Editing Smog (section)

=== Asia ===
==== India ====
{{See also|Environmental issues in Delhi}}
[[File: Aerial view of Air Pollution in North India, Agriculture Fires, November 2013.jpg|300px|thumb|During the autumn and spring months, some 500 million tons of [[stubble burning|rice and wheat crop residues are burnt]], and [[western disturbances|winds blow from India's north and northwest towards east]].<ref>Badarinath, K. V. S., Kumar Kharol, S., & Rani Sharma, A. (2009), Long-range transport of aerosols from agriculture crop residue burning in Indo-Gangetic Plains—a study using LIDAR, ground measurements and satellite data. Journal of Atmospheric and Solar-Terrestrial Physics, 71(1), 112–120</ref><ref>Sharma, A. R., Kharol, S. K., Badarinath, K. V. S., & Singh, D. (2010), Impact of agriculture crop residue burning on atmospheric aerosol loading—a study over Punjab State, India. Annales Geophysicae, 28(2), pp 367–379</ref><ref>{{cite journal|first1=Tina|last1=Adler|title=Respiratory Health: Measuring the Health Effects of Crop Burning|journal=Environmental Health Perspectives|date=November 2010|volume=118|issue=11|page=A475|doi=10.1289/ehp.118-a475|pmc=2974718|pmid=21465742}}</ref> This aerial view shows India's annual crop burning, resulting in smoke and air pollution over Delhi and adjoining areas.]]
For the past few years, cities in northern [[India]] have been covered in a thick layer of [[winter]] smog. The situation has turned quite drastic in the national capital, [[Delhi]]. This smog is caused by the collection of [[particulate matter]] (a very fine type of dust and toxic gases) in the air due to stagnant movement of air during winters.<ref>{{Cite news|url=https://www.honeywellsmarthomes.com/blog/causes-of-smog-and-how-to-protect/|title=Causes of Smog {{!}} How to Protect Yourself from Smog - Honeywell Blog|date=26 November 2017|work=Official Blog Updates - Honeywell Air Purifiers|access-date=7 March 2018|language=en-US}}</ref> Moreover, during the post-monsoon to winter transition, air quality in the [[Indo-Gangetic Plain]] (IGP) worsens significantly due to shifts in weather patterns, such as changes in wind, temperature, and boundary layer mixing.<ref name=":0">{{Cite journal |last1=Hassan |first1=Muhammad Azher |last2=Mehmood |first2=Tariq |last3=Liu |first3=Junjie |last4=Luo |first4=Xiaosan |last5=Li |first5=Xinghua |last6=Tanveer |first6=Mohsin |last7=Faheem |first7=Muhammad |last8=Shakoor |first8=Awais |last9=Dar |first9=Afzal Ahmed |last10=Abid |first10=Muhammad |date=2023-02-01 |title=A review of particulate pollution over Himalaya region: Characteristics and salient factors contributing ambient PM pollution |url=https://linkinghub.elsevier.com/retrieve/pii/S1352231022005374 |journal=Atmospheric Environment |volume=294 |pages=119472 |doi=10.1016/j.atmosenv.2022.119472 |bibcode=2023AtmEn.29419472H |issn=1352-2310}}</ref> The impact of emissions from both [[Biomass (energy)|biomass]] burning and [[Urbanization|urban]] activities has intensified, leading to a rise in [[Aerosol|aerosols]] mainly particulate matters.