Beijing air quality publicly outed by US Embassy

PR Log (Press Release) – Jul 02, 2009 – Hong Kong.

Most industrial countries and the World Health Organization believe PM2.5 is a more accurate standard of measuring air quality than PM10 used by China. Foreign doctors suggest that breathing Beijing's air is as damaging to the lungs as smoking one packet of cigarettes every day.

China's government does not openly publish air quality data. Critics predict further damage to the country's environmental image, reduced foreign investments and social unrest if they did
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The US embassy in Beijing is privately monitoring the air quality and defying the official claim of air quality has significantly improved in Beijing since the 2008 Olympic Games. Beijing publicly declared their measures to reduce pollution a success by hitting their target of 256 ‘blue sky days' for 2008 one month early in November. A ‘blue sky day' means a reading of 100 or less on Beijing's API scale.

More recent contradictory data collected by the US embassy has been uploaded on Twitter on an hourly basis for public viewing. The posts have quickly become very popular among expatriates and locals who often distrust China's official statistics.

According to the Beijing Environmental Protection Bureau, on 24 June 2009, the official air quality reading of the city was measured as "moderate". The Air Pollution Index (API) showed a reading of 69 - the level of pollutants of 10 microns (PM10) from noon to noon.

On the same day, the US embassy data showed the fine particles with a median diameter less than 2.5 microns (PM2.5) was at 184, sufficient to classify the air quality as "unhealthy" based on U.S. Environmental Protection Agency standards.

Previously, the US embassy recorded a maximum PM2.5 reading of 500 for several hours on 18 June, sufficient to classify the air quality as "hazardous" while Beijing's official figures measured only as "slightly polluted" for the same day.

What is API & PM?

API is also known as the Air Quality Index (AQI): A number used by government agencies to characterize the quality of the air at a given location. As the API increases, an increasingly large percentage of the population is likely to experience increasingly severe adverse health effects.

PM - Particulate matter, is the term for particles found in the air, including dust, dirt, soot, smoke, and liquid droplets. Particles can be suspended in the air for long periods of time. Some particles are large or dark enough to be seen as soot or smoke. Others are so small that individually they can only be detected with an electron microscope.

PM10 - Particle matter less than 10 micrometers in diameter. It poses a health concern because of inhalation and accumulation in the respiratory system.

PM2.5 - Particles less than 2.5 micrometers in diameter are referred to as "fine" particles. They pose the greatest health risks because finer particles can lodge deep into the respiratory system.

The huge discrepancy between the official figures and the US embassy's reading is partially due to the different measuring standards the two countries follow. Other factors such as the location of monitoring stations also make comparisons difficult. Furthermore, critics have suggested that the Beijing monitoring stations have been moved to less polluted areas of the city to produce cleaner results.

The US Environmental Protection Agency measures air quality on PM2.5, the smaller yet more dangerous fine particles.

US Air Pollution Index

API:  Air pollution level;  Health implications

0-50: Good: No health implications

51-100: Moderate: Acute health effects are not expected but chronic effects may be observed if one is persistently exposed to such levels

101-150: Unhealthy for sensitive group: People with existing heart or respiratory illnesses may notice mild aggravation of their health conditions. Generally healthy individuals may also notice some discomfort

151-200: Unhealthy: People with existing heart or respiratory illnesses may notice mild aggravation of their health conditions. Generally healthy individuals may also notice some discomfort

201-300: Very unhealthy: Moderate aggravation of symptoms and decreased tolerance in persons with heart or lung disease; more widespread symptoms of transient irritation in the healthy population

301-500: Hazardous: Significant aggravation of symptoms in susceptible persons; and decreased exercise tolerance in healthy persons. API levels above 400 may be life-threatening to ill and elderly persons

The China Environmental Protection Bureau measures air quality on PM10, the less harmful larger particles that are likely to be coughed out after inhalation.

China Air Pollution Index

API:  Air Pollution Level:  Health implications

0 – 50: Excellent: No health implications

51-100: Good: No health implications

101-150: Slightly Polluted:   Slight irritations may occur, individuals with breathing or heart
problems should reduce outdoor exercise

151-200: Lightly Polluted: Slight irritations may occur, individuals with breathing or heart problems should reduce outdoor exercise

201-250: Moderately polluted: Healthy people will be noticeably affected. People with breathing or heart problems will experience reduced endurance in activities. These individuals and elders should remain indoors and restrict activities

251-300: Heavily polluted: Healthy people will be noticeably affected. People with breathing or heart problems will experience reduced endurance in activities. These individuals and elders should remain indoors and restrict activities.

300+: Severely polluted: Healthy people will experience reduced endurance in activities.

There may be strong irritations and symptoms and may trigger other illnesses. Elders and the sick should remain indoors and avoid exercise. Healthy individuals should avoid outdoor activities.  

The China government has been reluctant to release data about Beijing's pollution for many years.

The Beijing Environmental Protection Bureau began collecting air quality data in 1981, but only began to publish them in 1998. It was the last major Chinese city to make the API readings available to the public, effectively concealing the severity of Beijing air pollution from foreign investors.

The authorities have frequently stated significant achievements in improving the city's air quality. In an effort to clean up Beijing skies before the Olympic Games, the local government closed factories, shut down construction sites and limited traffic. On the opening day the world was impressed by its clear blue sky.

In reality, the air quality of the Beijing Olympics was the worst of any Games in history. Even with some favorable weather patterns helping reduce the problem, official API readings reported by the government were on average 30 percent lower than actual figures.

The Environmental Science and Technology journal revealed last week that both PM10 and PM2.5 readings were above safe levels throughout most of the Games. Furthermore, the PM2.5 levels surpassed World Health Organization safe thresholds every single day of competition.  

However, both China's Environmental Protection Bureau and the US embassy have down played the apparent differences in air quality data. Susan Stevenson, a spokesperson for the US Embassy, said the move was only aimed at providing environmental data for the people who work for the embassy and the American expatriate community.