Taiwan National Poison Center survey of glyphosate--surfactant herbicide ingestions

Forensic significance of Roundup Full® II effect on the development of Dermestes maculatus (Coleoptera: Dermestidae) and Lucilia sericata (Diptera: Calliphoridae)

The most widely used herbicides in the world are glyphosate formulations. These have been used in self-poisoning and accidental poisoning. Dermestes maculatus (Coleoptera: Dermestidae) and Lucilia sericata (Diptera: Calliphoridae) are associated with decomposing human and animal remains. The aim of the study was to evaluate Roundup Full® II effects on saprophagous insects´ development. For this, green bottle flies and hide beetles were exposed to different doses of the herbicide. The duration of life cycles was recorded by observations made every 8 and 24 h. To register possible variations in size, external morphology, and female proportion, specimens of all developmental stages were collected. The duration of developmental stages in L. sericata did not change due to the herbicide, but this reduced all size parameters of puparium with pupae inside, the weight of L1, and of adults. The larval stage and total duration in D. maculatus were decreased by the highest dose, while size parameters of hide beetles remained unchanged at all development stages. In both flies and beetles, there was no evidence of abnormal external morphology and the female proportion did not change in response to the herbicide. Finally, this study exhibited an impact on L. sericata and D. maculatus, so the possibility that the herbicide may affect other forensically important species should be considered, but more work is needed. Taxonomic determination could be done as usual; however, caution should be exercised when estimating the postmortem interval. This study represents the first to analyze a glyphosate-based herbicide associated with Forensic Entomology.

Predicting mortality in paraquat poisoning through clinical findings, with a focus on pulmonary and cardiovascular system disorders

BACKGROUND

Paraquat, one of the most widely used herbicides, poses a significant risk of mortality through self-poisoning and subsequent multiple organ failure. The primary objective aimed to identify the factors associated with death in patients poisoned by paraquat.

METHODS

A cross-sectional retrospective review was conducted at a tertiary referral hospital over five years. Eligible patients presented with acute paraquat toxicity between 1 January 2016 and 31 December 2020. Medical records of 148 patients were reviewed.

RESULTS

The in-hospital fatality rate was found to be 21.8%. Multivariate analysis revealed that the amount of paraquat ingested and clinical presentations, particularly pulmonary and cardiovascular system disorders, were significantly associated with mortality.

CONCLUSION

Our study highlights that the amount of paraquat ingested, along with the presence of pulmonary and cardiovascular system disorders, can serve as prognostic indicators for mortality rates in cases of paraquat poisoning. These findings have important implications for physicians in predicting the prognosis and mortality of paraquat poisoning patients.

Evaluation of the herbicide glyphosate, (aminomethyl)phosphonic acid, and glyphosate-based formulations for genotoxic activity using in vitro assays

Glyphosate, the most heavily used herbicide world-wide, is applied to plants in complex formulations that promote absorption. The National Toxicology Program reported in 1992 that glyphosate, administered to rats and mice at doses up to 50,000 ppm in feed for 13 weeks, showed little evidence of toxicity, and no induction of micronuclei was observed in the mice in this study. Subsequently, mechanistic studies of glyphosate and glyphosate-based formulations (GBFs) that have focused on DNA damage and oxidative stress suggest that glyphosate may have genotoxic potential. However, few of these studies directly compared glyphosate to GBFs, or effects among GBFs. To address these data gaps, we tested glyphosate, glyphosate isopropylamine (IPA), and (aminomethyl)phosphonic acid (AMPA, a microbial metabolite of glyphosate), 9 high-use agricultural GBFs, 4 residential-use GBFs, and additional herbicides (metolachlor, mesotrione, and diquat dibromide) present in some of the GBFs in bacterial mutagenicity tests, and in human TK6 cells using a micronucleus assay and a multiplexed DNA damage assay. Our results showed no genotoxicity or notable cytotoxicity for glyphosate or AMPA at concentrations up to 10 mM, while all GBFs and herbicides other than glyphosate were cytotoxic, and some showed genotoxic activity. An in vitro to in vivo extrapolation of results for glyphosate suggests that it is of low toxicological concern for humans. In conclusion, these results demonstrate a lack of genotoxicity for glyphosate, consistent with observations in the NTP in vivo study, and suggest that toxicity associated with GBFs may be related to other components of these formulations.

