Trash clogs up a polluted canal at the edge of Beijing on March 16, 2012. China said that two-thirds of its cities currently fail to meet new air-quality standards introduced this week that are based on the pollutants most harmful to health. Under pressure from a worried Chinese public, the government this week issued revised air-quality targets based on the smallest particulates, which make up much of the country's air pollution. AFP PHOTO/Mark RALSTON (Photo credit should read MARK RALSTON/AFP/Getty Images)
