Toxicology on aluminium phosphide, the characteristics, fatal dose,fatal period, sign and symptoms, postmortem appearance and medicolegal importance are discussed.
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
(PH3) when come in contact with moisture
HCl in stomach accelerate the convertion
4.
5. Mode of poisoning & fatal dose
1. Ingestion
Fatal dose: 0.5 g (1-3 tablets)
Fatal period: 1-4 hours. Majority die within 24
hours
2. Inhalation
Fatal dose: inhale phosphine 400-600 ppm
Fatal period: 1-4 hours. Majority die within 24
hours
6. 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
7. Action
Inhibits respiratory chain enzymes and has
cytotoxic action
Inhibits electron transport; inhibits cytochrome
oxidase
8. Signs and SymptomsINHALATION
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 (PH3> 0.3 ppm): adult respiratory
distress syndrome, cariac arrhythmias, congestive
cardiac failure, pulmonary edema, convulsions,
coma
10. Complications
Cardiogenic shock (most common cause of
death)
Pericarditis
Acute congestive cardiac failure
Acute massive GI bleeding
ARDS (high mortality)
11. 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
12.
13.
14. 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
15. 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
16. 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)
17. REFERENCES
K.S NARAYAN REDDY,The Essentials of
Forensic Medicine and Toxicology, 33rd Edition, p.
527-529
R.K. SHARMA, Concise Textbook Of Forensic
Medicine & Toxicology, 2nd Edition
V V PILAY, Textbook of Forensic Medicine &
Toxicology, 15th Edition