In p>2114, Xi 'an Indoor Environmental Monitoring Center conducted indoor air sampling inspection on more than 111 renovated houses in Xi 'an. The monitoring results were not optimistic. The monitoring results showed that the formaldehyde exceeded the standard rate by 74.1%, with an average exceeding multiple of 1.8 times and the highest exceeding multiple of 1.9 times. The over-standard rate of total volatile organic compounds was 72.3%, the average over-standard multiple was 1.4 times, and the highest over-standard was 58.7 times. The rate of ammonia exceeding the standard is 42.7%, the average multiple is 2.4 times, and the highest is 5.8 times. The rate of radioactive radon exceeding the standard is 14.2%, the average multiple of exceeding the standard is 1.48 times, and the highest exceeds the standard by 1.9 times. The rate of benzene exceeding the standard is 27.5%, with the average exceeding standard multiple of 1.2 times and the highest exceeding standard of 1.75 times. After removing abnormal points, the average exceeding standard multiple is 2.2 times and the highest exceeding standard is 8.2 times. The over-standard rate of toluene is 16.5%, the average over-standard multiple is 3.2 times, and the highest over-standard multiple is 17.3 times. After removing abnormal points, the average over-standard multiple is 1.3 times and the highest over-standard multiple is 17.3 times. The over-standard rate of xylene is 31.8%, the average over-standard multiple is 2.9 times, and the highest over-standard is 11.8 times. The above survey results show that the over-standard rate of environmental pollution in newly decorated rooms in Xi 'an is over 71%, in which formaldehyde and total volatile organic compounds almost universally exist in all over-standard rooms. It can be seen that indoor environmental pollution has developed into a common problem. Environmental awareness and pollution prevention measures for indoor decoration have become an urgent problem to be solved. In addition, from the situation that xylene exceeds benzene, it can be seen that the main pollutants of decoration materials containing benzene series have gradually changed from benzene to xylene.
In addition, In the process of monitoring, we also found that some cases exceeded the standard seriously. On April 3, 2114, Xi 'an Indoor Environmental Monitoring Center was entrusted by users to monitor the environment in a residential building on Fenghao East Road. The monitoring results showed that the benzene content in the residential building was as high as 19.36mg/m3 (indoor air quality standard GB/T 18883-2112 stipulated that indoor benzene should not exceed 1.11 mg/m3). The multiple of exceeding the standard is as high as 1.75 times. The benzene content is so high that it is the first case in home decoration in our city. According to the analysis, the main reason for this pollution is that the owner used improper waterproof materials indoors. Xi 'an Indoor Environmental Monitoring Center informed the owner in time through monitoring and modified the decoration scheme, thus avoiding the harm caused by indoor decoration pollution.
Second, the main types of indoor air pollutants in Xi 'an, Hazards and sources
The common pollutions after indoor decoration are: formaldehyde, ammonia, radon, total volatile organic gas (TVOC) and benzene.
1 Formaldehyde mainly comes from building materials, furniture, various adhesives, paints, synthetic fabrics such as (chemical fiber carpets, foam plastics), etc. In addition, incomplete combustion of fuel and tobacco leaves, cosmetics, detergents and pesticides, The use of preservatives may cause formaldehyde pollution. The harm of formaldehyde to human body is as follows:
The effects of low concentration formaldehyde on human body are mainly manifested in skin allergy, inhibition of sweat gland secretion, cough, excessive phlegm, insomnia, nausea, headache, etc.
High concentration formaldehyde is harmful to nervous system, immune system, Liver and others are toxic.
2 There are three main sources of ammonia in indoor air. One is concrete antifreeze in building construction, etc. This kind of additive containing a large amount of ammonia is reduced to ammonia gas in the wall with the changes of environmental factors such as temperature and humidity, and is slowly released from the wall. The concentration of ammonia in indoor air is greatly increased. Second, synthetic wooden boards used in furniture manufacturing use adhesives made of formaldehyde and urea during pressure molding, which release gaseous formaldehyde and ammonia at room temperature, causing ammonia pollution in indoor air. Third, additives and brighteners used in furniture finishing release gaseous ammonia at room temperature, resulting in excessive ammonia concentration in indoor air. Pollution of indoor environment.
3 Radon (Rn) gas is one of the main environmental carcinogens confirmed by the World Health Organization. It can be precipitated from the soil of houses and from building materials, especially from stones, tiles and gypsum.
