Forensic toxicology ( forensic science).ppt
- 1. Crimean federal university named after V.I. Vernadsky Medical academy named after S.I. Georgiyevsky Department of forensic medicine FORENSIC MEDICINE. FORENSIC TOXICOLOGY.
- 2. Lecture items General concepts Classification of toxicants Sources and circumstances of intoxication Conditions of toxic action Ways of penetration and elimination the toxic the body. Habituation to toxic. • • • • • in
- 3. General concepts Toxicology is the science that deals with: • identification and quantitative determination of toxic substances study of their physico-chemical peculiarity mechanisms of action on the body consequences of toxicants action signs of intoxication isolation, treatment and antidotes used in intoxication • • • • •
- 4. ) The origin of notion toxic and poison Toxic comes from: → toxikon (τοξικον) → toxo (τόξο) = bow, arrow → toxikos (τοξικές) → tako (τaκο) destruction, death ... → yew (English or European “Taxus Baccata” contains the alkaloid taxin = damage,
- 5. General concepts Toxic is a substance which penetrate from outside the body in small quantities and under certain conditions, by its chemical and physical- chemical action cause health disorder or death. Health disorder or death, together with the complex of symptoms and morphological changes caused by penetration of toxic in the body are known as intoxication or poisoning.
- 6. Pathophysiological classification of toxicants (By their action on the body, organs and tissues) marked morphological changes, mainly local. (caustic) with dystrophic and necrotic changes. directly. Corrosive Destructive severe toxic action on organs and tissues, Hematic cause changes in the blood components producing death or serious disorder without Functional macro and microscopic morphological changes.
- 7. Sources and circumstances of intoxication (Socio-juridical classification of intoxication) 1. Intentional or voluntary: • • • homicides by poisoning suicide toxicomania (addiction) – intentional form of periodic or chronic intoxication by repeated consumption of toxic substances
- 8. Sources and circumstances of intoxication (Socio-juridical classification of intoxication) 2. Accidental or involuntary: accidental itself - ingesting toxic as a result of carelessness, imprudence, ignorance; drug consumption - errors of doctor, pharmacist, the patient himself, unlawful medicine. May be errors of prescribing or drug delivery, administration, etc.. professional - can be industrial, agricultural due to ignoring the work protective measures. They are usually chronic. food intoxication - consumption of poisonous food or drink by their chemical or bacteriological
- 9. Conditions of toxic action The condition and severity of poisoning depends on: • • • • the the the substance introduced into the body body way of administration toxic behavior in the body, etc..
- 10. Conditions dependent on the substance Origin The extraction of substances from not recommended food sources, may make them toxic origin Oldness The age of some substances may induce or decrease the toxic effect.
- 11. Conditions dependent on the substance Dose The pharmaceutical dose is the amount of substance that can produce a determined result. Distinguish therapeutic, toxic, lethal doses. Concentration sulphuric acid Concentrate - aggressive corrosive Diluted - sulfuric lemonade 0.002%; poisoning with lead and barium. antidote in
- 12. Conditions dependent on the substance Physical state of toxic liquid solid gaseous Most dangerous are liquids and gases which readily dissolves in the body fluids and tissues ! However, the solubility can be changed ex: calomel (Hg2Cl2) + chloride (NaCl) → to sublimate (HgCl2) lead salts administered with coffee → tannate of lead (PbTiO3)
- 13. Conditions age sex weight dependent on the body • • • • • • individual predispositions hypo or hypersensitivity to toxic habituation to toxic
- 14. Conditions dependent on the body Age young people and children are more susceptible to toxicants as adults elders are susceptible to vascular, vomitive and purgative substances Sex women are less resistant to the toxic than men, especially pregnant women, lactating period, menstruation.
- 15. Conditions dependent on the body Health status of the determine: body • • • • absorption rate elimination rate transformation of toxic in toxins tolerance, etc.. the body Diseases generally decrease body resistance toxic. to
- 16. Hypersensitivity or intolerance Manifest reaction of the body to the toxic congenital acquired Excessive susceptibility - idiosyncrasy ("Idios" – own and "sincrasus" - constitution). Idiosyncratic was called the uncharacteristic response of a subject to a chemical substance that normally does not occur by the administration or its use.
- 17. Hyposensitivity or tolerance Diminished reaction of the body to the toxic congenital acquired Gained tolerance can occur to the alcohol, tobacco, opium, drugs etc.. It is considered that it is due to decrease the absorption and fixation of receptor cells, increasing the detoxification process, etc..
- 18. Habituation to toxic Habituation to the toxic is obtained by continuous administration of low dose and gradually increased, reaching to withstand, without clinical manifestations, toxic and even fatal doses.
