The main harm of formaldehyde is irritation to skin and mucosa. When indoor formaldehyde reaches a certain concentration, people will feel uncomfortable. More than 0.08 mg/m? The concentration of formaldehyde can cause envy, itchy eyes, sore throat, hoarseness, sneezing, chest tightness, asthma, dermatitis and so on. The high formaldehyde content in newly renovated rooms is the main cause of many diseases.
When its concentration reaches 0.08-0.09mg/m3 per cubic meter of air, children will have mild asthma. When the indoor air reaches 0. 1mg/m3, there will be odor and discomfort; When it reaches 0.5mg/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 30mg/m3, it will kill people immediately.
The hazards of long-term exposure to low-dose formaldehyde include: chronic respiratory diseases, nasopharyngeal carcinoma, colon cancer, brain tumor, menstrual disorder, nuclear gene mutation, DNA single-strand cross-linking and DNA-protein cross-linking, inhibition of DNA damage repair, pregnancy syndrome, neonatal chromosome abnormality, leukemia? , leading to the decline of teenagers' memory and intelligence.
Different signs and symptoms of formaldehyde poisoning:
Inhaling formaldehyde can irritate the nose, eyes and throat, causing headaches and skin damage. When formaldehyde is swallowed by mouth, it will cause burning sensation in stomach and esophagus.
Other common symptoms include chest tightness, nausea, skin, rash and asthma. In severe cases, the intake of formaldehyde can lead to coma and even death.
Carcinogenesis and cancer promotion:
Formaldehyde is a highly toxic substance, ranking second in the priority control list of toxic chemicals in China. It has been identified as carcinogenic and teratogenic substances by the World Health Organization. It is one of the recognized allergens and 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 poisoning on human health mainly include abnormal sense of smell, irritation, allergy, abnormal lung function, abnormal liver function and abnormal immune function.
Extended data:
Symptoms of formaldehyde poisoning:
Mild poisoning: obvious irritation to eyes and upper respiratory mucosa. The main manifestations are conjunctival congestion, redness, dyspnea, heavy breathing, hoarse throat, dry or dull speech or wet greasy. Poisoned people can still feel their breathing getting thicker. Another specific symptom of mild formaldehyde poisoning is one to two degrees of throat edema.
Moderate poisoning: persistent cough, expectoration, chest tightness, dyspnea and dry and wet gongs. During chest X-ray, the lung texture becomes substantial, becoming scattered spots or flaky shadows, which is medical machine-made bronchopneumonia. The edema of throat is aggravated to grade three. Blood gas analysis will be accompanied by mild and moderate hypoxemia.
Severe poisoning: the lung and larynx deteriorated, pulmonary edema and fourth degree laryngeal edema appeared, and the blood gas analysis was also serious, which was severe hypoxemia.
Prevention and control of formaldehyde;
1, ventilation mode
The ventilation mode does not need to be explained too much, that is, the harmful gas is discharged to the outside through the flow of air. This is a simple and effective method, but the disadvantage is that the formaldehyde release cycle is long, usually three to fifteen years. It is obviously unrealistic to leave the new house idle for more than three years after renovation. So simple ventilation can't meet the requirements.
2. Physical adsorption
In order to deeply explore the role of species on the surface of Corydalis and the interaction mechanism between adsorbents, the Institute of Process Engineering of China Academy of Sciences adopted chlorobenzene as a model to study its adsorption characteristics, and the interaction between chlorobenzene and surface species was clarified by means of TPD-MS, XPS, FTIR and Raman.
This research was supported by the National Natural Science Foundation (No.21129) and the National "863" Project (No.20 12AA06250 1), and the research results have been published in Chemistry.
