Acute and chronic benzene poisoning
Modern production is impossible to imagine without such a substance as benzene. He entered our life in 1825 and since then it can be found in many areas, including human life. The widespread use of benzene in the industry can not exclude man-made accidents that have existed in history. For example, accidents at enterprises in China, Lipetsk and other regions led to the leakage of this hydrocarbon. No one is insured against poisoning, especially since people who work with this substance and have been in contact with it for a long time.
Benzene - what is this substance, where is it used and how does it affect a person? How to provide first aid in acute poisoning, what is the treatment of chronic intoxication?
What is benzene and where does it apply
Benzene is an aliphatic hydrocarbon compound, which is a liquid without color, with a characteristic aroma. Benzene refracts light well and evaporates quickly at room temperature. It boils at 80.5 ºC, freezing, turns into a crystalline substance. When mixed with air, benzene vapors form a flammable mixture. Well soluble in all solvents (chloroform, ethanol, ether), except water. It is a solvent for oils, fats, gums, sulfur, alkaloids, iodine, phosphorus.
Benzene is derived from acetylene. The catalyst for this reaction is nickel. Methods for producing benzene:
- coking coal (used less and less, benzene obtained in this way has impurities);
- processing of petrol fractions of oil (half of benzene is produced in this way);
- from acetylene at high temperature in the presence of activated carbon.
Where is benzene used? This is the most common aromatic hydrocarbon used in production.
It is part of:
- synthetic fibers;
- motor fuel;
- solvent paints and varnishes.
In the chemical industry, it is used as a solvent. Its main use at the moment is the synthesis of ethylbenzene, cumene, cyclohexane. From these substances, drugs and dyes are subsequently produced.
The risk of benzene intoxication has the following categories of population:
- people directly involved in its production, storage, transportation;
- persons who wash benzene-carrying tanks;
- refinery workers;
- laboratory assistants involved in the distillation of oil;
- pump repairmen;
- house painters;
- affected by the fire from burning plastic, rubber, rubber.
Benzene enters the human body with inhaled air in the form of vapor. Penetration through the respiratory system is the leading route of entry for this substance. In second place is the percutaneous path. But it is less important than air.
What is harmful to benzene? With short-term inhalation of benzene vapor poisoning does not occur. With prolonged contact or exposure to high doses of this poisonous substance, it enters the blood and begins to circulate in the body. It is then excreted mainly through the respiratory tract, partly by the kidneys. When breastfeeding, it is excreted in milk.
Upon contact with the skin, benzene causes its dryness, cracks, itching, redness, swelling, and vesicular rashes appear.
Benzene has a toxic effect on all organs and systems of the body. Poisoning is acute and chronic. In acute poisoning, the respiratory system, blood vessels, brain, adrenal glands, and liver are more severely affected, while in the chronic system, the hematopoietic system is mainly affected.
Toxic dose for benzene vapor poisoning is 319 mg / m³. The lethal inhalation dose is 63803 mg / m³ for 5 minutes. When consumed orally, 10–20 ml is enough for death. Systematic exposure to a dose of 0.12–0.19 mg / l leads to chronic poisoning.
When systematic intoxication with benzene on the body is the following action:
- harmful effects on the embryo and fetus;
- negative impact on reproductive organs.
Additional effects of benzene:
- imbalance of vitamins of group B;
Acute poisoning with benzene is rare, unlike chronic.
Acute poisoning with benzene can occur as a result of an accident, a man-made accident, a violation of the rules in production, and substance abuse. At the same time, a large dose of a substance enters the body simultaneously or within a short period of time.
The nervous system reacts first:
- dizziness appears;
- noise in ears;
- euphoric state, which is replaced by headache, nausea, vomiting, loss of coordination of movements.
If intoxication was easy, then the poisoning will be limited to the above symptoms and after some time will pass without a trace.
With a moderate degree of poisoning, a person’s behavior becomes inadequate, restless, the skin turns pale, the body temperature drops, breathing becomes faster, and the pulse begins to weaken. If help is not provided in time, the situation may be complicated by convulsions and coma. Such poisoning can pass without a trace, and it can leave behind itself the astheno-vegetative syndrome (a violation of the transmission of nerve impulses to the tissues).
