{"id":7921,"date":"2019-04-24T17:10:14","date_gmt":"2019-04-24T09:10:14","guid":{"rendered":"https:\/\/smartairfilters.com\/?p=7921"},"modified":"2021-03-11T19:30:08","modified_gmt":"2021-03-11T11:30:08","slug":"china-blame-seouls-air-pollution","status":"publish","type":"post","link":"https:\/\/smartairfilters.com\/en\/blog\/china-blame-seouls-air-pollution\/","title":{"rendered":"Is China to Blame for Seoul\u2019s Air Pollution?"},"content":{"rendered":"<p>Air pollution is a serious problem in Seoul, which South Koreans have often <a href=\"https:\/\/www.scmp.com\/news\/asia\/east-asia\/article\/2181967\/south-korea-chokes-smog-and-once-again-seeks-blame-china\">blamed China<\/a><span> for<\/span>. Is that fact or a convenient scapegoat? After all, Seoul is a densely populated, developed city that <a href=\"https:\/\/www.npr.org\/sections\/parallels\/2016\/06\/03\/478796463\/koreas-air-is-dirty-but-its-not-all-close-neighbor-chinas-fault\">depends on coal power plants<\/a>. South Korea certainly has its <a href=\"https:\/\/www.npr.org\/sections\/parallels\/2017\/10\/10\/552264719\/armed-with-nasa-data-south-korea-confronts-its-choking-smog\">own sources of pollution<\/a>. To get to the bottom of it, I analyzed where exactly Seoul\u2019s air pollution comes from.<\/p>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter\"><img fetchpriority=\"high\" decoding=\"async\" width=\"840\" height=\"560\" src=\"\/wordpress\/wp-content\/uploads\/2019\/04\/1.-factory-smog.jpg\" alt=\"Seoul's air pollution: factory smog\" class=\"wp-image-7922\" srcset=\"https:\/\/smartairfilters.com\/wordpress\/wp-content\/uploads\/2019\/04\/1.-factory-smog.jpg 840w, https:\/\/smartairfilters.com\/wordpress\/wp-content\/uploads\/2019\/04\/1.-factory-smog-300x200.jpg 300w, https:\/\/smartairfilters.com\/wordpress\/wp-content\/uploads\/2019\/04\/1.-factory-smog-768x512.jpg 768w\" sizes=\"(max-width: 840px) 100vw, 840px\" \/><\/figure><\/div>\n\n\n\n<h3 class=\"gb-headline gb-headline-e10d2cde gb-headline-text\">How Much of Seoul\u2019s Pollution Is Local?<\/h3>\n\n\n\n<p>One way to answer this question is see what happens to Seoul\u2019s air pollution when the wind blows from China. To do that, I analyzed data on Seoul\u2019s <a href=\"http:\/\/berkeleyearth.lbl.gov\/air-quality\/maps\/cities\/South_Korea\/Seoul\/\">PM2.5<\/a> and <a href=\"https:\/\/www.meteoblue.com\/en\/weather\/archive\/export\/seoul_republic-of-korea_1835848\">wind speed and direction<\/a> from 2016 to 2018.<\/p>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter\"><img decoding=\"async\" width=\"960\" height=\"720\" src=\"\/wordpress\/wp-content\/uploads\/2019\/04\/Wind-Direction.jpg\" alt=\"Seoul's air pollution: wind direction\" class=\"wp-image-7925\" srcset=\"https:\/\/smartairfilters.com\/wordpress\/wp-content\/uploads\/2019\/04\/Wind-Direction.jpg 960w, https:\/\/smartairfilters.com\/wordpress\/wp-content\/uploads\/2019\/04\/Wind-Direction-300x225.jpg 300w, https:\/\/smartairfilters.com\/wordpress\/wp-content\/uploads\/2019\/04\/Wind-Direction-768x576.jpg 768w\" sizes=\"(max-width: 960px) 100vw, 960px\" \/><\/figure><\/div>\n\n\n\n<h3 class=\"gb-headline gb-headline-8dfa4905 gb-headline-text\">Wind Analysis<\/h3>\n\n\n\n<p>Anytime the wind blows from the South-West to North-North-East direction (the arrows below), Seoul\u2019s air is getting at least some air from China. If most of Seoul\u2019s air pollution is coming from China, we should see air pollution spike whenever the wind comes from that direction.<\/p>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter\"><img decoding=\"async\" width=\"1766\" height=\"1241\" src=\"\/wordpress\/wp-content\/uploads\/2019\/04\/map-of-skorea.png\" alt=\"Seoul 's air pollution wind direction map china \" class=\"wp-image-7923\" srcset=\"https:\/\/smartairfilters.com\/wordpress\/wp-content\/uploads\/2019\/04\/map-of-skorea.png 1766w, https:\/\/smartairfilters.com\/wordpress\/wp-content\/uploads\/2019\/04\/map-of-skorea-300x211.png 300w, https:\/\/smartairfilters.com\/wordpress\/wp-content\/uploads\/2019\/04\/map-of-skorea-768x540.png 768w, https:\/\/smartairfilters.com\/wordpress\/wp-content\/uploads\/2019\/04\/map-of-skorea-1024x720.png 1024w\" sizes=\"(max-width: 1766px) 100vw, 1766px\" \/><\/figure><\/div>\n\n\n\n<h3 class=\"gb-headline gb-headline-158e954e gb-headline-text\">Does Wind Direction Affect Seoul PM2.5?