Air pollution topped 20 times the World Health Organisation's recommended exposure levels.
According to Metro, traffic officer Zhang said: "The smog has gotten worse in the last two to three years.
"I often cough, and my nose is always irritated. But what can you do? I drink more water to help my body discharge the toxins."
The world's most beautiful sunsets
Beijing watches sunrise on giant screen due to smog
How stunning is Alaska at sunset? See the sun disappear behind the US state's supersized nature at the Denali National Park, where North America's highest peak Mt McKinley can be seen in its own Reflection Pond.
In Brazil, there's nothing quite like watching the sun slip down behind the double peak of the Morro Dois Irmaos. Do it with a caipirinha in hand at one of the bars near the beach or simply sit on the sand and be mesmerised by the view.
Zanzibar is famed for its glorious sunsets, whether watched from somewhere iconic like Africa House Hotel's aptly named Sunset Bar or on a dhow cruise. The white sand beaches of the Spice Island, especially those of the north coast, also offer an idyllic setting to witness sun down.
Sunset at Angkor Wat is such a beautiful sight that Cambodian authorities have launched a website suggesting alternative lookout spots to reduce the crowds in certain areas and preserve the ancient attraction. Angkor Sunsets allows you to select several criteria, such as atmosphere and crowd size, so you can be recommended the best alternative perch from a list of 34 vantage points.
Some people say there's no better place on Earth than the Grand Canyon for watching the sunset. Sunset is when the great drama begins at the breathtaking canyon - Hopi Point is unquestionably a desirable viewpoint attracting the crowds, while Yaki and Pima Points are less congested and offer views accompanied by the sound of the Colorado River a mile below.
When we asked you on Facebook where we could find the best sunset, one of you suggested that Cafe Mambo in San Antonio was a top spot to share sun down. We see what you mean! The bar sits in the centre of what is known as the sunset strip, offering an amazing view of one of the world's most famous sunsets.
Iconic Cable Beach in Western Australia claims to be one of the most stunning beaches in the world with 22 kilometres of pristine white sand and clear turquoise water. It just so happens to offer a wonderful sunset view too. For a unique experience hop on a camel for a romantic sunset stroll along the beach.
One of the world's greatest sunsets can be found in Oia on the Greek island of Santorini, where hundreds of people gather at every vantage point to witness the magical sight. The population of Oia is only a thousand but before sunset this doubles and tourists fill the streets for the daily event.
Just when you thought paradise couldn't get more perfect, the sunset creates spectacular hues in the Maldivian sky making your Indian Ocean island holiday even more idyllic!
Hundreds of tourists flock to Mallory Square Dock in Key West, Florida to see its famous Sunset Celebration. It's not just viewing the sun sink into the Gulf of Mexico that attracts visitors, as arts and crafts exhibitors, street performers and psychics entertain the masses before the sun sets.
For a fabulous city view at sun down, look no further than Hong Kong. The bustling metropolis can be enjoyed from the water on a Sunset Cruise and those after a bit of romance should head for the 869 metre-high Sunset Peak for gorgeous sunsets and a challenging hike.
One of Bali’s most photographed sites Tanah Lot is a small picture-perfect temple located on a small rock, off the west coast. At sunset, the red sky acts as a background for the temple and even though it's a sight you'll have to share with the crowds, you won't want to miss this spectacular setting at sunset.
The iconic pyramid-shaped mountain might mainly attract climbers and explorers, but everyone can appreciate it at sunset. When viewed from the Gorner Glacier at sunset, the majestic Matterhorn peak appears to be touched with fire like a huge candle.
'Manhattanhenge' in New York occurs four times a year and sees the sun line up with Manhattan's street grid, spreading light across the north and south sides of every cross street. The phenomenon turns the city's bustling streets into a Stonehenge-type sundial.
Looking for a wonderful place to watch the sun set in Britain? The Isle of Skye is apparently at its most photogenic when seen from a sea kayak and attracts photographers armed with lenses to witness its captivating light show.
Kenya's Maasai Mara National Reserve is one of the most amazing places to photograph wildlife and at sunset the gorgeous sky offers more brilliant photo opps. We love this picture of a herd of wildebeest gathering at the top of a hill at sunset after successfully crossing the Mara River during the annual migration.
We asked you on Facebook where we could find the world's best sunset and a few of you said Woolacombe in North Devon. Sand, sea and sparkling sunsets - we love. And you don't need to get on a plane to witness it!
The Taj Mahal is beautiful any time of day but visit at sunset and you'll see a fantastic orange glow on the white dome. For an exceptional view, watch it at Mehtab Bagh, a park across the Yamuna River.
At 1.2km long, U Bein's Bridge in Myanmar is the world's longest teak bridge, crossing the Thaungthaman Lake in Amarapura. Sunset is the perfect time to capture the bridge on camera when the locals walk and even cycle across it, and the sky turns yellow and red.
The romantic Italian city is at its most beautiful at sunset. From a silhouette of Santa Maria Della Salute, to catching the Grand Canal light up from the majestic Rialto Bridge, there are more than a million ways to capture Venice as the sun goes down.