The Significance of Estimated Glomerular Filtration Rate for Predicting Mortality in Glyphosate Herbicide-Intoxicated Patients: A Single-Center, Retrospective Observational Study

Background: Glyphosate herbicide (GH) is widely used worldwide. It has a higher fatality rate than expected. GH-poisoned cases are increasingly reported. Acute kidney injury in poisoned patients is one of several predictors of GH mortality. The aim of this study was to determine whether estimated glomerular filtration rate (eGFR) could predict kidney injury in GH intoxication. Methods: This was a retrospective study conducted at the emergency department (ED) of a single hospital between January 2004 and December 2021. A total of 434 patients presented with GH intoxication via oral ingestion, and 424 were enrolled. Their demographic characteristics, laboratory variables, complications, and mortality were analyzed to determine clinical predictors associated with GH-induced mortality using a logistic regression analysis. The relationship between GH intoxication and eGFR was determined based on the results of dominance analysis. Additionally, the comparison of creatinine and eGFR was performed through receiver operating characteristic (ROC) curves. Results: A total of 424 GH-poisoned patients were enrolled. Of them, 43 (10.1%) died. In the multivariable analysis, initial GCS (OR: 0.874; 95% CI: 0.765−0.998, p = 0.047), albumin (OR: 0.874; 95% CI: 0.765−0.998, p = 0.027), pH (OR: 0.002; 95% CI: 0.000−0.037, p < 0.001), QTc interval (OR: 1.018; 95% CI: 1.007−1.029, p = 0.001), and eGFR (OR: 0.969; 95% CI: 0.95−0.989, p = 0.003) were independent factors for predicting in-hospital mortality. In the dominance analysis of the relative importance of the predictive factors, pH accounted for the largest proportion at 35.8%, followed by QTc (20.0%), GCS (17.3%), eGFR (17.0%), and albumin (9.9%). Additionally, eGFR had a larger area under the ROC curve (0.846; 95% CI, 0.809−0.879) than that of creatinine (0.811; 95% CI, 0.771−0.848, p = 0.033). Conclusion: In sum, eGFR, considered a surrogate of renal function, was a useful prognostic factor for mortality in glyphosate herbicide-poisoned patients.

Case Fatality as an Indicator for the Human Toxicity of Pesticides-A Systematic Scoping Review on the Availability and Variability of Severity Indicators of Pesticide Poisoning

Objective: To investigate if case fatality and other indicators of the severity of human pesticide poisonings can be used to prioritize pesticides of public health concern. To study the heterogeneity of data across countries, cause of poisonings, and treatment facilities. Methods: We searched literature databases as well as the internet for studies on case-fatality and severity scores of pesticide poisoning. Studies published between 1990 and 2014 providing information on active ingredients in pesticides or chemical groups of active ingredients were included. The variability of case-fatality-ratios was analyzed by computing the coefficient of variation as the ratio of the standard deviation to the mean. Findings: A total of 149 papers were identified of which 67 could be included after assessment. Case-fatality-ratio (CFR) on 66 active ingredients and additionally on 13 groups of active ingredients were reported from 20 countries. The overall median CFR for group of pesticides was 9%, for single pesticides 8%. Of those 12 active ingredients with a CFR above 20% more than half are WHO-classified as “moderately hazardous” or “unlikely to present acute hazard”. Two of seven pesticides considered “unlikely to present hazard in normal use” showed a CFR above 20%. The cross-study variability of reported case fatality was rather low. Studies most often utilized the Glasgow Coma Score for grading the severity of poisoning. Conclusion: Although human pesticide poisoning is a serious public health problem, an unexpectedly small number of publications report on the clinical outcomes within our study period. However, CFRs of acute human pesticide poisoning are available for several groups of pesticides as well as for active ingredients showing moderate cross-study variability. Our results underline that CFR is an indicator of the human toxicity of pesticides and can be utilized to prioritize highly hazardous pesticides especially since there is limited correspondence between the animal-test-based hazard classification and the human CFR of the respective pesticide. The reporting of available poisoning data should be improved, human case-fatality data are a reasonable tool to be included systematically in the periodic statutory review of pesticides and their regulation.

Protective effect of melatonin against herbicides-induced hepatotoxicity in rats

Exposure to the herbicides Paraquat and Roundup® may cause cell lesions due to an increase in oxidative stress levels in different biological systems, even in the liver. The aim of this study was to analyze the effect of melatonin on liver of rats exposed to herbicides. A total of 35 rats were randomly divided into seven equal-sized groups: control, Paraquat, Roundup®, Paraquat + Roundup®, Paraquat + melatonin, Roundup® + melatonin, and Paraquat + Roundup® + melatonin. Samples of blood and hepatic tissue were collected at the end of the seventh day of exposure and treatment with melatonin. Body weight, hematological parameters, and histopathological, biochemical analyses and determination of oxidative stress levels in liver were evaluated. Body weight was compromised (P < 0.01). Alterations of hematologic parameters were significant when compared to control (P < 0.001). Biochemically, serum levels of albumin decreased (P < 0.001), but serum levels of alanine aminotransferase, aspartate aminotransferase, and alkaline phosphatase increased (P < 0.001). Histopathology revealed necrotic hepatocytes, portal and central-lobular inflammatory infiltrate, congestion of capillaries. Serum levels of thiobarbituric acid reactive substances were found to be significantly elevated (P < 0.05; P < 0.001), and serum level of reduced glutathione was significantly lower (P < 0.05; P < 0.001). The groups treated concomitantly with melatonin revealed results similar to those of the control. However, melatonin acted as a protective agent for the liver against experimentally induced hepatic toxicity, promoting prevention of body weight, oxidative stress, and normalization of hematological and biochemical parameters.

