Metz beam weather

Frequent foggy weather is hard to prevent. In recent days, fog has enveloped half of China. The reporter found from the respiratory department of Beijing 309 Hospital and Xiyuan Hospital of Chinese Academy of Traditional Chinese Medicine that the foggy weather in recent days has led to an increase in patients with various respiratory diseases. "Cloudy weather is more likely to cause cancer than cigarettes." Zhong Nanshan, academician of China Academy of Engineering and director of Guangzhou Institute of Respiratory Diseases, once pointed out at a forum that in the past 30 years, the smoking rate of the public in China has been declining, but the prevalence of lung cancer has increased more than four times. This may be related to the increase in haze days. Not only foggy days with very low visibility will have an impact on human health, but also foggy days and cloudy days will have the same problem. Zhang Jinliang, a researcher at the Environmental Pollution and Health Research Office of china environmental science Research Institute, said that air pollution has long-term and chronic effects on lung cancer. Dr. Peng, a researcher at Beijing Academy of Environmental Protection Sciences, also pointed out that foreign studies have shown that toxic particles in the air in haze days are also an important cause of cardiovascular diseases. Besides cancer, smog is also a heart killer. Zhang Jinliang said that research shows that when pollutants in the air deteriorate, the mortality rate of patients with cardiovascular diseases will increase. Harvard University School of Public Health has proved that particulate pollutants on cloudy days will not only cause myocardial infarction, but also cause myocardial ischemia or injury. Common respiratory diseases such as chronic bronchitis, emphysema, asthma, bronchitis, rhinitis and upper and lower respiratory tract infections may also be caused by foggy days. Peng pointed out that foreign studies show that every increase of inhalable particulate matter concentration of 65438±00ug/m3 will increase respiratory diseases by 3.4%, cardiovascular diseases by 65438 0.4%, and total daily mortality by 65438 0%. The source of toxic particulate matter in cities is mainly automobile exhaust particulate matter pollutants. The continuous smog has made many people form the habit of paying close attention to technical terms such as "air pollution index" and "inhalable particulate matter". Peng explained that different cities have different testing items to determine the air pollution index. In Beijing, it is mainly the content of sulfur dioxide, nitrogen oxides and inhalable particles in the air. The first two are gaseous pollutants, and the last one is the chief culprit that aggravates smog weather pollution. Coupled with fog, they make the sky dark in an instant. Zhao Yue, director of the Monitoring Center of Beijing Environmental Protection Bureau, once said that more than 95% or even a higher proportion of pollutants in Beijing are inhalable particles. The abbreviation of particulate matter is PM. At present, what Beijing is monitoring is PM 10, that is, pollutant particles with a diameter less than 10 micron. This particle itself is not only a pollutant, but also a carrier of toxic substances such as heavy metals and polycyclic aromatic hydrocarbons. Where do toxic particles in cities come from? Peng said that the first is automobile exhaust. Large vehicles that use diesel are "recidivists" who emit PM 10, including buses, shuttle buses of various units and large transport trucks. He stressed that although small cars that use gasoline will emit gaseous pollutants, such as nitrogen oxides, when they encounter foggy days, they can easily be converted into secondary particulate pollutants, which will aggravate the smog. Secondly, the waste gas produced by burning coal for heating in winter in the north. The third is the waste gas emitted by industrial production. For example, industrial kilns and boilers in metallurgy and electromechanical manufacturing industries, as well as a large amount of waste gas generated by the combustion of automobile repair and painting and building materials production kilns. The fourth is the dust generated by construction sites and road traffic. Why is foggy weather the most common in late autumn and early winter in the north? Peng pointed out that this has a lot to do with the low temperature and high humidity in this season, and it is easy to form foggy days. In the south, smog is easy to appear in wet seasons. In addition, big cities are more prone to smog. Taking Beijing as an example, less than 10% of the urban areas concentrate 90% of the city's population and motor vehicles, resulting in a high accumulation of pollutants. Coupled with the dustpan-like terrain surrounded by mountains on three sides, pollutants are not easy to spread, as is the case with the northern semi-basin structure of Taiyuan and Lanzhou. How serious is the air pollution in China? In recent days, online discussion about whether China can monitor PM2.5, that is, pollutant particles with a diameter less than 2.5 microns, has become the focus of discussion. In this regard, Peng said that air pollution control in China has made great progress than in the past. For example, in Beijing, gaseous pollutants such as sulfur dioxide and nitrogen oxides have been well controlled, but there is indeed a certain distance from developed countries in the formulation, control and management of PM2.5, a finer particulate matter standard. From the health point of view, PM2.5 is more harmful to human body than PM 10. The latter will only be inhaled into the lungs, and the former will be directly inhaled into the alveoli. Compared with foreign countries, which have a vast territory and a sparse population, widely use clean fuels and have a high level of pollution control technology, China's population and automobile use density are high, mainly coal, and pollution control technology needs to be improved, which determines that we still have a long way to go to meet foreign air quality standards.