Phosphine Gas Research Articles

Fumigation Monitoring and Modeling of Hopper-Bottom Railcars Loaded with Corn Grits

IntroductionBulk railcars are a common method of moving commodities in the USA. Allowances are given for the practice of treating railcars with fumigates during transit because the routes are limited access and not on public roads. Recent technology has become available for monitoring phosphine gas (PH3) fumigation on railcars which logs the phosphine concentration and temperature of the test point in the railcars.Materials and MethodsTwo hopper bottom railcar shipments of corn grit were monitored for phosphine during 8-day transit from mill to processor. Several phosphine-sensing units were used in each railcar and spaced across the top layer. Mathematical modeling of the railcar fumigation was carried out using computational fluid dynamic software. Because access to lower depths in the railcar was not available, supplement experiments were performed with small columns of corn grits (2.5 m height x 0.55 m diameter) to test for phosphine at greater depths. Also, in the grain columns, bioassays of both phosphine susceptible and resistant, adult Rhyzopertha dominica (F.), lesser grain borer, and Tribolium castaneum (Herbst), red flour beetle, were included at the 0 cm, 25 cm, and 60 cm below the surface.ResultsThe phosphine concentrations in the railcar headspace varied with time with phosphine spiking over 1600 ppm and gradually settling to over 300 ppm at the end of the 8 days. Total gas dosage was estimated as concentration*time (CT) over the 8 days as 115,000 and 125,000 ppm*h at the top of each railcar. The supplement grain column fumigation tests found significant phosphine penetration into the column at 2 m depth with ~380 ppm after 2 days which reduced to ~260 ppm after 8 days, and all insects, at all locations, were dead after 8 days. The CFD simulation models were shown to provide estimates of the phosphine concentration and distribution which matched well with the observed data, validating the CFD approach as a useful tool.DiscussionThe simulation models were shown to provide estimates of the phosphine concentration and distribution which matched well the observed data, validating the CFD approach as an efficient tool for future planning and analysis of similar fumigations.

Resistance to Phosphine In Rice Weevil <i>Sitophilus oryzae</i> (L.) from South India

Rice weevil Sitophilus oryzae (L.) is one of most serious insect pests of stored grains. Management of this is thus vital and fumigation with phosphine gas is the most common method. However, overreliance on this has resulted in the development of heritable resistance in S. oryzae. The detection of frequency and distribution of phosphine resistance is crucial for the development of resistance management strategy. This study assesses the frequency, strength and distribution of phosphine resistance in S. oryzae populations from four southern states of India viz., Tamil Nadu, Kerala, Andhra Pradesh and Telangana. The bioassay results revealed that all these survived at both the discriminating concentrations of 0.04 and 0.25 mg/ l. There were no susceptible and weak resistant populations, and exhibited varied frequency of strong resistance ranging from 13.33 to 80.90%. The populations from Pudukottai (80.90%) recorded high frequency of strong resistance followed by Trichy (68.97%) and Tirunelveli (67.82%) ones; the one from Thiruvarur exhibited lowest (13.33%). The results indicated that the resistance to phosphine in S. oryzae was common and prevalence of strong resistant individuals was prevalent across the sampled regions.

Investigation of structural properties of Mg-doped twisted bilayer graphene for phosphine gas detection

ABSTRACT This study has investigated the adsorption of phosphine toxic gas molecule on monolayer graphene, bilayer graphene and twisted bilayer graphene with, and without Magnesium impurity. The results of absorption energy studies using density functional theory (DFT) showed that bilayer graphene provides better adsorption than monolayer graphene and a difference in adsorption energy will be observed for twisted bilayer graphene with a rotation angle of 21.78°. By adding Mg impurity to the configurations, the sensitivity, and working temperature of the twisted bilayer graphene with Mg impurity increase compared to twisted bilayer graphene. Also, working temperature, and value of adsorption energy were calculated for bilayer graphene with Mg impurity less than Mg-doped twisted bilayer graphene, and monolayer graphene with Mg impurity.

