smog

An octopus-shaped kite flies over visitors on a smoggy day during a kite festival in Chongqing.

China Daily/Reuters

An octopus-shaped kite flies through the smog during a kite festival in Chongqing, southwest China

the Eiffel tower in central Paris through a haze of pollution.

Kenzo Tribouillard/AFP/Getty Images

Eiffel Tower in central Paris through a haze of pollution. More than 30 departments in France have been hit by maximum level pollution alerts since Thursday, prompting the ecology minister to say air quality was “an emergency and a priority for the government”.

Girls wearing masks on haze-covered Tiananmen Square in Beijing.  China's National Meteorological Centre issued a "yellow" smog alert for much of the country's north, the fifth consecutive day of heavy pollution which has slashed visibility and seen pollution reach hazardous levels.

AFP

China’s National Meteorological Centre issued a “yellow” smog alert for much of the country’s north, the fifth consecutive day of heavy pollution that has cut visibility and seen pollution reach hazardous levels, affecting areas such as Tiananmen Square (above) in Beijing.

Residents cover their face from dust as they ride their bicycles along a street on a hazy day in Zhengzhou, Henan province. Commentaries by two of China's most influential news outlets suggesting that an ongoing air pollution crisis was not without a silver lining drew a withering reaction on Tuesday from internet users and other media. The Global Times said smog could be useful in military situations, as it could hinder the use of guided missiles, while CCTV listed five "unforeseen rewards" for smog, including helping Chinese people's sense of humour.

Reuters

Cyclists cover their faces on a hazy day in Zhengzhou, Henan province, China. Two of the country’s most influential news outlets were criticised after trying to put a positive spin on China’s air pollution problem. The Global Times newspaper said smog could be useful in military situations, as it could hinder the use of guided missiles, while state broadcaster CCTV listed five “unforeseen rewards” of smog, including helping Chinese people’s sense of humour.

A traffic policeman signals to drivers during a smoggy day in Harbin, Heilongjiang province, October 21, 2013. The second day of heavy smog with a PM 2.5 index has forced the closure of schools and highways, exceeding 500 micrograms per cubic meter on Monday morning in downtown Harbin, according to Xinhua News Agency.

China Daily/Reuters

A traffic policeman signals to drivers during a smoggy day in Harbin, Heilongjiang Province. The second day of heavy smog forced the closure of schools and highways on Monday, according to Xinhua News Agency.

A teacher helps her student put on a face mask due to the haze in Putrajaya

Bazuki Muhammad/Reuters

A teacher helps her student put on a face mask at a school in Putrajaya, outside Kuala Lumpur, on Wednesday. The Malaysian capital remains shrouded in haze, as the environmental crisis continues after a week of thick hazardous smog covered the country and its neighbour Singapore

A motorist wearing a face mask rides across a bridge covered by light haze in Klang, outside Kuala Lumpur, Malaysia, Tuesday, June 25, 2013. Indonesian President Susilo Bambang Yudhoyono apologized Monday to Singapore and Malaysia for record-setting pollution caused by forest fires in his country.

Lai Seng Sin/AP

A motoristcyclist wearing a face mask rides across a bridge covered by light haze in Klang, outside Kuala Lumpur, Malaysia, on Tuesday. Indonesian president Susilo Bambang Yudhoyono apologised on Monday to Singapore and Malaysia for record-setting pollution caused by forest fires in his country.

Children cover their noses near burnt land in Marpoyan Damai sub district, in the outskirts of Pekanbaru, in Indonesia's Riau province June 20, 2013. Haze from fires in Indonesia blanketing Singapore could persist for weeks or longer, Singapore's Prime Minister Lee Hsien Loong said on Thursday, as the smoke drove air quality to "hazardous" levels and disrupted business and travel in the region.

Azwar/Reuters

Children cover their noses near burnt land in Marpoyan Damai sub district, in the outskirts of Pekanbaru, in Indonesia’s Riau province. Haze from fires in Indonesia blanketing Singapore could persist for weeks or longer, Singapore Prime Minister Lee Hsien Loong said on Thursday, as the smoke drove air quality to “hazardous” levels and disrupted business and travel in the region.

A junk sails past the city's skyline shrouded in a dense blanket of toxic smog in Hong Kong on April 15, 2013. The air pollution index reached the 'severe' level for the third time in 2013 with high concentrations of nitrogen dioxide present.

Philippe Lopez/AFP

A junk sails past the city’s skyline shrouded in a dense blanket of toxic smog in Hong Kong on April 15 2013. The air pollution index reached the “severe” level for the third time in 2013 with high concentrations of nitrogen dioxide present.