Twelve aerosol pollutants around us

Twelve aerosol pollutants around us

From surveys around the world, the number one pollutant in indoor air is aerosol pollutants. Aerosol pollution has caused widespread concern among relevant professionals.

The definition of aerosol in physics and chemistry is: any colloidal substance whose dispersion medium is gas. In order to facilitate the distinction, sometimes the solid particles are called smoke or dust, or dust or dust, the liquid particles are called fog or mist, and sometimes the aerosol mixed with solid and liquid particles is called smoke. No matter what the name is, the air in our daily life is full of particles in aerosol state, and we are living in aerosol.

Since March 11, 2011, nuclear leakage accidents have occurred one after another at Japanese nuclear power plants. After a nuclear leak occurs, radioactive materials are mainly polluted by aerosols, that is, suspended particulate matter in the atmosphere. They will also be concentrated in the clouds, and then enter the ground through rain to pollute.

In fact, in addition to the aerosol hazards that may be caused by extraordinary events such as nuclear leaks, indoor and outdoor aerosols are always eroding people's bodies and endangering people's health.

There are many types of aerosols in the air, including dust, smog, smoking smoke, kitchen oil fume, lead dust, radon dust, microbial aerosols, pollen, sand (coal) dust storms, aerosols and environmental hormones. These pollutants have a serious impact on human health in local areas or in some specific environments, and sometimes form a synergistic effect of multiple aerosol pollutants. Our common aerosol pollutants in the air mainly include:

1. Dust

We live in a city, and we have the feeling that as long as the room is not cleaned for a day, it will be dusty. This is dust that is visible to the naked eye. In fact, there are a lot of dust particles in the air that are invisible to the naked eye. We call it aerosol. The particles in aerosols with a diameter of 0.5-10 microns are called inhalable particulate matter. This kind of particulate matter can be suspended in the air for a long time and is easily inhaled by the human body. After being inhaled into the human body, about 50% of it is adsorbed on the lung wall and can penetrate deep into the lung tissue, causing bronchitis and pneumonia. , Asthma, emphysema, and lung cancer, leading to decreased cardiopulmonary function and even failure.

Indoor dust particles mainly come from the intrusion of atmospheric dust particles, the carrying of people's clothing, and the dander of people and pets. A large amount of dust accumulates in the air conditioning system. If it is not cleaned in time, it will become a source of indoor dust particles.

Dust particles are carriers of bacteria, various chemical pollutants, including radioactive substances. For example, some people have detected more than 300 kinds of adsorbed organic substances from inhalable particles, and many of them have strong carcinogenic, teratogenic, and mutagenic polycyclic aromatic hydrocarbons. With oxygen-containing heterocyclic compounds. Inhalable particulate matter is often mixed with metals, metal compounds and radioactive materials, such as lead dust, mercury dust, radon dust, etc. After these substances invade the lung tissues, they can cause various diseases such as metal poisoning or radioactive contamination. Inhalable particulate matter may also adsorb acidic oxides in the air, forming acid mist under the action of water. After this aerosol is inhaled into the lungs, its toxicity doubles, causing pulmonary edema, pulmonary sclerosis, and even death.

We must develop the habit of frequent cleaning, and clean windows and spotlessness must be our motto. Most of the dust on the surface of the object settled down from the air. If it is not cleaned in time, the external force will return to the air. More suspended particles in the air that are invisible to the naked eye can only be removed by air purifiers. Air purifiers in developed countries are very popular, and more than 95% of them are used to remove dust particles in the room.

2. Haze

From "Oliver Twist" (English: Oliver Twist) written by British writer Dickens, we know that there is a foggy London in the world. In many cases, Chongqing, the foggy city of our country, is also famous in the world. The fog has always been a kind of poetry and picturesque in people's memory. For a long time, people still choose morning fog for exercise. Since the fog and haze are linked together, it has formed a kind of air killer.

Haze is a typical aerosol pollutant. The fine powdery aerosols in the haze carry dust, sulfuric acid, nitric acid, hydrocarbons and bacteria and other pollutants that can directly enter the bronchi and even the lungs through the respiratory system. Therefore, the biggest impact of haze is the human respiratory system, and the diseases caused are mainly concentrated in respiratory diseases, cerebrovascular diseases, nasal inflammation and other diseases. At the same time, in the haze weather, the air pressure decreases, the inhalable particles in the air increase sharply, and the air fluidity is poor. The spread of harmful bacteria and viruses to the surrounding area slows down, resulting in an increase in the concentration of pathogenic microorganisms in the air, and the risk of disease transmission is high.

In December 1952, the heavy fog in London, England lasted for four days. A high-risk pollution layer was formed at a low altitude of 100 meters. The concentration of sulfur dioxide in the air was 7 times that of normal, and the concentration of particulate pollutants was 9 times that of normal. The whole city was filled with intense intensity. The smell of "rotten eggs" claimed the lives of 4,700 people within a few days.

