METALLIC POISONS ARSENIC MERCURY LEAD ARSENIC n n

METALLIC POISONS ARSENIC MERCURY LEAD

ARSENIC n n Metallic arsenic (black coloured) is not poisonous as it is not absorbed from the alimentary canal. Poisonous compounds of arsenic are: n n Arsenious oxide or arsenic trioxide. Known as white arsenic occurs as n n n Smooth white, heavy crystalline powder White and solid opaque mass Coopper arsenite (Scheele’s green) copper aceto arsenite (paris green or Emerald green. Arsenic acid Sodium and potassium arsenate Arsine – Arseniuretted hydrogen (Colourless gas with a garlie like odour).

Action n n Interferes with cellular respiration. Particularly vascular endothelium leading to increased permeability, tissue oedema and haemorr hge. Particularly intestinal canal. Locally : Irritation Remotely : Depression of the nervous system Uncouples mitochondrial oxidative phosphorylation

SIGNS AND SYMPTOMS Fulminant type n Massive doses (3 -5 gm) n Death in 1 to 3 hours. n From shock and peripheral vascular failure. n GIT symptoms are absent.

THE GASTROENTERIC TYPE n n n Commonest form. Resemble bacterial food poisoning. Symptoms appear ½ to 1 hr after ingestion. Sweetish metallic taste. Constriction in the throat and difficulty in swallowing. Burning colicky pain in GIT. Intense thirst. Severe vomiting – may be projectile. Purging with tensesmus, pain and irritation of the anus. Stool: - expelled frequently and involuntarily. First-dark coloured, stinking and bloody Later-Resembles rice water stools of cholera.

n n n Hepatic: Fatty infilteration Renal: Oliguria, uraemia, albuminuria with painful micturition, RBC and casts in urine. CVS: Acute circulatory collapse with vasodilatation vascular permeability, ventricular tachycardia, ventricular fibrillation. CNS: Headache, vertigo, hyperthermia tremors, convulsion, coma, general paralysis. Skin: Delayed loss of hair, skin eruptions.

NARCOTIC FORM n n n n GIT symptoms are very slight. Giddiness Formications Tenderness of muscles. Delirium Coma Death Rarely complete paralysis of extremities.

Arsine gas n when inhaled Acts as direct poison to Hb. n Haemolysis n Haemoglobinuria n Renal failure n Instantaneous death. n FATAL DOSE : 0. 1 -0. 2 gms of arsenic trioxide n FATAL PERIOD: 1 -2 days n

TREATMENT v v v v v Emetics Gastric lavage with large amounts of water and milk. Stomach wash at intervals. Demulsents BAL 400 to 800 gm on first day. 200 -400 mg on 2 nd day in divided doses. EDTA is superior to BAL DMSA (Succimer) 10 mg/kg orally. Penicillamine 100 mg/kg-4 divided doses for 5 days. Glucose saline with Na. HCO 3 Haemodialysis or exchange transfusion if necessary. Chelation therapy is ineffective in arsine poisoning.

P. M. APPEARANCES External n Eyeballs sunken n Skin- cyanosed Internal n Mouth, pharynx, oesophagus sometimes ulcerated n Stomach mucosa- swollen, oedematous and red either generally or in patches- esp: pyloric region. n Groups of petechiae on mucosa sometimes hge: s n Acute erosions or large ulcerations in pyloric end. n Sticky mucous with arsenic particles.

Intestines Ø Flaccid Ø Large flakes of mucous and very little feacal matter Ø Mucosa pale violet Ø Shows signs of inflammation Ø Submucous hges along the whole length

n Caecum and rectum n n Lungs n n Slight inflammation Congested and oedematous Liver and Kidneys Degenerative changes n In a decomposed body-stomach discoloured yellow by formation of arsenic sulphide n n Brain n n Oedema Arsenic values in blood-excess of 1 mgm %

CHRONIC POISNONING n n n n Accidental ingestion by those who work with the metal. Signs and symptoms CNS: Poly neuritis, anaesthesias, parasthesia encephalopathy. Skin: Pigmentation (Rain drop type) on skin flexures, temples, eyelids and neck. Hyperkeratosis of palms and soles Aldrich-Mees lines with thickening of nails. Eyes: Congestion, lachrymation, photophobia. GIT: Cirrhosis of the liver, nausea, vomiting, abdominal cramps, diarrhoea, salivation.

n n n Hepatic: Hepatomegaly, jaundice Haematologic: Bone marrow suppression, anaemia, thrombocytopoenia, leukaemia. General: Anaemia and weight loss. CVS and Kidneys: Chronic nephritis, cardiac failure, dependent oedema. R. S: cough, haemoptysis , dyspnoea

POST MORTEM APPEARANCE Small intestine-dilated, reddened, with thickened mucosa n Stomach-chronic gastritis n Liver may be fatty n Jaundice n Kidneys show tubular necrosis n CHEMICAL TESTS n Marshs’ test n Reinschs’ test