Poisoning of glutaraldehyde-containing products: clinical characteristics and outcomes

OBJECTIVE

This study describes the clinical characteristics, outcomes, and factors at presentation associated with death of cases poisoned by glutaraldehyde (GA)-containing products.

METHODS

We performed a 5-year retrospective cohort study (July 2013-June 2018) using data from the Ramathibodi Poison Center.

RESULTS

There were 244 cases included in this study. Most were men with a median age of 37 years. The GA-containing products were mainly used as farm disinfectants (99.2%), with a median concentration of 15%. Most products (76.2%) contained co-formulants such as cationic detergents and formaldehyde.Most circumstances were accidental (56.9%). The others were suicide attempts by ingestion, except one patient who intentionally injected GA subcutaneously. The most common route of exposure was ingestion (95.0%). Local symptoms in areas of exposure were common. Ingestion resulted in more severe local effects than other routes, and corrosive effects occurred in 23 cases (9.4%). Systemic signs and symptoms occurred in 149 patients (61.1%). Systemic effects included abnormal vital signs, desaturation, altered mental status, hypo/hypernatremia, hypokalemia, low bicarbonate/metabolic acidosis, acute kidney injury (AKI), hepatitis, and rhabdomyolysis. Systemic effects mostly resulted from ingestion. Most patients had mild severity, received only supportive treatment, and fully recovered. The median length of hospital stay was 2 days. The one case of subcutaneous injection developed both local and systemic effects but survived. The mortality rate was 3.7%. Multivariate analysis indicated that either neurological symptoms or AKI at presentation were associated with death.

CONCLUSIONS

In our study, patients were exposed to GA-containing products that were mainly used as farm disinfectants and were generally co-formulated with other substances. Poisoning with these products commonly resulted in mild local irritative symptoms. However, some cases developed corrosive symptoms, systemic effects, or even died. As neurological symptoms or AKI could prognosticate deaths; physicians should look for these factors in patients with GA exposure at presentation for close monitoring and aggressive treatment.

Urinary glyphosate biomonitoring of sprayers in vegetable farm in Thailand

In Thailand, glyphosate is popular herbicide to control pests in the agricultural sector. This study aimed to measure glyphosate exposure concentrations through inhalation, dermal contact, and urinary glyphosate concentrations among 43 vegetable farmers spraying glyphosate in Bungphra Subdistrict, Phitsanulok Province. Four types of spraying equipment were used, manual pump backpack (n = 3), motorized spray backpack (n = 22), battery pump backpack (n = 16), and high pressure pump (n = 2). Breathing zone air samples were collected using glass fiber filters; dermal contact samples were collected using 100 cm2 cotton patches attached on 10 body locations and urine samples were collected at 3 time points: morning void urine the day before spraying, the end of spraying event, and the morning void urine the next day of spraying. The results showed that the geometric mean (GM; geometric standard deviation [GSD]) of breathing zone concentrations of glyphosate exposure were 9.37 (10.17) μg/m3. The GM (GSD) of total dermal patches exposure concentrations were 7.57 (0.01) mg/h. The legs, back, and arms were the most exposed body areas. The GM (GSD) of urinary glyphosate was found highest among vegetable farmers using manual backpack 46.90 (1.35) μg/g creatinine. Farmers should wear masks and boots to reduce glyphosate exposure by inhalation and dermal contact.

Surgical treatment of pyloric stenosis caused by glyphosate poisoning: A case report

RATIONALE

Oral ingestion of glyphosate can induce gastrointestinal symptoms such as vomiting, abdominal pain, and hematochezia. Timely and effective treatment of pyloric stenosis caused by glyphosate poisoning is important.

PATIENT CONCERNS

The patient had a poor appetite, accompanied by nausea and vomiting of a small amount of dark brown material that resembled blood clots several times a day. Gastroscopy revealed gastric ulcer, a large pyloric antrum ulcer, and a deformed stomach cavity.

DIAGNOSIS

Pyloric stenosis due to glyphosate poisoning in a 36-year-old man.

INTERVENTIONS

The patients received distal gastrectomy and subsequently transferred to the ICU for further treatment. A mechanical ventilator was used to assist breathing.

OUTCOMES

Follow-up was conducted 3 years after surgery. The patient had no problem with food ingestion and experienced no discomfort, such as vomiting, nausea, coughing, or expectoration.

LESSONS

Gastrectomy is necessary to treat pyloric stenosis caused by glyphosate poisoning.

