Quantcast

Beijing Air Pollution Mystery Could Be Solved, Scientists Say

Climate
Air pollution in Beijing. DuKai photographer / Getty Images

More than one million people die each year in China from particulate matter air pollution, but despite 15 years and billions of dollars of efforts to clean up the country's air, dangerous winter smog persists.

Now, an international team of scientists think they have discovered the reason why: The instruments used to measure Beijing's particulate matter pollution were misinterpreting their readings.


"Our research points towards ways that can more quickly clean up air pollution. It could help save millions of lives and guide billions of dollars of investment in air pollution reductions," said Jonathan M. Moch, first paper author and graduate student at the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS), in a Harvard press release.

In the past, instruments had picked up on the high level of sulfur compounds and read them as sulfates. The Chinese government therefore focused on reducing sulfur dioxide pollution from coal burning power plants. But while the government was successful in those efforts, the overall air pollution levels did not decrease as expected.

That is because, as the team of researchers from Harvard, Tsinghua University and the Harbin Institute of Technology revealed in Geophysical Research Letters Thursday, a lot of those sulfur compounds were actually hydroxymethane sulfonate (HMS)—a compound formed when sulfur dioxide reacts with formaldehyde in smog or fog. The type of instruments used to measure particulate matter in Beijing can easily confuse the two.

The researchers ran a computer model and found that HMS compounds could make up a lot of the particulate matter found in China's persistent winter smog.

"By including this overlooked chemistry in air quality models, we can explain why the number of wintertime extremely polluted days in Beijing did not improve between 2013 and January 2017 despite major success in reducing sulfur dioxide," Moch said.

Moch also said the findings explained why the government's efforts finally seemed to pay off last winter—sulfur dioxide fell below formaldehyde for the first time, so less HMS was formed.

"We think there could have been a shorter way if they had gone straight at formaldehyde," Moch told The Boston Globe.

Major sources of formaldehyde pollution in Eastern China include emissions from vehicles and chemical or oil refineries, so the researchers recommend that China now work on reducing pollution from these sources.

The research team now plans to directly measure HMS levels in Beijing using altered instruments and to use models to assess the importance of HMS formation to pollution across China.

EcoWatch Daily Newsletter

By Anne-Sophie Brändlin

October 16 marks World Food Day this year, a day celebrated every year by the United Nations' Food and Agriculture Organization (FAO).

World Food Day is a call to make healthy and sustainable diets affordable and accessible for everyone, while nurturing the planet at the same time.

Read More Show Less
Graphical representation of vertical pectoral herding by whale in Southeast Alaska. Prey are denoted in yellow. Whale deploys an upward-spiral bubble-net to corral prey and establish the first barrier; pectorals then protract to form a 'V' shape around the open mouth (depicted by blue arrows), creating a second physical barrier. Kyle Kosma / Royal Society Open Science / CC BY 4.0

When you have a whale-sized appetite, you need to figure out some pretty sophisticated feeding strategies. They mysteries of how a humpback whale traps so much prey have eluded scientists, until now.

Read More Show Less
Sponsored
California Yosemite River Scene. Mobilus In Mobili / Flickr / CC BY-SA 2.0

An advisory panel appointed by Trump's first Secretary of the Interior, Ryan Zinke, has recommended privatizing National Parks campgrounds, allowing food trucks in and setting up WiFi at campgrounds while also reducing benefits to seniors, according to the panel's memo.

Read More Show Less
Strips of native prairie grasses planted on Larry and Margaret Stone's Iowa farm protect soil, water and wildlife. Iowa State University / Omar de Kok-Mercado, CC BY-ND

By Lisa Schulte Moore

Iowa's first-in-the-nation caucuses bring the state a lot of political attention during presidential election cycles. But in my view, even though some candidates have outlined positions on food and farming, agriculture rarely gets the attention it deserves.

Read More Show Less
In Haiti, Action Against Hunger screens children for malnutrition. Christophe Da Silva / Action Against Hunger, Haiti

By Dr. Charles Owubah

As a child growing up on a farm in Ghana, I have personally known hunger. The most challenging time was between planting and harvesting – "the hunger season." There were many occasions when we did not know where the next meal would come from.

Today, on World Food Day, I think of the 820 million people around the world who are undernourished.

Read More Show Less
Sponsored
A Lyme disease warning on Montauk, Long Island, New York. Neil R / Flickr

Biomedical engineers have developed a new, rapid test capable of detecting Lyme disease in just 15 minutes.

Read More Show Less
Brown bear fishing for salmon in creek at Pavlof Harbor in Tongass National Forest, Alaska. Wolfgang Kaehler / LightRocket / Getty Images

The Trump administration has moved one step closer to opening Earth's largest intact temperate rainforest to logging.

Read More Show Less
The Democratic primary candidates take the stage during Tuesday's debate. SAUL LOEB / AFP via Getty Images

On Tuesday night, the Democratic presidential candidates gathered for what The Guardian said was the largest primary debate in U.S. history, and they weren't asked a single question about the climate crisis.

Read More Show Less