In severe intoxication, a person instantly loses consciousness, toxic coma sets in, and respiratory arrest is possible due to paralysis of the respiratory muscles. In most cases, the outcome of severe intoxication is death.
What other symptoms of acute benzene poisoning can be noticed?
Methemoglobin is formed in the blood. It does not bind with oxygen and does not transfer it to the tissues. The consequence is cellular oxygen starvation. The cells of the heart muscle and nerve cells suffer the most.
- Benzene has a destructive effect on red blood cells. Poisoning is accompanied by anemia.
- Liver damage may be signaled by jaundice.
- Damage to blood vessels causes the formation of hemorrhages and ulcers on the skin and mucous membranes.
- Some benzene compounds irritate the respiratory tract, causing coughing, tickling, and sneezing.
- Blood in the urine may indicate damage to the genitourinary system. Most often develops cystitis with hemorrhages and ulcers in the bladder.
Symptoms, depending on the severity of the poisoning, can occur several minutes or hours after the substance enters the body.
First aid and treatment for acute poisoning
First aid in case of poisoning with benzene is reduced to the following actions.
Termination of contact with benzene. The victim needs to ensure the flow of fresh air - take out of the room, open the window. In case of contact of caustic substances on the skin and mucous membranes - rinse with 1% sodium bicarbonate solution (baking soda).
- In severe cases - carrying out artificial respiration and indirect heart massage.
- Call the ambulance brigade.
Treatment of acute poisoning is to maintain and restore the functions of organs and systems:
- metabolic and antioxidant, oxygen therapy;
- elimination of heart rhythm disorders;
- elimination of seizures;
- restoration of a normal rhythm of breath.
This condition develops as a result of prolonged contact with small but toxic doses. Chronic intoxication with benzene, unlike acute, develops slowly. You can suspect it by chance or with a targeted search. The hematopoietic system is affected, namely the bone marrow. Following the hematopoiesis, the nervous system suffers.
The patient over time begin to bother:
- noise in the head and ears;
- increased heart rate.
Then joins nausea, vomiting, pain in the bones. Increased bleeding is manifested by nasal, uterine bleeding, the appearance of blood when brushing teeth, hemorrhages with minor injuries. Anemia is manifested by pallor, hair loss, brittle nails, a decrease in physical and mental performance.
In advanced cases, you can see the following signs of chronic benzene poisoning:
- muscle twitching, shaking hands, impaired speech and coordination of movements;
- pain in the legs, a violation of sensitivity;
- pain in the liver and increase its size, venous pattern on the abdomen around the navel with the development of cirrhosis;
- disorders of the digestive system: enzyme deficiency, increased acidity of the stomach, gastritis, ulcer;
- hypertension, increased heart size, high heart rate;
- in women - menstrual disorders, infertility, chronic miscarriage.
Benzene is a carcinogen. It causes mutations and leads to the appearance of atypical cells in the blood. Leukemia in chronic poisoning can develop in 5–10 years. Cessation of contact with benzene is not a guarantee of protection against leukemia. If chronic poisoning already exists, then everyone is at risk - both employees and employees who have left production.
Chronic poisoning can also cause aplastic anemia, myelodysplastic syndrome and diseases of the bone marrow.
Treatment of chronic poisoning
In chronic benzene poisoning, the following measures are taken:
- cessation of contact with the substance;
blood formation stimulation;
- plasma transfusions and blood products;
- vitamin therapy (groups B and PP);
- drugs that improve cerebral and cardiac blood flow are prescribed;
- metabolic therapy for the brain and heart;
- antioxidant therapy;
- shown are drugs that protect the liver, essential acids.
Benzene is a highly toxic, carcinogenic substance that, at high concentrations, causes acute poisoning, often accompanied by loss of consciousness and possible death. Severe cases of poisoning and chronic intoxication cause a long-term health disorder.