The impact of indoor environment on health is mainly divided into two types: one is called bad building syndrome, and the other is called building-related diseases. Bad building syndrome refers to the symptoms that will appear when living and working in buildings. The main symptoms are: inattention, depression, lethargy, fatigue, headache, anxiety, easy to catch a cold, chest tightness and so on. Once you leave this environment, the symptoms will naturally ease or disappear.
Building-related diseases (BRI) refer to diseases caused by poor indoor air quality due to improper building site selection, design and material selection, mainly including respiratory tract infection, cardiovascular diseases, legionnaires' disease and various cancers (such as lung cancer). Without an environment that causes construction-related diseases, symptoms may not disappear. Whether it is bad building syndrome or building-related diseases, we can reduce the occurrence of these symptoms by improving the living environment and indoor air quality.
There is a process for human beings to understand the harm of air pollution to health. The earliest air pollutants that people pay attention to are sulfur dioxide (SO2), nitrogen dioxide (NO2), carbon monoxide (CO), ozone (O3) and lead (Pb), which are collectively referred to as traditional air pollutants. Generally speaking, there are few analogies of traditional air pollution species; Except lead, it will not accumulate in the human body; Mainly causes respiratory diseases; In addition to nitrogen oxides, their effects on health are already clear; Generally speaking, the reaction will occur within a few minutes (acute) to several years (chronic) after ingestion. With the development of industry and the progress of human beings, more and more air pollutants have appeared, which are collectively called non-traditional air pollutants.
Generally speaking, there are many kinds of non-traditional air pollutants, all of which are bioaccumulative in the human body and can cause pathological changes in various organs of the human body (people are most concerned about cancer). At present, little is known about the health effects of non-traditional air pollutants. Indoor air pollutants mainly have the following forms: First, suspended particles. According to particle size, it can be divided into total suspended particles, suspended particles with particle size less than 10 micron (PM 10) and suspended particles with particle size less than 2.5 micron (PM2.5). Indoor combustion or other human activities during cooking and heating will obviously increase the indoor particle concentration. Many chemical pollutants, biological pollutants and radon decay daughters will attach to suspended particles and be inhaled into the body to cause harm. According to the research, the harm of PM 10 is greater than the total suspended particulate matter, and the harm of PM2.5 is greater than that of PM 10. Unfortunately, the research on PM2.5 is still not enough. The second largest indoor air pollutant is more and more chemicals. This includes most of the traditional air pollutants, non-traditional air pollutants and other human carcinogens mentioned above. The third kind of indoor pollution is radioactive pollution. Mainly radon and its short-lived decay daughters, ground G radiation rate and so on. The impact of radioactivity on health is mainly to increase the incidence of cancer. The fourth kind of indoor pollution is biological pollution. Mainly refers to the pollution caused by bacteria, viruses, molds, dust mites, pollen, spores, cockroaches, etc. At present, domestic attention to this aspect is not enough, but WHO has paid considerable attention to it and is drafting relevant proposals. Severe acute respiratory syndrome (SARS) is caused by biological pollution. In addition, the pollution caused by physical factors can not be ignored. Mainly manifested in light, noise, vibration, electromagnetic radiation belonging to non-ionizing radiation, ultrasonic waves, infrasound pollution and so on.
The construction site should be selected in a ventilated, sunny, dry and drainage-friendly place, far away from the main traffic lines, the foundation soil is not polluted, and the radionuclide content in the soil should be at a normal level. In architectural design, attention should be paid to hygiene requirements. Emphasize natural ventilation and reach 30 cubic meters of fresh air per person per hour. In the choice of building decoration materials, it is necessary to choose standards to avoid the release of harmful chemical solvents and adhesives indoors. Getting rid of bad living habits is also one of the important measures to maintain good indoor air quality, which deserves attention.
To ensure good indoor air quality, of course, corresponding measures should be taken according to the sources of pollutants. Among all the measures, strengthening indoor ventilation and maintaining a certain fresh air volume are the most important measures. China's Indoor Air Quality Standard was issued on June 1 65438+1October 19, 2002 and implemented on March12003. This is the basis of indoor air quality evaluation in China. In China's standards, only the standard value of 19 pollutant is given, which is of course far from enough. Various pollutants, especially chemical pollutants, should be given different standard values according to the exposure time. I believe these problems will be noticed in the next revision.
Urban air pollution depends on two factors: pollutant emission and atmospheric diffusion capacity. When the pollution source is relatively stable, the diffusion, migration, flow and transformation of pollutants in the atmosphere are closely related to the meteorological conditions at that time, and meteorological factors such as wind direction, wind speed, inversion stratification and precipitation play an important role in the diffusion of pollutants. For example, when there is precipitation or wind, it is often conducive to the diffusion of pollutants in the air; On the contrary, it is easy to aggravate air pollution when there is fog or the wind is very small. Therefore, air quality forecasting enables us to monitor air pollution in real time, predict the future air quality according to the changes of future meteorological conditions, and consciously reduce or reduce pollutant emissions, so as to achieve the goal of passive defense to active prevention.