<ref>{{Cite journal |last1=Ojha |first1=Narendra |last2=Naja |first2=Manish |last3=Singh |first3=K. P. |last4=Sarangi |first4=T. |last5=Kumar |first5=R. |last6=Lal |first6=S. |last7=Lawrence |first7=M. G. |last8=Butler |first8=T. M. |last9=Chandola |first9=H. C. |date=2012-10-27 |title=Variabilities in ozone at a semi-urban site in the Indo-Gangetic Plain region: Association with the meteorology and regional processes |url=https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2012JD017716 |journal=Journal of Geophysical Research: Atmospheres |language=en |volume=117 |issue=D20 |doi=10.1029/2012JD017716 |bibcode=2012JGRD..11720301O |issn=0148-0227}}</ref> The nearby [[Himalayas|Himalayan region]] is also affected,<ref name=":1">{{Cite journal |last1=Hassan |first1=Muhammad Azher |last2=Mehmood |first2=Tariq |last3=Liu |first3=Junjie |last4=Luo |first4=Xiaosan |last5=Li |first5=Xinghua |last6=Tanveer |first6=Mohsin |last7=Faheem |first7=Muhammad |last8=Shakoor |first8=Awais |last9=Dar |first9=Afzal Ahmed |last10=Abid |first10=Muhammad |date=2023-02-01 |title=A review of particulate pollution over Himalaya region: Characteristics and salient factors contributing ambient PM pollution |url=https://linkinghub.elsevier.com/retrieve/pii/S1352231022005374 |journal=Atmospheric Environment |volume=294 |pages=119472 |doi=10.1016/j.atmosenv.2022.119472 |bibcode=2023AtmEn.29419472H |issn=1352-2310}}</ref> where mountainous topography trap [[Air pollution|air pollutants]] and increase the air quality issues specifically in northern India.<ref>{{Cite journal |last1=Mehra |first1=Manisha |last2=Panday |first2=Arnico K. |last3=Puppala |first3=Siva Praveen |last4=Sapkota |first4=Vikrant |last5=Adhikary |first5=Bhupesh |last6=Pokheral |first6=Chiranjibi P. |last7=Ram |first7=Kirpa |date=2019-11-01 |title=Impact of local and regional emission sources on air quality in foothills of the Himalaya during spring 2016: An observation, satellite and modeling perspective |url=https://linkinghub.elsevier.com/retrieve/pii/S1352231019305369 |journal=Atmospheric Environment |volume=216 |pages=116897 |doi=10.1016/j.atmosenv.2019.116897 |bibcode=2019AtmEn.21616897M |issn=1352-2310}}</ref>

Delhi is the most polluted<ref>{{cite news|url=http://www.hindustantimes.com/india-news/delhi-has-dirtiest-air-china-data-foggy-who/article1-1216605.aspx |archive-url=https://web.archive.org/web/20140508004750/http://www.hindustantimes.com/india-news/delhi-has-dirtiest-air-china-data-foggy-who/article1-1216605.aspx |url-status=dead |archive-date=8 May 2014 |title=Delhi is most polluted city in world, Beijing much better: WHO study |work=Hindustan Times|access-date=8 May 2014}}</ref> city in the world and according to one estimate, air pollution causes the death of about 10,500 people in Delhi every year.<ref name="TimePollution">{{cite magazine|url=http://world.time.com/2014/02/10/smog-in-new-delhi/ |archive-url=https://web.archive.org/web/20140302085642/http://world.time.com/2014/02/10/smog-in-new-delhi/ |url-status=dead |archive-date=2 March 2014 |title=Delhi's Air Has Become a Lethal Hazard and Nobody Seems to Know What to Do About It |magazine=Time magazine |access-date=10 February 2014}}</ref><ref name="VOAPollution">{{cite web |url=https://www.voanews.com/a/indias-air-pollution-triggers-comparisons-with-china/1855331.html |title=India's Air Pollution Triggers Comparisons with China |publisher=Voice of America |access-date=20 February 2014 |archive-url=https://web.archive.org/web/20140221104928/http://www.voanews.com/content/indias-air-pollution-triggers-comparisons-with-china/1855331.html |archive-date=21 February 2014 |url-status=live }}</ref><ref name="EconomistPollution">{{cite news|url=https://www.economist.com/blogs/banyan/2012/11/air-pollution-india |title=A Delhi particular |newspaper=The Economist|access-date=6 November 2012}}</ref> During 2013–14, peak levels of fine [[Particle|particulate]] matter (PM) in Delhi increased by about 44%, primarily due to high vehicular and industrial emissions, construction work and crop burning in adjoining states.