<\/h3>\n\n\n\n<p>When the wind was NOT blowing from the direction of China, the average PM2.5 level was 25 micrograms. In contrast, when the wind was blowing from China, the PM2.5 level was 27 micrograms\u2014an 8% increase.<\/p>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter\"><img loading=\"lazy\" decoding=\"async\" width=\"1042\" height=\"706\" src=\"\/wordpress\/wp-content\/uploads\/2019\/04\/wind-vs-no-wind-bar-chart.png\" alt=\"Seoul's air pollution wind from china\" class=\"wp-image-7926\" srcset=\"https:\/\/smartairfilters.com\/wordpress\/wp-content\/uploads\/2019\/04\/wind-vs-no-wind-bar-chart.png 1042w, https:\/\/smartairfilters.com\/wordpress\/wp-content\/uploads\/2019\/04\/wind-vs-no-wind-bar-chart-300x203.png 300w, https:\/\/smartairfilters.com\/wordpress\/wp-content\/uploads\/2019\/04\/wind-vs-no-wind-bar-chart-768x520.png 768w, https:\/\/smartairfilters.com\/wordpress\/wp-content\/uploads\/2019\/04\/wind-vs-no-wind-bar-chart-1024x694.png 1024w\" sizes=\"(max-width: 1042px) 100vw, 1042px\" \/><\/figure><\/div>\n\n\n\n<p>The highest spike happens when the wind is from the northwest\u2014the direction of Pyongyang and Liaoning. Yet Seoul also sees higher pollution when air comes from east-southeast\u2014other parts of South Korea.<\/p>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter\"><img loading=\"lazy\" decoding=\"async\" width=\"1043\" height=\"831\" src=\"\/wordpress\/wp-content\/uploads\/2019\/04\/PM2.5-when-wind-from-different-directions.png\" alt=\"Seoul PM2.5 Wind direction from china\" class=\"wp-image-7924\" srcset=\"https:\/\/smartairfilters.com\/wordpress\/wp-content\/uploads\/2019\/04\/PM2.5-when-wind-from-different-directions.png 1043w, https:\/\/smartairfilters.com\/wordpress\/wp-content\/uploads\/2019\/04\/PM2.5-when-wind-from-different-directions-300x239.png 300w, https:\/\/smartairfilters.com\/wordpress\/wp-content\/uploads\/2019\/04\/PM2.5-when-wind-from-different-directions-768x612.png 768w, https:\/\/smartairfilters.com\/wordpress\/wp-content\/uploads\/2019\/04\/PM2.5-when-wind-from-different-directions-1024x816.png 1024w\" sizes=\"(max-width: 1043px) 100vw, 1043px\" \/><\/figure><\/div>\n\n\n\n<p>This data gives three (somewhat contradictory) takeaways:<\/p>\n\n\n\n<ul class=\"wp-block-list\"><li>Yes, Seoul\u2019s air pollution is 8% worse when the wind blows from China.<\/li><li>However, even when no air is coming from China, Seoul still averages more than twice the <a href=\"https:\/\/www.who.int\/en\/news-room\/fact-sheets\/detail\/ambient-(outdoor)-air-quality-and-health\">WHO annual limit<\/a> of 10 micrograms.<\/li><li>When the air is blowing from east-southeast (ESE) i.e., from other parts of South Korea, Seoul\u2019s PM2.5 increases.<\/li><\/ul>\n\n\n\n<p>Thus, even without the influence of China, Seoul still has significant <a href=\"https:\/\/www.scmp.com\/week-asia\/politics\/article\/2087447\/china-blame-koreas-pollution-really\">sources of air pollution<\/a> from within.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">A Mystery: Where\u2019s That ESE Pollution Coming From?<\/h3>\n\n\n\n<p>Air from China raises pollution 8%, but air from the ESE increases it even more\u201412%.<\/p>\n\n\n\n<p>Currently, we don\u2019t know where exactly this spike in pollution from the ESE originates. Besides the East Sea, a possible source outside of South Korea would be Japan. However, the provinces of <a href=\"http:\/\/berkeleyearth.lbl.gov\/air-quality\/local\/Japan\/Fukuoka\">Fukuoka<\/a>, <a href=\"http:\/\/berkeleyearth.lbl.gov\/air-quality\/local\/Japan\/Hiroshima\">Hiroshima<\/a> and <a href=\"http:\/\/berkeleyearth.lbl.gov\/air-quality\/local\/Japan\/Osaka\">Osaka<\/a> that lie in the ESE have much cleaner recorded air than Seoul.<\/p>\n\n\n\n<p>Thus, it is very likely that the ESE pollution originates within South Korea.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Does Wind Speed Affect PM2.5?