About 13 percent say they never wear masks even on days with high air pollution.

大约13%受访者表示即便空气污染爆表，他们也从不佩戴口罩。

youdao

In case of increased air pollution, normal precautions are advised, i. e. avoidance of strenuous exercise by people with asthma and respiratory symptoms in days with high air pollution.

因为增加的空气污染，建议使用通常的预防措施。也就是，有哮喘的或者呼吸疾病的人在严重空气污染的日子里，避免过度运动。

youdao

High places are free of air pollution.

高处没有空气污染。

youdao

The impact of high air-pollution levels on long-term health weighs on Chinese and foreigners alike.

WSJ: Why Leave Job in Beijing? To Breathe

"Fewer fireworks have helped to decrease air pollution in some Chinese cities, but high readings of air pollutants have made many wonder if greater efforts need to be made, " Xinhua news agency comments.

BBC: China media: New Year haze

The ALA analyzed particle pollution levels two ways: short-term particle pollution, or high spikes in the level of soot and other toxins in the air that last a few hours to a few weeks, and year-round particle pollution, or the annual average of particle pollution levels.

FORBES: List: America's Most Polluted Cities