Dioxins are a general term for two types of chemicals: polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs). There are 75 isomers of PCDDs, 135 isomers of PCDFs, and 210 chemicals in existence. The toxicity of this isomer varies according to the structure, and the United States Environmental Protection Agency has identified 30 dioxins that are very harmful, of which 7 are PCDDSand 10 are PCDFSpolychlorinated dibenzofuran. In all the isomers, the most toxic is 2,3,7, 8-tetrachlorodibenzo-dioxin (TCDD), which is 1000 times more toxic than the by-product of subconscious generated at this stage, and is called "the strongest harmful substances on the earth." It is reported that 28.35gTCDD would be enough to kill a million people.
To help you understand all aspects of dioxins
Dioxins are very stable lipophilic solid organic compounds, high dissolution point, dissolution temperature of more than 700℃, not easy to dissolve water, very easy to accumulate in plants. The saturated vapor pressure of dioxins is extremely low, so it is present in atmospheric aerosol fine particles.
The dissolution, hydrolysis and photolysis of microorganisms in nature do little harm to the molecular formula of dioxins, and the drug half-life of dioxins in natural deposits is estimated to be more than 100 years. In addition, people and animals and green plants do not have the function of dissolving dioxins, so its toxicity is difficult to be removed in the natural environment, only according to the gradual transmission and aggregation of food web.
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Dioxins are commonly found in the air, soil and water, and the key pollutants are the steel industry in chemical plants, waste incineration and power generation, paper industry and its production and manufacture of insecticides and other industrial chains. The commonly used adhesive cloth and polyethylene (PVC) soft adhesive in daily life are loaded with chlorine, and dioxins will be released into the air when ignited.
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Damage
Dioxin detection agencies can enter the body according to the skin, respiratory system, digestive system and other ways, but according to the food ingredients are very long chain fatty acids, the amount into the body through the digestive system to account for more than 90%, they accumulate in human fat and liver, to a certain level, it will lead to many negative effects. In 1994, WHO strongly recommended that the daily allowable intake (TDI) of dioxin-type harmful substances be 1 to 4pg/kg of rest weight. The harm of dioxins to human body is roughly sorted into the following many levels.
To help you understand all aspects of dioxins
1. Subacute toxic effect
Acute dioxin poisoning can kill animals and humans. In 1968, Japan produced benzene series of environmental pollution of rice sugar oil, resulting in hundreds of thousands of chickens and 16 people died. This kind of death effect of dioxins is mainly manifested after several weeks of poisoning, unlike other harmful substances which can be mainly manifested in a few hours or days, so the name delayed time to death effect.
2. Acute dioxin poisoning has negative effects on urinary system
For men, dioxins can reduce male estrogen levels, reduce male sperm count, resulting in malformation of male epididymal cysts, and reduce male sexual function. A data survey reported that in male workers exposed to 2,3,7,8-TCDD, blood cell testosterone levels were inversely proportional to blood cell 2,3,7,8-TCDD levels, indicating that information dioxins have anti-androgenic effects. Touching 30 years ago was still reported to reduce the sperm count of men in the current touching workers by 50 percent.
In women, dioxins can increase the rate of miscarriage, reduce the chance of pregnancy, alleviate the net weight of the uterus, and have endometriosis and even infertility. In the United States, an increased prevalence of endometriosis in women would be associated with dioxin dietary exposure.
3. Dioxins are carcinogens
Dioxin detection technology is a strong cancer promoter, it can cause multi-system software multi-location tumor. 2,3,7,8-TCDD was tested on mice, rats, hamsters and mice for 19 times, and carcinogens were all positive. During the Vietnam War, the United States sprayed a lot of 2,4-D and 2,4,5-T with dioxins (other known as orange Chinese medicine preparations) in Vietnam as necessary for the war. After the end of the war, a data survey reported that the tumor prevalence of American soldiers who had been exposed to orange herbal preparations was 4.95%, which was twice that of control trials (2.23%).
4. Harm to endocrine disorders metabolic system software
It causes similar effects of endocrine imbalance hormones in the human body, antagonizes the effects of endocrine imbalance hormones in all normal metabolism in the human body, destroys the whole process of production and metabolism of endocrine imbalance growth hormone in the body, and destroys the whole process of production and metabolism of endocrine imbalance growth hormone protein kinase.
Dioxins, as a natural environmental growth hormone, can disrupt the human nervous system. It can affect estrogen metabolism and cause problems with urinary system function. Exposure to dioxins during pregnancy can reduce the elevated level of thyroxine in fetal blood cells, while the level of thyrotropin glargine increases, indicating that it has the effect of inhibiting thyroid cysts.
Dioxins can reduce the level of insulin glargine or decrease its insulin receptor, resulting in the disorder of glucose metabolism. For example, during the war against Vietnam, American soldiers who touched orange Chinese medicine preparations and the environmental pollution accident of organic chemistry in Seviso, Spain, increased the prevalence of diabetes patients in the environmental pollution regional groups. In addition, it can also affect hormone drugs, VitA, blood sugar and porphyrin metabolism, resulting in a series of metabolic disorders.
5. Harm to the human immune system
Dioxins can also inhibit cellular immunity and immune cells. More sensitive to the significance of dioxin detection are aggressive T lymphocytes, which can cause continuous inhibition response at 0.04μg/kg rest weight. Dioxins can also inhibit the function of service T cells for a long time, and have toxic effects on lymph node stem cell beauty and NK cells in the spinal cord, thymus, liver and lung. Dioxins can immediately inhibit B cells, reduce the reactivity of immune response, and reduce the production of antigens (IgE, IgG).
