Original title: what is the harm of formaldehyde? What is the relationship with leukemia? Authoritative interpretation
Recently, a media article titled "Ali P7 Employee Leukemia Death, Rented Free Formaldehyde Room" said that Ali Employee Wang lived in a comfortable room in Hangzhou in January this year, only six months later, suffered from acute myeloid leukemia. For a while, the topic of formaldehyde will trigger leukaemia quickly. After all, in life, moving a new home, changing office decoration is everybody will encounter the problem, and decoration caused by formaldehyde pollution everybody more or less heard of, but formaldehyde harm exactly how much, and leukemia between what kind of relationship, it is not ordinary people can say clearly.
Indoor formaldehyde comes mostly from new furniture and flooring.
To talk about the relationship between formaldehyde and leukemia, first of all, we need to figure out what formaldehyde is. Formaldehyde is the lowest molecular weight aldehyde. It has a colorless and irritating odor in the gas state. It is a commonly used chemical raw material. It is mainly used in the production of industrial resins, such as particleboard and coatings, and often appears in building materials. The material is in the material.
"People are most concerned about home or office decoration, formaldehyde is the main source of adhesive, such as wood flooring in the use of adhesive. Again, after decoration, will generally buy new furniture, these newly bought furniture also exist in the problem of adhesive. Hao Fengtong said.
In fact, formaldehyde exists widely in nature, in the air, but it is not very stable, easily oxidized or metabolized by soil microorganisms. Formaldehyde is also produced in the human body, it is a metabolite of amino acids, human and other primates in the blood contains about 1 mM of formaldehyde. But don't worry, the body has a certain amount of formaldehyde metabolism, so trace formaldehyde is not accumulated.
As the molecular structure of formaldehyde is relatively basic, it is the precursor of many complex compounds, in the textile industry, such as in order to make clothes wrinkle-proof, will use some of the formaldehyde-containing reactive resin as a binder; and then in the automotive industry, building materials industry and other industries have a wide range of applications.
On the other hand, formaldehyde has the ability to kill most bacteria and fungi, so its aqueous solution and derivatives are also used to disinfect and treat certain diseases, and even to make animal feed.
Formaldehyde has another well-known name. Formaldehyde, which has a mass fraction of 37% or a volume fraction of 40%, is commonly known as formalin. Formalin is often used to make specimens because of a special property of formaldehyde, which binds proteins irreversibly to DNA and thus has the ability to fix tissues and preserve them.
Hao Fengtong said that most people talk about formaldehyde, the first impression is "the pungent smell of decoration." In an air of 0.1 ppm formaldehyde concentration, a marked irritation to the mucous membrane of the eye is felt. Inhaled formaldehyde may cause headaches, burning sensations in the throat, difficulty breathing, and trigger or aggravate asthma symptoms. The International Agency for Research on Cancer (IARC) listed formaldehyde as a "known human carcinogen" associated with nasal sinus and nasopharyngeal carcinoma, while the National Toxicology Program published the "Carcinogen Report (Twelfth Edition)" in 2011 explicitly listed formaldehyde as a "known human carcinogen".
"Popularly, formaldehyde levels are very high, and long-term exposure can lead to respiratory tumors, such as lung cancer, which has been confirmed by animal experiments. But the general family standards exceed the standard, individuals think that can not reach that level, and its relationship with leukemia is not conclusive at present. Hao Fengtong said.
Leukemia is dependent on susceptibility genes.
Leukemia, commonly known as "blood cancer", is a malignant proliferative disease of the blood system. Generally divided into acute and chronic, the former is very sudden onset, only a few days to diagnose; the latter from onset to diagnosis sometimes takes two or three years. Xiao Zhijian, professor of the State Key Laboratory of Experimental Hematology and the Hospital of Hematology, Chinese Academy of Medical Sciences, said.
But both acute and chronic leukemia are all caused by the same factors. Xiao Zhijian said that these factors include: radiation, the normal risk of leukemia in about 1/25,000, but once in the bomb circle within a kilometer of the residents, if survived, the risk of leukemia after several years is as high as 1/20. In addition, pregnant women receive abdominal X-ray irradiation, neonatal morbidity is also higher; there are specific groups, such as long-term exposure to organic benzene groups, such as workers engaged in leather, paint, paint production, their long-term exposure to formaldehyde, benzene, xylene environment, their risk of leukemia is higher than normal people; genetic or genetic abruption; Congenital chromosomal abnormalities such as Down's syndrome and Brunswick's syndrome may increase the incidence of leukemia. If someone in the family had a higher risk of disease, and then autoimmune factors, autoimmune deficiencies may be associated with chronic lymphoblastic leukemia.
