PM2.5 data in Beijing Chinese Academy of Sciences Research Fellow with the American response to the different embassies

Yesterday, the Beijing Municipal Environmental Protection Bureau of Air Quality Monitoring System central office staff in data processing. Published daily air quality data from published here, the big screen for the city’s 27 air quality monitoring stations and weather maps cloud. The reporter Sun Chunxia photo

Beijing haze caused by air quality monitoring days, the dispute led to public concern. In the city on Friday with the U.S. Environmental Protection Agency, California Environmental Protection Department staff seminar, Wang YS researcher at the Institute of Atmospheric Physics, Chinese Academy of Sciences, said the independent monitoring data are the data consistent with the Municipal Environmental Protection Bureau, Beijing, nearly 10 years of respirable particles in the air more large particles decreased significantly, but small particles has increased year by year.

WASHINGTON Friday, the United States before the California Air Resources Board executive officer Catherine and his party, visited the Beijing Municipal Environmental Protection Bureau, with Chinese officials and experts to monitor the exchange of air quality situation. Beijing air quality and monitoring data become the focus of the parties.

American experts to meet, many people agreed that the data of the U.S. Embassy issues.

“If California has a blog master does not believe the government’s data, their own monitoring to more particulate pollution, we will look at the bloggers to visit and see how he measured, the data is accurate If there really is much higher data, we will see whether there have been overlooked sources of pollution, considering whether to station. “Catherine said.

“Why is the Beijing Municipal Environmental Protection Bureau said PM10 declined year by year, but the public felt there was no significant improvement in air quality?

Beijing in recent years because of strong governance, the indicators with the PM10 closer relationship between the decline in the number of coarse particles, and haze associated with more fine particles rise, not fall, “Wang YS, Institute of Atmospheric Physics, Chinese Academy of Sciences researcher explained.

Wang YS fellow group nearly 10 years of monitoring data show that the mass concentration of PM10 in Beijing decreased by 2% -3% per year, but one of the PM2.5 mass concentration was about 3% -4% per year . Increase the proportion of total PM10 PM2.5.

Wang YS said that in addition to dust storms and other extreme weather, Beijing in recent years, the concentration of PM2.5 particles are generally about 60 to 70, rarely more than 150, but even so, “must admit, Beijing air pollution is very serious, this seven or eight years have been better, but did not improve much, but no worse. “

present, China’s environmental protection department has not been included in the PM2.5 air quality standards , has not announced a city of PM2.5 monitoring results.

Recently, the Beijing Municipal Environmental Protection Bureau spokesman Du said Beijing has the ability and equipment to monitor PM2.5, and there are monitoring data, but the publication of the data was subject to national unity arrangement. Monitoring of PM10 in Beijing, including PM2.5, after treatment of large particles, small particles will begin treatment.

■ doubts

Who’s monitoring data fly?

CAS monitoring data consistent with the Beijing

different air quality monitoring data, a network of hot topic.

10 30, Wang YS concentration of PM2.5 measured Beijing 145, while the U.S. Embassy hour rolling data is generally 250 to 350, why such a large difference in value?

“the U.S. Embassy can publish a 24-hour concentration values, but they did not do. Meaningful to human health evaluation index value is 24 hours.” Catherine said.

Peking University Research Center for Environment and Health Associate Huang Wei said, sampling a large time in the fog of humidity is more sensitive, if not done correct and drying, the weight of particulate matter will be much higher, even a times to twice as much.

“as a third party monitoring, we observed data and Beijing is consistent with the observed data, the data is no problem in Beijing is currently the U.S. embassy in the observed data and our data is not consistent.” Wang YS said.

PM2.5 Why has increased?

mainly from industrial and vehicle emissions

Huang Wei introduced larger respirable particles, mainly from dust, dust mechanical process, and fine particulate matter is mainly from fossil fuel combustion, including toxic and hazardous substances from the mechanical process than larger particles.