알루미늄 포스파이드 중독 사망 사례

Aluminum phosphide is a fumigant used to kill insects or other animals in stored grains. We report a suicidal case using aluminum phosphide and phosphine gas was detected in the post-mortem specimen. Headspace gas chromatographic method with mass detector(HS-GS/MS) was used to detect phosphine from the gastric contents and the scene evidence.

Treatment of critical aluminum phosphide (rice tablet) poisoning with high-dose insulin: a case report

BackgroundAluminum phosphide (rice tablet) is a highly efficient agent for preserving grains against rodents and insects. It accounts for a large number of poisoning cases. Aluminum phosphide poisoning has a high mortality rate of about 90%, and to date, no antidote is available. It releases phosphine gas after exposure to moisture, and this reaction is catalyzed by the acidity of the stomach. Phosphine is then absorbed throughout the respiratory or gastrointestinal tracts and causes toxicity through inhibition of cytochrome c oxidase and formation of highly reactive free radicals. Treatment of patients with aluminum phosphide poisoning is supportive, including mechanical ventilation and vasopressors. The usage of infusion of glucose-insulin-potassium in rice tablet poisoning has been suggested, after its positive beneficial cardiac inotropic effects in patients with beta-blocker and calcium channel blocker poisoning.Case presentationWe report the case of a 30-year-old Iranian woman with critical aluminum phosphide poisoning, presented with hypotension and other signs of shock and severe metabolic acidosis, successfully treated with high-dose regular insulin and hypertonic dextrose and discharged from hospital in good condition. In contrast to our previous experiences, in which nearly all patients with critical aluminum phosphide poisoning died, this patient was saved with glucose-insulin-potassium.ConclusionAluminum phosphide poisoning has a high mortality rate, and to date, no antidote is available. Administration of high-dose intravenous regular insulin and dextrose is suggested as a potential life-saving treatment for patients with critical aluminum phosphide poisoning.

Inhibition of mitochondrial permeability transition pore and antioxidant effect of Delta-9-tetrahydrocannabinol reduces aluminium phosphide-induced cytotoxicity and dysfunction of cardiac mitochondria

Previous studies have demonstrated that phosphine gas (PH3) released from aluminium phosphide (AlP) can inhibit cytochrome oxidase in cardiac mitochondria and induce generation of free radicals, oxidative stress, alteration in antioxidant defense system and cardiotoxicity. Available evidence suggests that cannabinoids have protective effects in the reduction of oxidative stress, mitochondrial and cardiovascular damages. The objective of this study was to evaluate the effect of trans-Δ-9-tetrahydrocannabinol (THC) on AlP-induced toxicity in isolated cardiomyocytes and cardiac mitochondria. Rat heart isolated cardiomyocytes and mitochondria were cotreated with different concentrations of THC (10, 50 and 100 μM) and IC50 of AlP, then cellular and mitochondrial toxicity parameters were assayed. Treatment with AlP alone increased the cytotoxicity, depletion of cellular glutathione (GSH), mitochondrial reactive oxygen species (ROS) generation, lipid oxidation, mitochondria membrane potential (ΔΨm) collapse and mitochondrial swelling, when compared to control group. However, incubation with THC (10, 50 and 100 μM) attenuated the AlP-induced changes in all these parameters in a THC concentration-dependent manner. Interestingly, the obtained results showed remarkably significant protective effects of THC by attenuation the different parameters of cytotoxicity, mitochondrial toxicity and oxidative stress induced by ALP in isolated cardiomyocytes and cardiac mitochondria. It is the first report showing the protective effects of THC against AlP-induced toxicity, and these effects are related to antioxidant potential and inhibition of mitochondria permeability transition (MPT) pore. Based on these results, it was hypothesized that THC may be used as a potential therapeutic agent for the treatment of AlP-induced mitochondrial dysfunction and cardiotoxicity.

Analysis of the Distribution of Total Phosphine and the Characteristics of Phosphine Poisoning in 29 Victims.

