2.
Examination and Significance of Toxicological Cases
Slide 1: Title Slide
Title: Examination and Significance of Toxicological Cases
Subtitle: An Introduction to Forensic Toxicology
Slide 2: Preliminary Investigation
Case History: Gather background information from medical personnel,
family, eyewitnesses, or the crime scene to help toxicologists narrow down
potential toxins.
Symptoms Observed: Recording clinical symptoms helps in suspecting
specific poison groups.
Duration: The time between exposure and medical attention helps
classify the poisoning as acute, chronic, or delayed.
Slide 3: Clinical Treatment
Key Point: Knowing the treatments administered, such as activated
charcoal or antidotes, is vital because they can alter the concentration of
toxins in biological fluids.
Slide 4: Symptoms and Causes
Excessive salivation, cramps: Organophosphate poisoning.
Pinpoint pupils: Opiates (e.g., morphine, heroin).
Dilated pupils: Atropine, cocaine, amphetamines.
Convulsions: Strychnine, organochlorines.
Cherry red skin: Carbon monoxide poisoning.
Hallucinations, confusion: Deliriants, LSD, alcohol.
Slide 5: Post-Mortem Appearances (External)
The surface of the body and clothes may show stains of vomit or poison.
Corroded skin can show a color change:
o Nitric acid: brown skin
o Sulphuric acid, HCI: grey or black skin
o Carbolic acid: greyish-white skin
o Oxalic acid: grey skin
o Zinc chloride: whitish skin
o Hydrofluoric acid: reddish-brown skin
Slide 6: Post-Mortem Staining and Odor
Post-mortem staining: Can be dark-brown or yellow (phosphorus, acute
copper poisoning), or cherry-red (carbon monoxide poisoning).
Odor:
o Garlic-like smell: Phosphorus, arsenic, thallium.
o Sweet or fruity smell: Ethanol, chloroform.
o Rotten eggs smell: Hydrogen sulphide.
o Fishy or musty smell: Zinc phosphide.
Slide 7: Post-Mortem Appearances (Internal)
Smell: Unusual odor from brain tissues (cyanide, alcohol, phenol).
Mouth, Throat, Oesophagus: Examination can reveal inflammation,
erosion, or staining.
Upper Respiratory Tract: Look for signs of volatile irritants, such as
congestion and desquamation.
Slide 8: The Stomach
Hyperaemia: An irritant poison causes a patchy, deep crimson redness.
Softening: Corrosive poisons, especially alkaline ones, can soften the
stomach lining.
Ulcers: Poison-induced ulcers have thin margins, unlike those from a
disease.
Slide 9: Other Organs
Perforation: Can be seen in the stomach with strong mineral acids.
Stomach contents: Should be examined for fragments of poison.
Liver: Poisons like phosphorus, arsenic, and carbon tetrachloride can
cause liver necrosis.
Slide 10: Additional Organs
Kidneys: Parenchymatous degenerative changes are common in irritant
metal poisoning.
Heart: Subendocardial hemorrhages can occur with acute arsenic
poisoning.
Bladder, Vagina, and Uterus: Examined especially in cases of
suspected abortion.
Slide 11: Significance of Forensic Toxicology
A toxicology report provides crucial information on the substances present
in a person’s body and whether the amount is therapeutic or harmful.
Accurate diagnosis of poisoning is essential for medical and legal
purposes.
Slide 12: Xenobiotics and Toxicity
Toxicity: The fundamental capacity of a chemical to harm an organism.
Xenobiotics: Foreign substances that can harm an organism, including
drugs and industrial chemicals.
Toxicity Rating: An arbitrary grading of doses that cause toxic effects.
Toxicity Classification: Grouping chemicals based on their most
significant toxic effect (e.g., neurotoxic).
3. Collection and Preservation of Biological Evidence in Toxicological
Cases
Slide 1: Title Slide
Title: Collection and Preservation of Biological Evidence in Toxicological
Cases (Viscera/Body Fluids)
Slide 2: Collection in Survival Cases
This slide outlines the materials to be collected when a victim is still alive:
o Vomit/Stomach Content: Collect up to 300 mL.
o Stomach Wash: Collect up to 500 mL.
o Blood: Collect 10 mL (or up to 100 mL if a larger quantity is
available).
o Urine: Collect 100-200 mL (or the entire amount if a larger quantity
is available).
Slide 3: Collection in Fatal Cases (Autopsy)
This slide details the specimens to be collected during a post-mortem
examination:
o Stomach: The entire stomach should be collected.
o Small Intestine: Collect 100 cm in adults or 200 cm in children.
o Liver: The entire liver, preferably with the gall bladder, should be
collected.
o Spleen: Collect 500 mg.
o Kidneys: Collect one and a half kidneys from an adult or the entire
quantity from a child.
o Vitreous Humor: Collect the maximum amount possible.
Slide 4: Additional and Circumstantial Evidence
This slide shows specific materials to be preserved based on the
suspected poison:
o Alcohol: 10 mL of peripheral blood and vitreous humor.
o Drug of Abuse: 10 mL of blood.
o Carbon Monoxide: 10 mL of blood.
o Heavy Metals: A 10 cm shaft of bone, scalp hair with roots, and
nails.
o Inhalation/Volatile Substances: Lungs in an airtight container.
o Injected Poison: Skin, subcutaneous tissue, or muscle from the
injection site, along with a control sample.
Slide 5: Collection in Special Cases
This slide covers specific circumstances for collecting evidence:
o Criminal Abortion: Preserve the vagina, uterus, and ovaries.
o Exhumed Bodies: Preserve soil samples from around the body.
Slide 6: Preservation of Samples
This slide details the correct preservatives for various samples:
o Urine: Rectified spirit.
o Human Viscera: Saturated saline solution.
o Heart (Histopathological exam): 10% formalin.
o Blood (Carbon monoxide poisoning): A 1-2 cm layer of liquid
paraffin to prevent oxygen exposure.
o Blood (general): EDTA.
Slide 7: Submission to the Laboratory
Human viscera samples must be placed in separate glass bottles.
The lid of each bottle should be tightly sealed and labeled.
The bottles are then put in a locked box and sealed.
