What harm does benzene do to human body?

Because benzene is volatile, it spreads easily when it comes into contact with air. Inhalation or skin contact of large amounts of benzene by humans and animals can cause acute and chronic benzene poisoning. Some research reports show that benzene poisoning is partly caused by benzene producing phenol in the body.

Please pay special attention to:

(1) Long-term inhalation will damage people's nervous system, and acute poisoning will lead to nerve spasm and even coma and death.

(2) A large number of leukemia patients have a history of exposure to benzene and its organic products.

Toxicological data

LD50: rat 3306 mg/kg (oral); 48 mg/kg (transdermal absorption in mice)

LC50: 10000 ppm for 7 hours (inhaled by rats)

Because everyone's health and contact conditions are different, their sensitivity to benzene is also different. When you smell benzene, its concentration is about 1.5ppm. Pay attention to the danger of poisoning. During the examination, it is easy to find out the degree of benzene poisoning through urine and blood examination.

Contact limit

The maximum allowable concentration in China is 40 mg/m3.

American ACGIH 10ppm, 32mg/m3 TWA: OSHA 1ppm, 3.2mg/m3.

To metabolize.

Benzene mainly enters the human body through respiratory inhalation (47-80%), gastrointestinal absorption and skin absorption. Part of benzene can be excreted in urine. Under the action of cytochrome P450 monooxygenase in liver, unexposed benzene is oxidized by oxygen molecules to epoxy benzene (7- oxabicyclo [4. 1.0] hept-2,4-diene). Epoxy benzene is in equilibrium with its rearrangement product oxetane, which is a toxic intermediate produced during benzene metabolism. Then there are three metabolic pathways: combining with glutathione to produce phenylmercaptouric acid; Continue to metabolize into phenol, catechol, hydroquinone, trimellitic, hydroquinone, etc. And discharged in the form of glucuronide or sulfate combination; And oxidized to adipic acid. Ethanol and toluene can reduce the toxicity of benzene.

When benzene metabolites enter cells, they combine with deoxyribonucleic acid (DNA) in the nucleus, which will cause chromosome changes, such as some breaking and some combining. This is canceration (figuratively speaking, mutation), because chromosomes are genetic materials, which control the structure and life activities of cells. ). If this happens for a long time, it will lead to cancer.

poisoning symptom

Short-term contact

Benzene can paralyze the central nervous system and lead to acute poisoning. In severe cases, there will be headache, nausea, vomiting, confusion, loss of consciousness, coma, convulsions and so on. In severe cases, people will die because of paralysis of the central system. A small amount of benzene can also cause drowsiness, dizziness, increased heart rate, headache, trembling, confusion and unconsciousness. Intake of foods containing too much benzene can lead to vomiting, stomachache, dizziness, insomnia, convulsions, increased heart rate and even death. Inhalation of 20000ppm benzene vapor for 5- 10 minutes will be fatal.

Long term contact

Long-term exposure to benzene will do great harm to blood and cause chronic poisoning. Cause neurasthenia syndrome. Benzene can damage bone marrow, reduce the number of red blood cells, white blood cells and platelets, and distort chromosomes, thus leading to leukemia and even aplastic anemia. Benzene can cause a lot of bleeding, thus inhibiting the function of the immune system and allowing diseases to take advantage of it. It is reported that the incubation period of benzene in the body can be as long as 12- 15 years.

After inhaling too much benzene, women will have irregular menstruation and ovarian atrophy for several months. The effects on fetal development and male fertility are still unknown. Inhalation of benzene in pregnant animals will lead to underweight, delayed bone development and bone marrow damage in larvae.

It can irritate skin and mucous membrane. The International Centre for Research on Cancer (IARC) has been identified as a carcinogen.

Benzene is a colorless aromatic hydrocarbon, which is transparent, volatile, flammable and explosive. The principle of benzene poisoning is to invade the human body from the respiratory tract. Acute poisoning can be caused by inhaling high concentration benzene vapor, polluting the skin with a large amount of benzene liquid or taking it by mistake. The lethal oral dose is about 10 ml. Its toxic effect is to inhibit the central nervous system, and it is also harmful to hematopoiesis and respiratory system.

Clinical manifestations of acute benzene poisoning

1. Slightly poisoned people may have headache, dizziness, tears, dry throat, cough, nausea and vomiting, abdominal pain, diarrhea and unsteady gait; Purple skin, nails and mucous membrane, acute conjunctivitis, tinnitus, photophobia, palpitation, pale face.

2. Patients with moderate and severe poisoning, in addition to the above symptoms, also have aggravation, lethargy, unresponsiveness, trance and so on. Coma, rapid pulse, decreased blood pressure, cyanosis of skin and mucous membrane, rapid breathing, convulsion and muscle tremor may also occur, and some patients may also have restlessness, euphoria, delirium and peripheral nerve damage, and even dyspnea and shock.

Emergency treatment

1. Inhalation poisoning patients should quickly move the patients to fresh air, take off contaminated clothes and loosen all the clothes and buttons on the neck and chest. Belt, make it lie flat, if there is dirt in the mouth and nose, it should be removed immediately to ensure normal ventilation and smooth breathing of the lungs. And keep warm.

2. Oral poisoners should use 0.005 activated carbon suspension or 0.02 sodium bicarbonate solution to gastric lavage and induce vomiting, and then take cathartic diuretics to speed up the excretion of poisons in the body and reduce the absorption of poisons.

3. People with skin poisoning should replace contaminated clothes, shoes and socks, and wash their skin and hair repeatedly with soapy water and clear water.

4. Coma and convulsion patients should remove oral foreign bodies as soon as possible, keep the respiratory tract unobstructed, and be escorted to the hospital for treatment by special personnel.

Relevant laws and regulations

According to the List of Dangerous Goods in People's Republic of China (PRC) (GB 12268-90), benzene belongs to the middle flash point liquid in the flammable liquid of the third kind of dangerous goods. Moreover, due to its volatility, it may cause local accumulation of steam, so it is required to stay away from fire sources and heat sources during storage and transportation to prevent static electricity.