To study the distribution of total phosphine in phosphine poisoning victims and summarize the characteristics of phosphine poisoning cases. The phosphine and its metabolites in the biological samples of 29 victims in 16 phosphine poisoning cases were qualified and quantified by headspace gas chromatography-mass spectrometry. Five victims among 29 were poisoned by ingestion of aluminium phosphide and 24 by inhalation of phosphine gas. Phosphine metabolites were detected in the biological samples of 23 victims, and the concentrations of total phosphine in blood ranged 0.5-34.0 μg/mL. The total concentration of phosphine in liver tissue was up to 71.0 μg/g. Phosphine was not detected in the blood of the other six survived victims, which may be related to the small amount of phosphine exposure and the delay in blood sampling. The total concentration of phosphine in blood and tissues caused by aluminum phosphine ingestion is higher than that caused by phosphine gas inhalation. The death cases of phosphine inhalation are characterized by long exposure time, repeated exposures and age susceptibility.

Biochemical Toxic Response of Phosphine on Human Health Estimated From Enzymatic Variance in Trogoderma granarium.

The primary purpose of the current study was to study the possible pernicious effects of phosphine gas on enzyme activity alterations in Trogoderma granarium to determine its harmfulness to human beings after its prolonged exposure and intake. The saline extract of the adult Khapra beetle was biochemically analyzed at different doses, that is, from 10ppm to 30ppm, to accurately evaluate the effects of various phosphine concentrations (LC30 and LC50) on 2 distinct strains of this insect pest gathered from different godowns of Pakistan as resistant (Chitral [Chi], Haroon Abad [Hbd], and Lahore [Lhr]) and susceptible (Faqeer wali [Fqw], Khanewal [Khw], and Rawalpindi [Rwp]) populations. Our experimental results suggest that the enzyme levels (AcP, AkP, ALAT, ASAT, LDH, and ICDH) seemed to be elevated with increasing dosage of phosphine from 10ppm to 30ppm in the resistant populace of the susceptible ones. It also illustrates that phosphine and its residues can inhibit the workability of certain enzymes that are vital for respiration and neuro reactions in hexapods and mammals. It has detrimental effects of phosphine on human health profile to consume stored food products containing such tenacious enemies.

Reactivity passivation of red phosphorus with thin plasma-deposited carbon coating

Red phosphorus, when exposed to humid environments in air, breaks down into toxic phosphine gas and acidic phosphorus species, presenting a challenge for many applications, such as flame retardants or pyrotechnic obscurants. We have developed and characterized a method of plasma-deposited carbon to form a nanometer-thick, chemically stable carbon layer on red phosphorus particles to suppress phosphine and acidic phosphorus production. Using a combination of XPS surface analysis and a novel IR headspace analysis method, we developed and quantified an understanding of the reaction of red phosphorus with water vapor and the suppression of decomposition products using plasma-deposited carbon coatings. Phosphine production, quantified by IR, was accompanied by the formation of surface POx species produced as the particles react with water vapor. Increasing plasma deposition time increased thickness and uniformity of graphitic carbon coating, corresponding to a marked decrease in phosphine generation and formation of surface POx species.

Reducing the risk of death induced by aluminum phosphide poisoning: The new therapies

Numerous people suffer from accidental or deliberate exposure to different pesticides when poisoning with aluminum phosphate (AlP) is increasing in the eastern countries. Aluminum phosphate is a conventional insecticide that quickly reacts with water or the moistures in the atmosphere and produces fatal phosphine gas, which absorbs quickly by the body. Oral consumption or inhalation of AlP leads to excessive reaction of the body such as fatigue, vomiting, fever, palpitation, vasodilatory shock, increasing blood pressure, cardiac dysfunction, pulmonary congestion, shortness of breath, and death. The garlic smell from the patient's mouth or exhale is one of the methods to recognize the positioning. Due to the lack of individual antidotes, several supportive treatments are required. The present study focused on the available and new therapies that help reduce the effect of AlP poisoning and the mortality rate. The therapies are divided into the antioxidant-related agent and the other agents. The impacts of each agent on the experimental cases are reported.