  This is a well-known London smog incident recorded in the history of the world's environmental protection, which has made the world alert to the smog. It is said that the smog in London no longer exists, and the range and frequency of my country's smog climate is still increasing year by year. We don't need to go to Chongqing to experience the smog now. We travel north to Jinan, Beijing, Harbin, and east to Nanjing and Shanghai. The seasonal smog is shrouded in haze, and sometimes we can stay away from the sun for several days. Some people in China claim that the harmful substances in the haze are more toxic than the smoke produced by smoking. This is not alarmist.

Environmental protection departments in some parts of our country have already listed the haze climate as the content of weather forecasts. When the smog comes, we remind users, especially in the rooms where vulnerable people such as the old, the weak, sick, etc. live, they should close the doors and windows and turn on the air purifier to minimize the impact of the smog on the room.

3. Smoking smoke

Smoking is another important source of indoor aerosol pollution. Smoking mainly produces fine particles below 1 μm. The world's authoritative magazine "British Medicine" reported that as far as China's current smoking situation is concerned, one-third of all deaths will be caused by smoking-related diseases in the future, and the number of deaths due to smoking will reach 2 to 3 million each year. So huge, smoking has become the number one killer of human health.

Cigarette smoke contains more than 3,000 chemical components. Among them, benzopyrene and nitrosamines contained in cigarette tar are strong carcinogens in the form of aerosols. According to clinical observations and experimental results, in addition to lung cancer, smoking can also induce oral cancer, pancreatic cancer, gastric cancer, cervical cancer and bladder cancer. Smoking and lung cancer deaths account for 95% of lung cancer deaths, 25% of cardiovascular and cerebrovascular diseases, and 75% of chronic respiratory diseases.

Studies have shown that the amount of toxic substances inhaled by passive smoking is several to tens of times more than that of mainstream smokers. The toxic substances in second-hand smoke can invade the lungs and vital organs of the body, damage the inner wall cells of the arteries, promote atherosclerosis, and can cause lung cancer, brain cancer, thyroid cancer, stomach cancer, breast cancer, and cervical cancer. Frequent exposure to secondhand smoke increases the risk of cancer by 2.8 times, and the risk of dying from heart disease is as high as 170% compared to those who stay away from smokers. In view of the dangers of passive smoking, the World Health Organization passed a resolution to propose: non-smokers have the right to maintain their health against passive, forced or involuntary smoking, and the health of non-smokers should be protected from this The harm caused by similar environmental pollution.

Therefore, in order to protect the health of non-smokers and to restrict or prohibit smoking indoors, my country and many countries have formulated laws or regulations prohibiting smoking in public places, public transportation and workplaces. Our country's anti-smoking and tobacco control work is not going well. The degree of disregard for smoking and passive smoking largely depends on people's insufficient understanding of the seriousness of aerosol pollution caused by smoking. Therefore, it is necessary to vigorously promote the importance of controlling aerosol pollution caused by smoking, sand (coal) dust storms, smog, and nuclear leakage, and recommend high-quality air purifiers and other products to the public to prevent the health effects of aerosols.

4. Kitchen fume

The fumes from the kitchens of hotels, restaurants, restaurants, canteens and families have a great impact on the environment and the human body. The Hong Kong Environmental Agency has detected the same pollutants as kitchen oil fume in the atmosphere, and believes that kitchen oil fume is the most important air pollutant after urban car exhaust. Kitchen fumes have become a public hazard.

The composition of kitchen oil fume is complex, among which a large number of organic substances such as acrolein, 3,4-benzopyrene and cycloaromatic hydrocarbons exist in aerosol state, which directly cause mutagenic, teratogenic, and carcinogenic effects on the kitchen personnel. The survey confirmed that the incidence of lung cancer among cooks is higher than that of other general occupations. It has been reported that there is a significant correlation between kitchen oil fume and the incidence of lung cancer in women. According to statistics, among the risk factors for lung cancer among non-smoking women, more than 60% of women have long-term exposure to kitchen fumes. Worldwide, the majority of lung cancer patients among Asian women are related to long-term exposure to kitchen fumes.

At present, most of the range hoods sold on the market are made with the principle of cyclone inertia. The purification efficiency of the aerosol state of the range hood is not high. Some people call it "only drain but not shed", and the pollution to the environment still exists. When the user chooses to buy a range hood, he should choose a larger power, deep cover, and it is required to completely remove the lampblack and exhaust gas generated during cooking. If possible, an air purifier that efficiently removes oily fume should be added to the kitchen. The processing air volume of the air purifier should be 40 times the volume of the kitchen space.

When cooking, some users try to use low-temperature oil for cooking, and the oil temperature does not exceed 200°C, which is very scientific.