3. Soak in water, vinegar and black tea to remove formaldehyde.
It is a fact that formaldehyde is easily soluble in water, alcohol and ether. Free formaldehyde in the air will dissolve into it when it meets water during movement, which is similar to the adsorption principle of activated carbon. one
4. Activated carbon adsorption
Teacher Li, who specializes in activated carbon in Nankai University, told the reporter that the initial use of activated carbon did have an effect, because the pores had adsorption potential, which was formed by the mutual attraction of carbon molecules and adsorbed molecules. The smaller the aperture, the stronger the adsorption potential. In addition, according to the theory of molecular motion, all objects are composed of molecules or atoms, and there are gaps between them, and at the same time they are in an endless state of random thermal motion, and molecules collide frequently. According to relevant data, in the standard state, the free movement speed of formaldehyde molecule is about 450m/s, and one formaldehyde molecule collides with other molecules 109 times per second. At this time, if the diameter of the collision molecule matches the pore of the activated carbon, it is adsorbed. Both traditional activated carbon and fried modified activated carbon have limited adsorption capacity because of too large pores.
5, photocatalyst to remove formaldehyde
Under the irradiation of light, photocatalyst will produce a photocatalytic reaction similar to photosynthesis, producing free hydroxyl and reactive oxygen species with oxidation ability. It has strong redox function, can oxidize and decompose various organic compounds and some inorganic substances, can destroy the cell membrane of bacteria and solidify the protein of viruses, can kill bacteria and decompose organic pollutants, and can decompose organic pollutants into pollution-free water (H? O), carbon dioxide (CO? ) and other harmless substances, so it has the functions of sterilization, deodorization, mildew prevention, antifouling and self-cleaning and air purification.
6. Fruits such as oranges and pineapples adsorb formaldehyde.
This is a method that many people like to use in the past, and it can be said to be a folk law. Many folk indigenous laws are the summary of long-term life experience and the truth that has been tested by time and practice.
7. Vinegar fumigation
Vinegar is an acidic substance, which can slightly neutralize ammonia in the air, but will not react with other harmful components such as formaldehyde.
8, negative ion purification method
According to research and application, it has a natural negative ion diffusion function, which can effectively absorb harmful gases such as indoor formaldehyde, purify indoor air, remove negative energy from other rocks and purify environmental energy.
The best way to improve the indoor environment is to increase the content of negative oxygen ions. Scientific experiments show that negative oxygen ions called "air vitamins" are beneficial to physical and mental health. Negative oxygen ions in the air can effectively decompose decoration pollutants such as formaldehyde and toluene, and the products are carbon dioxide and water, which is a good choice to solve decoration pollution. According to the efficacy of in addition to formaldehyde, the experiment of Chinese Academy of Sciences confirmed that the effective rate of in addition to formaldehyde, an artificially generated small particle negative ion, was over 73.33%, and it reached 99% after long-term use. When decorating a new house, negative ions can be used to remove indoor odor. ?
9. in addition to formaldehyde air purifier
The calculation of the purification efficiency of air purifiers is done in the laboratory, and it is measured under the condition of eliminating persistent pollution sources, which means that these data are obtained under certain conditions, so in actual use, the purification efficiency will be lower than that claimed by manufacturers. In essence, the air purifier only plays an auxiliary and remedial role. For example, in the case of indoor air pollution, the use of air purifiers can reduce the degree of pollution to a certain extent, but it does not mean that air pollution can be fundamentally eliminated.
10, chlorine dioxide
The World Health Organization (WHO) and the World Food Organization (FAO) also listed it as A 1 safe and efficient disinfectant. It has three effects (no carcinogenesis, teratogenicity and mutation), three effects (broad spectrum, high efficiency and rapidity) and peculiar functions of deodorization, preservation, algae removal and bleaching, and has been incorporated into health regulations.
It is difficult to remove the harmful gas after decoration by one method alone, so it is best to choose several methods according to the actual situation. Minimize indoor harmful gases. The above methods are remedial measures after renovation. In fact, the most effective way is to fully consider the harm of formaldehyde before decoration, and choose environmental protection materials as much as possible during the decoration process to plan ahead.
The chopping block will also release formaldehyde, which will seriously lead to gastric perforation. The doctor reminded that long-term consumption of foods containing formaldehyde can lead to loss of appetite, abdominal distension, and even gastric mucosal erosion and gastric perforation.
References:
Formaldehyde poisoning-Baidu Encyclopedia Formaldehyde-Baidu Encyclopedia