Radon is the only natural radioactive inert gas produced by radium decay. Radon and its daughters form radioactive aerosol in the air at room temperature, which pollutes the air and is easily intercepted by the respiratory system. In addition, granite and marble used in house decoration also contain a certain amount of radon gas.
4 The total volatile organic gas refers to the boiling point <: Organic matter at 2611C is the most common pollutant discharged by petroleum, chemical, pharmaceutical, printing, building materials, spraying and other industries. The sources of indoor volatile organic gas pollutants are as follows: First, burning coal, natural gas, liquefied petroleum gas products, cooking oil fume and so on; The second is the smoke of smoking; Third, paint, wood-based panels, wallpaper, wood preservatives, carpets and other building decoration materials; Fourth, household appliances, daily chemicals (cleaning, disinfection, insecticidal), printers, desiccants, glue, fabrics, cosmetics and other daily necessities. The impact on human health is mainly to stimulate the eyes and respiratory tract, skin allergies, causing headaches, sore throat and fatigue.
5 Benzene exists in a large number of organic solvents in various building materials, and the glue, paint and coating used in decoration will cause indoor benzene pollution. Long-term inhalation of stupid things is harmful to hematopoietic tissue and nervous system (as people often say, diseases such as aplastic anemia).
In recent years, the indoor air pollution problem has become more and more prominent in China. Recently, it was learned from the hearing of the model text of Beijing Commercial Housing Pre-sale Contract that "if the important indicators such as air quality, energy saving and waterproof are not up to standard, buyers can choose to return the house." The official text is expected to be published in March this year.
Third, the main treatment methods of indoor air pollution
The removal methods of indoor air pollution can be divided into physical, chemical, biological and covering methods, and the specific methods are as follows:
(1) Physical methods: adsorption of activated carbon, silica gel and molecular sieve, ventilation and ventilation.
(2) Chemical methods: oxidation, reduction and neutralization. Bio-oxidation.
(4) Masking method: using fragrance to mask the odor.
Among the above treatment methods, the most common ones are activated carbon adsorption, photocatalysis and ozone sterilization.
In addition to the above treatment methods, there are some special indoor air treatment equipment on the market at present, and the main treatment principle is mostly activated carbon adsorption. Photocatalysis or ozone sterilization, etc. Take the comparative test of a certain brand of indoor air purifier done by Xi 'an Environmental Monitoring Station as an example. Under the condition of closing the doors and windows in the room of 15M2, the removal rate of various harmful substances by the purifier in 24 hours is: formaldehyde 71.1%, ammonia 75.1%, benzene 79.2%, toluene 66.3% and xylene 85.6%. This kind of equipment has a certain removal effect on indoor air pollutants. < P > Fourth, countermeasures for indoor air pollution prevention and control in decoration engineering < P > From the whole process of decoration engineering, only the whole process control of the project, that is, effective control from every link of design, material selection and construction, Only in this way can air pollution be truly and effectively reduced.
Environmental protection design is the premise to prevent decoration pollution.
The source of decoration pollution mainly depends on the content of harmful substances in decoration materials. Therefore, in indoor decoration, reasonable design should be carried out according to the frequency and use of the room, and the decoration should be as simple as possible, with less materials, The concept of "light decoration".
Keeping good materials is the key to prevent decoration pollution.
Choosing qualified decoration materials and building materials can minimize the amount of pollutants. The amount of indoor pollutants is related to the amount of decoration materials and the environmental protection degree of materials. Therefore, materials with low pollutant content and emission should be selected as much as possible when selecting materials. At present, most of the main decoration materials in China can provide pollutant content data of this material. Users can choose materials reasonably according to these data and their own economic ability.
Effective control of the construction process is a necessary measure to prevent decoration pollution.
Radon gas mainly comes from underground soil and rocks, and the cracks in the ground and wall should be closed as much as possible. Necessary sampling and re-inspection should be carried out for the holes in the pipeline. All the surfaces and edges of wood-based panels are edge-sealed, such as painting and coating, to fully cure them and form a stable layer to inhibit formaldehyde emission; Avoid using chemical poisons to pollute the environment during construction. For example, it is forbidden to use toluene, xylene, gasoline, etc. in large-scale oil painting and paint removal operations, and use mechanical polishing as much as possible.
It is an effective means to prevent decoration pollution by carrying out necessary environmental protection acceptance for houses after renovation.
For newly renovated houses, the environmental protection department should be entrusted to carry out indoor ambient air quality acceptance at the same time as engineering quality acceptance. Only in this way can we know the indoor air pollution in time, deal with the rooms that exceed the standard, and minimize the harm of decoration pollution.