<ref name="TimePollution" /><ref name="WSJPollution">{{cite news|url=https://blogs.wsj.com/indiarealtime/2014/02/15/how-crop-burning-affects-delhis-air-pollution/ |title=How Crop Burning Affects Delhi's Air |newspaper=Wall Street Journal |access-date=15 February 2014}}</ref><ref name=Gardiner>{{cite news|last=Harris|first=Gardiner|title=Beijing's Bad Air Would Be Step Up for Smoggy Delhi|url=https://www.nytimes.com/2014/01/26/world/asia/beijings-air-would-be-step-up-for-smoggy-delhi.html?emc=edit_tnt_20140126&tntemail0=y|access-date=27 January 2014|newspaper=New York Times|date=25 January 2014}}</ref><ref>{{cite news|last=Bearak|first=Max|title=Desperate for Clean Air, Delhi Residents Experiment with Solutions|url=http://india.blogs.nytimes.com/2014/02/07/desperate-for-clean-air-delhi-residents-experiment-with-solutions/?emc=edit_tnt_20140208&tntemail0=y|access-date=8 February 2014|newspaper=New York Times|date=7 February 2014}}</ref> Delhi has the highest level of the airborne particulate matter, [[PM2.5]] considered most harmful to health, with 153 micrograms.<ref>{{cite news|author=Madison Park|title=Top 20 most polluted cities in the world|url=http://www.cnn.com/2014/05/08/world/asia/india-pollution-who/index.htm|publisher=CNN|date=8 May 2014}}</ref> Rising air pollution level has significantly increased lung-related ailments (especially asthma and lung cancer) among Delhi's children and women.<ref name="TodayPollution">{{cite magazine|url=http://indiatoday.intoday.in/story/pollution-in-delhi-cng-children-in-delhi/1/344904.html |title=Children in Delhi have lungs of chain-smokers! |magazine=India Today |access-date=22 February 2014}}</ref><ref name="DNAPollution">{{cite web|url=http://www.dnaindia.com/health/report-pollution-increasing-lung-cancer-in-indian-women-1959054 |title=Pollution increasing lung cancer in Indian women |publisher=DNA |access-date=3 February 2014|date=3 February 2014 }}</ref> The dense smog in Delhi during winter season results in major air and rail traffic disruptions every year.<ref name="ReutersPollution">{{cite news |url=http://in.reuters.com/article/india-delhi-winter-smog-idINDEE9BH0D420131218 |title=Delhi blanketed in thick smog, transport disrupted |work=Reuters |access-date=18 December 2013 |date=18 December 2013 |archive-date=20 December 2013 |archive-url=https://web.archive.org/web/20131220012916/http://in.reuters.com/article/2013/12/18/india-delhi-winter-smog-idINDEE9BH0D420131218 |url-status=dead }}</ref> According to Indian meteorologists, the average maximum temperature in Delhi during winters has declined notably since 1998 due to rising air pollution.<ref>{{Cite news|url=https://timesofindia.indiatimes.com/city/delhi/January-days-getting-colder-tied-to-rise-in-pollution/articleshow/29429495.cms|title=January days getting colder, tied to rise in pollution |website=The Times of India|date=27 January 2014 }}</ref>
[[File: Smog in the skies of Delhi, India.jpg|thumb|left|Dense smog blankets [[Connaught Place, New Delhi]]]]

Environmentalists have criticized the Delhi government for not doing enough to curb air pollution and to inform people about air quality issues.<ref name="VOAPollution"/> Most of Delhi's residents are unaware of alarming levels of air pollution in the city and the health risks associated with it.<ref name=Gardiner/> Since the mid-1990s, Delhi has undertaken some measures to curb air pollution – Delhi has the third highest quantity of trees among Indian cities<ref>{{cite web|url=http://www.ndtv.com/news/cities/delhi_third_greenest_city.php |title=Delhi 'third greenest' city |publisher=Ndtv.com |access-date=11 March 2011}}</ref> and the [[Delhi Transport Corporation]] operates the world's largest fleet of environmentally friendly [[compressed natural gas]] (CNG) buses.