5. Lead dust

Lead is a heavy metal element with neurotoxicity. The human body has almost no ability to discharge lead poison, and more than 60% of the lead dust inhaled into the human body will remain in the body permanently. Lead prevents the production of hemoglobin in the human body through a variety of ways. The blood lead level of the human body is directly related to the exposure to the air environment with lead dust. The ideal blood lead content in the human body should be zero.
Urban air contains a lot of heavy metal pollutants. The harm caused by lead and its compounds to people, especially children, has attracted widespread attention. The irreversibility of lead as a central nervous system toxicant to children's psychological, intellectual, and behavioral developmental damage makes the prevention and research of lead injury an important topic in pediatrics and children's health care.
Lead and its compounds exist in the air as aerosols, often mixed with dust particles, and are called lead dust. Lead dust can be seen everywhere, heavier than air, and the concentration of lead dust in the air below 1 meter above the ground is higher. The place 75～100cm from the ground is just the child’s breathing zone. In addition, children have a large demand for oxygen. The absorption rate of lead in the respiratory tract of children is higher than that of adults, 1.6-2.7 times that of adults. Therefore, children inhale from the respiratory tract. There is more lead than adults.
Unqualified leaded gasoline used in motor vehicles, industrial exhaust gas, and weathering of leaded paint are the main reasons why the lead dust content in the air exceeds the standard. In recent years, the use of unleaded gasoline has been promoted internationally, and the total amount of lead dust emissions in industrial exhaust gas in large cities has been strictly controlled, and the concentration of new lead dust may be greatly reduced. However, a large amount of lead accumulates in the natural environment all year round, and the soil becomes the largest storage reservoir of lead in nature. Lead element has actually become one of the chemical components of the earth's crust. The lead in soil and dust has an accumulating effect on environmental hazards, and the impact is relatively long-term. It will fly up again under natural or man-made conditions and re-disperse in the air.
Some shocking reports are disturbing. The lead dust concentration in the air in some industrial cities and the investigation report of the blood lead concentration of children indicate that the pollution of lead dust has reached a point that cannot be ignored.
Once upon a time, from milk to eggs, from aquaculture to feed processing, the ubiquitous melamine seemed to make people talk about it. Nowadays, major blood lead pollution incidents in children have come and gone: Fengxiang in Shaanxi, Wugang in Hunan, Dongchuan in Kunming, Jiyuan in Henan, Huixian in Gansu, Pizhou in Jiangsu, and Longyan in Fujian.

The mothers had just been liberated from the shadow of melamine and were shrouded in dark clouds of blood lead contamination. Everyone is at risk, is there any lead on our children's heads?

In the past, melamine has infringed on the health of many children, but now the blood lead pollution is infringing on the health of many children. Lead is more poisonous than tigers and even more toxic than melamine.

The melamine pollution storm was quickly subsided. People can prevent melamine from being harmed by rejecting melamine-containing milk powder or even not eating milk powder. But we cannot choose to breathe. How can we keep our children away from lead poisoning? Some people were forced to leave their homes to avoid the lead dust plague.

Now we know that although blood lead and melamine are both preventable and curable. However, the intellectual impairment of children caused by lead poisoning is irreversible.

Indoor lead dust is one of the important sources of lead exposure of children. The content of indoor lead dust has a very obvious correlation with the blood lead level of children. Controlling indoor lead dust can effectively reduce the lead level of children.
People of insight exclaimed: Preventing lead poisoning in children is a test of society, parents and people's livelihood.

6. Nuclide aerosol

If SARS in 2003 increased people's awareness of preventing airborne microorganisms, and the pollution caused by home decoration increased people's awareness of preventing formaldehyde pollution, then the Japanese nuclear leak increased people's awareness of preventing aerosol pollution.

In terms of the hazards of nuclear radiation to human health, inhaling polluted air and ingesting polluted food, water and milk are the most important radiation pathways. Because the main ways that cause internal radiation alpha particles to enter the body are breathing and food. What needs to be emphasized is that aerosols with nuclides cross the ocean and pollute water and soil through rain. The prevention of air, food, drinking water, and especially air should be the focus.

On the other hand, the impact of radiation also depends on the half-life of nuclear material, and in the final analysis is also the long-term radiation effect of nuclear material. Although according to the Japanese government, the currently monitored nuclear radiation pollution is not large, but the long-term effects of small doses of nuclear radiation on human health damage cannot be ignored. Moreover, the impact of nuclear radiation on human health has not been studied in depth, and some results can only be speculated at present, so we need to take precautions from the worst.

Radioactive aerosols are no different from other aerosols in terms of particle diameter. The best way to use indoor aerosols is to use an air purifier. Air purifiers using high-efficiency filtration and electrostatic dust removal technology can remove aerosols. Nuclear-grade activated carbon fibers used in nuclear power plants in my country can effectively remove radioactive substances such as iodine 131. It is necessary to point out that to remove aerosols, indoor air quality should reach a certain standard, which is 20 μg/m3. Indoor air at such aerosol concentration is safe.

7, radon dust

We already knew about radon before we knew about radioactive substances such as iodine and cesium.

Radon (Re) is the only natural radioactive noble gas in nature, which is formed by the decay of radium. Radon exists in the air as an aerosol and is often mixed with dust particles to form radon daughters, or radon dust. This kind of radon dust in aerosol state is easily inhaled into the human body and trapped in the respiratory system. Radon will accumulate locally in the respiratory system and induce lung cancer. The incubation period of lung cancer is more than 15 years. 20% of lung cancer patients in the world are related to radon dust pollution. Some people regard radon dust and smoking as the two major killers of lung cancer. The World Health Organization lists radon dust as one of 19 carcinogens.
Radon is widely distributed in nature and may exist around you. Almost 20% of the residents in the U.S. live