Inhalational toxicity of aluminum phosphide, an ongoing concern

Introduction: Aluminum phosphide (AlP) poisoning as a suicidal attempt or accidental poisoning has become notorious in Iran over the past decades. Phosphine gas as a colorless, flammable and highly toxic substance is released in contact of Phosphide with water (moisture) or acid. Common clinical manifestations include gastrointestinal symptoms, progressive metabolic acidosis, refractory hypotension, and dysrhythmia. Most reports of AlP poisoning are following ingestion of AlP. Unfortunately phosphine gas inhalation also may lead to life threatening toxicity, even at large areas. We aimed at reporting this incident for taking a public health emergency viewpoint, as this type of Aluminium Phosphide (AlP) poisoning may be reoccurred (although is relatively uncommon), at least in countries where AlP is still used by general population.Case reportA 60-year-old woman, with her 29-year-old daughter was referred to clinical toxicology department (CTD) in Imam Reza (p) hospital with upper abdominal discomfort and nausea, initially suspicious to food poisoning. The 29-year-old patient had a seizure attack once admission and after a short time cardiac arrest occurred. She immediately was intubated and CPR was performed. Unfortunately, resuscitation efforts were unsuccessful and she deceased after an hour. The course of events was so rapid that there was no time for any laboratory test.Mother suffered from shortness of breath, weakness, dizziness, restlessness, and nausea once admission. The patient had no fever and was alert and able to answer questions. There was an increase in QTC in ECG taken. The patient had no oral tolerance. Serum therapy, oxygen therapy, cardiac monitoring and other supportive measures were performed. Routine toxicology tests were negative. Metabolic acidosis was evident in the first VBG (PH: 7.31 PCO2:18.2 HCO3:9.2) Cardiology consult and echocardiography was performed and LVEF was 35%. With diagnosis of AlP poisoning, based on clinical and para clinical findings, magnesium sulfate, vial bicarbonate, pantazole and N-acetylcysteine were initiated. VBG was repeated several times and improved with supportive acidosis treatment. After taking a more accurate history it was revealed that the patient s neighbor had used a pesticide his home two days earlier and had left the house. Following investigations it was determined that the mentioned poison was rice tablet (aluminum phosphide) which was prepared from an invalid center and was placed in a large number in the neighboring house. The mother and daughter had inhaled the poison odor for the past two days and had been at home all the time until they had progressive symptoms leading to refer to hospital. History, clinical signs, and results of laboratory tests were in concordance with inhalation poisoning with AlP. On the fourth day of hospitalization after partial recovery, mother was discharged with acceptable general condition and self consent.Discussion and conclusionPhosphine gas toxicity following unintentional inhalation is not a common report in medical literature, although suicidal ingestions of aluminum phosphide tablets have been reported frequency in our country. Unfortunately because there is no accepted definitive treatment for this lethal poisoning, supportive measure is the only treatment option at present. A high level of vigilance and more restrictive policy is needed for prohibition of general population access to these pesticides and consequently prevention of the high rate of mortality following this preventable poisoning in our community.