Standardize the decoration and monitor the market to fundamentally eliminate indoor pollution
In addition to the owners' scientific and reasonable design and management of their own house decoration, the relevant departments are also very important for the management of the whole decoration market. At present, there are many decoration and decoration companies in Xi' an. There are countless decoration guerrillas. Many companies and guerrillas lack environmental awareness or know their harmfulness, but they are confused by the interests, ignoring the health of the owners, and some irregular monitoring units collude with the decoration party to issue untrue monitoring results to deceive the owners. These behaviors provide possibilities for various decoration pollution. Therefore, only by standardizing decoration and monitoring the market, In order to fundamentally prevent indoor environmental pollution, the decoration pollution monitoring report provided by the monitoring organization is the only basis for the owner to measure the maintenance pollution situation, so it is particularly urgent to manage the monitoring organization. At present, there are nearly 11 indoor monitoring organizations in Xi' an, which belong to the Environmental Protection Bureau, the Construction Committee and the health and epidemic prevention departments respectively. Due to the lack of unified management and norms and vicious competition in the field of indoor environmental monitoring, It has caused confusion in the indoor monitoring market. Due to the cross-management of various industries and departments, it is impossible to define the boundaries of power, which makes the indoor monitoring industry go out of its own way. It has led to a variety of monitoring standards and charging basis for monitoring projects, which has caused confusion in the indoor environmental monitoring market, thus affecting the normal work and limiting the development of the monitoring market. On the other hand, due to the existence of many monitoring units, Give many units or individuals who do not have monitoring qualifications an opportunity. These units compete maliciously and charge fees at will for the purpose of making profits. Due to the low quality of monitoring personnel, lack of systematic study and training, lack of corresponding professional knowledge and skills, and inability to operate in strict accordance with the norms, their monitoring data lacks accuracy and fairness, which has caused bad influence among the masses. These behaviors have greatly affected the work of formal departments. It affects the image of the environmental protection system among the masses. As we all know, environmental quality issues should be supervised and managed by the environmental protection department. It is also based on this understanding that the State Council decided to put the law enforcement and management of indoor environmental issues under the jurisdiction of the State Environmental Protection Administration. Indoor environmental monitoring, as an important work related to the health of the broad masses of people, needs to be audited by relevant departments. It is carried out by a formal unit with corresponding technical strength. The monitoring standards and charging basis implemented in the work should also be unified and consistent. The jurisdiction of this work should be clear. Of course, this work is a systematic project, and the fields involved are complicated. It is also necessary for all departments to cooperate and cooperate with each other. However, its final jurisdiction should be clear, and the right to handle and interpret problems should be implemented by a unified department. Only in this way can the market be regulated. Prevent vicious competition, do not give those illegal personnel an opportunity, and embody the concept of people-oriented, creating a harmonious society and a civilized society.
6. Strengthen environmental protection publicity to raise citizens' awareness of environmental protection
Environmental protection departments and other relevant units should increase relevant publicity to raise people's awareness of environmental protection. Make the majority of urban residents truly realize that indoor environmental problems are practical problems related to their own health, and make the people bring this awareness into their own lives, so as to improve the health quality of the whole people and embody the humanistic spirit.
Five, some suggestions on preventing and controlling environmental pollution in the city
It is very necessary to correctly understand indoor environmental pollution problems, improve indoor environmental awareness, and develop good health habits from daily life. It is suggested that the general public should:
1. Open windows for ventilation to keep the indoor air smooth and fresh.
2. Kitchen, bathroom and office should be equipped with air purification devices to strengthen effective ventilation.
3. Try to use household chemicals with high efficiency and low pollution.
4. Care for the social environment, pay attention to social morality, advocate smoke-free offices and conference rooms, and minimize indoor smoking opportunities. Pay attention to persisting in and increasing outdoor activities as much as possible, strengthen physical exercise and absorb fresh and clean air. Improve physical resistance.
References:
Qian Chen's toxic and harmful substances in the environment and international standardized general methods for monitoring, evaluation and control of workplace and indoor pollution. Xinxing Publishing House in 2114
Indoor air pollution and healthy chemical industry publishing house in 2113
Indoor environment and health of the Science and Technology Standards Department of the State Environmental Protection Administration. China Environmental Science Publishing House in 2112
Liu Zhuo's indoor pollution monitoring and control methods and standard specifications.