Some experts said that the above factors, genetic or genetic mutations can be said to lead to leukemia, the other can be called external causes. It needs to be clear that when there is an internal cause, coupled with the influence of external causes, accelerating the process of cell mutation, cancer (leukemia) will be triggered; if there is no internal cause, external causes will not cause leukemia. The role of internal and external causes is called the "two strike" of carcinogenesis.
Xiao Zhijian also believes that whether leukemia can be caused is related to an individual's genetic susceptibility genes, if there are susceptibility genes in the body, once in contact with toxicants in the environment, it is easy to be affected. At the same time, it is also related to the gene function in the human body. "There are detoxification genes in the human body, but some detoxification genes have activity, some people have no activity, no active genes do not have detoxification function, therefore, its exposure to toxicants in the environment is not feasible. It also explains why some people are easy to get sick in the same environment, while others are all right. Xiao Zhijian said.
Does formaldehyde cause leukaemia? Xiao Zhijian said that if long-term exposure to benzene, xylene, formaldehyde, it will cause chromosomal aberrations, gene mutations, may lead to leukemia is more certain. Because formaldehyde and benzene, xylene, have aromatic benzene ring structure, such chemicals can migrate into DNA, causing chromosomal and genetic mutations, thereby carcinogenic. Studies have also shown that formaldehyde exposure is positively associated with the risk of leukemia, especially myeloid leukemia. Funeral and cadaver preservation workers, compared with ordinary people, have an increased risk of leukemia and brain cancer.
But Xiao Zhijian also emphasized that the carcinogenic effect of formaldehyde is closely related to the concentration. Studies have shown that high concentrations of formaldehyde (> 1.0mg/m3) can cause cell mutation and cancer (including leukemia), if the indoor air formaldehyde concentration does not exceed this level, generally not cause leukemia. As for benzene, the minimum exposure dose associated with the occurrence of leukemia caused by occupational benzene exposure is 32-80mg/m3, while the concentration of benzene is limited to 0.9mg/m3 in China's Indoor Air Quality Standard.
How long can I stay after housing renovation?
Some people may ask, how long will it be after the house is renovated?
In this regard, Hao Fengtong said that this mainly depends on the source of pollutants, household decoration in the main pollutants are five kinds: formaldehyde, benzene, ammonia, radioactive radon, TVOC (total volatile organic compounds). Among them, formaldehyde and benzene are the most common and hardest two kinds. As we all know, the acute toxicity of benzene is mainly paralysis of the central nervous system, chronic toxicity mainly affects the hematopoietic tissue and nervous system, if the hematopoietic function is completely destroyed, it may cause leukemia.
"The paints and paints produced will contain benzene, which will cause great harm and volatilization. Benzene is notorious for its harmfulness, which has been widely recognized at home and abroad, and is not cheap in itself. Therefore, it is unnecessary for everyone to use it, and there are sufficient substitutes for it." As for formaldehyde, Hao Fengtong said, newly purchased cabinets or bookcases, open the door will smell irritating odor, which is mainly adhesive solidified, volatilization is slower. But the levels are usually very low, and it's okay to stay after a few weeks. There are no confirmed cases of formaldehyde-induced illness in the clinic.
Activated carbon, green, and Chlorophytum... In order to remove formaldehyde, people are forced to kill it. In this regard, experts said that the truly effective solution, in addition to avoiding excessive decoration and the use of formal qualified materials, only ventilation.
The results show that the concentration of formaldehyde in indoor air can be reduced by about 70% - 90% after 10 minutes of ventilation. When the weather is good, you may as well open the windows. In summer and autumn, the temperature is high, and the harmful substances such as formaldehyde can be released more seriously. Therefore, more attention should be paid to ventilation.
How long will it take to decorate? Xiao Zhijian believes that this varies from person to person, it is better to ask a professional body to test before residence, China's "indoor air formaldehyde hygiene standards" clearly stipulated that the maximum allowable concentration of formaldehyde in the indoor air is 0.08mg/m3.
Newspaper reporter Fu Lili
Source: ScienceDaily daily
Editor in chief: Zhang Yiling
Waonews is a news media from China, with hundreds of translations, rolling updates China News, hoping to get the likes of foreign netizens