Dioxin (Miscellaneous) dioxin/two bad English

Wikipedia

Https://zh.wikipedia.org/wiki/%E4%BA%8C%E5%99%81%E8%8B%B1

two (1,4-dioxin), which is a single-ring organic compound, is a byproduct of no practical use in industry. The toxicity of dioxin and its derivative compounds are different, and the compounds may accumulate in animal adipose tissue and some parts of the plant because of its fat-soluble (liposolubility).

The chemical structure of dioxins belongs toPolychlorinated biphenyls (polychlorinated dibenzodioxins,-,pcdds) compounds of polychlorinated diphenyl dichloride (polychlorinated dibenzofuran, PCDF) Similar, often written as "pcdd/fs" or commonly known as "dioxin" (dioxins), including polychlorinated biphenyls (polychlorinated biphenyl,pcbs) chemical composition, toxic similar to the carbon, chlorine, benzene organics, belong to Multi-halogenated compound (polyhalogenated Compounds,phcs)^{[4]. , generally speaking, the term "dioxin" broadly refers to the derivative compounds containing the aforementioned structure, such as impurities in the orange agent, often used in animal experiments, "four chlorine double benzene ring dioxin" (2,3,7,8-tetrachlorodibenzo-p- DIOXIN,TCDD).}

Directory [hide]

• 1 Preparation
  • 1.1 Laboratory Preparation
  • 1.2 environmental Sources
• 2 Toxicology
• 3 Military Use
• 4 Impact on health
• 5 Two historical cases of dioxin poisoning
• 6 Elimination of dioxin
• 7 See also
• 8 Reference Sources
• 9 External Links

preparation [edit ] Laboratory Preparation [edit ]

Dioxin can be prepared by Diels-Alder reaction (da reaction):

Environmental Sources [edit ]

When organic matter is burned in a chlorine-containing environment (which can exist in the form of organic chlorides or ions), it may produce two of dioxin-like substances.

In the natural environment, forest fire ; There are many ways through human activity, such as Thermal generation , incineration Span style= "color: #ff0000;" > plants , polyvinyl chloride (PVC), garbage incineration and smoking and so on, also can be produced through non-burning environment, such as bleach paper or fabric , production with chloro-phenol the operation of substances, in addition to waste incineration, iron ore sintering, electric arc furnace steelmaking , recycled non-ferrous metal production and other industries belong to dioxin pollution prevention and control key industries ^{[5] . The incineration temperature of the incinerator can be up to standard and the normal working flue purification system guarantees a reduction of two dioxin emissions; (including smoking), open burning Straw , burning waste "> cable and poorly managed steam locomotive plants are the main way for human beings to discharge dioxin into the environment. [Source Request ".}

Firefighters seem to be absorbing a lot of carcinogenic substances ....

toxicology [edit ]

Dioxin is a kind of cell poison . Taking TCDD as an example, its entry into the human body will induce δ amino acetyl propionate synthase (aminolevulinic acid synthetase,alas) Production, this enzyme is heme synthesis of speed-limiting enzymes. ^{[6]too much alas destroys cell tissue and may exhibit symptoms similar to porphyrins. Dioxins can induce apoptosis of lymphocytes, inhibit the production of killer T cells (cytotoxic T-CELL,TC or CTL) and promote the high expression of immunosuppressive agents [7], causing the immune system to regulate dysfunction. Dioxin can also invade DNA molecules, induce mutations, and thus have teratogenic and carcinogenic effects. Dioxins are not easily metabolized in the body and can enter the environment with excreta.}

military use [edit ]

The Stockholm International Peace Research Institute treats two of dioxins as a potential military agent in the chemical and biological warfare issue, in part for the following reasons:

• Toxicity: Most dioxin-like compounds are highly toxic to mammals. Experiments with rats as materials showed that the toxicity of TCDD was similar to that of Sandy Forest [LD50 (TCDD): 0.447mg/ld50 (Sarin): 0.55mg].
• Diagnosis and Treatment: Long course, the damage caused by long-term, and no special effects drugs.
• Durability: Highly stable in nature, difficult to wash, long-term exposure to poison.
• Cast: Can form aerosol, easy to use.
• Raw materials: A wide range of sources, but the current yield is still low.

impact on Health [edit ] 2,3,7,8-four-dichloro-bis (TCDD) structure

In dioxin compounds, 2,3,7,8-tetrachlorodibenzo-p-dioxin (hereinafter referred to as TCDD) is considered to be the most toxic, so most animal studies use TCDD as a standard for the detection of dioxin-like compounds toxicity, The effects of the remaining two of these compounds on humans are yet to be confirmed. Dioxin-like compounds are fat-soluble, so they are easy to be biologically accumulative. In the case of TCDD, the study of mammals indicated that although there was a lethal dose, the tolerable dose difference between different species was considerable. In addition, although the TCDD does not have a direct mutagenicity and genetic toxicity ^{[8], but may be through indirect physiological pathways and carcinogenic. since there have been no cases of acute death of dioxin compounds in humans, it is inferred that the two levels of dioxin in human exposure are relatively low doses, but may still have chronic symptoms through bioaccumulation. In this case, the TCDD of human health risks inferred from animal and clinical cases include:}

