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Air pollution


Air pollution has become a major issue in China and poses a threat to Chinese public health. In 2016, only 84 out of 338 prefecture-level (administrative division of the People's Republic of China (PRC),ranking below a province and above a county) or higher cities attained the national standard for air quality.

Zhong Nanshan, the president of the China Medical Association, warned in 2012 that air pollution could become China's biggest health threat. Measurements by Beijing municipal government in January 2013 showed that highest recorded level of PM2.5 (particulate matter smaller than 2.5 micrometers in size), was at nearly 1,000 μg per cubic meter. Traces of smog from mainland China has been observed to reach as far as California.

Sulfur dioxide emission peaked at 2006, after which it began to decline by 10.4% in 2008 compared to 2006. This was accompanied by improvements on related phenomenons such as lower frequency of acid rainfall. The adoption by power plants of flue-gas desulfurization technology was likely the main reason for reduced SO2 emissions.

Large-scale use of formaldehyde in make home building products in construction and furniture also contributes to indoor air pollution.

Particulates
Particulates are formed from both primary and secondary pathways. Primary sources such as coal combustion, biomass combustion and traffic directly emits particulate matter also known as "PM". Whereas, high secondary aerosol (particulates formed through atmospheric oxidation and reactions of gaseous organic compounds) contribution to particulate pollution in China is found. According to the U.S. Environmental Protection Agency, such fine particles can cause asthma, bronchitis, and acute and chronic respiratory symptoms such as shortness of breath and painful breathing, and may also lead to premature death.

According to the World Bank, the Chinese cities with the highest levels of particulate matter in 2004 of those studied were Tianjin, Chongqing, and Shenyang. In 2012 stricter air pollution monitoring of ozone and PM2.5 were ordered to be gradually implemented from large cities and key areas to all prefecture-level cities, and from 2015 all prefecture-level or higher cities were included. State media acknowledged the role of environmental campaigners in causing this change. On one micro-blog service, more than a million mostly positive comments were posted in less than 24 hours although some wondered if the standards would be effectively enforced.

The US embassy in Beijing regularly posts automated air quality measurements at @beijingair on Twitter. On 18 November 2010, the feed described the PM2.5 AQI (Air Quality Index) as "crazy bad" after registering a reading in excess of 500 for the first time. This description was later changed to "beyond index", a level which recurred in February, October, and December 2011.

In June 2012, following strongly divergent disclosures of particulate levels between the Observatory and the US Embassy, Chinese authorities asked foreign consulates to stop publishing "inaccurate and unlawful" data. Officials said it was "not scientific to evaluate the air quality of an area with results gathered from just only one point inside that area", and asserted that official daily average PM2.5 figures for Beijing and Shanghai were "almost the same with the results published by foreign embassies and consulates".

By January 2013 the pollution had worsened with official Beijing data showing an average AQI over 300 and readings of up to 700 at individual recording stations while the US Embassy recorded over 755 on 1 January and 800 by 12 January 2013.

On 21 October 2013, record smog closed the Harbin Airport along with all schools in the area. Daily particulate levels of more than 50 times the World Health Organisation recommended daily level were reported in parts of the municipality.

In 2016, Beijing's yearly-average PM2.5 was 73 μg/m3, 9.9% improvement compared to 2015. In total, 39 severely polluted days were recorded, 5 fewer compared to 2015. [[File:2016_Air_pollution_in_Beijing.svg|link=https://en.wikipedia.org/wiki/File:2016_Air_pollution_in_Beijing.svg|center|thumb|1000x1000px|2015 Air pollution in Beijing as measured by Air Quality Index (AQI) {{legend|#7e0023| Severely Polluted }} {{legend|#8f3f97| Heavily Polluted }} {{legend|#ff0000| Moderately Polluted }}

{{legend|#ff7e00| Lightly Polluted }} {{legend|#ffff00| Good }} {{legend|#00e400|Excellent}} ]]

Government's response to the air pollution
In an attempt to reduce air pollution, the Chinese government has made the decision to enforce stricter regulations. After record-high air pollution in northern China in 2012 and 2013, the State Council issued an Action Plan for the Prevention and Control of Air Pollution in September 2013. This plan aims to reduce PM2.5 by over 10% from 2012 to 2017. The most prominent government response has been in Beijing, aiming to reduce PM2.5 by 25% from 2012 to 2017. As the capital of China, it is suffering from high levels of air pollution. According to Reuters, in September 2013, the Chinese government published the plan to tackle air pollution problem on its official website. The main goal of the plan is to reduce coal consumption by closing polluting mills, factories, and smelters and switching to other eco-friendly energy sources.

These policies have been taken effects, and in 2015, the average PM2.5 in 74 key cities in monitoring system is 55 μg/m3 ,showing a 23.6% decrease as to 2013. Despite the reduction in coal consumption and polluting industries, China still maintained stable economic growth rate from 7.7% in 2013 to 6.9% in 2015.

On 20 August 2015, ahead of the 70th-anniversary celebrations of the end of World War II, the Beijing government shut down industrial facilities and reduced car emissions in order to achieve a "Parade Blue" sky for the occasion. This action resulted in PM2.5 concentration lower than the 35 μg/m3 national air quality standard, according to data from Beijing Municipal Environmental Protection Monitoring Centre (BMEMC). The restrictions resulted in an average Beijing PM2.5 concentration of 19.5 μg/m3, the lowest that had ever been on record in the capital.

China’s strategy has been largely focusing on the development of other energy sources such as nuclear, hydro and compressed natural gas. The latest plan entails closing the outdated capacity of the industrial sectors like iron, steel, aluminum and cement and increasing nuclear capacity and other non-fossil fuel energy. It also includes an intention to stop approving new thermal power plants and to cut coal consumption in industrial areas.

According to research, substituting all coal consumption for residential and commercial use to natural gas requires additional 88 billion cubic meters of natural gas, which is 60% of China's total consumption in 2012, and the net cost would be 32-52 billion dollars. Substituting the share of coal-fired power plant with renewable and nuclear energy also requires 700GW additional capacity, which cost 184 billion dollars. So the net cost would be 140-160 billion dollars considering value of saved coal. Since all the above policies have been already partially implemented by national and city governments, they should lead to substantial improvements in urban air quality.