Poisoning with dichloroethane

Among toxic lesions dangerous substances for the human body, experts distinguish poisoning with dichloroethane - a saturated halide (chlorinated) derivative of ethylene.

Dichloroethane (ethylene dichloride or 1,2-DCE) is produced in large quantities and is used in the production of PVC and other polymeric materials, fumigants, glues and solvents, including for the removal of paraffins in the processing of petroleum, lead from leaded gasoline, for stain removal in everyday life.

What is the harm of dichloroethane?

For a person the harm of dichloroethane, like all chlorinated unsaturated hydrocarbons, not only in its narcotic, but also nephrotoxic effects. When poisoning with ethylene dichloride, all other body systems are affected, from the lungs and stomach to the brain and CNS. Teratogenic and carcinogenic effects of 1,2-DHE in animals have been demonstrated in vivo.

Is it possible to die from dichloroethane? A single entry into the body of about 20-30 ml of a liquid substance leads to acute intoxication and is identified as a lethal dose at which death can occur in a day; 85-125 ml lead to death in five hours, and 150 ml or more - after three hours. The lethal content of 1,2-DCE in the blood is 90 or more μg / ml (or 500 mg / l.).

As the clinical statistics of the last three decades show, even after cleansing the blood by hemodialysis, the overall survival in acute poisoning with dichloroethane did not exceed 55-57%. And without hemodialysis, the level of lethality in severe poisoning reaches 96%.

Causes of the poisoning with dichloroethane

Dichloroethane is a flammable and volatile liquid, transparent, with a sweetish taste and odor of chloroform, poorly soluble in water (8.7 g / L at + 20 ° C).

The main causes of poisoning: inhalation of vapors of ethylene dichloride (that is, ingestion through the lungs) and ingestion of liquid substance or liquids containing it. Prolonged contact of vapors with unprotected skin or the ingress of liquid substance to large areas of the skin also leads to negative consequences - the development of severe dermatitis, and eye contact - to clouding the cornea.

[1], [2], [3], [4], [5], [6]

Risk factors

The risk factors for the toxic effects of 1,2-DCE on the body, in the first place, include the careless handling of this substance at work and at home. Although cases of deliberate poisoning with suicides are not excluded.

In addition, poisonings of varying degrees of severity can occur when people breathe toxic dichloroethane vapor that seeps from hazardous waste disposal sites of industrial waste and landfills: by standards, the level of dichloroethane in the air should not be above 3 mg / m. Cu. (in production facilities - three times higher), and in reservoirs - no more than 2 mg / l. At the same time, according to the European Chemicals Agency (ECHA), the average background concentration in the cities of Western Europe is 0.4 μg-1.0 μg / m3, and near gas stations, garages and production facilities is increased to 6, 1 μg / m3 cube.

You can poison yourself by using contaminated water: according to FDA regulations, the maximum permissible level of 1,2-DHE in drinking water is 1 μg / l, and domestic sanitary standards allow its presence up to 3 μg / dm. Cu.

According to some reports, in total, enterprises producing dichloroethane and products with its use produce up to 70% of harmful substances in the air, at least 20% - for soil and almost 1.5% - for water.

[7], [8]

Pathogenesis

Explaining the mechanism of action of dichloroethane, which belongs to the category of protoplasmic toxins (acting at the cellular level), the researchers found that after oral ingestion in the gastrointestinal tract, systemic absorption lasts no more than an hour with a maximum plasma concentrations on average three to four hours later.

Further pathogenesis is due to toxic effects, not so much by dichloroethane itself, as by its metabolites, which flow into the tissues of internal organs with blood flow directly into the cells. The liver suffers most of all, since under the influence of its enzymes - in particular, microsomal cytochrome P450 - oxidation of dichloroethane with the elimination of chlorine electrons (dechlorination) occurs in the endoplasmic cytoplasm of hepatocytes. The result is the formation of toxic 2-chloroacetaldehyde and no less toxic monochloroacetic (chloroethanoic acid), which damage the protein structure of cells and completely destabilize trophic tissue at the cellular level.

In addition, dichloroethane binds to cytosolic glutathione-S-transferases (GSTT1 and GSTM1) - enzymes that metabolize xenobiotics and carcinogens. It has been experimentally established that, by binding to glutathione, dichloroethane is transformed to form S- (2-chloroethyl) glutathione, which is essentially an alkylating agent, which introduces radicals with a positive charge into the proteins and nucleotides of cells. Thus, it becomes a catalyst for reactions leading to nephrotoxic effects, as well as damage to the vascular endothelium, as a result of which the volume of circulating blood decreases and metabolic acidosis develops  .