Enhanced biological phosphorus removal from wastewater by current stimulation coupled with anaerobic digestion

The integrated wastewater discharge standard for phosphorus has become increasingly strict. In this study, a synergetic current stimulation system coupled with anaerobic digestion was used to enhance phosphorus removal from wastewater. The effects of current intensity, pH, and methane (CH4) synthesis on phosphorus removal were investigated. As direct current was supplied to an anaerobic bioreactor, the removal of sewage total phosphorus was significantly enhanced. The conditions of weak acid and low negative oxidation-reduction potential facilitated the phosphorus removal from wastewater. The optimal parameters for the dephosphorisation process were a current intensity of 100 mA and a pH of 6.0. When the anaerobic digestion process was inhibited by the reagent 2-bromoethanesulphonic acid sodium (BES), abundant metabolic intermediates accumulated and methanogenesis clearly decreased. Affected by the current stimulation and the inhibition of CH4 synthesis, the formation of gaseous phosphine (PH3) was greatly improved, and then PH3 escaped from the digestion mixture after it was absorbed by microbial cells. The maximum PH3 content of the digestion gas was 41.8 mg m−3 in the reactor supplied with a current of 100 mA and BES addition of 10 mmol L−1, and the phosphorus removal in this digestion system reached 55.2% at 6 d; however, the removal in the conventional anaerobic digestion system was only 17.7% after the same amount of time. Finally, a pathway of enhanced anaerobic biological phosphorus removal was proposed to better understand the inherent synergistic mechanism.

Management of aluminium phosphide poisoning with a holistic approach at NHL municipal medical college and hospital, Ahmedabad

Background: Aluminium phosphide is a usual ingredient of rodenticide and its poisoning is a common cause of suicide in India. Signs and symptoms of its toxicity are well-known. Its toxic effects are mainly due to liberation of phosphine gas which causes cell hypoxia due to inhibition of oxidative phosphorylation and results in circulatory failure. Aims and Objectives: Mortality with aluminium phosphide is high as there is no specific antidote available yet. And hence we need to explore holistic treatment approach to improve patient outcomes in aluminium phosphide poisoning. Materials and Methods: Present study discusses a holistic treatment approach to aluminium phosphide poisoning in this retrospective analysis of 100 cases from a tertiary care hospital in this study. Results: Around 65% patients survived due to the holistic treatment approach and correct treatment protocol with supportive therapy. Conclusions: The aggressive and appropriate management with continuous hemodynamic monitoring and holistic treatment approach can reduce the mortality significantly in aluminium phosphide poisoning.

Acute Aluminium Phosphide Poisoning: An Under reported Problem in India.

One of the foremost methods of committing suicide in India is aluminium phosphide (AlP) poisoning. AlP toxicity is induced by the discharge of phosphine gas, which induces cell hypoxia and circulatory failure because of suppression of oxidative phosphorylation. There is no specific antidote for AlP toxicity and treatment is mostly supportive. Although it is a common suicidal agent, the documented numbers are small due to the lack of patients who eventually reach tertiary care, due to the extreme toxicity of AlP.

The Effect of Levosimendan on Phosphine-Induced Nephrotoxicity: Biochemical and Histopathological Assessment.

Aluminum phosphide (AlP) toxicity is associated with a high risk of death due to heart, liver, and kidney failure as the target organs. Phosphine gas released due to the ingestion is the main factor involved in the multi-organ failure with various mechanisms. Levosimendan (LEV) is a calcium sensitizer with a pleiotropic effect on multiple organs. This study aimed to investigate whether LEV can alleviate AlP-induced nephrotoxicity in the rat model. Six groups included control group (almond oil only), sole LEV group (48 µg/kg), AlP group (LD50=10 µg/kg), and the poisoned groups treated with LEV at doses of 12, 24, and 48 µg/kg 30 min after AlP gavage. After 24 hours of treatment, serum and kidney samples were taken for biochemical and histopathological analyses. Biochemical analysis of the AlP group showed that the activity of complexes I, II, and IV was significantly reduced, while the levels of lipid peroxidation (LPO) and reactive oxygen species (ROS), lactate, and myeloperoxidase (MPO) activity significantly increased. Also, AlP reduced live renal cells and elevated necrosis. However, the levels of serum creatinine and blood urea nitrogen were not affected by the poisoning. LEV co-treatment could increase mitochondrial complex activity and reduce MPO activity, LPO, ROS, and lactate levels. Additionally, the histopathological analysis showed the detrimental effects of AlP on kidney tissue, which was mitigated by LEV administration. Our findings showed that LEV can potentially improve oxidative stress, imbalance in the redox status, necrosis, and pathological injuries in kidney tissue following AlP-poisoning.

