Ministry of Environmental Protection to amend air quality testing standards

The MEP Standing Conference at the end of August reported on the revision of the Ambient Air Quality Standard.

According to the revised version of this standard that was solicited for public comment at the beginning of this year, the 8-hour monitoring value of ozone will be increased; PM2.5 inhalable particulate matter has not yet been included in the new standard, but it has started to serve as a reference value for various local indicators. This is currently the two most controversial indicators of domestic air quality indicators.

It is understood that the revision is still in the stage of soliciting opinions, and the new standard may eventually be introduced at the end of the year.

Wide standard still protects public health

In 1982, China established the "Atmospheric Environmental Quality Standard", and there are only six pollutants. In 1996, the first revision was made, and the name was changed to Ambient Air Quality Standard. The number of pollutants was expanded to 10 items. Since then, the Ministry of Environmental Protection has carried out partial modifications in 2000, canceled the nitrogen oxide index, and relaxed the Nitric oxide and ozone standards.

One of the most interesting issues of this revision is the addition of an 8-hour average concentration limit for ozone.

The Ministry of Environmental Protection's "Environmental Air Quality Standards (Exposure Draft)" (hereinafter referred to as the "Explanation") stated that the air quality standard for ozone, which is based on the maximum concentration limit of 8 hours in a row, has become the ozone air quality of all countries in the world. With the development trend, the one-hour concentration limit can no longer meet the needs of environmental management.

This revision sets the 8-hour ozone concentration limit secondary standard to 160 micrograms/m3. Although the concentration limit is relatively wide internationally, it can basically protect public health.

According to the “Notes”, there is a health hazard in 6 to 8 hours exposure to ozone concentrations below 120 μg/m3. The ozone hour concentration in Beijing from 2001 to 2002 was between 14.4-232 μg/m3, with an average of 88.9 μg/m3.

Prior ozone standards were monitored for one hour

China's previous ambient air quality standards were not without ozone monitoring, but were based on a one-hour monitoring value, ie, the maximum hourly ozone concentration monitored during the day. However, this time value cannot reflect the long-term cumulative ozone concentration. Chronic injuries caused by the human body.

"It should be said that this is a scientific advancement and more comprehensive consideration of the effects of ozone pollution," said Shao Min, a professor at Peking University's School of Environmental Science and Engineering. He also said that the establishment of standards and disclosure of information are two different things. The ozone hour monitoring value was previously included in the national standard but has not been disclosed.

Background information

Inhalable particles

PM2.5 refers to particles in the atmosphere that are less than or equal to 2.5 microns in diameter, and its diameter is less than 1/20 of the thickness of human hair. At present, PM10 is the standard for PM10 in urban air quality daily or weekly reports. It refers to particulates with a diameter equal to or less than 10 microns and that can enter the human respiratory system.

ozone

It is a trace gas in the Earth’s atmosphere that contains three oxygen atoms. Although ozone plays an important role in protecting the human and the environment in the stratosphere, if it increases in the troposphere, it will have harmful effects on human health. Ozone has stimulatory effects on the eyes and respiratory tract, and also affects lung function. Higher concentrations of ozone are also harmful to plants.

focus

Inhalable particulate matter temporarily does not implement more stringent standards In this revised standard, PM2.5 is listed for the first time, but it is not included in the mandatory unified standard, but is used as a reference value for local reference.

In many cities in China, respirable particulate matter is the main pollutant. Inhalable particulate matter with a particle size of 10 microns or less is called PM10, and PM2.5 with a particle size of 2.5 microns or less.

"PM2.5 is even smaller, and even more into the human lungs," said Pan Xiaochuan, a professor at the School of Public Health of Peking University's School of Public Health, because particulate matter attaches to toxic substances, causing more particles when entering the body. The damage is even greater.

Research shows that from 2004 to 2006, when the daily average concentration of PM2.5 in the Peking University observation point increased, the number of cardiovascular emergency patients in the Third Hospital of Beida about 4 kilometers away also increased.

Whether there is PM2.5 monitoring value is the primary difference between China's ambient air quality standards and WHO guidelines and many other countries' ambient air quality standards, and it is also the most controversial one among China's environmental air indicators. The current monitoring in China only has PM10 particles. Although there are a number of cities and research institutes that monitor PM2.5, because there is no national standard, assessment and disclosure cannot be conducted.

The major developed countries in the world have already established PM2.5 environmental air quality standards, and Japan, Thailand, and India in Asia have also established this standard.

Beijing Environmental Protection Bureau: Local mission will be much heavier

Du Shaozhong, deputy director of the Beijing Municipal Environmental Protection Bureau, said that once the PM2.5 standard has been issued, it will take on much heavier tasks for local government environmental assessment and environmental protection departments.

"Beijing Environmental Protection Bureau will certainly do according to national standards. The more indicators, the greater the pressure will certainly be." Du Shaozhong said, "Like blood pressure and other people's health indicators, the three indicators have been increased to four, and qualified people are also Less, but if you want to be healthy, you should exercise, and the atmosphere is the same. To improve air quality, emission reduction is the last word."

It is understood that Beijing has divided its air operations into 16 stages and implemented more than 200 policies. It is the most implemented policy in all cities. Beijing also began implementing a five-year "Clean Air Action Plan" from this year. However, because of Beijing’s unique geographical location, rapid urban economic development, complex economic structure, and growing motor vehicle ownership, the task of atmospheric governance is still very arduous. Last year’s “attainment standards” accounted for only 78%. The level of days is only 14.5%.

dispute

"Do not implement because you can't meet the standards"

For PM2.5, which is not included in the mandatory unified standards, Ma Jun, director of the Public Environmental Research Center, said, “This is quite disappointing.”

According to the Ministry of Environmental Protection's “Notes”, although PM2.5 pollution is heavy, the average annual concentration of 113 key cities in China in 2008 is much higher than WHO's guideline value, but if the development and implementation of PM2.5 ambient air quality standards, will Excessive standards, in addition, China still lacks the basis for the monitoring of PM2.5, therefore, the development of the national standard PM2.5 standards is still early.

Ma Jun believes that "it is impossible to set this standard because it will exceed the standard. The standard setting should be based on whether it will cause damage to human health. We must not disclose this standard because we cannot meet the standards."

Ma Jun said that monitoring of PM2.5 will be affordable for China's economic development. The establishment of standards involves the public's important right to know the environment. “It may have a potentially big impact on hundreds of millions of people. The impact of such a serious public health cannot be forever and we should tell the public that we have this problem and explain why we cannot reach this target now. If it cannot be resolved in five years, it can be resolved in ten or twenty years. This is the greatest motivator to stimulate public participation in environmental protection."

However, Pan Xiaochuan, a professor at the School of Public Health of Peking University's School of Medicine, believes that “if a standard 80% would exceed the standard, then the standard would be meaningless. Setting standards would require economic and technical feasibility. Of course, from a health perspective, the lower the index The better."