It's a sign of the Chinese capital's ability to control its notorious smog when it needs to. It's also indicative of the progress China has made in tackling air pollution in recent years, both by shutting down and upgrading elderly factories and passing new restrictions to tackle emissions.

That's seen Beijing fall out of the top 100 most-polluted cities in Asia in recent years, with overall pollution levels 10% lower across Chinese cities between 2017 and 2018, according to a report by Greenpeace and AirVisual . Shanghai, the country's largest city and financial capital, has also made environmental advances, such as adopting stringent recycling regulations

At 146 globally on the AirVisual list, Wuhan, in northeastern China, is not among China's most polluted cities, but residents aren't taking any chances. Recent weeks have seen major protests there -- in themselves a rarity in China -- over plans for a new garbage incineration plant.

Holding banners with slogans such as "we don't want to be poisoned, we just need a breath of fresh air," thousands of people took to the city's streets over two weeks in June and July calling for the suspension of plans to build the plant.

"We are fearful that the plant is too close to residence area," one protester in the city of 10 million people told state media . Others expressed concern that emissions could worsen air pollution and harm residents' health.

Local officials were apparently surprised by the scale and size of the protests, which came after several similar waste plants were reportedly found to be giving off dangerous emissions. Photos and videos shared on social media showed large crowds marching in the streets near where the plant was to be built, and police arresting numerous protesters.

The government has since suspended building of the plant, which locals said had halted protests, but a heavy police presence remains in the city where the situation is tense.

Smoggy success

Since 2008, China's government has expended a huge amount of energy and money in addressing the country's air quality problems. And in 2014, Chinese Premier Li Keqiang declared a "war on pollution," which he described as "nature's red-light warning against the model of inefficient and blind development."

While China's smog issues are nowhere near solved -- the country is still home to a large number of urban hubs battling air pollution issues -- there are signs of improvement. Neighboring India, meanwhile, now has a far worse problem on its hands, with 22 of the 30 most polluted cities, according to the Greenpeace/AirVisual report.

That's partly because the Indian government has not faced significant civil unrest around this issue. Public pressure has been the driving force of pollution policy in China, and it shows no sign of letting up.

Only worker unrest, which has remained a pervasive problem , is a more consistent cause of mass action.

But the government faces an uneasy balancing act: it needs to handle the public's environmental concerns, while avoiding taking action that would slow growth, all the time dealing with an economy that has grown rapidly and often without the safety and emissions standards people are now demanding.

Ordinary Chinese people, however, are painfully aware that the central government can issue all the enlightened policies it wants, but that does not mean they will be implemented locally, or escape being undermined by corruption and vested interests.

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Pollution protests

Despite considerable progress, there remains geographic divide in environmental standards in China. Of the top 20 cities with the worst air in China, almost all are in central or western China, with only one, Xuzhou in Jiangsu province, on the wealthy east coast.

The cities are generally located in poorer and less developed region than China's main coastal hubs -- this leaves them more vulnerable to the type of corruption and corner cutting that prevents regulations being fully implemented.

According to Caixin , a leading Chinese investigative magazine, "glaring falsifications and outright corruption persist in some of China's fundamental environmental monitoring data."

Citing government reports and whistleblowers, Caixin said the privatization of environmental testing operations since 2015 had led to "chaos," with testing not carried out, done poorly, or companies purchasing bills of good health when they should have failed checks.

Around the same time that report was released, the government announced investigations into more than 12,000 officials and 18,000 companies for lax enforcement or abuse of environmental standards.

This could explain why protesters, such as those in Wuhan, are unwilling to believe officials when they say plants will meet modern safety and emissions standards. In a rare state media report on the Wuhan protests, tabloid Global Times said that part of the issue "was related to insufficient communication between the government and the public."

"Analysts also noted that emissions monitoring along with a lack of transparency in sharing emissions data with the public helped stir complaints," the paper said.

The Chinese government is highly sensitive to the threat of protests like those in Wuhan, with the shadow of the 1989 Tiananmen massacre looming large. Calls for collective action are among the most censored subjects online, and people organizing protests or working for civil society groups can face harassment and imprisonment.

But while people may be willing to put political concerns aside for the sake of economic growth, they are not prepared to take risks with their children's health for GDP. The government knows this and has made a concerted effort to reduce air pollution.

For many, however, particularly those far from the capital, not enough is being done.

And in Wuhan thousands showed they would rather defy police batons and potential imprisonment than choke on bad air.