High Concentration Organic Wastewater with High Phosphorus Treatment by Facultative MBR

Phosphorus is one of the main factors causing water eutrophication, and the traditional phosphorus removal process causes phosphorus-rich sludge pollution. The facultative MBR process uses phosphate-reducing bacteria to convert phosphate into directly recyclable gaseous phosphine to solve this malpractice and make sewage become a new phosphorus resource. In order to investigate the phosphorus removal efficiency and the mechanism under facultative conditions, run the facultative MBR reactor for 30 days. The COD value, phosphate concentration, and phosphine yield were measured, and the changes of sludge metabolic pathway abundance and community composition in different periods were detected. According to the measurement, the maximum phosphorus removal efficiency is 43.11% and the maximum yield of phosphine is 320 μg/m3 (measured by the volume of sewage). Combined with thermodynamic analysis, the microbial mechanism of the reactor was proposed, and the possible transformation pathway of phosphorus was analyzed. At last, changes the phosphorus removal process from the ‘removal type’ to the ‘recycling type’.

Blocking vicious cycle of cardiac dysfunction by external cardiopulmonary resuscitation is the key to rescue acute aluminium phosphide poisoning.

Aluminium phosphide (ALP) and aluminium zinc phosphide (ZnP), the two main ingredients of fumigation drugs, are commonly used to kill insects or rodents in grain. When exposed to water, highly toxic phosphine gas is released and absorbed through the respiratory or digestive tract. Phosphine gas could non-selectively block cytochrome oxidase, inhibit electron transfer and suppress oxidative phosphorylation, leading to cellular hypoxia and organ dysfunction. The characteristic clinical manifestations are refractory shock and metabolic acidosis with high mortality. However, patients with ALP poisoning have a chance to be cured. Here, we report a case of oral ALP poisoning that was successfully treated by extracorporeal membrane oxygenation (ECMO) combined with continuous renal replacement therapy (CRRT) during frequent ventricular fibrillation and cardiac dysfunction.

Transcriptomic Characterization of Inhalation Phosphine Toxicity in Adult Male Sprague-Dawley Rats.

Phosphine (PH3) is a highly toxic, corrosive, flammable, heavier-than-air gas that is a commonly used fumigant. When used as a fumigant, PH3 can be released from compressed gas tanks or produced from commercially available metal phosphide tablets. Although the mechanism of toxicity is unclear, PH3 is thought to be a metabolic poison. PH3 exposure induces multiorgan toxicity, and no effective antidotes or therapeutics have been identified. Current medical treatment consists largely of supportive care and maintenance of cardiovascular function. To better characterize the mechanism(s) driving PH3-induced toxicity, we have performed transcriptomic analysis on conscious adult male Sprague-Dawley rats following whole-body inhalation exposure to phosphine gas at various concentration-time products. PH3 exposure induced concentration- and time-dependent changes in gene expression across multiple tissues. These gene expression changes were mapped to pathophysiological responses using molecular pathway analysis. Toxicity pathways indicative of cardiac dysfunction, cardiac arteriopathy, and cardiac enlargement were identified. These cardiotoxic responses were linked to apelin-mediated cardiomyocyte and cardiac fibroblast signaling pathways. Evaluation of gene expression changes in blood revealed alterations in pathways associated with the uptake, transport, and utilization of iron. Altered erythropoietin signaling was also observed in the blood. Upstream regulator analysis identified several therapeutics predicted to counteract PH3-induced gene expression changes. These include antihypertensive drugs (losartan, candesartan, and prazosin) and therapeutics to reduce pathological cardiac remodeling (curcumin and TIMP3). This transcriptomics study has characterized molecular pathways involved in PH3-induced cardiotoxicity. These data will aid in elucidating a precise mechanism of toxicity for PH3 and guide the development of effective medical countermeasures for PH3-induced toxicity.

