Aluminium Phosphide Poisoning

Toxicology on aluminium phosphide, the characteristics, fatal dose,fatal period, sign and symptoms, postmortem appearance and medicolegal importance are discussed.

1. MARYAM JAMILAH BINTI ABDUL HAMID 082013100002 IMS BANGALORE Aluminium Phosphide

2. LEARNING OUTCOME Source Characteristics Mode of poisoning & fatal dose Signs and symptoms Post-mortem appearance Medicolegal importance

3. Source & characteristics Greyish green tablet, metallic taste , garlicky odour Solid fumigant pesticide, insecticide and rodenticide Widely used as grain preservative ( phosphite & hypophosphite of aluminium are non-toxic residues left in the grains) Celphos , Alphos , Quickphos , Phostoxin , Phosphotex Each tablet is 3g, can liberate 1g of phosphine (PH 3 ) when come in contact with moisture HCl in stomach accelerate the convertion

4. Mode of poisoning & fatal dose Ingestion Fatal dose: 0.5 g (1-3 tablets) Fatal period: 1-4 hours. Majority die within 24 hours Inhalation Fatal dose: inhale phosphine 400-600 ppm Fatal period: 1-4 hours. Majority die within 24 hours

5. Absorption & Excretion Ingest Absorbed from GI tract by simple diffusion Then, some ALP metabolised in liver & phosphine is slowly released Phosphine is oxidised slowly to oxyacids Excreted in urine as hypophosphine Inhale Rapidly absorbed from the lungs Excreted unchanged form through lungs

6. Action Inhibits respiratory chain enzymes and has cytotoxic action Inhibits electron transport; inhibits cytochrome oxidase

7. Signs and Symptoms INHALATION MILD : irritation of mucous membrane, acute respiratory distress , dizziness, easy fatigue, tightness in the chest, nausea, vomiting, diarrhoea, headache MODERATE : ataxia, numbness, paraesthesia , tremors, diplopia , jaundice, muscular weakness, incoordination and paralysis SEVERE (PH 3 > 0.3 ppm ): adult respiratory distress syndrome, cariac arrhythmias, congestive cardiac failure, pulmonary edema, convulsions, coma

8. INGESTION MILD : nausea, vomiting, headache, abdominal pain (patients usually recover) MODERATE & SEVERE : systemic manifestations are early and progressive and mostly fatal GIT : nausea, vomiting, diarrhoea , retrosternal pain CVS : hypotension, shock, arrhythmias, myocarditis, pericarditis, acute congestive heart failure RS : cough, dyspnoea , cyanosis, pulmonary edema, respiratory failure HEPATIC : jaundice, hepatitis, hepatomegaly RENAL : renal failure CNS : headache, dizziness, altered mental state, restlessness, convulsions, acute hypoxic encephalopathy, coma RARE : muscle wasting, tenderness and bleeding diathesis

9. Complications Cardiogenic shock (most common cause of death) Pericarditis Acute congestive cardiac failure Acute massive GI bleeding ARDS (high mortality)

10. Postmortem appearances Garlic-like odour at the mouth & nostrils & gastric content Blood-stained froth in the mouth & nostrils Mucous membrane of the lower part of esophagus, stomach & duodenum are congested Decreasing congestion of GI in small intestine Lungs, liver, spleen, kidneys & brain are congested Centrizonal haemorrhagic necrosis of the liver may be seen

11. Histopathology Stomach : congestion, edema, leucocytic infiltration, sloughing of gastric mucosa Lung : congestion, edema, desquamation of respiratory epithelium, thickened alveoli, lymphocytic infiltration Kidneys : congestion, necrosis, tubular degeneration and regeneration Adrenals : congestion, haemorrhage , necrosis, area of lipid depletion in cortex Heart : congestion, edema, fragmentation of fibres , focal necrosis, leucocytic infiltration Brain : congestion, edema

12. Medicolegal importance Suicidal in rural area of india Accidental poisoning by farmer who sleep near godown ; leaking phosphine from godown is possible Accidental poisoning by children which mistakenly ingest the tablets

13. Chemical tests 5 ml of gastric aspirate + 15 ml of water are put in a flask and the mouth is covered with a filter paper impregnated with 0.1 N silver nitrate. Flask is heated at 50C for 15-20 minutes. Filter paper turns black if phosphine present. A piece of filter paper impregnated with 0.1 N silver nitrate solution is used in the form of mask through which the patient breathes for 5-10 minutes. Filter paper turns black if phosphine present. (POSITIVE only when >6 g is ingested)

14. REFERENCES K.S NARAYAN REDDY,The Essentials of Forensic Medicine and Toxicology, 33 rd Edition, p. 527-529 R.K. SHARMA, Concise Textbook Of Forensic Medicine & Toxicology, 2 nd Edition V V PILAY, Textbook of Forensic Medicine & Toxicology, 15 th Edition

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