The qSOFA Score: A Simple and Accurate Predictor of Outcome in Patients with Glyphosate Herbicide Poisoning

This study aimed to investigate whether the quick Sequential Organ Failure Assessment (qSOFA) score at emergency department (ED) presentation can help improve the risk assessment of glyphosate-surfactant herbicide (GlySH) poisoning complications. A total of 150 patients presenting with acute glyphosate herbicide ingestion were enrolled in this retrospective observational study. The qSOFA scores at presentation, ΔqSOFA (calculated by subtracting the worst qSOFA score from 1 hr after admission from the qSOFA score at presentation), baseline characteristics, clinical courses and outcome were collected and analysed. A total of 41 patients had life-threatening complications (27.3%), and 14 patients died (9.3%). Patients with a qSOFA score of 0 at presentation had a 1.5% incidence rate of complications. As the qSOFA score at presentation increased from 1 to 3, the rate of life-threatening complications significantly increased from 29.6% to 100%. Patients with a ΔqSOFA of 1 had a higher frequency of complications than did patients with a ΔqSOFA of 0. The qSOFA score (OR: 8.39, 95% CI: 3.51-26.67) and ΔqSOFA (OR: 27.60, 95% CI: 3.87-575.67) were associated with the development of life-threatening complications in the multivariate analysis. The qSOFA score showed high sensitivity (97.56%), and the ΔqSOFA score showed high specificity (99.08%). The values of area under the curve were significantly higher in the models using the qSOFA and ΔqSOFA than they were in the models using previously known prognostic factors (p < 0.01). The clinician should pay more attention to patients with high qSOFA scores at presentation or an increase in the qSOFA score 1 hr after admission.

Prognostic Factors in Emergency Department Patients with Glyphosate Surfactant Intoxication: Point-of-Care Lactate Testing

An increasing number of suicide attempts involve the ingestion of glyphosate surfactant; hence, clinical toxicologists may encounter severe cases of glyphosate surfactant intoxication. In several other clinical conditions, serum lactate is used to predict outcome. We investigated the relationship between lactate levels and 30-day mortality from glyphosate surfactant poisoning. This retrospective analysis involved 232 patients who were admitted to the emergency department after acute glyphosate surfactant poisoning between January 2004 and June 2014. We used a receiver operating characteristic (ROC) curve to define the optimal cut-off point for lactate levels. A Kaplan-Meier 30-day survival curve was then analysed in terms of the defined cut-off level. We used multi-variate Cox proportional hazards regression analysis to determine the risk factors for 30-day mortality. Of the 232 patients, 29 died, yielding a case fatality rate of 12.5%. Lactate was significantly higher in non-survivors (6.5 ± 3.1 mmol/L) than in survivors (3.3 ± 2.2 mmol/L; p < 0.001), and elevated lactate was significantly associated with 30-day mortality. The area under the ROC curve of lactate levels was 0.836 [95% confidence interval (CI): 0.716-0.869]. Lactate levels higher than 4.7 mmol/L were associated with increased mortality in multi-variable analysis (hazard ratio: 3.2; 95% CI: 1.1-8.7). Besides lactate, age >59 years, corrected QT interval >495 ms and potassium >5.5 mmol/L were independent risk factors for 30-day mortality. Lactate is an independent predictor of 30-day mortality in patients with glyphosate surfactant poisoning. Early measurement of lactate levels may be a simple and practical way to assess the severity of intoxication.

Glyphosate-rich air samples induce IL-33, TSLP and generate IL-13 dependent airway inflammation

Several low weight molecules have often been implicated in the induction of occupational asthma. Glyphosate, a small molecule herbicide, is widely used in the world. There is a controversy regarding a role of glyphosate in developing asthma and rhinitis among farmers, the mechanism of which is unexplored. The aim of this study was to explore the mechanisms of glyphosate induced pulmonary pathology by utilizing murine models and real environmental samples. C57BL/6, TLR4-/-, and IL-13-/- mice inhaled extracts of glyphosate-rich air samples collected on farms during spraying of herbicides or inhaled different doses of glyphosate and ovalbumin. The cellular response, humoral response, and lung function of exposed mice were evaluated. Exposure to glyphosate-rich air samples as well as glyphosate alone to the lungs increased: eosinophil and neutrophil counts, mast cell degranulation, and production of IL-33, TSLP, IL-13, and IL-5. In contrast, in vivo systemic IL-4 production was not increased. Co-administration of ovalbumin with glyphosate did not substantially change the inflammatory immune response. However, IL-13-deficiency resulted in diminished inflammatory response but did not have a significant effect on airway resistance upon methacholine challenge after 7 or 21 days of glyphosate exposure. Glyphosate-rich farm air samples as well as glyphosate alone were found to induce pulmonary IL-13-dependent inflammation and promote Th2 type cytokines, but not IL-4 for glyphosate alone. This study, for the first time, provides evidence for the mechanism of glyphosate-induced occupational lung disease.

Heart rate-corrected QT interval predicts mortality in glyphosate-surfactant herbicide-poisoned patients

BACKGROUND

Glyphosate-surfactant herbicide is promoted by the manufacturer as having no risks to human health. Glyphosate surfactant has recently been used with increasing frequency in suicide attempts, so clinical toxicologists occasionally encounter cases of severe systemic toxicity. The purpose of this study was to identify the early predictive factors of patients at risk for mortality and the usefulness of the corrected QT interval (QTc interval) for predicting mortality from glyphosate-surfactant intoxication.

METHODS

This was a retrospective cohort study conducted from January 2005 to December 2012. A total of 153 patients with acute glyphosate-surfactant ingestion were included. To identify the predictive factors for mortality, objective variables easily assessed at presentation including previously reported predictive factors for mortality and severity were retrospectively analyzed for their association with mortality using univariate and multiple logistic analyses.

