The role of PM2.5 monitoring in environmental protection
What is the harm of PM2.5?
According to the World Health Organization, PM2.5 has a huge impact on human health.When the average annual PM2.5 concentration reaches 35 micrograms per cubic meter. The risk of death increases by about 15 percent compared with 10 micrograms per cubic meter. So it is vital to use a PM2.5 monitoring system.
1) The impact of PM2.5 on respiratory health.When PM2.5 enters the lungs, it can block local tissues, reduce the ventilation function of local bronchi, and lose the ventilation function of bronchioles and alveoli. PM2.5, which absorbs harmful gases, can stimulate or erode the alveolar wall, and the long-term effect can damage the respiratory defense function. Resulting in bronchitis, emphysema and bronchial asthma.PM2.5 can also directly or indirectly activate the oxidative stress system in lung macrophages and epithelial cells, stimulate the secretion of inflammatory factors, neutrophil and lymphocyte infiltration, and cause lipid peroxidation in animal lung tissues.A large number of epidemiological studies have found that both short-term and long-term exposure to high concentrations of particulate matter can increase the incidence and mortality of respiratory diseases in the population.
2) The impact of PM2.5 on cardiovascular health.At present, studies on the effects of PM2.5 on the cardiovascular system are in-depth and comprehensive.After entering the human body, PM2.5 induces systemic inflammatory response and oxidative stress, leading to vasoconstriction, dysfunction of vascular endothelial cell function, and release of a large number of reactive oxygen species into the blood, thus promoting coagulation function, resulting in thrombosis, elevated blood pressure and formation of atherosclerotic plaques.
On the other hand, PM2.5 can also stimulate the sympathetic and parasympathetic nerve centers through the autonomic reflex arc of the lungs, affecting the blood system and vascular system at the same time, but also the autonomic nervous system of the heart, resulting in reduced heart rate variability, increased heart rate and arrhythmia.A large number of epidemiological studies have shown that short-term exposure to high concentrations of PM2.5 (even hours of exposure) can significantly increase the daily attendance rate and mortality rate of cardiovascular events (such as coronary heart disease, myocardial infarction, heart failure, arrhythmia, stroke, etc.) in the population.
3) Carcinogenic effects of PM2.5.Several components in PM2.5 are carcinogenic or cancer-promoting, such as polycyclic aromatic hydrocarbons, heavy metals such as cadmium, chromium and nickel.It was found that both organic and inorganic extracts of PM2.5 had mutagenic and genotoxic properties.
4) The influence of PM2.5 on other systems of the body.After entering the mother, PM2.5 can cause systemic oxidative stress, inflammation, changes in hemorheology and dynamics, causing harm to the fetus and a series of adverse reproductive problems.
Chinese Academy of Engineering academician zhong nanshan pointed out: "to the tracheal bronchus 5 or more words, but the following 5, especially in 1-3 micron, will be entered into the alveolar, alveolar is used for gas exchange, those particles engulfed by macrophages, will never stay in the alveoli, makes an impact on cardiovascular system, nervous system, not simply to respiratory system."
The characteristics of PM2.5 monitoring system
(1) Replaceable particle cutter, PM10, PM5, PM2. 5, PM1.0 and TSP particle separation cutter compatible, through the metrological certification.
(2) Online filter film sampler, which realizes the compatibility of continuous monitoring of dust concentration and filter film sampling, can analyze the components of collected particles and calculate the value of mass concentration conversion coefficient K of the site.
(3) Using laser light source, the mass concentration conversion coefficient is not affected by the color of particles.
(4) Directly measure the mass concentration value (mg/m3) in accordance with the MINISTRY of Health WS/T206-2001 standard.
(5) Using large screen LCD Chinese characters display, Chinese characters menu prompt.
(6) Equipped with optical standard scattered plate, to ensure high stability of the instrument.
(7) With special protective air curtain, to avoid dust pollution to the core components of the instrument - optical system, to ensure the high reliability of the instrument.
(8) The alarm threshold value of dust concentration exceeds the standard can be set. When dust exceeds the standard, the buzzer will automatically alarm.
Therefore, PM2.5 detector has an important impact on monitoring the environment