Air pollution faced by modern people
With the development of cities and the accelerating pace of industrialization, urban air pollution has increasingly threatened the lives of urban residents. It has been proposed to reduce the damage to the body caused by the lack of window opening. But is the air in the house safe and healthy?
In fact, more and more indoor pollution is also threatening people's lives. So what are the threats to physical health in the invisible air outside and indoors?
Formaldehyde is a colorless, strongly irritating gas that is readily soluble in water, alcohols and ethers. Formaldehyde is gaseous at normal temperature. Formaldehyde is currently recognized as the first indoor killer in the world. Its harm is not temporary or one-time, and the potential danger is countless. In general, the release period of formaldehyde is 3-15 years, in addition to the damage to the healthy adult body, for newborn infants, pregnant and lactating women, growing adolescents, weak constitution, long-term illness The effects of the more, middle-aged and chronically ill patients are more serious.
Due to the continuous expansion of the urbanization process and insufficient supervision, the vast areas of China have become the ubiquitous formaldehyde in the hardest hit areas of formaldehyde. Where is it?
Formaldehyde is abundant in its production process due to its simple production process. Currently in China's fast-growing economic environment, it is widely used in various fields of products. Formaldehyde is used in synthetic resins, surfactants, plastics, rubber, leather, paper, dyes, pharmaceuticals, pesticides, building materials, and disinfection, fumigation, and antiseptic processes. It can be said that formaldehyde is a versatile chemical industry, containing formaldehyde. Therefore, there are a large number of items in daily office and home life, which are in keeping with people. To give a few simple examples, we can easily find the extensive use of formaldehyde.
1, in the production process of each mattress, formaldehyde is widely available in the form of fillers and adhesives:
At present, due to the limited detection capacity, a large amount of fabrics and sponges with excessive formaldehyde are used as a bedding material to fill the mattress, and the formaldehyde exceeds the standard.
It is widely believed that healthy or natural coir or mountain brown mattresses also contain a large amount of formaldehyde. In the process of making mattresses for bedding materials, in order to enhance the strength and hardness of the brown sheets and reduce the cost of raw materials, blindly added a large number of adhesives, causing serious excess of formaldehyde.
In a variety of spring beds, formaldehyde is also present in large quantities. According to the investigation, in the spring mattress products currently on the market, the pad filler is mainly made of urea resin and formaldehyde composite film, and the production standard is not strict and it is easy to cause formaldehyde pollution.
2, formaldehyde is widely used in daily clothing, textile production process, in the form of additives:
A large number of ironing-free shirts are convenient for people's life and work, but anti-wrinkle, anti-shrinkage and flame retardant additives are inseparable from formaldehyde;
Bright and non-fading clothing is not a reflection of high quality. Formaldehyde is a printing, dyeing and durable additive.
Soft clothing or comfortable fabric, formaldehyde is an additive to improve the feel and increase the stiffness of cotton textiles.
In the fabric we are in contact with, formaldehyde not only affects our health through the skin, but also releases free formaldehyde when it comes into contact with the skin. It is absorbed by the body through the respiratory tract and is highly carcinogenic.
3, formaldehyde in the form of adhesives in a variety of sheet furniture:
Formaldehyde, the biggest culprit of indoor carcinogens, is the main component of sheet adhesives. Man-made boards such as large core sheets and high-density boards are widely used, so that formaldehyde is everywhere. Even if the family chooses pure wood furniture, it is inevitably in the office. Other public environments are exposed to large amounts of formaldehyde pollution.
What is even more worrying is that most of the interior of the panel furniture (such as wardrobes, desks, etc.) on the market does not have a cover treatment. The sheet exposes a large amount of formaldehyde and directly contaminates the clothes placed in the clothes. In particular, some cotton pajamas, baby clothing and intimate clothing. The relevant test data shows that the formaldehyde content in the clothes containing the formaldehyde closet greatly exceeds the formaldehyde content of the furniture itself.
4, the floor is the largest indoor air pollution source
In the production process of the floor, in order to ensure the hardness and wear resistance of the floor, it is necessary to use a strong glue containing a large amount of formaldehyde;
In the winter, the indoor space of floor heating is used. When the floor is exposed to high temperature for a long time, the release of formaldehyde and other harmful substances will increase significantly, and the pollution time will be extended to 15-20 years. In addition, the winter indoors are closed and the air flow is poor, which is more harmful to the human body.