RESULTS

The average age of the patients was 56 years (range, 19-93 years). Of the 153 patients, 19 (12.4%) died. The most common abnormal electrocardiogram findings were prolonged QTc interval followed by intraventricular conduction delay and first-degree atrioventricular block. Nonsurvivors had a significantly more prolonged QTc interval when compared with that of survivors (survivors: 453.4 ± 33.6 milliseconds vs nonsurvivors: 542 ± 32.0 milliseconds, P < .001). Corrected QT interval and age were associated with a significantly increased risk of death in a multiple logistic regression. In a receiver operating curve analysis, the QTc interval had significant discriminatory power.

CONCLUSION

Prolonged QTc interval seems to be a useful prognostic factor for mortality in patients intoxicated with glyphosate-surfactant herbicide.

Use of a glyphosate-based herbicide-induced nephrotoxicity model to investigate a panel of kidney injury biomarkers

Accidental or intentional ingestion of glyphosate surfactant-based herbicides, like Roundup(®), leads to nephrotoxicity as well as death. In this study, a panel of kidney injury biomarkers was evaluated in terms of suitability to detect acute kidney injury and dysfunction. The Roundup(®) intoxication model involved oral administration of glyphosate to rats at dose levels of 250, 500, 1200 and 2500 mg/kg. Urinary and plasma biomarker patterns were investigated at 8, 24 and 48 h after dosing. Biomarkers were quantified by absolute concentration; by normalising to urine creatinine; and by calculating the excretion rate. The diagnostic performances of each method in predicting of acute kidney injury were compared. By Receiver Operating Characteristic (ROC) analysis of the selected biomarkers, only urinary kidney injury molecule-1 (KIM-1) best predicted histological changes at 8h (best cut-off point>0.00029 μg/ml). Plasma creatinine performed better than other biomarkers at 24 h (best cut-off point>0.21 mg/dl). Urinary KIM-1 was the best early biomarker of kidney injury in this glyphosate-induced nephrotoxicity model.

Hemodialysis clearance of glyphosate following a life-threatening ingestion of glyphosate-surfactant herbicide

CONTEXT

Ingestion of glyphosate-surfactant herbicides (GlySH) can result in acute kidney injury, electrolyte abnormalities, acidosis, cardiovascular collapse, and death. In severe toxicity, the use of hemodialysis is reported, but largely unsupported by kinetic analysis. We report the dialysis clearance of glyphosate following a suicidal ingestion of a glyphosate-containing herbicide.

CASE DETAILS

A 62-year-old man was brought to the emergency department (ED) 8.5 h after drinking a bottle of commercial herbicide containing a 41% solution of glyphosate isopropylamine, in polyoxyethyleneamine (POEA) surfactant and water. He was bradycardic and obtunded with respiratory depression necessitating intubation and mechanical ventilation. Initial laboratory results were significant for the following: pH, 7.11; PCO2, 64 mmHg; PO2, 48 mmHg; potassium, 7.8 mEq/L; Cr 3.3, mg/dL; bicarbonate, 22 mEq/L; anion gap, 18 mEq/L; and lactate, 7.5 mmol/L. Acidosis and hyperkalemia persisted despite ventilation and fluid resuscitation. The patient underwent hemodialysis 16 h post ingestion, after which he demonstrated resolution of acidosis and hyperkalemia, and improvement in clinical status. Serum glyphosate concentrations were drawn prior to, during, and after hemodialysis. The extraction ratio and hemodialysis clearance were calculated to be 91.8% and 97.5 mL/min, respectively.

DISCUSSION

We demonstrate the successful clearance of glyphosate using hemodialysis, with corresponding clinical improvement in a patient with several poor prognostic factors (advanced age, large volume ingested, and impaired consciousness). The effects of hemodialysis on the surfactant compound are unknown. Hemodialysis can be considered when severe acidosis and acute kidney injury complicate ingestion of glyphosate-containing products.

Influence of zinc supplementation on histopathological changes in the stomach, liver, kidney, brain, pancreas and spleen during subchronic exposure of Wistar rats to glyphosate

A subchronic toxicity study was carried out to determine the glyphosate-induced histopathological changes in the stomach, liver, kidney, brain, pancreas and spleen of rats and the attendant ameliorative effect when pretreated with zinc at the dose rate of 50 mg/kg body weight. The rats were exposed to two doses of the glyphosate (375 and 14.4 mg/kg body weight) for the period of 8 weeks which was the duration of the study, and some groups were exposed to the glyphosate after pretreatment with zinc. The histopathological changes recorded during the study were only in the rats exposed to the glyphosate at the dose rate of 375 mg/kg body weight except the vacuolation encountered in the brains and haemosiderosis in the spleens of rats exposed to zinc alone. Degenerated mucosal epithelial cells which involved the muscularis mucosa and the glands in the stomachs of rats were seen microscopically. Hepatic cells degeneration especially at the portal areas of the livers of rats was observed. The histopathological examination of the kidneys showed glomerular degeneration, mononuclear cells infiltration into the interstices of the tubules and tubular necrosis. The conspicuous changes seen in the brains were neuronal degeneration. Pancreatic acinar cells were degenerated while the spleen of the rats showed depopulated splenic cells in both the red and the white pulps. It was concluded that zinc supplementation in rats prior to glyphosate exposure ameliorated the histopathological changes observed in the stomach, liver, kidney, brain, pancreas and spleen with no observable alteration in the histoarchitecture in the organs of the zinc-supplemented rats.

