Above: A satellite image reveals air pollution blanketing  the Korean Peninsula. Credit: GeoEye, Wikimedia Commons (https://upload.wikimedia.org/wikipedia/commons/0/08/Asia_dust_2000-04-07.jpg)

By: Don Mosteller, Research Fellow

More than half of South Korea’s citizens regularly breathe dangerously polluted air, producing serious health effects for the highly urbanized nation. In 2013, more than 20,000 premature deaths were blamed on the country’s foul air. On a typical day, 25 million South Koreans inhale an unsafe amount of microscopic particles of various sizes (PM2.5, PM10 and others). In April of this year, the nation suffered through pernicious levels of PM2.5 half of all days. These particles get lodged in people’s lungs and other cardiovascular tissues, enter their bloodstreams, and over time they can lead to lower respiratory infections, heart disease, lung disease, and cancer.  Even suicides in Korea have been empirically linked to particulate matter and other concentrations of air pollutants like tropospheric ozone.

South Korea’s poor air quality – ranking 173rd out of 180 in its category in the 2016 EPI – along with its weak performances on the 2016 EPI’s Agriculture and Biodiversity & Habitat indicators (126/180 and 133/166, respectively), overshadowed the country’s improvements on other measures, pushing the nation’s global EPI ranking down from 43rd in 2014 to 80th place this year. South Korea ranked 103 out of 180 on the EPI’s new Environmental Risk Exposure measure, which assesses the mortality burden associated with poor air and water quality. The country’s poor air quality risk factor was disproportionately responsible for its overall low performance on this indicator (see Figure 1).

Figure 1: This chart illustrates data from the five environmental risk factors that inform the Health Impacts’ Environmental Risk Exposure indicator in the 2016 EPI. Higher numbers quantify higher risks on a scale from 0 to 1. 100 percent of South Korea’s health risks in this indicator stem from poor air quality. Visit “Calculating Disease Burden” in the 2016 EPI’s Health Impacts Chapter to learn more about how these sub-indicators comprise  the summary ERE statistic.


These unflattering results were not lost on Korea’s news media. Citing the 2016 EPI, The Seoul Times characterized South Korea’s air as “one of the worst in the whole world.” The Korea Times pulled a passage from the 2016 EPI report to underscore the threat South Koreans face. Both articles were quick to blame these “shocking” revelations on transboundary pollution drifting over from China, a commonly cited problem by the Korean media and government. But as the Op-Ed charges, a not-so-insignificant portion of the country’s airborne particulates are homegrown.

According to Greenpeace, a 2013 study found that winds carrying dust from China contributed between 30-50% of South Korea’s ambient PM2.5 (depending on the season and wind conditions) [1]. A 2011 study of the Seoul area found similar results, concluding that 51% of the area’s local fine particulate matter is formed within South Korea. Other outlets, like The Seoul Times, claim that dust blown from the over-grazed, over-logged, and severely desertified Gobi Desert are “mainly” to blame. Indeed, dust and pollution originating from northern China, which has a discernable influence on air quality half a world away, cannot be discounted. The truth, however, lies somewhere in between, but one thing is certain: South Korea’s air pollution has worsened faster than the national government has been able to cope, and it’s not for a lack of trying.

South Korea’s Legislative History on Air Quality

South Korea has implemented a range of policies and management efforts to address air pollution for more than three decades. South Korea promulgated its first regulation on air quality in 1993 and the country’s first PM10 standard in 1995. In 2002, the ESI (Environmental Sustainability Index) ranked South Korea 136th out of 142 countries overall. They placed 139th in the air quality category. Concerned by their performance, South Korean officials convened stakeholder summits and developed an array of mostly transportation-oriented measures to reduce particulate matter, NOx and SOx, in urban areas. The Special Act on Metropolitan Air Quality Improvement passed in 2003 and went into effect in 2005.

By some measures, their efforts paid off. From 2001 to 2011, the annual average total mass of airborne PM2.5 and PM10 in Seoul fell significantly, from 70.0 to 46.9 mg/m3 and 44.4 to 23.4 mg/m3, respectively. The Korean government strengthened its PM2.5 standards in 2012, and South Korea’s Asian Institute for Energy and Environmental Sustainability partnered with the EPI team to develop new indicators for air pollutants including particulate matter, persistent organic pollutants (POPs), ozone and mercury – a compendium of research that appeared in a special issue of Atmospheric Environment in 2013.


Figure 2: South Korea’s performance on the 2016 EPI air quality indicators.