CIRCUMSTANCES OF POISONING n n n n n Homicide Orally mixed with some articles of food occasionally mixed with tobacco or cigars. Suicide- rare-because of pain. Accidental Admixture with articles of food, Improper medicinal use. Chronic poisoning Drinking well water containing arsenic Occasionally to produce abortion. Animal poison

DIFFERENCES BETWEEN ARSENIC POISONING AND CHOLERA Trait Arsenic poisoning Cholera 1. Pain in throat Before vomiting After vomiting 2. Purging After vomiting Before vomiting 3. Stools Rice watery, may contain blood Like rice water, no blood, passed in a jet. 4. Tenesmus and irritation Present Absent

5. Vomited matter Contains mucous, bile and blood 6. Voice Not affected Watery without mucous, bile and blood. Rough and whistling 7. Conjunctivae Inflamed Not inflamed 8. Analysis of excreta Arsenic present Cholera vibrio present 9. Circumstantial Of Arsenic poisoning evidence Other cases of cholera in the locality

MERCURY (QUICK SILVER) • • Liquid metal Bright silvery appearance Volatile at room temperature Two series of compounds Mercuric-soluble and intensely poisonous Mercurous- less soluble and less active Metallic mercury is not poisonous if swallowed as it is not absorbed. • Absorbed – If breathed or swallowed as vapour • If applied on skin or mucous membranes in finely divided state.

ACTION Affinity for cellular components essential for function and survival of the cell. Poisonous compounds Mercuric chloride- white or colourless-crystalline Mercuric oxide – Brick red crystalline Mercuric iodide – Scarlet red powder Mercuric cyanide – White prismatic Mercuric sulphide – Cinnabar- Artificial preparation is called vermilion Mercuric chloride – (Calomel) Mercuric nitrate Mercuric sulphate – etc.

SYMPTOMS First phase Acrid metallic taste Feeling of constriction in the throat Hoarse voice Difficult breathing Mouth, tongue, fauces-corroded, swollen, grayish white coating Hot burning pain in mouth extending down to stomach and abdomen Followed by nausea, retching, vomiting Vomit- Grayish slimy, mucoid material, blood, shreds of mucous membrane. Diarrhoea- blood stained stools, tenesmus Circulatory collapse.

INHALATION OF FUMES Ataxia Restriction of visual field Paresis Delirium

Second phase In 1 -3 days Glossitis and ulcerative gingivitis within 24 -36 hours. Severe infection, loosening of teeth and necrosis of jaw. 2 -3 days- Renal tubular necrosis Transient polyuria, albuminuria, cylindruria, uraemia, acidosis Recovery may occur with in 10 -14 days After many days- membraneous colitis- produces dysentery, ulceration of colonic mucosa, haemorrhage.

Organis mercurials CNS: Ataxia Dysarthria Paraesthesia Neuropathy Mental deterioration Coma Fatal Dose 1 -2 gm of mercuric chloride Fatal Period 3 -5 days

POST-MORTEM APPEARANCES Mucosa of GIT shows inflammation, congestion, coagulation and corrosion. If the person survives for a few days. Large intestine shows necrosis Acute tubular and glomerular degeneration or hemorrhagic glomerular nephritis. Liver-congested, shows cloudy swelling or fatty change.

CHRONIC POISONING (HYDRARGYRISM) From continuous, accidental absorption by workers. Excessive therapeutic use. Recovery from a large dose. Ointment as ext: application for a long time.

Symptoms Salivation Inflammation and occasionally blue line of gums and junction with teeth. Sore mouth and throat Loosening of teeth. GIT disturbances Anaemia Anorexia and loss of weight Chronic inflammation of kidneys with uraemia.

Tremors (Danbury tremors) First in hands Progresses to lips and tongue Finally involves arms and legs Moderately coarse and interspersed by jerky movements. Advanced condition is called Hatter’s shake or Glass blowers’ shake Patient is unable to dress himself, write legibly or walk properly Severest form “concussio mercurialis” no activity possible

Mercurial Erythism Psychological effects of Hg toxicity. Seen in persons working with Hg in mirror manufacturing. Signs & symptoms Anxiety Depression Shyness Timidity

Irritability Loss of confidence Mental depression Delusions and hallucinations Suicidal melancholia or maniac depressive psychosis Emotional instability Loss of memory Insomnia

Mercurialentis Eye change due to exposure of vapour of Hg. Brownish deposit of Hg through cornea on anterior lens capsule. Bilateral No effect on visual acuity.

Acordynia or Pink disease Idiosyncratic hypersensitivity reaction. Particularly seen in children Chronic mercury exposure in any form. Irritation of hands and feet Desquamation Loss of hair Hyper keratosis Excessive sweating

Circumstances of poisoning Accidental – use of strong solution in washing abscess cavities or irrigating the vagina, uterus or rectum. Sometimes abortifacient Homicidal and suicidal poisoning rare.