<ref name="cities.expressindia.com">{{cite news|url=http://cities.expressindia.com/fullstory.php?newsid=85665 |title=Smog city to clean capital How Delhi did it|newspaper=Express India |access-date=11 March 2011 |url-status=dead |archive-url=https://web.archive.org/web/20101231054504/http://cities.expressindia.com/fullstory.php?newsid=85665 |archive-date=31 December 2010 }}</ref> In 1996, the [[Centre for Science and Environment]] (CSE) started a public interest litigation in the [[Supreme Court of India]] that ordered the conversion of Delhi's fleet of buses and taxis to run on CNG and banned the use of leaded petrol in 1998. In 2003, Delhi won the [[United States Department of Energy]]'s first 'Clean Cities International Partner of the Year' award for its "bold efforts to curb air pollution and support alternative fuel initiatives".<ref name="cities.expressindia.com"/> The Delhi Metro has also been credited for significantly reducing air pollutants in the city.<ref>{{Cite web|url=https://www.indiatoday.in/india/north/story/delhi-metro-helps-reduce-vehicular-air-pollution-delhi-school-of-economics-160315-2013-04-28|title=Delhi Metro helps reduce vehicular air pollution, indicates research|first=Neetu|last=Chandra|date=28 April 2013|website=India Today}}</ref>

However, according to several authors, most of these gains have been lost, especially due to [[stubble burning]], rise in market share of [[diesel exhaust|diesel cars]] and a considerable decline in bus ridership.<ref name="kumari">{{cite journal |author1=R. Kumari |author2=A.K. Attri |author3=L. Int Panis |author4=B.R. Gurjar | title = Emission estimates of Particulate Matter and Heavy Metals from Mobile sources in Delhi (India)| journal = J. Environ. Science & Engg.| volume = 55 | issue = 2 | pages = 127–142 |date=April 2013 |url=https://www.researchgate.net/publication/259827470}}</ref><ref name="Pollution">{{cite web|url=http://cseindia.org/node/835 |title=What is the status of air pollution in Delhi? |publisher=CSE, India |access-date=2 March 2014}}</ref> According to CUE and System of Air Quality Weather Forecasting and Research (SAFER), burning of agricultural waste in nearby Punjab, Haryana and Uttar Pradesh regions results in severe intensification of smog over Delhi.<ref name="Antipollution">{{cite news|url=http://articles.economictimes.indiatimes.com/2014-11-06/news/55835957_1_pm-2-5-level-air-quality-weather-forecasting-pollution-levels |archive-url=https://web.archive.org/web/20141111083702/http://articles.economictimes.indiatimes.com/2014-11-06/news/55835957_1_pm-2-5-level-air-quality-weather-forecasting-pollution-levels |url-status=dead |archive-date=11 November 2014 |title=Delhi's air quality deteriorating due to burning of agriculture waste |newspaper=Economic Times }}</ref><ref name="CSE2Pollution">{{cite magazine|url=http://indiatoday.intoday.in/story/smog-delhi-winter-low-wind-speed-emissions/1/398601.html |title=Thick blanket of smog envelopes Delhi, northern India |magazine=India Today }}</ref> The state government of adjoining Uttar Pradesh is considering imposing a ban on crop burning to reduce pollution in Delhi NCR and an environmental panel has appealed to India's Supreme Court to impose a 30% cess on diesel cars.<ref>{{Cite web|url=http://timesofindia.indiatimes.com/city/noida/Straw-burning-ban-soon-to-reduce-smog-in-NCR/articleshow/2835975.cms|title=Straw burning ban soon to reduce smog in NRC, Times of India, 4 January 2014|website=[[The Times of India]]}}</ref><ref>{{Cite news|url=https://timesofindia.indiatimes.com/home/environment/pollution/Impose-30-cess-on-diesel-cars-panel-tells-Supreme-Court/articleshow/30180391.cms|title=Impose 30% cess on diesel cars, panel tells Supreme Court - Times of India|website=The Times of India|date=11 February 2014 }}</ref>