Spectrum of corrosive esophageal injury after intentional paraquat or glyphosate-surfactant herbicide ingestion

BACKGROUND

Data on the spectrum of corrosive injury to the esophagus after paraquat or glyphosate-surfactant ingestion are sparse in the literature and confined to case studies and brief reports. Therefore, this study aimed to examine the clinical features, degrees of esophageal injury, and clinical outcomes after paraquat or glyphosate herbicide ingestion, and sought to determine what association, if any, may exist between these findings.

METHODS

We performed an observational study on 47 patients with paraquat or glyphosate ingestion who underwent endoscopic evaluation over a period of 11 years (2000-2011).

RESULTS

Corrosive esophageal injuries were classified as grade 1 in 14 (glyphosate-surfactant) and three (paraquat), grade 2a in nine (glyphosate-surfactant) and 18 (paraquat), and grade 2b in one (glyphosate-surfactant) and two (paraquat) patients. No patients had grade 0, 3a, or 3b esophageal injuries. Therefore, the severity of corrosive injury was more severe in the paraquat group (P = 0.005). After toxin ingestion, systemic toxicity occurred, with rapid development of systemic complications in many cases. Neurologic complications occurred more frequently in the glyphosate-surfactant group (29.2% versus 0%, P = 0.005), although respiratory failure (4.2% versus 34.8%, P = 0.008), hepatitis (12.5% versus 52.2%, P = 0.004), and renal failure (20.8% versus 52.2%, P = 0.025) developed more frequently in the paraquat group. Patients with glyphosate poisoning had shorter hospital stays than patients with paraquat poisoning (13.3 ± 15.1 days versus 26.8 ± 10.2 days, P = 0.001). Nevertheless, there was no significant difference in mortality rate between the glyphosate-surfactant and paraquat groups (8.3% versus 13.0%, P = 0.601). We ultimately found that patients with grade 2b esophageal injury suffered from a greater incidence of respiratory (100.0% versus 5.9%, P = 0.001) and gastrointestinal (66.7% versus 11.8%, P = 0.034) complications than patients with grade 1 injury, regardless of herbicide type.

CONCLUSION

Paraquat and glyphosate are mild caustic agents that produce esophageal injuries of grades 1, 2a, and 2b only. Our data also suggest a potential relationship between the degree of esophageal injury and systemic complications.

Serum biochemical assessment of hepatic and renal functions of rats during oral exposure to glyphosate with zinc

A subchronic toxicity study was carried out to assess hepatic and renal functions of rats during oral exposure to glyphosate with zinc for the period of 8 weeks. Forty-eight Wistar rats used for the study were randomized into six groups of eight Wistar rats each, and each group had equal number of male and female Wistar rats. The Wistar rats administered with distilled water at 2 ml/kg body weight served as the control group (DW); others were administered with zinc at 50 mg/kg body weight (Z) group, glyphosate at 375 mg/kg body weight (G) group, a combination of zinc and glyphosate at 50 and 375 mg/kg body weight, respectively (Z + G), group, glyphosate at 14.4 mg/kg body weight (GC) group, and a combination of zinc and glyphosate at 50 and 14.4 mg/kg body weight, respectively (Z + GC), group. At the end of the study, blood samples were collected from each rats; from which, sera samples were obtained and assayed for total protein, albumin, alanine and aspartate aminotransferases, alkaline phosphatase, Na⁺, K⁺, Cl⁻, \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$ \mathrm{HCO}_3^{-} $$\end{document}, Ca²⁺, \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$ \mathrm{PO}_4^{-} $$\end{document}, urea and creatinine using autoanalyzer, and globulin was calculated. The albumin concentration was significantly high (p < 0.05) in GC group compared to DW group, and this change was ameliorated following supplementation with zinc. The total protein and globulin concentrations did not differ significantly between the groups (p > 0.05), and the relative changes were ameliorated by supplementation with zinc. The alkaline phosphatase activity was relatively low in GC group; however, supplementation with zinc in Z + GC group made it to be significantly high (p < 0.05) compared to GC group. The alanine and aspartate aminotransferases in G and GC groups were relatively high compared to DW group, which were ameliorated by supplementation with zinc. The relatively low Ca²⁺ concentration in G and GC groups compared to DW were ameliorated in Z + G group, and it was significantly high in Z + GC group at p < 0.01 compared to DW, p < 0.001 compared to G and GC groups and p < 0.05 compared to Z + G group. There were only slight changes in the electrolytes concentrations (Na⁺, K⁺, Cl⁻, \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$ \mathrm{HCO}_3^{-} $$\end{document} and \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$ \mathrm{PO}_4^{-} $$\end{document}), which were differentially ameliorated by zinc supplementation. The reasons for the various changes recorded were discussed. It was concluded that subchronic oral exposure to glyphosate caused both hepatic and renal functions toxicity in rats, which were ameliorated by zinc supplementation.