Addendum: Phosphine gas in the cloud deck of Venus

We published spectra of phosphine molecules in Venus' clouds, following open-science principles in releasing data and scripts (with community input leading to ALMA re-processing, now benefiting multiple projects). Some misconceptions about de-trending of spectral baselines have also emerged, which we address here. Using the JCMT PH3-discovery data, we show that mathematically-correct polynomial fitting of periodic ripples does not lead to "fake lines" (probability < ~1%). We then show that the ripples can be characterised in a non-subjective manner via Fourier transforms. A 20 ppb PH3 feature is ~5{\sigma} compared to the JCMT baseline-uncertainty, and is distinctive as a narrow perturber of the periodic ripple pattern. The structure of the FT-derived baseline also shows that polynomial fitting, if unguided, can amplify artefacts and so artificially reduce significance of real lines.

Successful Treatment of Acute Aluminum Phosphide Poisoning by Aloe Vera Syrup: A Case Report

Background: Aluminum phosphide, known as rice pill in Iran, is a very effective pesticide for commercial and industrial ‎use. The high lethality of Aluminum phosphide is due to Phosphine gas (PH3) which is released by its ‎reaction with water. One of the most important properties of aluminum phosphide, which despite being ‎very lethal to almost all living creatures, still makes it one of the most widely used pesticides, is its very ‎high yield, ease of use, and, most importantly, the absence of residues in products after application; while ‎its exposure to the human body is associated with high mortality.‎ Case Presentation: In this article, we reported the successful treatment of rice pill-induced poisoning in a 30-year-old man using a novel approach. Accordingly, we used sodium bicarbonate (50 ccs) and aloe vera syrup (1-2 L), followed by olive oil (150 cc olive oil was given every 2 hours). Conclusion: While numerous studies recommend observing patient conditions as the treatment approach, our presented case was a successful experience of treating acute aluminum phosphide poisoning.

Intentional pesticide poisoning and pesticide suicides in Nepal

Introduction Intentional pesticide poisoning is a major clinical and public health problem in agricultural communities in low and middle income countries like Nepal. Bans of highly hazardous pesticides (HHP) reduce the number of suicides. We aimed to identify these pesticides by reviewing data from major hospitals across the country and from forensic toxicology laboratories. Methods We retrospectively reviewed medical records of 10 hospitals for pesticide poisoned patients and two forensic laboratories of Nepal from April 2017 to February 2020. The poison was identified from the history, referral note, and clinical toxidrome in the hospitals and from gas chromatography analysis in the laboratories. Data on demographics, poison, and patient outcome were recorded on a data collection sheet. Simple descriptive analysis was performed. Results Among hospital cases (n = 4148), the commonest form of poisoning was self-poisoning (95.8%) while occupation poisoning was rare (0.03%). Case fatality was 5.3% (n = 62). Aluminum phosphide (n = 38/62, 61.3%) was the most commonly identified lethal pesticide for deaths. Forensic toxicology laboratories reported 2535 deaths positive for pesticides, with the compounds most commonly identified being organophosphorus (OP) insecticides (n = 1463/2535; 57.7%), phosphine gas (n = 653/2535; 25.7%; both aluminum [11.8%] and zinc [0.4%] phosphide) and organochlorine insecticides (n = 241/2535; 9.5%). The OP insecticide most commonly identified was dichlorvos (n = 273/450, 60.6%). Conclusion The data held in the routine hospital medical records were incomplete but suggested that case fatality in hospitals was relatively low. The pesticides identified as causing most deaths were dichlorvos and aluminum phosphide. Since this study was completed, dichlorvos has been banned and the most toxic formulation of aluminum phosphide removed from sale. Improving the medical record system and working with forensic toxicology laboratories will allow problematic HHPs to be identified and the effects of the bans in reducing deaths monitored.