Appreciation of calligraphy works about the environment
Pictures of calligraphy works about the environment 1
Pictures of calligraphy works about the environment 2
Pictures of calligraphy works about the environment 3
Pictures of calligraphy works about the environment 4
Small knowledge of indoor environment after the holiday
First, the most common indoor pollution
China's first indoor air quality standard was formally implemented on March 1 last year. Experts divide indoor environmental pollution into three categories according to the nature of pollutants.
The first category-chemical pollution: mainly from decoration, furniture, toys, gas water heaters, pesticide spray, cosmetics, smoking, kitchen fumes, etc.
The second category-physical contamination: noise, light and radioactive pollution of outdoor and indoor electrical equipment;
The third category-biological pollution: mainly comes from indoor decoration materials, daily necessities, mites and other bacteria parasitic on air conditioners.
The interaction of these harmful substances will aggravate the harm of indoor pollution to human health. For example, chemical pollution in indoor air will irritate and inflame human skin, mucosa and conjunctiva, even paralyze respiratory cilia and damage mucosal epithelial tissue. In this case, the human body's resistance to diseases will be greatly weakened, making it easy for pathogenic microorganisms to invade and endangering people's health. Therefore, people should pay attention to indoor environmental pollution, especially new houses and newly renovated families.
2. What is formaldehyde and where does it come from in the indoor environment?
Formaldehyde is a colorless and irritating water-soluble gas. It has the function of curing protein, and its 35%~40% aqueous solution is commonly known as formalin, which is often used as the solution for impregnating specimens. Formaldehyde is a highly toxic substance, ranking second in the priority control list of toxic chemicals in China.
Formaldehyde in indoor environment can be roughly divided into two categories according to sources:
Outdoor air pollution:
Industrial waste gas, automobile exhaust and photochemical smog can all emit or produce a certain amount of formaldehyde to a certain extent, but the content of this part is very small. According to related reports, the average annual concentration of formaldehyde in urban air is about 0.005~0.0 1mg/m3, generally not exceeding 0.03mg/m3. This part of the gas can enter the room at some time and is the indoor formaldehyde pollution source.
Pollution from indoors:
Mainly based on the indoor use of chemical products such as building materials, decoration items and daily necessities, but it also includes some secondary factors such as fuel and tobacco leaves that are not completely burned.
Formaldehyde has a strong adhesion, and at the same time, it can strengthen the hardness, insect resistance and corrosion resistance of the board. Therefore, all kinds of particleboard, medium density fiberboard and plywood on the market use urea-formaldehyde resin as adhesive, which inevitably contains formaldehyde. In addition, new furniture, walls, floor decoration auxiliary materials should use adhesives, so wherever adhesives are used, formaldehyde gas will always be released, which will cause harm to the indoor environment. Urea-formaldehyde foam resin insulation material made of urea-formaldehyde resin has good insulation effect, so it is often made into building envelope structure, so that the indoor temperature is not affected by outdoor. In addition, formaldehyde can also come from cosmetics, detergents, pesticides, disinfectants, preservatives, ink, paper and so on.
So generally speaking, the sources of formaldehyde in indoor environment are still very extensive. Generally, the formaldehyde content of newly renovated houses can reach 0.40mg/m3, and some may reach 1.50mg/m3. The research shows that the content of formaldehyde in indoor environment is closely related to the use time, temperature, humidity and ventilation of the house. Generally speaking, the longer the house is used, the less formaldehyde remains in the indoor environment; The higher the temperature, the greater the humidity, which is more conducive to the release of formaldehyde; The better the ventilation condition, the faster the formaldehyde in building and decoration materials will be released, which is more conducive to the cleaning of indoor environment.
3, the way of formaldehyde release
Wood itself releases very little formaldehyde under the action of temperature and humidity.
In the process of manufacturing urea-formaldehyde resin, some free formaldehyde will inevitably be released.
During the curing process of wood-based panel, part of linear resin did not form a network structure, and it was decomposed into free formaldehyde and distributed to the outside world.
The partially cured resin decomposes under the action of heat and moisture, forming free formaldehyde and releasing it.
The measured data show that the formaldehyde concentration can be lower than 0. 1 mg/m3 after 5 months of indoor decoration under normal decoration. After 7 months of transformation, it can be reduced to below 0.08 mg/m3. Japanese research shows that the release cycle of indoor formaldehyde is generally 3 to 15 years.
Third, the harm of formaldehyde pollution to human health
Formaldehyde has been identified as a carcinogen and teratogenic substance by the World Health Organization. It is considered as an allergen and one of the potential strong mutagens.
