Lhasa riot took its toll on city's pure environment

LHASA: The riot here last month not only left the city with casualties and economic losses, but also caused considerable environmental damage, with the city's air quality being the worst in its history.

"Air quality on March 14 was the worst on record since Lhasa began daily air quality reporting in 2000," Zhang Yongze, the regional environmental protection bureau director, said.

The density of sulfur dioxide was 10 micrograms per cubic meter on the day, double the city's average. The nitrogen dioxide level was 60 micrograms per cubic meter, more than double the daily average, the bureau said.