[9], [10], [11]

Symptoms of the poisoning with dichloroethane

A short inhalation effect - dichloroethane vapor poisoning - at high concentrations initially affects the central nervous system, and the first signs of a toxicogenic stage of poisoning include headache, dizziness, weakness and drowsiness, and a decrease in muscle tone. Euphoria, inadequacy of reactions, loss of orientation and hallucinations attest to the violation of the functions of the brain and CNS.

After a short-term improvement in the general condition lasting several hours, the kidneys undergo severe toxic effects of metabolites of 1,2-DCE with the development of  acute renal failure  and the cessation of urine formation and excretion. There are muscle cramps, cyanosis (due to respiratory insufficiency), a sharp decrease and increase in blood pressure, vomiting, gastralgia and diarrhea, as well as weakening of cardiac muscle contractions (a symptom of myocardial dystrophy). A person can fall into an unconscious state (toxic coma), followed by a lethal outcome.

At low concentrations of vapors, respiratory symptoms appear: irritation and inflammation of the respiratory tract with cough and wheezing, increased salivation. People with respiratory diseases get toxic vapors into the lungs quickly leading to their swelling and stopping breathing.

Symptoms of acute oral exposure to liquid dichloroethane are similar to those of poisoning in pairs, but they are more pronounced and are manifested by pain along the esophagus and in the epigastric region, nausea and frequent vomiting (with a trace of blood), bloody diarrhea. Since dichloroethane is referred to hepatotoxic (hepatotropic) poisons, the main impact is on the liver - with damage to the hepatocytes, an increase in the size of the organ, its inflammation (there may be fever and jaundice of the skin). Clearly localized hepatic pain is noted on the third to fourth days after the appearance of the first symptoms of poisoning, that is, at the somatogenic stage.

If the most unfavorable variant of the development of the clinic for dichloroethane poisoning was avoided, after two to three weeks - thanks to treatment - the patient will begin to recover, but complications from certain organs can worsen his health for a long time.

Diagnostics of the poisoning with dichloroethane

Not always symptoms of poisoning indicate the substance that provoked it. Analyzes of blood and urine can establish the presence of dichloroethane metabolites in the first day after the toxic substance enters the body.

The blood test also reveals anemia and neutrophilic leukocytosis in the affected people.

Instrumental diagnosis consists in removing the ECG.

More information in the material -  Diagnosis of acute poisoning

[12], [13], [14]

Differential diagnosis

The task that differential diagnostics should solve is to distinguish between ethylene dichloride poisoning from food poisoning, manifestations of acute anthropozoonotic infections, acute forms of gastroenteritis or pancreatitis.

[15], [16]

Treatment of the poisoning with dichloroethane

The first aid rendered in time will facilitate the condition of the victim and will improve the prognosis of the poisoning outcome, for which it is necessary:

• call a medical resuscitation team or emergency care;
• Ensure the access of fresh air, while stopping breathing - doing artificial;
• when a toxic substance enters the stomach - the reception of activated carbon and intensive  washing of the stomach  with water (up to 15 liters).

Antidotes for poisoning with dichloroethane are limited to the synthetic derivative of L-cysteine (a precursor in the synthesis of the endogenous antioxidant glutathione) - Acetylcysteine (5% solution is injected into the vein drip at a rate of 70-140 mg / kg). This agent helps to accelerate the molecular cleavage of toxic metabolites of 1,2-DCE and activates the synthesis of glutathione in liver cells.

A clear symptomatic focus has drugs used to treat the effects of toxic effects of dichloroethane:

• glucose (infusion of 5% solution) and plasma-substituting drugs (Polyglukin, Reopoliglyukin, etc.);
• Unitiol (5% solution - 0.5-1 ml / kg, four times a day, IM);
• Cimetidine (in / m for 0.2 g every 4-6 hours);
• Lipoic acid (0.5% solution in / m - 3-4 ml);
• injections of GCS (most often prednisolone).

For functional maintenance of metabolic processes in the body against a background of damage to the kidneys and liver, plasmapheresis, hemosorption, hemodialysis is performed; more -  Hemodialysis for acute poisoning

Appoint vitamins: ascorbic acid, thiamine, pyridoxine, cyanocobolamine.

Also read -  Symptomatic intensive therapy for poisoning

Prevention

Measures to prevent poisoning with dichloroethane and other chlorinated hydrocarbons - compliance with all safety regulations at work and at home.

Workers of enterprises dealing with this toxic substance must work in premises with constant forced ventilation, in industrial filter respirators (gas masks) and in protective clothing.

[17], [18], [19]

Forecast

It is possible to predict the outcome of dichloroethane poisoning, and specialists in the field of intensive care and resuscitation do this by objectively evaluating the physiological and functional parameters of the patient's body and its individual organs. For this, doctors have clear criteria and systems. Read more -  Assessment of the severity of patients and predicting the outcome

[20], [21], [22]