Biology Effect of benzene on organisms How benzene causes cancer

The efficacy and role of bio-organic fertilizer in detail.

As early as the 1920s, benzene was a commonly used solvent in industry, mainly for metal degreasing. Due to the toxicity of benzene, benzene is no longer used as a solvent in the production process where the human body can directly contact the solvent.

Benzene has the effect of reducing knocking and can be used as a gasoline additive. Before tetraethyl lead was introduced in the 1950s, all antiknock agents were benzene. However, with the fading of leaded gasoline, benzene has been re-used.

Due to the adverse effects of benzene on the human body and the pollution of underground water quality, European and American countries limit the content of benzene in gasoline to no more than 1%.

The most important industrial use of benzene is as a chemical raw material. Benzene can be synthesized into a series of benzene derivatives:

A series of compounds produced by benzene substitution reaction, addition reaction, oxidation reaction, etc., can be used as raw materials for the preparation of plastics, rubber, fibers, dyes, detergents, pesticides, etc. About 10% of benzene is used as a basic raw material for the manufacture of benzene intermediates.

Benzene and ethylene produce ethylbenzene, which can be used to produce styrene for plastics; Benzene and propylene are produced into cumene, which can be used to produce acetone and phenol for resins and binders by cumene method; cyclohexane for nylon; Synthetic maleic anhydride.

nitrobenzene used to make aniline; various chlorobenzenes that are mostly used in pesticides; Synthesis of various alkylbenzenes used in the production of detergents and additives. Synthesis of hydroquinone, anthraquinone and other chemical products.

Solvents such as fats, resins, and iodine. Determination of the mineral refractive index. Organic synthesis. Optically pure solvents. High-pressure liquid chromatography solvents.

Main uses: used as solvents and derivatives of synthetic benzene, spices, dyes, plastics, medicines, explosives, rubber, etc.

The consumption structure of pure benzene in China is as follows: 2 7 2 5 is used for the synthesis of styrene, and polyamide resin (cyclohexane) accounts for about it.

12 6 5, phenol accounts for about 11 3 7, chlorinated benzene accounts for about l0 98, nitrobenzene accounts for about 9 8, alkylbenzene accounts for about 7 8 4, agrochemicals account for about 5 56, maleic anhydride accounts for about 4 7l, and other pharmaceutical, light industry and rubber products industry accounts for about 9 84.

Solvents for waxes, resins, oils: intermediates in synthetic chemicals and pharmaceuticals. 86 Benzene is used in the manufacture of styrene, phenol, bad ethane, and other organic substances.

The remainder is mainly used to make detergents, pesticides, and paint removers. Benzene can be used as a component of gasoline with a content of <2.

In addition, the ink widely used in the packaging and printing industry is currently used as a solvent with toxic organic reagents such as benzene and ether, and the organic solvent content in the ink is generally 30 70.

Benzene mainly enters the human body through respiratory inhalation (47-80%), gastrointestinal and ** absorption. A part of benzene can be excreted in the urine, and benzene that is not excreted by hand is first excreted in the liver with cytochrome P450

Under the action of monooxygenase, it is oxidized by oxygen molecules to epoxybenzene (7-oxabbicyclo[hep-2,4-diene). Epoxybenzene is in equilibrium with its rearrangement product oxhetaheptene and is a trapped toxic intermediate produced during benzene metabolism. Next there are three metabolic pathways:

with glutathione.

Combines to produce phenylmercaptouric acid; It continues to be metabolized into phenol, catechol, bihe hydroquinone, hydroglucinol, o-benzoquinone, p-benzoquinone, etc., and is discharged in the form of glucuronide or sulfate conjugates; and being oxidized to adienedioic acid. Ethanol.

and toluene can reduce the toxicity of benzene.

Toxic, benzene, lead, mercury and so on are all toxic.

Benzene mainly enters the human body through respiratory inhalation (47-80%), gastrointestinal and simple absorption. A portion of benzene can be excreted in the urine, and the unexcreted benzene is first oxidized by oxygen molecules to epoxybenzene (7-oxabbicyclo[g-2,4-diene) by the action of cytochrome P450 monooxygenase in the liver. Epoxy is in equilibrium with its rearrangement product oxhetaheptene and is a toxic intermediate produced in the process of benzene metabolism.