- 19. Ways of penetration direct the toxic into the body indirect Direct contact hypodermic intramuscular Intravenous ... They are: with blood Indirect contact gastrointestinal respiratory Transcutaneous They are: less dangerous slower widespread with blood ... more dangerous faster
- 20. Corrosive substances Features: Action mainly irritating sear necrosis fusion. local, with effects: represented by acids, bases, phenol, formalin, hydrogen peroxide, potassium permanganate, etc.
- 21. Corrosive substances Acids are substances which molecules, in aqueous solution, dissociates into H + ions and saline radicals. The degree of dissociation determines the strength of the acid and toxicity. Ways of entry: Per os (most cases), Inhalation, Transcutaneous Transmucosal, etc..
- 22. Acids The mechanism of action Hydrogen ion (H +) • • • captures the tissue water coagulates protein acidic denatures proteins albumin HNO3 (> 30%) • Xantoproteic reaction: denatured proteins which contain cyclic amino acids (phenylalanine, tyrosine, tryptophan) form nitrocompounds (yellow) HCI, H2SO4 • heat emanation thermal action СН3СООН • high resorptive properties hemolysis
- 23. Morphological appearances The acute period The belated period stomatitis oesophagitis gastritis mediastinitis peritonitis pneumonia dystrophic changes • chemical burns (coagulative necrosis) around the mouth and on the mucosa of the digestive tract local inflammatory reactions. • in the myocardium, liver, kidney
- 24. Morphological appearances Coagulative necrosis (coagulation necrosis): • • • • • • relatively hard and dry (dehydrated) relatively superficial with rough crust on the surface surrounded by local inflammation color dark brown or brown-black (H + → Hb → hematoporphyrin, methemoglobin, acidhematin)
- 25. Morphological differentiation of acids acid Morphological appearance Sulphuric acid H2SO4 deep necrosis, brown-black Nitric acid HNO3 (> 30%) yellow burns Hydrochloric HCl acid mucosa of the digestive tract color get a dirty-gray • • acetic acid СН3СООН specific odor tumefaction of the mucosa of the upper segments of the digestive tract with dark-red pigment imbibition Oxalic acid HOOC-COOH Phosphoric acid H3PO4 marked mucosal hyperemia with multiple small hemorrhages
- 26. Corrosive substances Alkalis are substances containing hydroxyl group (OH) and an anion of the metal. As acids, the alkali strong depends on the Ways of entry: Per os (most cases) Inhalation Transcutaneous Transmucosal, etc.. degree of dissociation.
- 27. Alkaliеs Mechanism of action. OH group tumefies, merges and dilutes the proteins → alkali-albuminates, soluble in water. Due to high solubility alkalis penetrate deep into the tissues, forming a moist necrosis (the colliquative necrosis). Strong alkali degenerates not only soft tissue, the strong (hair, nails) is affected too. ! Heated alkali shows a greater destructive action.
- 28. Morphological appearances The acute period Deep colliquative necrosis: The belated period • forming multiple ulcers sometimes perforated mediastinitis peritonitis pneumonia • • no demarcation zone marked tumefaction and edema, mucosal folds disappear white-grey, sometimes greenish color. • • • • • dystrophic changes the internal organs in
- 29. Destructive substances substances which cause mainly destruction (dystrophic and necrotic action) on internal organs (kidney, liver, tract, brain). representatives: myocardium, digestive • Heavy metals – Mercury – lead Metalloids and – Arsenic • their compounds
- 31. Alcohol intoxication and his surrogates Ethyl alcohol (C2H5OH) surrogates: Insignificant risk (alcohol-based tinctures, alcohol-based water-solutions, colognes, lotions, etc.) Medium risk (technical liquids based on alcohol) High risk (imminent danger) (methanol, ethylene glycol, dichloroethane)
- 32. Alcohol intoxication and his Mechanisms of action: CNS depression Narcotic action (dichloroethane) Neurovascular (methylic alcohol) Due to their toxic metabolites surrogates Other action dependent impurities
- 33. Alcohol intoxication and its surrogates Alcohol dosage: <0.3 ‰ - no influence of alcohol (physiological) 0.3-0.5 0.5-1.5 1.5-2.5 ‰ ‰ ‰ - insignificant influence of alcohol – easy inebriety (drunkenness) – medium inebriety (drunkenness) severe inebriety (drunkenness) 2.5-3 ‰ – > 3 ‰ - severe alcohol intoxication 5-6 ‰ - fatal intoxication > 15 ‰ - sample contamination