MERCURY (QUICK SILVER) Properties of Mercury (as a transition metal): It has a Metallic taste. Since transition metals possess the shades of grey- brown-white, mercury decolourizes the mucous membranes (e.g gums) grey, and the lens of the eye brown. It has a melting point of -38.83 °C and boiling point of 356.73°C. It forms complex ions with variable oxidative states. Metallic Mercury is insoluble in water, but its ions do possess variable solubility in water.
MERCURY (QUICK SILVER) Liquid Mercury is not poisonous because: It has little to no solubility. It flows down the GI tract quickly (owing to its quick flowing property).
MERCURY (QUICK SILVER) Although Mercury is liquid at room temperature, it exhibits great tendency to vaporize even at room temperature. However, the vapourized mercury itself is not so much soluble.
MERCURY (QUICK SILVER) But vapourized mercury is toxic because instead of going down the GI tract, it enters the respiratory tract!! -- where it is easily diffused into the blood simply by following diffusion gradient.
MERCURY (QUICK SILVER) Whatother forms of mercury are poisonous? Mercurous ions, which have an oxidative state of 1 e.g Mercury (I) oxide are less soluble and less toxic. Mercuric ions, which have an oxidative state of 2, e.g Mercury (II) Oxide are more soluble and hence more toxic.
MERCURY (QUICK SILVER) Things to remember: Metallic Mercury and Mercury (I) compounds are not toxic. Vapourized Mercury and Mercury (II) compounds are toxic.
MERCURY (QUICK SILVER) Effects of Mercury toxicity on the body: Hypersensitivity reaction. Characterised by generalised body rash. Puffy, pinkish, painful, paraesthetic, perspiring & peeling hands & feet.
MERCURY (QUICK SILVER) Effects of Mercury toxicity on the body: Mercury binds to sulphydryl groups and inactivates key enzymes involved in preventing oxidative damage. So, typical signs of oxidative stress appear. Of all the organs, kidneys are most affected by oxidative stress, leading to Renal Failure. Oxidative stress also leads to brain damage, producing many neurological symptoms.
MERCURY (QUICK SILVER) Effects of Mercury toxicity on the body: Mercuryirreversibly inactivates S-adenosyl- methionine, which is necessary for catecholamine metabolism by COMT.
MERCURY (QUICK SILVER) Effects of Mercury toxicity on the body: So, due to the bodys inability to degrade catecholamines (e.g. Epinephrine), a person suffering from mercury poisoning may experience sympathomimetic effects: nervousness, profuse sweating, tachycardia, increased salivation, and hypertension.
MERCURY (QUICK SILVER) Effects of Mercury toxicity on the body: Mercury has a selective destructive effect on intestines, especially large intestine, from where it passes on to be excreted, leading to intestinal ulceration.
MERCURY (QUICK SILVER) Effects of Mercury toxicity on the body: Abortion: Exposure to mercury can also lead to abortion, as it can pass through the placental circulation.
AN EASY WAY TO REMEMBER ORGAN EFFECTSOF MERCURY POISONINGH (Acute+Chronic)– Hypersensitivity ReactionsA (Chronic) – AbortionR (Acute+Chronic) – Renal Failure (with brain damage)I (Chronic) – Intestinal ulcerationS (Acute+Chronic) – Sympathomimetic effects
ACUTE POISONING Effects appear soon if the vapourized poison is inhaled, and slowly if mercury (II) compounds are swallowed. It has a metallic taste, with a feeling of constriction in the throat, a burning sensation from mouth to stomach, and pain radiating over the abdomen. The Mouth, tongue and fauces become corroded and the mucous membrane appears grayish white.
ACUTE POISONING Nausea, vomiting (long stringy masses of white mucous, mixed with blood). Hypersensitivity reactions Sympathomimetic effects Collapse and Shock may ensue. Syncope and Convulsions may occur before eventual death.
ACUTE POISONING If death is delayed, on the 2nd-3rd day, salivation may further increase, the gums become swollen, and the breath foul. Renal lesions soon appear due to nephrotoxicity of mercury. The urine contains albumin and blood, and death ensues from renal failure (uraemia).
FATAL PERIOD Death may occur within a few hours, but is usually delayed for 3-5 days. Delayed deaths are usually due to renal failure (uraemia).
TREATMENT Stomach should be washed out with 250 ml of a 5 percent solution of sodium formaldehyde sulphoxylate. This substance reduces the Mercury (II) perchlorate (more soluble) to Mercury (I) chloride (less soluble).
TREATMENT Egg Albumin may be administered, which forms mercury albuminate (which is insoluble).
TREATMENT Medicinal Charcoal – Mercury adsorbs with charcoal’s surface, and hence gets removed without being absorbed by enterocytes.
TREATMENT If poison has been absorbed, British Anti-Lewisite (BAL) and penicillamine derivates (cuprimine) are effective antidotes. If Kidneys show signs of damage, alkaline fluids, peritoneal dialysis or hemodialysis may be necessary. Treatment of shock and collapse are also required.
POSTMORTEM APPEARANCE The tongue is white and sodden in appearance, and the mouth generally has a diffuse grayish white escharotic appearance. Mucous membranes of alimentary tract are inflamed and corroded. The muscular coats are softened, so that removing an organ causes its entire rupture.
POSTMORTEM APPEARANCE Kidneys show toxic nephritis. Liver shows fatty degeneration. Subendocardial haemorrhages are present in the heart.
CHRONIC POISONING (HYDRARGYRISM) This maybe the result of: The aftereffects of the acute attack, where absorbed mercury accumulated in body organs. Continuous accidental absorption in those working with the metal or its salts (as in the manufacture of thermometers, mirrors, or in police officers engaged in finger print detection work where finger print powder contains mercury).
SIGNS & SYMPTOMS OF CHRONIC POISONING Excessive salivation with metallic taste in mouth. Loosening of teeth with painful inflamed gums. Hypersensitivity Reaction. Abortion. Nephritis, leading to renal failure (serious complication). Intestinal ulceration, gangrene (especially of large intestine). Sympathomimetic effects.
SIGNS & SYMPTOMS OF CHRONIC POISONING Neurological Symptoms: Hatter’s shake tremor: It is an intentional tremor, which affects the hands, arms, tongue and later the legs. Erethism: Disturbance of personality, characterised by shyness, irritability, tremors, loss of memory and insomnia. Brown discoloration of the capsule of lens of the eye due to deposition of mercury (mercuria lentis) – It is observed through a slit lamp.
TREATMENT Removal of the patient from exposure to mercury, and promoting elimination of mercury by bowels and kidneys. Giving alkaline solution to the patient to fight metabolic acidosis, which has resulted from renal insufficiency.
POSTMORTEM APPEARANCE Drastic changes in the large intestine, with spreading necrosis, which may even involve whole of the large intestine. Renal damage, particularly tubular nephritis. Fatty degeneration of liver and cardiac muscle.
MEDICOLEGAL ASPECTS OF MERCURYPOISONING Accidental poisoning: Accidental ingestion of antiseptic solutions containing Mercury perchloride. Absorption of mercurial preparations applied to skin. Intravenous administration of organic mercurials as diuretics.
MEDICOLEGAL ASPECTS OF MERCURYPOISONING Accidental poisoning: In children, the use of ammoniated mercury in some bleaching creams Swallowing the sulphocyanide of mercury stick or tablet.
MEDICOLEGAL ASPECTS OF MERCURYPOISONING Homicidal, Suicidal cases of mercury poisoning are rare to none.