BEIJING — The first red alert over air pollution in the Chinese capital almost brought this city to a standstill in December, with schools shut, construction halted and driving restricted. Now, in a swift policy shift, Beijing plans to issue a red alert based on higher thresholds, despite government pledges to better address the toxic air.
A red alert, the highest level of a four-tier warning system, will be issued if the daily average air quality index is forecast to exceed 500 for one day, 300 for two days or 200 for four days, Xinhua, the state news agency, reported on Sunday, quoting Beijing’s environmental agency. The new standards will take effect before the end of March, it said.
The air quality index, used in many countries, is an aggregate measure of various pollutants in the air. Currently, any reading above 200 for more than three days in Beijing will prompt a red alert, which activates numerous contingency plans that can disrupt jobs and businesses.
Beijing’s air quality is among the worst in the world, and much of the smog comes from industrial pollution and the burning of coal.
The red alert issued in December came as a surprise to many because air pollution in the city had routinely been worse. A number of times during the winter over the past three years, the air quality index exceeded 500, a level deemed hazardous to human health. Those “off-the-charts” episodes did not activate red alerts, even though the state news media instructed people to reduce their outdoor activities.
The new standards will also be applied to neighboring provinces that have suffered from severe air pollution, Xinhua reported.
Ma Jun, a prominent environmental researcher in Beijing, said the change highlighted officials’ worries about the social disruption a red alert could cause. With the new standards, he said, officials must reassess some of the contingency measures that come with the warning.
“There will be multiple times of red alerts in a year if we continue using the current standards, which will bring about a high social and economic cost,” Mr. Ma said, alluding to the contingency measures. They include the closing of factories and schools and strict limits on the use of cars.
Among the issues at stake is children’s health, he said, arguing for the need to re-evaluate the emergency measures after the imposition of the new standards. The Xinhua report said the response measures would remain the same, but each city affected would be able to decide if primary and middle schools should be temporarily closed.
Mr. Ma argued that schools should continue to be closed even if Beijing declared a lower warning.
Next week, the Chinese Communist Party will convene its Parliament, where air pollution is expected to be a major topic.
The Chinese news media reported over the weekend that Beijing was considering a plan to build five ventilation corridors to improve urban air circulation. The corridors, each at least 1,500 feet wide, would run though the city, passing through parks, inner-city lakes and public spaces. Also being planned, the reports said, are an unspecified number of narrower corridors. It is not clear how much the project would cost or when it would be finished.