==== China ====
{{main|Beijing#Air quality}}
Joint research between American and Chinese researchers in 2006 concluded that much of [[Beijing]]'s pollution comes from surrounding cities and provinces. On average 35–60% of the [[ozone]] can be traced to sources outside the city. [[Shandong]] Province and [[Tianjin]] Municipality have a "significant influence on Beijing's air quality",<ref>David G. Streetsa, Joshua S. Fub, Carey J. Jangc, Jiming Haod, Kebin Hed, Xiaoyan Tange, Yuanhang Zhang, Zifa Wangf, Zuopan Lib, Qiang Zhanga, Litao Wangd, Binyu Wangc, Carolyne Yua, [https://web.archive.org/web/20130724181603/http://www.cee.mtu.edu/~reh/papers/pubs/non_Honrath/streets07.pdf Air quality during the 2008 Beijing Olympic Games]. Accessed 23 April 2012</ref> partly due to the prevailing south/southeasterly flow during the summer and the mountains to the north and northwest.

==== Iran ====
In December 2005, schools and public offices were forced to close in [[Tehran]] and 1,600 people were taken to hospital, in a severe smog blamed largely on unfiltered car exhaust.<ref>{{cite news |url=http://news.bbc.co.uk/1/hi/world/middle_east/4516430.stm |title=Hundreds treated over Tehran smog |work=[[BBC]] News |date=10 December 2005 |access-date=3 August 2006}}</ref>

==== Mongolia ====
In the late 1990s, massive immigration to [[Ulaanbaatar]] from the countryside began. An estimated 150,000 households, mainly living in traditional Mongolian [[Yurt|gers]] on the outskirts of Ulaanbaatar, burn wood and coal (some poor families burn even car tires and trash) to heat themselves during the harsh winter, which lasts from October to April, since these outskirts are not connected to the city's central heating system. A temporary solution to decrease smog was proposed in the form of stoves with improved efficiency, although with no visible results.

Coal-fired ger stoves release high levels of ash and other particulate matter (PM). When inhaled, these particles can settle in the lungs and respiratory tract and cause health problems. At two to 10 times above Mongolian and international air quality standards, Ulaanbaatar's PM rates are among the worst in the world, according to a December 2009 World Bank report. The Asian Development Bank (ADB) estimates that health costs related to this air pollution account for as much as 4 percent of Mongolia's GDP.<ref>{{cite news | url = http://www.eurasianet.org/departments/news/articles/eav032310e.shtml | title = Mongolia: Ulaanbaatar Grapples with Smog Problem | date = 22 March 2010 | first = Andrew | last = Cullen | publisher = EurasiaNet.org | access-date = 1 October 2012 | archive-url = https://web.archive.org/web/20120828095515/http://www.eurasianet.org/departments/news/articles/eav032310e.shtml | archive-date = 28 August 2012 | url-status = dead }}</ref>

==== Southeast Asia ====
{{See also|Asian brown cloud|haze}}
[[File:Downtown Core, Singapore, Oct 06.JPG|thumb|left|[[Singapore]]'s [[Downtown Core]] on 7 October 2006, when it was affected by [[wildfire|forest fires]] in [[Sumatra]], [[Indonesia]]]]