Studies have shown that formaldehyde has a strong carcinogenic and cancer-promoting effect. According to a large number of documents, the effects of formaldehyde on human health are mainly manifested in abnormal smell, irritation, allergy, abnormal lung function, abnormal liver function and abnormal immune function. When its concentration reaches 0.06 -0.07 mg/m3 per m3 of air, children will have mild asthma. When the formaldehyde content in indoor air is 0. 1 mg/m3, there will be odor and discomfort; When it reaches 0.5 mg/m3, it can irritate eyes and cause tears; Up to 0.6 mg/m3, which may cause throat discomfort or pain. When the concentration is high, it can cause nausea and vomiting, cough and chest tightness, asthma and even pulmonary edema; When it reaches 30 mg/m3, it will immediately lead to death.
Long-term exposure to low-dose formaldehyde can cause chronic respiratory diseases, nasopharyngeal carcinoma, colon cancer, brain tumor, menstrual disorder, gene mutation in the nucleus, DNA single-strand cross-linking and DNA-protein cross-linking, inhibition of DNA damage repair, pregnancy syndrome, chromosomal abnormalities in newborns, leukemia, and memory and intelligence decline in adolescents. Among all the contacts, children and pregnant women are particularly sensitive to formaldehyde, which is more harmful.
The working group of the World Health Organization (WHO) has defined the potential carcinogenic threshold of formaldehyde to odor, eye irritation and respiratory irritation, and pointed out that when the formaldehyde concentration in indoor environment exceeds 10%, it should be paid enough attention.
Places with serious formaldehyde pollution hazards
Newly renovated rooms, offices, conference rooms, hotels, KTV rooms, furniture stores, building materials stores, etc.
Formaldehyde pollution in indoor air
People have to decorate their new homes and offices and buy furniture. Because a large number of man-made boards (such as plywood, core board, density board, particleboard, laminate flooring and composite wood flooring, etc. ) is used in decoration and furniture manufacturing, and adhesives made of highly toxic formaldehyde are widely used in wood-based panel production. Because the release period of formaldehyde in adhesives is long, generally as long as 15 years, formaldehyde has become the main pollutant in indoor air.
In August of 20001year, China Consumers Association announced an amazing survey result. After sampling indoor air in Beijing and Hangzhou, it was found that the formaldehyde concentration exceeded the standard by 73.3% and 79. 1% respectively, and the highest exceeded the standard by more than 40 times.
Last year, the testing department tested the air quality of nine furniture cities in Beijing, and found that the average test result of formaldehyde was 3.3 times of the hygienic standard of public places. The maximum value is 15.8 times of the hygienic standard of public places, and the over-standard rate of samples is 98% respectively.
In July, 20001year, the Health Department of Hefei reported the results of air monitoring in offices and rooms of five monitoring points in the whole city1year: all formaldehyde exceeded the standard, up to 85 times. Indoor air pollution is frightening. It has been 15 months since office decoration, the branch of Hefei Industrial and Commercial Bank of China, but the two offices have been filled with "bad smell", and a large number of dead insects are often found. Employees have repeatedly reported symptoms such as tears, sore throat, chest tightness and headache. The monitoring results showed that formaldehyde in one office exceeded the standard by 45 times, while that in another office exceeded the standard by 29 times.
According to a staff member surnamed Qian of Nanjing Indoor Environment Monitoring Center, nearly 30 newly renovated houses of Nanjing residents have been monitored at the request of the citizens since the center was established two months ago, and almost none of them can fully meet the "China Hygiene Standard Indoor Environment Standard". The main problem is that formaldehyde exceeds the standard, up to 40 times.
Sichuan Institute of Occupational Disease Prevention and Control has learned that recently, more than 500 renovated rooms, offices and office buildings in/kloc-0 were tested, and it was found that indoor air pollution greatly exceeded the national hygiene standards. More than 95% of indoor formaldehyde exceeds the hygienic standard, exceeding the standard by more than 60 times; The formaldehyde content in the indoor air of some government agencies exceeds the standard by several times to dozens of times.
In view of the formaldehyde pollution of furniture, the State Bureau of Quality and Technical Supervision randomly selected 87 kinds of furniture products distributed by 30 commercial enterprises in Beijing, Shanghai and Guangzhou, and the unqualified rate of the products was 64.4%.
How serious is the decoration pollution-350 people die every year in Beijing.
There are more than 400 acute poisoning incidents caused by toxic building decoration materials in Beijing every year, with 65,438+10,000 people poisoned and 350 people killed. This is the information obtained by the author from Beijing Chemical Toxicity Identification Center.
According to the survey, 2.8 million people in the world die directly or indirectly from decoration pollution every year, and decoration pollution has been listed as one of the five biggest environmental problems that harm the public. According to the information provided by Chinese Academy of Preventive Medicine, people spend 66% of their time at home on average, so bad indoor air environment will cause the most direct harm to people's health. According to the statistics of Indoor Pollution Detection and Observation Center of China Interior Decoration Association, toxic materials account for 68% of many decorative materials, which will produce more than 300 kinds of volatile organic compounds (VOC) and cause more than 30 diseases. Among them, the elderly and children are the most vulnerable because they spend the longest time indoors, especially children like to sit on the floor.