Aluminium phosphide poisoning is
poisoning that occurs as a result of excessive exposure to
aluminium phosphide (AlP), which is readily available as a
fumigant for stored cereal grains and sold under various brand names such as QuickPhos, Salphos and Celphos. Aluminium phosphide is highly toxic, especially when consumed from a freshly opened container.[1][2] Acute aluminium phosphide poisoning (AAlPP) is a large though under-reported problem throughout the world, particularly in the
Indian subcontinent.
Signs, symptoms, and diagnosis
After ingestion, toxic features usually develop within a few minutes. The major lethal consequence of aluminium phosphide ingestion is profound
circulatory collapse, and is reportedly secondary to these toxins generated, which lead due to direct effects on
cardiomyocytes,[3] fluid loss, and adrenal gland damage.[4] The signs and symptoms are non-specific, dose dependent and evolve with time passing. The dominant clinical feature is severe
hypotension refractory to
dopamine therapy.[5] Other features may include dizziness, fatigue, tightness in the chest, headache,
nausea, vomiting,
diarrhoea,
ataxia, numbness,
paraesthesia, tremor, muscle weakness,
diplopia and
jaundice.[6][7][8][9] If severe inhalation occurs, the patient may develop
acute respiratory distress syndrome (ARDS),
heart failure,
arrhythmias,
convulsion and
coma. Late manifestation include liver and kidney toxicities.[6][7][8][9] Death can result from profound shock,
myocarditis and
multi-organ failure.[10]
The diagnosis of AAlP usually depends on the clinical suspicion or history (self-report or by attendants). In some nations, tablets of AlP are also referred to as "rice tablets" and, if there is a history of rice tablet ingestion, then it should be treated differently from other types of rice tablets that are made up of herbal products.[11] For a
silver nitrate test on gastric aspirate, diluted gastric content can be positive.[4]
Mechanism of toxicity
The toxicity of aluminium phosphide is attributed to the liberation of
phosphine gas, a
cytotoxic compound that causes
free radical mediated injury, inhibits vital cellular enzymes and is directly corrosive to tissues. The following reaction releases phosphine when AlP reacts with water in the body:
AlP + 3 H2O → Al(OH)3 + PH3, and
AlP + 3 HCl → AlCl3 + PH3 (stomach)
Management and outcome
The management of AAlPP remains purely supportive because no specific cure exists.[12] Mortality rates approach 60%. Correction of
metabolic acidosis is a cornerstone of treatment.[13] The role of
magnesium sulfate as a potential therapy in AlP poisoning may decrease the likelihood of a fatal outcome, and has been described in many studies.[10][9]
Prognosis
Aluminium phosphide has a fatal dose of between 0.15 and 0.5 grams (0.0053 and 0.0176 oz).[14] The mortality rates from AAlPP vary from 35 to 85 percent.[15] The actual numbers of cases may be much larger, as less than five percent of those with AAlPP eventually reach a tertiary care center.[10] Since 1992, when aluminium phosphide became freely available in the market, it had, reportedly, overtaken all other forms of deliberate poisoning, such as
organophosphorus and
barbiturate poisoning, in North India.[16] In a 25-year-long study on 5,933
unnatural deaths in northwest India, aluminium phosphide poisoning was found to be the major cause of death among all cases of poisonings.[17]
Incidents
It has been reported to be the most common method of suicidal death in
North India.[18][19] Deaths have also been reported in
Iran.[20] In January 2017, four children died at a
trailer park in
Amarillo, Texas, after the pesticide was used under the home to kill rats.[21] Several incidents of death in travelers in
Thailand and other parts of
Southeast Asia may have been caused by aluminum phosphide or
chlorpyrifos, an
organophosphate insecticide, used in an attempt to kill
bedbugs in hotels.[22][23] On November 16 2019, 2 children and an adult were killed in
Timișoara,
Romania, after the residential complex they were living in had been improperly vented after fumigation with AlP. It was later found there were other cases in the country that could have been linked to the misuse of this chemical.[24] In February 2020, aluminum phosphide poisoning resulted in one death and three serious injuries aboard a cargo ship traveling near France,[25] as the result of a botched fumigation procedure.[26]
The
CDC has classified
phosphine as immediately dangerous to life at 50
parts per million.[27] In a study from Saudi Arabia, poisoning was most common during fumigation of households.[28]
References
^Chugh, SN; Dushyant; Ram, S; Arora, B; Malhotra, KC (1991). "Incidence & outcome of aluminium phosphide poisoning in a hospital study". The Indian Journal of Medical Research. 94: 232–5.
PMID1937606.
^Singh S, Singh D, Wig N, Jit I, Sharma BK (1996). "Aluminum phosphide ingestion—a clinico-pathologic study". J Toxicol Clin Toxicol. 34 (6): 703–6.
doi:
10.3109/15563659609013832.
PMID8941200.
^Chugh, SN; Pal, R; Singh, V; Seth, S (1996). "Serial blood phosphine levels in acute aluminium phosphide poisoning". The Journal of the Association of Physicians of India. 44 (3): 184–5.
PMID9251315.
^Chugh SN, Kumar P, Aggarwal HK, Sharma A, Mahajan SK, Malhotra KC (1994). "Efficacy of magnesium sulphate in aluminium phosphide poisoning--comparison of two different dose schedules". J Assoc Physicians India. 42 (5): 373–5.
PMID7829435.
^
abGoel, A; Aggarwal, P (2007). "Pesticide poisoning". The National Medical Journal of India. 20 (4): 182–91.
PMID18085124.
^Chugh, SN; Dushyant; Ram, S; Arora, B; Malhotra, KC (June 1991). "Incidence & outcome of aluminium phosphide poisoning in a hospital study". The Indian Journal of Medical Research. 94: 232–5.
PMID1937606.
^Singh, D; Jit, I; Tyagi, S (1999). "Changing trends in acute poisoning in Chandigarh zone: A 22-year autopsy experience from a tertiary care hospital in northern India". The American Journal of Forensic Medicine and Pathology. 20 (2): 203–10.
doi:
10.1097/00000433-199906000-00019.
PMID10414665.
^Singh, D; Dewan, I; Pandey, AN; Tyagi, S (2003). "Spectrum of unnatural fatalities in the Chandigarh zone of north-west India—a 25 year autopsy study from a tertiary care hospital". Journal of Clinical Forensic Medicine. 10 (3): 145–52.
doi:
10.1016/S1353-1131(03)00073-7.
PMID15275009.
^Siwach, SB; Gupta, A (1995). "The profile of acute poisonings in Harayana-Rohtak Study". The Journal of the Association of Physicians of India. 43 (11): 756–9.
PMID8773034.