located. The best explanation is a rise in aerosols -- little particles that include soot, dust and even smaller bits produced by burning fossil fuels such as coal and oil, Huizheng Che and colleagues at the Chinese Academy of Sciences in Xian reported in this week's issue of Geophysical Research Letters. They measured several components of sunniness, including daily global radiation, annually averaged solar direct radiation and daily diffuse radiation, as well as the annually averaged daily clearness index. "Almost all stations in China showed decreasing trends in the clearness index," they wrote in their report. "From these results, we conclude that the increasing emissions of anthropogenic (human-made) aerosols have likely affected the magnitude and variability of solar radiation and sunshine duration over much of China, especially the eastern part of the country." ---SP 0048 Local Time 2148 GMT