Guangzhou Municipal Environment Protection Working Conference says today that Guangzhou's general environment quality improves further. Last year, sulfur dioxide of the air in the city proper was 0.045 milligram per cubic meter, decreased 16.7% than in 1999. Nitrogen dioxide was 0.061 milligram per cubic, a decrease of 13.2%. The dust volume was 7.34 tons per 1,000 cubic meters/monthly, a decrease of 10%...