Environmental Problems in China Indicated by PM2.5

MENG Jianjun
Visiting Fellow, RIETI

1. How the debate over PM2.5 began

At the beginning of 2013, the problem of PM2.5 in China suddenly began attracting attention around the world, and PM2.5 has now become a common term in Japan as well. Why did the PM2.5 problem start drawing such worldwide attention? It all started when the U.S. Embassy in Beijing installed an air-monitoring device on its rooftop right after it relocated in the spring of 2008. The U.S. Environmental Protection Agency (EPA) monitors the status of air pollution around the U.S. Embassy in Beijing hourly based on its air quality indicator (AQI) in order to determine the amount of pollution in the air. The EPA also measures PM2.5, or microparticles in the air that are 2.5 micrometers in diameter or smaller based on the AQI standard.

On November 1, 2011, the U.S. Embassy began posting a Twitter feed of the PM2.5 data it was monitoring (around the Chaoyang District where it is located). According to this data, the air quality in Beijing differed significantly from that published by the Beijing Municipal Bureau of Environmental Protection (BMBEP), and this immediately received much attention on the Internet from Beijing residents.

For example, according to the AQI established by the United States, a PM2.5 density between 301 and 500 is recognized as "hazardous level." According to some reports, on December 4, 2011, the U.S. Embassy posted that the PM2.5 density it monitored in the air at 7:00 p.m. on that day was 522 micrograms per cubic meter, indicating that air quality was severely polluted, with the highest measured value being over 500. However, on that same day, the BMBEP announced that the AQI per cubic meter at 8:00 p.m. was 150-170, and reported the air quality as Class 3, or "light pollution." Protests grew from Beijing citizens, wondering what on earth the difference meant.

The BMBEP's value of 150-170 was not that of PM2.5 density, but actually of PM10, or microparticles in the air that are 10 micrometers in diameter and smaller. This difference in judgment criteria resulted in the huge disparity in the numerical results published by the two organizations.

2. Development of a system based on rapid information disclosure

The press attache at the U.S. Embassy stressed that its data differed from that of the BMBEP in terms of the observed object and observation range, and said that the values announced by both organizations could not be compared. However, Beijing citizens demanded that the government publish data on PM2.5 density. That's how the government's response to PM2.5 came to attract attention around the country.

Beijing started monitoring air pollution in 1984 at eight points as part of its efforts to determine the degree of environmental pollution. It has increased its number of observation points to 27 since 2000. From 1999, it started publishing air pollution status reports almost daily, and weather reports began reporting on air quality from 2001. Beijing actually began monitoring PM2.5 in 2006, but prior to that, PM2.5 was mainly regarded as air pollution research data, and publicly released air pollution measurements were based on PM10 criteria.

As a result of increasing demand from Beijing citizens, PM2.5 was finally included in the state's "ambient air quality standards" that were recently revised on February 29, 2012. The Ministry of Environmental Protection of the People's Republic of China also announced that it would commence comprehensively monitoring PM2.5 levels across the country by 2016. Even earlier, in January 2012, in addition to carbon dioxide, sulfur dioxide, nitrogen dioxide, ozone, and PM10, PM2.5 started being included in the air quality evaluation standards for Beijing. On February 2, 2012, the website for the Beijing Municipal Environmental Monitoring Center began publishing the daily average PM2.5 density as well as the hourly changes. This is a direct consequence of the government bowing to public opinion.

Furthermore, news is spreading that the Chinese terms for particulate matter were established on February 27, 2013. According to these reports, the terms for PM2.5, PM10, and PM1 have been established as "xi ke li wu (fine particulate matter)," "ke xi ru ke li wu (inhalable particulate matter)," and "chao xi ke li wu (ultrafine particulate matter)," respectively. Nevertheless, public demand that the government be proactive by implementing as many effective countermeasures as possible to combat the increasingly serious air pollution is growing daily.

3. Causes and countermeasures

PM2.5 travels deep inside the lungs and is caused by man-made factors such as smoke from factories and automobile emissions in many cases. China is still dependent on coal for its energy consumption, and approximately 70% of thermal power is still generated from coal-fired thermal power stations. In addition, in most areas in northern China, coal is used to heat homes over the long winter from November to March (or from October to April in areas with longer winters). This year, Beijing's air pollution was serious from the beginning, and days with a vigilance level of "heavy pollution" and "severe pollution" have been occurring frequently due to the particularly worsening of air quality from smoke in the area north of the city. According to research, in Beijing, 40% of the pollution from PM2.5 is caused by coal smoke and 30% by automobile emissions. The remaining 30% is caused by dust, etc.

The number of automobiles in Beijing already exceeded five million by the end of 2012, doubling in just four years, and continues to increase at a rate of 20,000 per month. Another reason for the aggravated PM2.5 problem is the lax automobile fuel regulations. In China, the regulation standard for the sulfur in gasoline is 150 parts per million (ppm) or below, which is 15 times higher than the 10 ppm or below in Japan and Europe.

Although information disclosure and the investigation of causes as described above are certainly important, what matters most are countermeasures against air pollution. It is estimated that approximately 40% of China's 1.35 billion people today are living in highly polluted areas with a high density of harmful fine particles. This environmental problem is one of the most important agenda for the National People's Congress, and many people feel that the government's environmental protection measures are insufficient.

So far, Beijing has established eight steps to take to reduce PM2.5 density, which include screening significantly older automobiles, stricter emissions regulations, large-scale planting and forestation, retrofitting coal boilers, promoting the use of gas, and changing the industrial structure. It also plans to invest 100 billion yuan (1,500 billion yen) in antipollution measures over the next three years. It has been reported that the city has made it a policy to work on improving its air pollution and treating sewage and waste.

In addition, the following measures are already being promoted: switching from coal to natural gas in areas where central heating is provided in the winter, and remodeling heating systems from charcoal based to electricity based in one-story houses such as siheyuan in older urban areas. The daily average PM2.5 density officially announced by the BMBEP shows very good results of 16-25 micrograms per cubic meter on days when the air quality is good.

However, the worst reading in the city's history was recorded in late January 2013, with a PM2.5 density exceeding 900. As expressed by the Chinese proverb "Bing dong san chi, fei yi ri zhi han" (literally, "a river doesn't freeze three feet deep in a day"), great things can't be accomplished in a short period of time.

April 16, 2013

April 16, 2013