This is followed by three metabolic pathways: binding to glutathione to produce phenylmercaptouric acid; It continues to be metabolized into phenol, catechol, hydroquinone, hydroglucinol, o-benzoquinone, p-benzoquinone, etc., and is discharged in the form of glucuronide or sulfate conjugates; and being oxidized to adienedioic acid. Ethanol and toluene can reduce the toxicity of benzene.

After the metabolites of benzene enter the cell, they bind to the deoxyribonucleic acid (DNA) in the nucleus, which will cause changes in the chromosomes, such as some breaking and some combining, which is carcinogenesis (figuratively speaking, it is mutation, because chromosomes are genetic materials, it controls the structure and life activities of cells, etc.), and in the long run, it will cause cancer.

Benzene is a slightly aromatic organic solvent that has a wide range of industrial uses, but it has been found that benzene can cause acute poisoning, chronic poisoning, and even leukemia and malignant lymphoma. So how does benzene cause acute poisoning, chronic poisoning, and even leukemia and malignant lymphoma?

The first factor is the concentration of exposure to benzene.

Some workers brush benzene-containing paint or paint in unventilated cabins and basements, or use benzene-containing neoprene to glue leather shoes in unventilated workshops, which can inhale high-concentration benzene vapor in a short period of time, causing acute poisoning, headache, dizziness, nausea, vomiting, unsteady walking, like drunkenness, and serious cases are delirious and falling, which can cause death if not rescued in time.

The second factor is the time of exposure to benzene.

After a century of research, scientists have proven that long-term exposure to low concentrations of benzene can lead to aplastic anemia and leukemia. The main symptoms of chronic benzene poisoning are weakness, a decrease in white blood cells in the blood, a decrease in the body's immune function, and a decrease in whole blood cells (including white blood cells, red blood cells, and platelets) in severe poisoning patients, also known as aplastic anemia.

When it comes to leukemia, it is more serious, it is a malignant blood disease, mainly the malignant proliferation of naïve white blood cells in the bone marrow and blood, which is more than 10 times more than normal people. We have collaborated with the American Agency for Cancer Research for more than 10 years to prove that the incidence of leukemia and malignant lymphoma in workers exposed to low concentrations of benzene is significantly higher than that of the general population, and many leukemias are developed from patients with severe chronic benzene poisoning.

The third factor is genetic traits.

As we all know, not all workers who work in the same occupational environment develop poisoning or leukemia. In other words, some people have some genetic deletions, or mutations that are difficult to repair, thus weakening these.

Benzene is a widespread environmental pollutant in industrial cities, which has attracted widespread attention from scholars at home and abroad. Workers exposed to benzene are very common, and people who are exposed to benzene for a long time can cause chronic benzene poisoning, which is manifested as leukopenia, thrombocytopenia, and severe pancytopenia, which can develop into aplastic anemia.

There is no specific carcinogenicity rate. 】

Benzene is a carcinogen that is toxic and can be susceptible to leukemia if people are exposed to it regularly. Benzene is a slightly aromatic organic solvent with a wide range of industrial uses, but it has been found that benzene can cause acute poisoning, chronic poisoning, and even leukemia and malignant lymphoma.

Phenylalanine is a kind of essential amino acid, which can be metabolized to produce tyrosine, tyrosine is the raw material for the synthesis of melanin, tyrosine will also be converted into thyroid hormone and form urinary melanic acid, and finally metabolized to produce CO2 and H2O, phenylalanine lacks the enzyme to form tyrosine, which will be converted into phenylpyruvate, thus suffering from phenylketonuria.

It is one of the 20 amino acids that make up proteins, and one of the 8 essential amino acids, without which some proteins cannot be synthesized.

It is also a raw material for the production of adrenaline, thyroxine and melanin.

1. Phenylalanine is a physiologically active aromatic amino acid, which participates in protein synthesis and is one of the essential amino acids that cannot be synthesized naturally by the human body and animals, and is an important ingredient in the infusion of compound amino acids.

2. It is a precursor for the synthesis of other substances, L-phenylalanine can be irreversibly converted into L-tyrosine (L-tyrosine) by coenzyme tetrahydrobiopterin in living organisms, and is also a raw material for the production of adrenaline, thyroxine and melanin.