South Korea’s performance on the 2016 EPI’s air quality indicators (see Figure 2 above) show a complicated, mixed picture. Comparing South Korea’s air quality a decade ago to the latest measurements, positive  trends are clear. Outdoor concentrations of fine particulate pollution and nitrogen dioxide (NO2) have fallen (see Figure 3 below), yet the country’s performance is still amongst the global worst. Part of the reason for such low performance is simply due to the fact that most countries meet the target of 10 micrograms/m3 for average exposure to PM2.5, the level considered “safe” by the World Health Organization. South Korea essentially falls short of reaching this threshold, with average exposure nearly double safe levels. More than two-thirds of the 180 countries ranked on the 2016 EPI were beneath this threshold, pushing South Korea to the bottom. For NO2, the picture is worse (see Figure 3 below) for South Korea, who has the third highest average exposure to NO2 and the worst among all countries in Asia, including China and India. Only Belgium and the Netherlands, countries who are phasing out a major source of NO2 – diesel vehicles, perform worse.


Figure 3: Only a few countries have elevated exposure to Nitrogen Dioxide (NO2). For the full map, visit http://visuals.datadrivenlab.org/airmap_2016/

It’s Not the Thought That Counts

South Korea’s drop in EPI rankings is in part a result of other countries leapfrogging their position, yet research from a trio of scientists at Korea University suggests that the nation’s policy failures are also to blame. The researchers found that the relative risk of death from acute exposure to ambient particulate matter – PM10 and PM2.5 actually increased in South Korea from 1998 to 2011, which, according to the authors, indicate that the country’s policy “interventions seemed not to consistently improve air quality” with respect to “human health risks” [authors’ emphasis]. These high mortality rates, they speculated, could stem from increasing concentrations of ultrafine particles (UPs) in the PM2.5 mix, which have been shown to have even stronger correlations with adverse health outcomes.

The researcher’s findings about the influence on Asian dust storms was even more conclusive: the “association of PM with mortality was enlarged when excluding days with Asian dust intrusion.” What these findings suggest is that South Korea’s air was no more harmful to breathe when dust was blowing over from South Korea’s western neighbors – namely China – than on days when there was no transboundary dust. They reasoned that these dust storms tend to contribute smaller fractions of toxic particulates, and that people often take evasive action to protect themselves from dust events. Nevertheless, they went as far as to caution other researchers that failing to account for Asian dust intrusions in their statistical analyses could actually underestimate the effects of particulate matter on mortalities during non-Asian dust periods.

Shanghai Smog  SmogChongqingChina
Smog over Shanghai, China (left) and a factory in Chongqing Shi, Chongqing, China (right) – Flickr Creative Commons (https://www.flickr.com/photos/bribri/3198569878/; https://www.flickr.com/photos/fungleo/4771589650/)

China or South Korea, Which is It?

The question remains: where are these particles coming from? While the previous argument might suggest that Korea’s own emissions are mostly to blame, other studies have, however, confirmed that China’s emissions have substantially undermined South Korea’s air quality. An older study, conducted between August 2002 and December of 2003, provides solid evidence for transboundary movement of pollution from China to South Korea.. This research found that huge seasonal spikes of airborne chemicals associated with residential biomass and coal-burning ovens in China accounted for as much as 82% of those measured in Seoul, due to prevailing westerly winds blowing pollutants over the Yellow Sea. A more recent study conducted on the Western coast of Seoul from June 2009 to May 2010 also found strong evidence that transboundary pollution from China corrupted South Korea’s air quality.

Figure 4: Potential source contribution function (PSCF) map for (a) secondary nitrate, (b) secondary sulfate, (c) biomass burning, and (d) soil that were identified using positive matrix factorization at the sampling site in Korea during 2009 and 2010.

The process of “source apportionment” (i.e., assigning pollution origination) is, however, an extraordinarily complex and evolving science that relies on sophisticated chemistry, remote sensing, statistics, and modelling. This spring, NASA, in partnership with South Korea, began
flying research planes along the Korean coastline to help distinguish foreign pollutants from home-grown ones. Korea’s foreign direct investments (FDI) in China, moreover, are so significant – 6 to 10% of China’s total FDI – that even South Korea’s outsourced emissions are boomeranging back to their shores. Clearly, South Korea and China’s industrial might and the pollution that results is inextricably linked.

Adding Fuel to the Fire?

