A man wearing a mask is seen on a street in Beijing May 2, 2013. Street-level anger over air pollution that blanketed many northern cities this winter spilled over into online appeals for Beijing to clean water supplies, especially after rotting corpses of thousands of pigs were found last month in a river that supplies tap water to Shanghai. REUTERS/Kim Kyung-Hoon (CHINA – Tags: SOCIETY ENVIRONMENT HEALTH) – RTXZ7EU