Determination of glyphosate and AMPA in blood and urine from humans: about 13 cases of acute intoxication

Acute intoxications after ingesting glyphosate are observed in suicidal or accidental cases. Despite low potential toxicity of this herbicide, a number of fatalities and severe outcomes are reported. Indeed, some authors have described the clinical features associated with blood and urine concentrations following intoxication. The purpose of this study is to describe the clinical feature and determinate the utility of the glyphosate concentration in blood and urine and the dose taken for predicting clinical outcomes. In 13 glyphosate poisoning cases treated in our laboratory within 7 years period from 2002 to 2009, we registered clinical observations and collected blood and urine samples to HPLC-MS-MS analysis. We classified our patients by the intoxication severity using simple clinical criteria. We obtained clinical observations from 10 patients and the others three patients were treated in forensic cases. Among the 10 patients, one was asymptomatic, 5 had mild to moderate poisoning and 2 had severe poisoning. There were 6 deaths whose 3 were forensic cases. The most common symptoms were oropharyngeal ulceration (5/10), nausea and vomiting (3/10). The main altered biological parameters were high lactate (3/10) and acidosis (7/10). We also noted respiratory distress (3/10), cardiac arrhythmia (4/10), hyperkaleamia, impaired renal function (2/10), hepatic toxicity (1/10) and altered consciousness (3/10). In fatalities, the common symptoms were cardiovascular shock, cardiorespiratory arrest, haemodynamic disturbance, intravascular disseminated coagulation and multiple organ failure. Blood glyphosate concentrations had a mean value of 61 mg/L (range 0.6-150 mg/L) and 4146 mg/L (range 690-7480 mg/L) respectively in mild-moderate intoxication and fatal cases. In the severe intoxication case for which blood has been sampled, the blood glyphosate concentration was found at 838 mg/L. Death was most of the time associated with larger taken dose (500 mL in one patient) and high blood glyphosate concentrations. To predict clinical outcomes and to guide treatment support in patients who ingested glyphosate, blood concentrations of this compound and the taken dose have been useful.

Risk and prognostic factors of inpatient mortality associated with unintentional insecticide and herbicide poisonings: a retrospective cohort study

Introduction

Pesticide poisoning is an important public health problem worldwide. The study aimed to determine the risk of all-cause and cause-specific inpatient mortality and to identify prognostic factors for inpatient mortality associated with unintentional insecticide and herbicide pesticide poisonings.

Methods

We performed a retrospective cohort study of 3,986 inpatients recruited at hospitalization between 1999 and 2008 in Taiwan. We used the International Classification of Disease, 9th ed., Clinical Modification external causes of injury codes to classify poisoning agents into accidental poisoning by insecticides and herbicides. Comparisons in mortality rates were made between insecticide poisoning patients and herbicide poisoning patients by using the Cox proportional hazards models to estimate multivariable-adjusted hazard ratios (HRs) and their 95% confidence intervals (CIs).

Results

There were 168 deaths during 21,583 person-days of follow-up evaluation (7.8 per 1,000 person-days). The major causes of mortality for insecticide poisonings were the toxic effect of organophosphate and coma, and the major causes of mortality for herbicide poisonings were the toxic effect of other pesticides and the toxic effect of organophosphate. The mortality for herbicide exposure was fourfold higher than that for insecticide exposure. The factors associated with inpatient mortality were herbicide poisonings (HR = 4.58, 95% CI 3.29 to 6.37) and receiving mechanical ventilation treatment (HR = 3.85, 95% CI 2.73 to 5.42).

Conclusions

We demonstrated that herbicides stand out as the dominant agent for poisoning-related fatalities. The control of and limiting access to herbicide agents and developing appropriate therapeutic regimens, including emergency care, should be priorities.

Pathological and toxicological findings in glyphosate-surfactant herbicide fatality: a case report

Glyphosate herbicide is promoted by the manufacturer as having no risks to human health, with acute toxicity being very low in normal use. In Thailand, however, poisoning from glyphosate agricultural herbicides has been increasing. A case of rapid lethal intoxication from glyphosate-surfactant herbicide involved a 37-year-old woman, who deliberately ingested approximately 500 mL of concentrated Roundup formulation (41% glyphosate as the isopropylamine salt and 15% polyoxyethylene amine; Mosanto Company). The postmortem examination revealed that the stomach contained 550 mL of yellow fluid. The gastric mucosa of anterior fundus revealed hemorrhage and the small intestines had marked dilatation and thin walls. We used the high-performance liquid chromatography method for determination of serum and gastric content levels of glyphosate. The glyphosate levels of serum and gastric content were 3.05 and 59.72 mg/mL, respectively. Toxic effects of polyoxyethylene amine and Roundup were caused by their ability to erode tissues including mucous membranes and linings of the gastrointestinal and respiratory tracts. A mild degree of pulmonary congestion and edema was observed in both lungs. We proposed that the characteristic picture of microvesicular steatosis of the hepatocytes, seen predominantly in centrilobular zones of the liver, resembled drug-induced hepatic toxicity or secondary hypoxic stress.

