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Toxic substances and their effects on the human body

Toxic substances are any chemical compounds (toxins, drugs) that cause harm to the human body. These connections are in any aggregate state of gas, liquid, solid substance. Their effect on the body is local and General, and signs of lesions occur directly or remotely (in a few weeks, months, years).

Any toxic compounds that appeared in the Geosphere as a result of human activities, called anthropogenic toxic substances.

Specification chemical compounds

A variety of poisons of natural or industrial origin creates the need to divide them into groups. This is of practical importance – adequate first aid in case of poisoning by toxic substances.

When exposed to toxic substances disturbed physiological functioning of the organism. In some cases, this phenomenon is persistent, the professional poisoning. In their course they are acute (symptoms appear) and chronic, systematic poisoning in small doses over long periods of time.

Physiological classification of toxic substances:

  1. The nerve agents – sarin, VX, Tabun, soman. This is the most highly toxic substances that are currently prohibited for production and use. Signs of poisoning – reduced visual acuity, lacrimation, pupil constriction, chest pain, frequent heart contractions. Abruptly difficulty breathing, shortness of breath, then comes the spasm of the bronchi. In severe cases the first few minutes appear convulsions, death occurs from paralysis of the respiratory muscles.
  2. Skin-naivnye – mustard, lewisite. Enter the body by skin contact, causing inflammation and swelling. Substances have comprehensive defeat. A distinctive feature – the latent period before the appearance of the first signs of poisoning, at least 4 hours. The first symptoms – malaise, fever. Then appear skin lesions – redness, sores, blisters, rashes, burns. Once in the blood, toxic substances affect the nervous system and cause General poisoning of the body.
  3. Obscheyadovitym – hydrocyanic acid, carbon monoxide, cyanide compounds. Violate the the brain, heart, vessels, lungs. Symptoms – dizziness, nausea, disturbance of heart rhythms, chest pain type of heart attack, shortness of breath. In severe cases, convulsions, respiratory paralysis, cardiac arrest.
  4. Choking is phosgene, diphosgene. Mechanism of action – the defeat of the respiratory system. First, there is a toxic inflammation of the mucosa of the upper respiratory tract, then enter the toxic bronchitis and pneumonia. In severe cases, swelling and burns the lungs. Symptoms of severe intoxication temperature to 39° C and above, the lack of air. Then falls the blood pressure, quickens the pulse, develops collapse. Death occurs from pulmonary edema or complications – abscess, gangrene, bacterial pneumonia.
  5. Chemical irritant – adamsite, chloropicrin, chloracetophenone, diphenylchlorarsine. When breathing the poison gets on the mucous membranes of the eyes, nose, throat, quickly absorbed into the blood and is an irritant on nerve endings. Distinguishing feature – a person experiences severe pain. Symptoms – burning pain in the nose, throat, eyes, chest. Severe tearing, runny nose, shortness of breath, sneezing, coughing. Half an hour later the pain subside. Complications: conjunctivitis, severe bronchitis, pulmonary edema.
  6. Psihodelicheskaya – BZ. The first symptoms of poisoning appear not later than 3 hours after contact with toxic substances in the body – drowsiness, reduced efficiency. Then quickens the heart rate, skin and mucous membranes become dry. Later joined by confusion, and slurred speech. The period of action of toxic substances lasts up to 4 hours.

The same substance has different effects on the body. Minerals and vitamins contained in food, in moderate doses are useful to man in large quantities, become toxic and dangerous.

Classification of chemical elements:

  1. Carcinogenic Nickel, chromium, asbestos. Trigger mechanisms of origin and development of cancer cells, accelerate the process of metastasis.
  2. Mutagenic, mercury, lead. The effect on the human body manifests itself in the form of chromosomal damage and gene mutations. These minerals are slow, the years accumulate in the body.
  3. Sensitizing – drugs of chemical origin (antibiotics), dust, allergens. Weaken the immune system, and increase sensitivity to external stimuli, lead to allergies.
  4. Chemical compounds, acids, alkalis. Cause of chronic functional disorders in the body affect the reproductive system.

Hazard classes of toxic substances

Characteristics of toxic substances is the toxic effects of harmful substances, the degree of damage of the internal organs and systems, and other characteristics that divide the poisons into hazard classes. Is a reference value which is set in accordance with the regulations. Every toxic substance belongs to a hazard class.

1st class – extremely dangerous toxic substances. The list of these compounds includes:


  • Plutonium – a heavy, radioactive metal. It is most toxic in contact with skin, if inhaled or swallowed, leading to lung cancer, stomach. Tends to accumulate in the bone marrow, leading many years later to a violation of hematopoiesis.
  • Polonium is a soft radioactive metal. It is highly toxic, radiation induced skin lesions. Instantly penetrates deep into the body, irreversibly destroying tissue.
  • Beryllium, a highly toxic solid metal. Has a carcinogenic and irritant action. Causes severe lesions of the respiratory system.

2nd class – highly hazardous toxic substances. Chemical elements and compounds:

  • Arsenic is a brittle semi – metal. Ingestion causes pain, vomiting, diarrhea, affects the Central nervous system.
  • Hydrogen fluoride – a colorless sharp-smelling gas. Causes burns and ulceration of mucous membranes of eyes, mouth, respiratory tract. If skin symptoms do not manifest immediately. After a few hours starts swelling, pain and a General toxic effect on the body.
  • Lead – legkoplavkim metal. Affects the blood, joints, bones. In large concentrations, it leads to convulsions and loss of consciousness. In children it affects the brain, as a consequence, mental retardation.
  • Chlorine, a halogen, a poisonous gas. Cause suffocation, burns the lungs.

3rd class – moderately hazardous toxic substances. List of compounds and substances:

  • Phosphates are salts of phosphoric acid. Activate the cancer cells or during pregnancy pose a threat of miscarriage or premature birth, causing General poisoning of the body.
  • Nickel – metal plastic. Causes allergic reactions, pigmentary changes of the skin.
  • Manganese – metal. Ingestion disturbs the metabolism and functioning of the brain, causing mental disorders – irritation, excitability and hallucinations.

4th class – low-hazard toxic substances. These include chlorides (compounds hydrochloric acid) and sulfates (salts of sulfuric acid).

As toxic substances enter the body

Routes of entry of toxic substances in the body are different and are determined from the condition of toxic compounds – gas, vapor, liquid, solid particles.

Most often the toxic elements enter through the respiratory system – nasal mucosa, larynx, bronchi and lungs. Large area of the alveolar system consists of thin membranes. In this case, the poisons quickly enter the bloodstream and spread throughout the body. The first will be under attack the Central nervous system. Penetrating poisons and aerosol substances. Their action comes 20 times faster than when taken orally.

Second place is a poisoning in which substances in the gastrointestinal tract with food and water. Absorption in the stomach and intestines is a slow process, so before the onset of symptoms takes some time. If the stomach were food, the absorption process is slowed down. The spread of toxic substances inhibit the receptors in the intestine and liver. So food poisoning is less dangerous.

Leather is a good protective barrier. Therefore, through the skin only penetrate those substances which easily destroy its integrity. Reduces the intensity of penetration of sweating, high humidity, intense sunshine.

Through the mucous membranes of toxic substances to penetrate quickly into the blood stream.

The wound surface is an ideal entry gate for toxic compounds. Muscle tissue has many capillaries, so the poisons are spreading rapidly through the body. In case of burns and frostbites the process of absorption slows down.

With potentially toxic substances people face every day. If their number exceeds the normal values, there is a poisoning of the body, the degree of which depends on the dose. For neutralization of toxic compounds administered antidotes and therapy that promotes rapid removal of toxins.