5, wallpaper, foam insulation materials, plastic sheets, decorative materials contain a lot of formaldehyde, benzene, etc.
Meteorologists and medical experts generally believe that the haze weather caused by fine particles is far more harmful to human health than sandstorms. Particles with a particle size of 10 microns or more will be blocked from the outside of the human nose; particles with a particle size between 2.5 microns and 10 microns will be less harmful to human health; and fine particles with a particle size below 2.5 microns, diameter Less than 1/20 of the size of human hair, when inhaled into the human body, it will directly enter the bronchi, interfere with the gas exchange in the lungs, and cause diseases including asthma, bronchitis and cardiovascular diseases.
Current research has confirmed that particulate matter will cause three major types of diseases:
1 infectious diseases: including influenza, tuberculosis and pneumonia;
2 Allergies: including asthma and alveolitis caused by natural allergens;
3 lung cancer, etc.
Most of the health effects are thought to be caused by the small particle size fraction of PM2.5 rather than the large particle size fraction. The degree of hazard depends mainly on its composition, concentration and particle size. If the concentration of PM2.5 in the air is higher than 10 μg/m3 for a long time, the risk of death will suddenly increase. For every 10 μg/m3 increase in concentration, the total risk of death increases by 4%, the risk of death from cardiopulmonary diseases increases by 6%, and the risk of death from lung cancer increases by 8% over the same period.
Third, volatile organic compounds (TVOC)
In addition to formaldehyde, another type of air quality that affects indoor air is: volatile organic compounds. It is also the most severe of the three major air pollution. The volatile organic compound means an organic substance having a saturated vapor pressure exceeding 133.32 Pa at room temperature, a boiling point of less than 250 ° C, and a compound which is present in the air at a normal temperature and can be evaporated. Most of these compounds have toxic, irritating, carcinogenic or human-like special odors that affect the skin and mucous membranes and cause damage to the human body.
Invade the immune system and nervous system
Indoors, the concentration of volatile organic compounds on the human body causes imbalances in the body's immune level, affecting central nervous system function, and symptoms such as dizziness, headache, lethargy, weakness, and chest tightness.
Destroy the digestive system and hematopoietic function
TVOC also affects the digestive system, causing loss of appetite and nausea. In severe cases, it can even damage the liver and hematopoietic system, and allergic reactions occur.
Genotoxicity and carcinogenicity, which seriously endanger children's health.
Some volatile organic compounds, such as benzene, vinyl chloride, trichloroethane, trichloroethylene, etc., are genotoxic and carcinogenic. Children are more vulnerable to indoor air pollution than adults. During the growth of children, the amount of breathing is 30% higher than that of adults, and children spend an average of more than 80% of indoor activities. Therefore, TVOC poses a greater threat to children's health.
difficult to govern
The release of VOCs from building materials and furniture increases as the temperature in the room increases, so concentrations of VOCs such as toluene are usually higher during the summer months. In addition, humidity also significantly affects the release rate of VOCs. When the indoor humidity is low, the amount of indoor VOCs released is high. Therefore, TVOC concentration has fluctuations and instability, and it is difficult to eradicate pollution by single detection and treatment, and long-term detection and timely pollution control are required.
In addition to aldehydes in TVOC, toluene, n-butyl acetate, styrene, n-undecane, p-xylene, o-xylene, ethylbenzene and the like are common. The main sources of indoor volatile organic compounds TVOC are:
Organic solvents such as paints, aqueous coatings, adhesives, cosmetics, detergents, quilting, etc.
Building materials such as wood-based panels, foam insulation, plastic sheets, etc.
Interior decoration materials, such as wallpapers, other decorations, etc.
Fiber materials such as carpets, tapestries, and chemical fiber curtains
Office supplies, such as inks, copiers, printers, etc.
Design and use of improper ventilation systems, etc.
Household fuel and cigarettes do not burn completely
Industrial waste gas, automobile exhaust, photochemical smog, etc. from outside