Smog is a regular problem in [[Southeast Asia]] caused by [[wildfire|land and forest fires]] in [[Indonesia]], especially [[Sumatra]] and [[Kalimantan]], although the term [[haze]] is preferred in describing the problem. Farmers and plantation owners are usually responsible for the fires, which they use to clear tracts of land for further plantings. Those fires mainly affect [[Brunei]], [[Indonesia]], [[Philippines]], [[Malaysia]], [[Singapore]] and [[Thailand]], and occasionally [[Guam]] and [[Saipan]].<ref>{{cite news|url=http://www.saipantribune.com/newsstory.aspx?cat=1&newsID=61706 |date=5 October 2006 |title=Indon haze spreads to NMI |first=Ferdie |last=de la Torre |work=Saigpan Tribune |url-status=dead |archive-url=https://web.archive.org/web/20070218044848/http://www.saipantribune.com/newsstory.aspx?cat=1&newsID=61706 |archive-date=18 February 2007 }}</ref><ref>{{cite news | url = http://www.sun2surf.com/article.cfm?id=15717 | title = 15 areas with unhealthy air (updated) | first = S.Tamarai | last = Chelvi | location = Petaling Jaya | publisher = Sun Media Corporation Sdn. Bhd. | archive-url = https://web.archive.org/web/20090110073337/http://www.sun2surf.com/article.cfm?id=15717 | archive-date = 10 January 2009}}</ref> The economic losses of the fires in 1997 have been estimated at more than US$9 billion.<ref>{{cite web | url = http://haze.asean.org/?wpfb_dl=12 | date = 28 June 2007 | title = Combating Haze in ASEAN: Frequently Asked Questions | author = ASEAN Secretariat, Jl. | publisher = ASEAN Haze Action Online | access-date = 25 October 2013 | archive-date = 29 October 2013 | archive-url = https://web.archive.org/web/20131029195409/http://haze.asean.org/?wpfb_dl=12 | url-status = dead }}</ref> This includes damages in agriculture production, destruction of forest lands, health, transportation, tourism, and other economic endeavours. Not included are social, environmental, and psychological problems and long-term health effects. The [[2006 Southeast Asian haze|second-latest bout of haze]] to occur in [[Malaysia]], [[Singapore]] and the [[Malacca Straits]] is in October 2006, and was caused by smoke from fires in [[Indonesia]] being blown across the Straits of Malacca by south-westerly winds. A similar haze has occurred in June 2013, with the PSI setting a [[Pollutant Standards Index#PSI in Singapore|new record]] in Singapore on 21 June at 12pm with a reading of 401, which is in the "Hazardous" range.<ref>{{cite news|url=http://www.channelnewsasia.com/news/singapore/psi-hits-new-all-time/719496.html |archive-url=https://web.archive.org/web/20130624015317/http://www.channelnewsasia.com/news/singapore/psi-hits-new-all-time/719496.html |archive-date=24 June 2013 |title=Singapore: PSI hits new all-time high of 401 on Friday |publisher=Channel NewsAsia |date=21 June 2013 |url-status=dead }}</ref>

The [[Association of Southeast Asian Nations]] (ASEAN) reacted. In 2002, the [[ASEAN Agreement on Transboundary Haze Pollution|Agreement on Transboundary Haze Pollution]] was signed between all ASEAN nations.<ref>{{cite web | url = http://haze.asean.org/?page_id=185 | title = ASEAN Agreement on Transboundary Haze Pollution | author = ASEAN Secretariat, Jl. | publisher = ASEAN Haze Action Online | access-date = 31 January 2019 | archive-url = https://web.archive.org/web/20150910063035/http://haze.asean.org/?page_id=185 | archive-date = 10 September 2015 | url-status = dead }}</ref> ASEAN formed a Regional Haze Action Plan (RHAP) and established a co-ordination and support unit (CSU).<ref>{{cite web | url = http://haze.asean.org/?page_id=244 | title = About Us | author = ASEAN Secretariat, Jl. | publisher = ASEAN Haze Action Online | access-date = 31 January 2019 | archive-url = https://web.archive.org/web/20150912134926/http://haze.asean.org/?page_id=244 | archive-date = 12 September 2015 | url-status = dead }}</ref> RHAP, with the help of [[Canada]], established a monitoring and warning system for forest/vegetation fires and implemented a Fire Danger Rating System (FDRS). The Malaysian Meteorological Department (MMD) has issued a daily rating of fire danger since September 2003.