Olympic facilities, like the Beijing 2008 Olympic Main Stadium, presumably are exempt from the Chinese government's two-month ban on construction in the city. (Xin Zhu photo)

It might not be full-speed re-browning, if a few of the measures taken this summer are made permanent. Most are temporary. Starting July 20, building construction projects are to be halted for two months. New York Times reporter Andrew Jacobs lists other temporary restrictions intended to clear the air by August 8:

City officials laid out an ambitious series of measures on Monday that will freeze construction projects, slow down steel production and shut down quarries in and around this capital during the summer in an attempt to clear the air for the Olympics. Even spray-painting outdoors will be banned during the weeks before and after sporting events...Government directives will also force coal-burning power plants to reduce their emissions by 30 percent through most of the summer. Officials said 19 heavily polluting enterprises, including steel mills, coke plants and refineries, would be temporarily mothballed or forced to reduce production. Gas pumps that do not have vapor-trapping devices will be closed, cement production will stop and the use of toxic solvents outdoors will be forbidden.

In Jacobs's article today, "Construction Halted Ahead of Games," he points to some changes that might be permanent. Chinese officials say they have forced local factories to upgrade pollution-control equipment, and shut down about 200 of the most noxious offenders.

The effort has been under way for a year or more, but not at this scale. Pollution from coal-burning heaters and stoves is measurably on the decline, but car ownership is on the rise, with about 1,200 new cars per day. The two trends cancel each other's impact, Jacobs reports. With such surging demand, gas stations might be compelled to upgrade pumps with vapor-trapping devices rather than be closed down.

What about indoor air quality? A proposed smoking ban has been relaxed so bar and restaurant patrons can exercise their presumed human rights to light up. Stadiums, however, are supposed to be non-smoking as of May 1.