<\/h3>\n\n\n\n<p>Another way to ask this question is to ask what happens when there\u2019s no wind. When there was no wind, the PM2.5 level averaged 24 micrograms, which is 8% below Seoul\u2019s average PM2.5. Thus, PM2.5 in Seoul is largely similar, even with no wind.<\/p>\n\n\n\n<p>I repeated the analysis of PM2.5 level at low and high wind speeds and came up with the same conclusion (see details <a href=\"https:\/\/smartairfilters.com\/en\/blog\/is-china-to-blame-for-seouls-air-pollution-supplemental-data\/\">here<\/a>).<\/p>\n\n\n<div class='bottom-line'><div class='bottom-line-top'>Bottom Line<\/div><div class='bottom-line-title'>Bottom Line<\/div><div class='bottom-line-content'>\nWhen wind blows from China, Seoul\u2019s PM2.5 increases 8%, which suggests that most of Seoul\u2019s pollution still comes from home.\n<\/div><div class='bottom-line-last'>Smart Air<\/div><\/div>\n\n\n\n<h3 class=\"gb-headline gb-headline-2d06c1f8 gb-headline-text\">Caveat<\/h3>\n\n\n\n<p>This data is for particulate pollution. Particulate \u201c<a href=\"http:\/\/www.who.int\/mediacentre\/factsheets\/fs313\/en\/\">affects more people than any other pollutant<\/a><span>s<\/span>,\u201d but there are also gas pollutants like ozone.\u00a0<a href=\"https:\/\/pdfs.semanticscholar.org\/b211\/2a066f19bb0d2343fec3cc369c8a5243b9a5.pdf\">According to this data<\/a>, South Korea also has unsafe levels of ozone.<\/p>\n\n\n\n<p>If I were in Seoul, I would protect myself from air pollution by following these <a href=\"https:\/\/smartairfilters.com\/en\/blog\/air-pollution-seoul\/\">measures<\/a>.<\/p>\n\n\n\n<p>Breathe safe, Seoul!<\/p>","protected":false},"excerpt":{"rendered":"<p>Air pollution is a serious problem in Seoul, which South Koreans have often blamed China for. Is that fact or a convenient scapegoat? After all, Seoul is a densely populated, developed city that depends on coal power plants. South Korea certainly has its own sources of pollution. To get to &#8230; <\/p>\n<p class=\"read-more-container\"><a title=\"Is China to Blame for Seoul\u2019s Air Pollution?\" class=\"read-more button\" href=\"https:\/\/smartairfilters.com\/en\/blog\/china-blame-seouls-air-pollution\/#more-7921\" aria-label=\"Read more about Is China to Blame for Seoul\u2019s Air Pollution?\">Read more<\/a><\/p>\n","protected":false},"author":4300,"featured_media":7936,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"_relevanssi_hide_post":"","_relevanssi_hide_content":"","_relevanssi_pin_for_all":"","_relevanssi_pin_keywords":"","_relevanssi_unpin_keywords":"","_relevanssi_related_keywords":"","_relevanssi_related_include_ids":"","_relevanssi_related_exclude_ids":"","_relevanssi_related_no_append":"","_relevanssi_related_not_related":"","_relevanssi_related_posts":"","_relevanssi_noindex_reason":"","footnotes":""},"categories":[17,126,261],"tags":[272,377,306,374,376],"class_list":["post-7921","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-air-pollution","category-smart-air-news","category-weather","tag-air-pollution","tag-blame","tag-china","tag-korea","tag-seoul","resize-featured-image"],"acf":[],"_links":{"self":[{"href":"https:\/\/smartairfilters.com\/en\/wp-json\/wp\/v2\/posts\/7921","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/smartairfilters.com\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/smartairfilters.com\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/smartairfilters.com\/en\/wp-json\/wp\/v2\/users\/4300"}],"replies":[{"embeddable":true,"href":"https:\/\/smartairfilters.com\/en\/wp-json\/wp\/v2\/comments?post=7921"}],"version-history":[{"count":7,"href":"https:\/\/smartairfilters.com\/en\/wp-json\/wp\/v2\/posts\/7921\/revisions"}],"predecessor-version":[{"id":15478,"href":"https:\/\/smartairfilters.com\/en\/wp-json\/wp\/v2\/posts\/7921\/revisions\/15478"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/smartairfilters.com\/en\/wp-json\/wp\/v2\/media\/7936"}],"wp:attachment":[{"href":"https:\/\/smartairfilters.com\/en\/wp-json\/wp\/v2\/media?parent=7921"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/smartairfilters.com\/en\/wp-json\/wp\/v2\/categories?post=7921"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/smartairfilters.com\/en\/wp-json\/wp\/v2\/tags?post=7921"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}