According to the research results on source apportionment of fine particulate matter (PM2.5) released by Beijing, among local emission contributions, mobile sources, fugitive dust sources, industrial sources, non-point living sources and coal sources accounted for 45%, 16%, 12%, 12% and 3% respectively. This also means that living sources have accounted for 12% of Beijing's local air pollution emissions, basically equivalent to industrial sources.
Shi Aijun, vice president of the Beijing Academy of Environmental Sciences, further explained that in Beijing, the proportion of living sources is increasing. The pollution discharge from living sources mainly comes from the daily life of citizens, such as "food, clothing, housing and transportation". For example, all scented consumer goods contain volatile organic compounds (VOCs), especially perfume, hair gel, air fresheners, pesticides, cleaning agents and other aerosols. "The content of volatile organic compounds in consumer goods is high".
How are the pollution values of perfume, hair gel and air freshener calculated? Is the 12% figure convincing? In the United States and other countries, will these living sources also be counted as pollution sources? How to control?
Some pollutants from daily necessities even reach three times of vehicle exhaust
Air pollution caused by perfume, hair gel, air freshener, etc. is mainly due to the emission of volatile organic compounds (VOCs) when used 。 VOCs are the general name of volatile organic compounds, including 8 categories of compounds, including alkanes, aromatic hydrocarbons, alkenes, halohydrocarbons, esters, aldehydes, ketones, etc., totaling more than 300. because VOCs are relatively active gases, which can generate PM2.5, PM10 or ozone for the second time.
Tang Xiaoyan, an academician of the Chinese Academy of Engineering and a professor of Peking University, said that VOCs emissions involve a wide range of aspects, including all aspects of life. For example, clothing dry cleaners mainly use tetrachloroethylene, petroleum solvents, and cleaning additives. These chemicals contain high VOCs, and the VOCs emissions can not be ignored. "Before the Beijing Olympic Games, all emergency measures were well prepared, but there was a large amount of air pollution from July 25-27, and the pollution continued to rise on August 5. At this time, the original Ministry of Environmental Protection, in addition to sending 6000 inspectors to various places to supervise, Beijing also took measures to stop all the washing yards, and the pollution situation improved by the evening of July 7."
"Usually inconspicuous factors play a key role in critical moments," said Tang Xiaoyan.
"Another example is perfume, air fresheners, etc., which will volatilize during the use process and produce VOCs." Peng Yingdeng, a researcher of the National Urban Environmental Pollution Control Technology Research Center, said in an exclusive interview with the reporter of Science and Technology Daily that the volatile organic compounds in some consumer goods are high.
A study published in the US journal Science also shows that daily chemical products containing compounds extracted from petroleum, such as various household cleaners, pesticides, perfumes, etc., pollute urban air at a level comparable to that of motor vehicle exhaust.
Brian MacDonald, the research leader and a scientist from the chemical department of the National Oceanic and Atmospheric Administration of the United States, said, "With the continuous reduction of vehicle emissions, the proportion of other major sources of urban air pollution is increasing."
MacDonald and his colleagues analyzed and evaluated the pollution level of daily chemical products that passed the inspection of the regulatory authority in Los Angeles, and then compared them with other air pollution sources such as local vehicle exhaust. The results show that the pollution level of daily chemical products has reached or exceeded the vehicle exhaust pollution in Los Angeles. The study also found that in terms of emission indicators of some fine particles, daily chemical products even greatly exceeded vehicle exhaust, and even reached three times of the latter.
The data of pollution emissions from domestic sources are generally accurate
"The source of living has accounted for 12% of Beijing's local air pollution emissions, and this 12% is estimated based on the statistical data of the daily consumption of consumer goods in a city or region." Peng Yingdeng explained that the daily consumption of consumer goods sold in stores and supermarkets in a city or region has corresponding data in the commerce or industry statistics department, and then according to the circulation The amount of VOCs emitted during use is converted.
"Although some small non mainstream purchase channels, and some of the daily necessities purchased on Taobao, JD and other websites are difficult to access for the time being, for example, buying perfume from Guangdong and using it in Beijing, there is still some error. However, the data of pollution emissions from living sources is generally accurate." Peng Yingdeng said that China is different from western countries, China entered the market economy from the planned economy. At present, the statistical channels of the planned economy are still available. Especially, the data of large enterprises and commercial sectors are relatively easy to be obtained by commercial and industrial sectors, and the data is reliable on the whole.
Peng Yingdeng said that the statistical data of cooking fume was not based on the business or industry statistics department, but was calculated by the environmental protection department according to the standing book of the emission list of pollution sources. At present, there is no specific control measures for kitchen fume pollution in daily life of residents in China. However, Changsha, Hunan, has started a pilot project, led by the local government and the development and reform departments, and the purification efficiency of the catering range hoods in colleges and universities has exceeded 87%. The purified "gutter oil" is made into soap, which is then replaced with the surrounding community residents. "The residents used the waste oil from their kitchen range hoods to replace soap, and the pilot effect was very good."
Greater impact on indoor air quality
MacDonald and other researchers have shown that since a large part of the consumption of daily chemicals occurs in buildings, VOCs generated during their use have a greater impact on indoor air quality. Taking Los Angeles as an example, the impact of volatile chemicals on indoor air is 7 times greater than its contribution to outdoor air pollution.
"California, Los Angeles and other areas in the United States are prone to photochemical smog, and VOCs are the focus of control in these areas." Peng Yingdeng said that although Europe, the United States and other countries require that "water paint" rather than "paint" must be used for wall painting, and "ink" rather than "ink" must be used for printing, more control measures are aimed at industry and motor vehicles, and VOCs control requirements for personal living goods are not very strict.
Peng Yingdeng said that at present, China's VOCs control thinking is also changing, and is moving towards refinement and precision. "For example, the dry cleaners in Beijing have specified the type and amount of dry cleaning agent per kilogram of clothing."
From September 1, 2017, Beijing, Tianjin and Hebei have implemented the Limit Standard for Volatile Organic Compounds Content of Architectural Coatings and Adhesives. Hu Zhongyuan, chief engineer of Chenyang Water Paint Technology, the core drafting unit of the Standard, said that this is the first unified mandatory environmental protection standard in Beijing Tianjin Hebei region. "It is conservatively estimated that this will reduce VOCs emissions of architectural coatings and adhesives by more than 20%".