<ref>{{cite web | url = http://www.met.gov.my/index.php?option=com_content&task=view&id=4749&Itemid=1157 | title = Fire Danger Rating System (FDRS) for Southeast Asia | author = Malaysian Meteorological Department | publisher = Ministry of Science, Technology, and Innovation (MOSTI), Malaysia | access-date = 25 October 2013 | url-status = dead | archive-url = https://web.archive.org/web/20131029192243/http://www.met.gov.my/index.php?option=com_content&task=view&id=4749&Itemid=1157 | archive-date = 29 October 2013 }}</ref> Indonesia has been ineffective at enforcing legal policies on errant farmers.{{citation needed | date = October 2013}}

==== Pakistan ====
Since the start of the [[Winter|winter season]], heavy smog loaded with pollutants covered major parts of [[Punjab, Pakistan|Punjab]], especially the city of [[Lahore]],<ref>{{Cite web|url=https://scroll.in/article/856628/smoke-signal-winter-smog-is-a-reminder-india-and-pakistan-need-to-talk-about-more-than-geopolitics|title=Smoke signal: Winter smog is a reminder India and Pakistan need to talk about more than geopolitics|website=Scroll.in|date=5 November 2017 }}</ref> causing breathing problems and disrupting normal traffic.<ref>{{Cite news|url=https://www.foxnews.com/world/polluted-smog-covers-pakistans-city-of-lahore/|title=Polluted smog covers Pakistan's city of Lahore|date=5 November 2016|newspaper=Fox News|language=en-US|access-date=6 November 2016}}</ref> A recent study from 2022 shows that the primary cause of pollution in Lahore is from traffic-related PM (both [[Exhaust system|exhausts]] and non exhaust sources).<ref>{{Cite journal|url=https://www.repository.cam.ac.uk/bitstreams/9fab52d7-4aac-4adf-ab2a-28ad0da46cc7/download|title=Biomagnetic Characterization of Air Pollution Particulates in Lahore, Pakistan|last=Sheikh|first=Hassan Aftab|journal=Geochemistry, Geophysics, Geosystems |date=18 January 2022|volume=23 |issue=2 |doi=10.1029/2021GC010293 |bibcode=2022GGG....2310293S |s2cid=245135298 }}</ref> Air quality in the Punjab, Pakistan deteriorates markedly during the post-[[monsoon]] to winter transition, driven by shifts in weather patterns like alterations in wind, temperature, and [[Boundary-Layer Meteorology|boundary layer]] mixing.<ref name=":0" /> In post-moonsoon, anthropogenic emissions from sources like [[Exhaust gas|vehicle exhaust]], industrial activities, and [[crop burning]] impact air quality across Punjab, Pakistan, affecting the region by 90–100%.<ref name=":1" /><ref>{{Cite journal |last1=Ojha |first1=Narendra |last2=Sharma |first2=Amit |last3=Kumar |first3=Manish |last4=Girach |first4=Imran |last5=Ansari |first5=Tabish U. |last6=Sharma |first6=Som K. |last7=Singh |first7=Narendra |last8=Pozzer |first8=Andrea |last9=Gunthe |first9=Sachin S. |date=2020-04-03 |title=On the widespread enhancement in fine particulate matter across the Indo-Gangetic Plain towards winter |journal=Scientific Reports |language=en |volume=10 |issue=1 |pages=5862 |doi=10.1038/s41598-020-62710-8 |pmid=32246046 |issn=2045-2322|pmc=7125076 |bibcode=2020NatSR..10.5862O }}</ref>

Doctors advised residents to stay indoors and wear facemasks outside.<ref>{{Cite news|url=http://www.dawn.com/news/1159190|title=Lahore smog: It's not a natural phenomenon|last=Khan|first=Rina Saeed|date=24 January 2015|newspaper=dawn.com|access-date=6 November 2016}}</ref>