South Korea’s influence on its own air quality may begin to increase significantly if some of its latest policy proposals come to pass. Our air pollution map last year, overlapped air toxin levels with the world’s most-polluting coal-fired power plant locations. The map shows that severe air pollution is closely associated with coal-fired energy production, and South Korea’s energy mix is moving in the wrong direction. From 2002 to 2012, the fossil fuel share of South Korea’s electricity generation (measured in terms of final energy) increased from 51% to 64%, and almost all of it came from coal and liquefied natural gas. According to South Korea’s Sixth Basic Plan for Long-Term Electricity Supply and Demand, which was released in 2013 and sets the country’s electricity policy, demand is supposed to increase 4% each year for a 60% increase by 2027 – and the plan states that most of the demand will be met with new coal and gas plants. Researchers from the Korea Environment Institute ran the numbers and found that these new fossil-fired plants  would increase air pollution from the energy industry by approximately 50%.


Korea Ulchin Nuclear Power Plant, Credit: IEA & Flickr Creative Commons: https://goo.gl/AZB0oO

Under pressure to reduce greenhouse gases – or facing
fuel and transmission facility challenges – Korea’s government scrapped plans for four of the eight coal plants and replaced them in the Seventh Basic Plan with plans for two new nuclear reactors. Even though nuclear plants do not release fossil fuel emissions laden with particulate matter, relying on nuclear as a lower pollution-emitting power source may not be an easy solution. South Korea’s multidecadal and well-established pro-nuclear industry has come under heavy fire. Writing in The Diplomat, Se Young Jang of the Harvard Kennedy School reveals that multiple scandals, including falsified safety certificates for faulty nuclear equipment and hundreds of thyroid cancer claims, have turned a majority of South Koreans against nuclear power to the point where more than 65% of them would pay higher electricity rates if it meant less nuclear plants. And according to another researcher, that’s exactly what will happen. Nuclear reactors are extraordinarily expensive. They take almost a decade to build and decades more to pay off, and to make matters worse, South Korea is facing a nuclear waste storage crisis.

Even India, which has long been seen as the last significant frontier in the fight against coal, announced in January 2016 that solar power is now cheaper than coal in its country. It’s puzzling to understand why South Korea’s energy officials are not only adhering to energy technologies of the past, but that energy efficiency has been almost completely unexplored. South Korea has one of the highest electricity consumption per capita rates in the world, which stands in stark contrast to other energy import-reliant countries like Japan.  Meanwhile, China is on pace to dominate clean energy production for the foreseeable future.

The Road Ahead

Pointing the finger at other nations
will not remedy South Korea’s air pollution problems.  In Southeast Asia, the lack of consensus on each country’s contribution to air pollution has caused a paralysis by analysis, as governments focus solely on the problem’s sources instead of its solutions. Finger-pointing and hand-wringing have prevented governments in the region from reaching an agreement on how to jointly tackle air pollution. Europe addressed its transboundary air pollution problems long ago with the Convention on Long-Range Transboundary Air Pollution, the first international, legally binding instrument to address regional air quality. Experts credit this agreement with reducing sulfur dioxide emissions substantially. Why haven’t South Korea and other Asian nations followed this European model of success?

Many Asian countries are careful not to upset the relative peace and economic growth of the last three decades, navigating a political minefield of thousands of years of disagreements that makes discussions about costs and pollution attribution tense. The recent climate agreement negotiated in Paris is, however, cause for optimism. The agreement demonstrates a willingness among nations rich and poor to act on climate change, and these actions to reduce emissions would also promote cleaner skies and improve human health. Merely the fact that the world’s countries were able to agree on international targets for mitigating climate change indicates that regional differences can also be overcome. In the months since, an infectious spirit of global solidarity on climate change has been almost palpable, and many countries – China and India included – are moving to decarbonize their economies in the coming years. In other words, the political climate may have shifted so that South Korea can look beyond its domestic air quality policies and begin to focus on regional actions to address the pollution in its skies.

[1] This article’s sentence, which originally read, “According to Greenpeace, up to 70% of South Korea’s ambient PM2.5 originates from domestic sources, although there are scant reports and other literature to support this figure” has been modified to its current version to more clearly reflect the range around and research associated with this figure. According to the Greenpeace report Silent Killers: Fine Particulate Matter, “a 2013 collaborative survey on The Comprehensive Plan on Fine Particulate Matter by related departments of the South Korean government indicates that dust in the wind shifting from China did impact local levels of fine particulate matter in South Korea, amounting to 30 to 50% depending on season and wind condition.”