6. Damage to skin and mucous membranes
Dioxins can change the metabolism of sebaceous glands, make skin hyperplasia, excessive keratinization, chlorine acne, and pigmentation of skin, mucosa, teeth, nails, etc. Chlorine acne can be combined with swelling, pus, invasion of the face, neck, chest, back and even limbs. Hair follicles before excessive keratinization often appear red rash, puffiness, and sometimes photosensitivity. Scales often last for years, and healing often leaves scars.
7. Harm to the growth and development of test-tube embryos and babies
Growing individuals, especially in vitro embryos, are particularly sensitive to dioxins. In the absence of maternal toxicity can cause fetal death, miscarriage, growth and development of stunted or delayed language development. Small doses in mice can cause cleft lip and cleft palate in mice, kidney deformity. Clinical epidemiological data survey reported that after the return of American soldiers exposed to orange experimental reagents during the war against Vietnam, the incidence of spontaneous miscarriages and developmental abnormalities in their wives increased by 30%. This will be based on the endotoxin gene passed from the embryo to the fetus, and the second is based on the discharge of milk, and the baby is also a victim.
To help you understand all aspects of dioxins
The plight of abandoned children exposed to Agent Orange after the end of the Vietnam War (see related news information for details)
8, other hazards to the human body
The harm of liver function test is the common toxic effect of dioxins, which can make the liver atrophy and increase the aminotransferase. In the rice bran oil incident, the American soldiers in Vietnam, and the Seveso safety accident victims, the liver damage is the most common manifestation. Dioxin exposure is also associated with cardiovascular and cerebrovascular diseases and respiratory disorders. Can cause diffuse cerebral ischemia myocardial infarction, rheumatoid myocardial infarction, high blood pressure and diffuse obstructive pulmonary disease increased mortality. Dioxins will cause psychosomatic disorders, such as anxiety, anger, fatigue, depression, etc. The key clinical manifestations were adenoconstriction, systemic muscle atrophy, and systemic muscle invasion.
dioxin
Dioxin test criteria
At present, the test method of dioxins is dominated by high discrimination meteorological chromatograph (HRGC) - high resolution mass spectrometry (HRMS), but there are great differences in the solution method before testing. The United States Ecological Environmental Protection Agency, the European Union standards body, the Japanese industry Standards Research Association and the National Fine Management Association in China have successively formulated the method of testing dioxins.
1, dioxin test standards National standards
GB5009.205-2013 Measurement of toxic dose of dioxins and analogues in food products
Measurement of dioxins and dioxin-like polychlorinated biphenyls in concentrate feeds-Radionuclide diluents - High pixel meteorological chromatographs/High image mass spectrometry
GB/T5009.190-2006 Measurement of labeled polychlorinated biphenyls in food products
2, dioxins test standards National standards
HJ77.1-2008 Measurement of dioxins in water body High discrimination Meteorological Chromatograph-High resolution mass spectrometry for radionuclide diluents
HJ77.2-2008 Measurement of dioxins in environmental quality and organic waste gases Radionuclide diluents by high resolution meteorological chromatograph-High resolution mass spectrometry
HJ77.3-2008 Measurement of dioxins in solid waste High discrimination meteorological chromatograph-High resolution mass spectrometry for radionuclide diluents
HJ77.4-2008 Measurement of dioxins in soil layers and deposits Radionuclide diluents by high resolution meteorological chromatograph-High resolution mass spectrometry
3, dioxin test standards United States Environmental Protection Agency specifications
EPA1613B:1997 Determination of tetrachloro-octachlorodioxins and furans in radionuclide diluents by high resolution mass spectrometry
EPA1668C:2010 High Discrimination chromatographic analysis/High resolution mass spectrometry - Determination of polychlorinated biphenyls in water, soil layers, deposits, microbial solid raw materials and institutions
EPA8290:2007 Determination of dioxins/furans by high resolution mass spectrometry
EPA23:1995 Test for dioxins/furans in waste incinerators
EPATO-9A:1999 Determination of polychlorinated dibenzoxins/furans and polybrominated dibenzoxins/furans in air
4, dioxin test standards EU national test standards
En 1948-2006 Determination of dioxins and dioxin-like polychlorinated biphenyls in the discharge of stationary pollutants
BSEN16215-2012 Feed raw materials -- Determination of dioxins, dioxin-like polychlorinated biphenyls and labeled polychlorinated biphenyls by high-resolution mass spectrometry
5, dioxin test standards International Maritime Organization specifications
ISO18073:2004 Radionuclide diluents - Determination of dioxins/furans in water by high resolution chromatography/high resolution mass spectrometry
ISO17858:2007 High Discrimination chromatography/High resolution mass spectrometry Method for the determination of dioxin-like polychlorinated biphenyls in water
6, dioxin test standard Japanese industry standard
Jisk031:2005 Determination of tetrachloro-octachlorodioxins/furans and dioxin-like polychlorinated biphenyls in the discharge of stationary pollutants
JISK0312:2005 - Determination of tetrachloro-octachlorodioxins/furans and dioxin-like polychlorinated biphenyls in industrial water and wastewater
