Chinanews, Beijing, January 31 – Bohai Sea is the worst polluted area in China. In 2006 alone, 1.58 billion tons of toxic waste were dumped into it.In the last five years, Bohai has always been the dirtiest sea in China, for 26% to 41% of its sea areas could not meet the required environmental standards. More than 81% of all the sewages around its shores has been dumped in to the sea. Last year, 11 red tides hit Bohai Sea.Experts call for central government's attention to the pollution in the Bohai Sea. It can be estimated that ecoenvironmental hazard in the Bohai Sea will be one of the most difficult challenges to provinces and municipalities around it.