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Officials propose real-time air quality index
By Ke Jiayun

THE people of Shanghai will soon be able to better plan their outdoor activities if a proposal to introduce hourly updates for all major pollutants comes to fruition.

The plan is to give members of the public real-time access to PM2.5 and PM10 levels, said Fu Qingyan, chief engineer at the Shanghai Environmental Monitoring Center.

Under the current system — which calculates the average concentration of PM2.5 and PM10 over the previous 24 hours — the information is often out of date, she said.

“A real-time air quality index is much more useful, as the average does not take account of sudden changes in weather conditions, which can significantly affect air quality,” she said.

For example, the real-time concentration of PM2.5 at a monitoring spot in Huangpu District at 2pm yesterday was 200.2 micrograms per cubic meter, while the average for the past 24 hours was just 138.5.

“With the new system, people will be able to make better decisions about whether or not to go out,” Fu said.

The Shanghai Environmental Protection Bureau said it has been studying the new system for some time and has submitted its plans to the city government for approval.

Shanghai has 52 air quality monitoring spots across the city, and information about the concentration of the six pollutants — PM2.5, PM10, sulfur dioxide, nitrogen dioxide, ozone and carbon monoxide — collected from 10 main spots is published on the environmental monitoring center’s website.

While readings for four of the pollutants are updated on an hourly basis, the PM2.5 and PM10 figures are given as the averages for the past 24 hours, in line with national standards.

PM2.5 and ozone are the most serious pollutants for Shanghai, with the former accounting for more than 70 percent of the polluted days recorded last year and ozone 26 percent.

Warm days ahead, though spring has not yet sprung

There will be a spring feel to the weather this week, with a mixture of sunshine and rain but generally higher temperatures, forecasters said.

Today’s high could be as much as 15 degrees Celsius, with a low of 6 degrees, they said.

The pollution seen yesterday — when the PM2.5 density rose to 162.6 milligrams per cubic meter, or more than double the national standard — should subside today.

“Southeasterly winds (today) should help to disperse the smog, while the rains forecast for Wednesday will also help the situation,” said Man Liping, a chief service officer at the Shanghai Meteorological Bureau.

A colder air mass from the north is set to start moving in tomorrow and that should bring some rain, though temperatures should still be in the range of 9 to 15 degrees. Thursday will see a slight dip to between 6 and 11 degrees, the forecasters said.

Friday will see the high return to 14 degrees, with a low of 3, while sunshine and a high of 15 are promised for Saturday.

Despite the generally warmer weather, forecasters will not commit to the arrival of a meteorological spring, which is called when average temperatures remain above 10 degrees for five consecutive days.

The smog that has been affecting north China should begin to disperse today with the arrival of a cold front, the National Meteorological Center said. However, it would not say if the bad air situation would relocate to Shanghai.

“Smog is most likely when there is a high concentration of particles in the air and certain dry, stable weather conditions,” said Zhang Ruiyi, also a chief service officer at the meteorological bureau.

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