Therefore, PM2.5 growth “and the relationship between the growth of motor vehicles.” Wang YS, “said construction dust, surface dust, diesel vehicles and coal reduced to coarse particles drop sharply; and gaseous organic emissions increase, exacerbated by photochemical reactions in and around the transmission, so that fine particles remains high. Control coarse particles, the local Environmental Protection Agency can make a difference, and the need to reduce fine particle regional collaborative governance.

Beijing and Tianjin now Hebei Province of pollution emissions, in the absence of wind, calm weather conditions, turn off all sources of pollution in Beijing, the concentration of fine particles may not be able to meet European standards. This is the environmental protection department said, Beijing’s air quality in a have to rely on the kind of weather. ” Wang YS said.

smog days that the pollution worse?

the highest concentration of PM2.5 serious haze

Wang YS said, “haze” and the unit volume of air within the relationship between the number of small particles is more To close, when there is a gray haze days, PM10 and PM2.5 mass concentration will certainly increase.

in Wang YS on 29 October to 3 November between the measured values ??to see, PM2.5 concentrations in the October 30, that is the worst haze days of the day reached a peak concentration of 145 micrograms/cubic meter, the total respirable particulate matter of 61%.

daily average PM2.5 concentrations and the WHO guideline value compared to the widest, October 30 in Beijing PM2.5 particulate matter concentration more than doubled; November 2, even if weather conditions are very good time, PM2.5 concentrations are also slightly exceeded.

most polluted in Beijing, when, still rely on weather conditions to eliminate pollution. “Under the summer rain, washed away by the first half-hour, the car has black spots. Half an hour later, the rain it is much cleaner.” Wang YS, said the same, slightly larger north wind blowing, you can quickly disperse the pollution things.

PM2.5 when to enter the national standard?

first value listed for reference conditions

with the environmental community believe that the current public PM2.5 in hot, to promote environmental protection departments may be included in faster air quality standards, or at least adopt a compromise approach, first introduced in some cities.

Huang Wei said that the United States from the 1970s began to study PM2.5, to 90 years for legislation to be included in the standard, in the middle spent nearly 30 years, the legislation was based primarily on Harvard and the American Cancer Society made two heavyweight epidemiological study.

she said, to be able to evaluate the quality of air, you first need to list a reference value in order for our comparison, the toxicity of our fine particles, North-South differences, which are more likely to be affected, these are the lack of research data. “

Wang YS said that in some of PM2.5 pollution in Beijing and other areas, you can advance at the same time parallel monitoring of PM2.5 and PM10 studies.

can be released PM2. 5 concentration and other raw data? Peking University School of Public Health, Professor Pan Xiaochuan believes that if there is no standard, then the light can not be evaluated published data in the previous study, the concentration of PM2.5 in Beijing and the cardiovascular, respiratory associated increase in the number of patients.

■ Tips

light pollution days to wear a mask

“EPA said the ‘light pollution’, in fact, very serious, this time for the elderly and children should go outside. If air circulation is not good, have stayed in the air pollutants, air quality will deteriorate. In such weather, city residents should drive less, ride mass transit to go out, if necessary, wear protective masks look. “Wang YS tips, market activity of 3 cents a mask, you can block 70% of small particles.

personally visited the Environmental Monitoring Center

Beijing Municipal Environmental Protection Bureau announced yesterday Beijing Municipal Environmental Protection Monitoring Center from today onwards for individual open every Tuesday afternoon to visit in two batches, each batch of 20.

If you are interested, you can advance telephone booking: 68413195

suspended in the air all kinds of natural and man-made emissions of particulate matter or form, which can be part of the respiratory system to inhaled PM10, particles less than 10 microns in diameter that is the general term. the smaller the diameter the deeper into the respiratory position.

PM10 PM2.5 contains the following in the particle composition, commonly known as “fine particles”; also contain this larger diameter PM2.5 to PM10 particles, commonly known as “coarse particles”.

Beijing News graphics/edition have written this reporter Kim Yu Guo Yu

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