• Chlorine Acne . This is the only confirmed and clinical case, the accumulation of high concentrations of two of dioxin caused by the phenomenon. ^[9]
• cancer . Animal experiments show that TCDD is highly carcinogenic to certain species of animals, but more than a certain threshold dose can occur. The carcinogenic nature of human beings is still being studied, but clinical cases after the Seveso event show that high concentrations of TCDD may slightly increase the likelihood of multiple myeloma and leukemia . ^[Ten]
• Other physiological symptoms in animal experiments include decreased immune function, decreased renal function, impaired dental development, and so on. The problem of tooth development is also a case of Seveso events ^{[one]. In addition, according to the study of Seveso events, TCDD may be related to diabetes mellitus, endometriosis, endocrine disorders and so on. []}

Two historical cases of dioxin poisoning [edit ]

• In 1976, after the explosion of the Icmesa chemical plant in Seveso , Italy , a high concentration of dioxin leakage occurred, about 2.5 kilograms of two dioxins covered 320 hectares of area, resulting in the local presence of about 200 people suffering from chlorine acne . The incident is also the most detailed two dioxin contamination event studied, and also shows that two of dioxins may raise the incidence of certain cancers. In addition, many of the symptoms are suspected to be caused by two of dioxin contamination, but more research is needed. ^[9]

• In the Vietnam War , the U.S. military used a deciduous agent known as orange Agent to litter the leaves, exposing the Viet Cong soldiers hiding in the jungle, there are still many veterans have been detected in the body accumulated excess of two of dioxin. In addition, it is found that the highest concentrations of dioxin in the body are also in Viet Nam (although mainly due to work-contact relationships). Although the concentration of TCDD in fat is as high as 144000pg/g, the patient has no other symptoms other than suffering from chlorine acne , depression and menstrual disorders . ^[]

• Dioxin was first used in the assassination of the Ukrainian presidential candidate in 2004, He began to experience physical discomfort in September, was confirmed to be poisoned in November, the body was detected a large amount of TCDD, concentration of 108000pg/g, This is also the first case of severe dioxin poisoning in humans. But in addition to the initial symptoms of depression and chlorine acne, there is no other clinical symptoms. ^[14]

Mr Yushchenko was poisoned by acute dioxin, leading to the birth of chlorine acne on his face. (2006 photo)Elimination of dioxin [edit ]

[15] Tomoyuki , a professor of microbiology at Kyoto University in the Journal of Natural Biotechnology, published on January 16, 2006, ^{referred to their research using genetic techniques to mix the genes of two different strains of the sheath-type Pseudomonas spp. Can devour two of dioxin compounds and decompose them in their bodies in less time than ever before. In addition, some countries and producers (such as the US East Coast Maine State [16]) have reduced or discontinued the manufacture of polyvinyl chloride products, and have introduced reduced-use plastic bags. In particular, the holding of food utensils, baby toys and medical supplies banned polyvinyl chloride and related chlorine-containing plastics.}

Japanese scientists produce super bacteria that can "swallowed" dioxins

Tokyo, January 16 (Xinhua) Japanese scientists have Chang a "big mouth" super-bacteria that can "swallowed" dioxin-like substances and decompose them quickly by genetic technology.

Makata, a professor at Kyoto University in Japan, published a paper on 16th in the online edition of Nature and biotechnology, saying they found a soil bacterium with a "big mouth" that could swallow a polymer, and implant the bacterium's gene into another bacterium that can break down dioxin-like substances, The rate at which the super bacteria are bred to decompose dioxins is twice times the original.

Professor Murata and others found a bacterium from the paddy field of the genus Salbutamol. Usually bacteria are first used enzymes in vitro decomposition of macromolecular substances, and then ingested by the decomposition of low-molecular material. This soil bacterium, although only 1 microns long, has a diameter of 0. 1 micron "Big Mouth", can be a large swallow of polymer material. The researchers implanted the bacteria in the bacteria "RW1" with 5 genes associated with "swallowing" and decomposing the substance, which has the ability to decompose dioxin-like substances in the body.

After cultivation, the surface of the RW1 bacteria also grows "big mouth", the ability to decompose and remove dioxins increased to twice times the original. The researchers believe that the same gene implanted in other bacteria may also be able to develop a super bacteria used to remove harmful heavy metals such as cadmium.

Dioxin (Miscellaneous) dioxin/two bad English