BEIJING
(AP)—Caving to public pressure, Beijing environmental authorities
started releasing more detailed air quality data Saturday that may
better reflect how bad the Chinese capital’s air pollution is. But one
expert says measurements from the first day were low compared with data
U.S. officials have been collecting for years.
The
initial measurements were low on a day where you could see blue sky.
After a week of smothering smog, the skies over the city were being
cleared by a north wind.
The
readings of PM2.5—particulate matter less than 2.5 micrometers in size
or about 1/30th the average width of a human hair—were being posted on
Beijing’s environmental monitoring center’s website. Such small
particulates can penetrate deep into the lungs, so measuring them is
considered a more accurate reflection of air quality than other methods.
It
is the first time Beijing has publicly revealed PM2.5 data and follows a
clamor of calls by citizens on social networking sites tired of
breathing in gray and yellow air. The U.S. Embassy measures PM2.5 from a
device on its rooftop and releases the results, and some residents have
even tested the air around their neighborhoods and posted the results
online.
Beijing
is releasing hourly readings of PM2.5 that are taken from one
monitoring site about 4 miles (7 km) west of Tiananmen Square,
the monitoring center’s website said Saturday. It said the data was for
research purposes and the public should only use it as a reference.
The
reading at noon Saturday was 0.015 mg per cubic meter, which
would be classed as “good” for a 24-hour exposure at that level,
according to U.S. Environmental Protection Agency standards. The U.S.
Embassy reading taken from its site on the eastern edge of downtown
Beijing said its noon reading was “moderate.” Its readings are posted on
Twitter.
Steven
Andrews, an environmental consultant who has studied Beijing’s
pollution data since 2006, said he was “already a bit suspicious” of
Beijing’s PM2.5 data. Within the 24-hour period to noon Saturday,
Beijing reported seven hourly figures “at the very low level” of 0.003 mg per cubic meter.
“In
all of 2010 and 2011, the U.S. Embassy reported values at or below that
level only 18 times out of over 15,000 hourly values or about 0.1% of the time,” said Andrews. “PM2.5 concentrations vary by area
so a direct comparison between sites isn’t possible, but the numbers
being reported during some hours seem surpisingly low.”
The
Beijing center had promised to release PM2.5 data by the start of the
Chinese Lunar New Year on Monday. It has six sites that can test for
PM2.5 and 27 that can test for the larger, coarser PM10 particles that
are considered less hazardous. The center is expected to buy equipment
and build more monitoring sites to enable PM2.5 testing.
Beijing
wasn’t expected to include PM2.5 in its daily roundups of the air
quality anytime soon. Those disclosures, for example “light” or
“serious,” are based on the amount of PM10, sulfur dioxide and nitrogen
dioxide in the air.
Beijing
interprets air quality using less stringent standards than the U.S.
Embassy, so often when the government says pollution is “light,” the
embassy terms it “hazardous.”
“There
has been tremendous amounts of attention in the Chinese media—whichever
newspaper you pick up, whichever radio station you listen to, channel
you watch—they are all talking about PM2.5 and how levels are so high,”
said Andrews.
“What
has been so powerful is that people are skeptical, and I think rightly
skeptical,” about the government’s descriptions of data, he said.
Beijing center’s readings (in Chinese)
The U.S. Embassy’s Twitter feed
SOURCE: The Associated Press