Aseptic meningitis in association with glyphosate-surfactant herbicide poisoning

INTRODUCTION

The mechanisms underlying early central nervous system (CNS) signs and symptoms of glyphosate-surfactant herbicide (GlySH) poisoning are unclear.

CASE PRESENTATION

A 58-year-old woman ingested approximately 150 mL of GlySH containing 41% glyphosate and 15% polyoxyethyleneamine. Two days later, she was admitted in the Emergency Center in a semicomatose state. Acute respiratory distress syndrome, circulatory collapse, acute renal failure, and disseminated intravascular coagulopathy were diagnosed. Meningitis was also suspected as she demonstrated Kernig's sign and significant neck stiffness with rigidity of the extremities as well as consciousness disturbance and fever (38.4°C). Investigations of cerebrospinal fluid (CSF) revealed the presence of glyphosate (122.5 μg/mL), significant elevation of IL-6 (394 μg/mL), and pleocytosis (32 cells/μL) with monocyte dominance. All bacteriological and virological tests were later found to be negative. She recovered completely after responding to aggressive supportive care in the intensive care unit. All signs and symptoms suggesting meningitis resolved as the concentration of glyphosate in CSF decreased. She was discharged on day 39 of hospitalization.

DISCUSSION

These findings suggest that the present case involved aseptic meningitis in association with GlySH poisoning.

CONCLUSION

CNS signs and symptoms induced by aseptic meningitis should be considered in cases of glyphosate-surfactant herbicide poisoning.

Predicting acute complicated glyphosate intoxication in the emergency department

BACKGROUND

Glyphosate herbicide intoxication results in a range of mortality and morbidity, depending on patients' factors. Predicting which patient will need intensive medical treatment might help reduce mortality by providing prompt treatment, as well as triage those patients not likely to develop complications. Thus, we sought to identify independent factors that could predict which patient will develop subsequent medical complications.

METHODS

Seventy-six patients presenting with acute glyphosate herbicide ingestion at Chonnam National University Hospital were enrolled in this retrospective study. To identify the predictive factors for complications, objective variables easily assessed at presentation including previously reported predictive factors for mortality, such as age, vital signs, X-ray abnormalities, and laboratory findings, were analyzed by univariate and multivariate stepwise logistic regression analyses.

RESULTS

Of the 76 patients, 32 (42.1%) had medical complications and 2 (2.6%) died. Metabolic acidosis was the most common medical complication. Whereas metabolic acidosis, respiratory failure, hypotension, acute kidney injury, hyperkalemia, and seizures developed within 24 h, acute pancreatitis occurred a few days after the ingestion. The univariate analysis showed that an advanced age, amount ingested >100 mL, X-ray abnormalities, elevated amylase, alanine aminotransferase (ALT), and blood nitrogen urea were significant factors. However, the multivariate analysis showed that advanced age, elevated ALT, and X-ray abnormalities were independent factors associated with serious complications and the need for intensive medical treatment.

CONCLUSIONS

The results of this study showed that age > 50 years, X-ray abnormalities, and ALT > 40 U/L were significant predictive factors for complications in patients with glyphosate surfactant herbicide poisoning; patients with these findings might require admission to the intensive care unit.

A prospective observational study of the clinical toxicology of glyphosate-containing herbicides in adults with acute self-poisoning

CONTEXT

The case fatality from acute poisoning with glyphosate-containing herbicides is approximately 7.7% from the available studies but these have major limitations. Large prospective studies of patients with self-poisoning from known formulations who present to primary or secondary hospitals are needed to better describe the outcome from acute poisoning with glyphosate-containing herbicides. Furthermore, the clinical utility of the glyphosate plasma concentration for predicting clinical outcomes and guiding treatment has not been determined.

OBJECTIVE

To describe the clinical outcomes, dose-response, and glyphosate kinetics following self-poisoning with glyphosate-containing herbicides.

METHODS

This prospective observational case series was conducted in two hospitals in Sri Lanka between 2002 and 2007. We included patients with a history of acute poisoning. Clinical observations were recorded until discharge or death. During a specified time period, we collected admission (n = 216, including five deaths) and serial (n = 26) blood samples in patients. Severity of poisoning was graded using simple clinical criteria.

RESULTS

Six hundred one patients were identified; the majority ingested a concentrated formulation (36%, w/v glyphosate). Twenty-seven percent were asymptomatic, 63.7% had minor poisoning, and 5.5% of patients had moderate to severe poisoning. There were 19 deaths (case fatality 3.2%) with a median time to death of 20 h. Gastrointestinal symptoms, respiratory distress, hypotension, altered level of consciousness, and oliguria were observed in fatal cases. Death was strongly associated with greater age, larger ingestions, and high plasma glyphosate concentrations on admission (>734 microg/mL). The apparent elimination half-life of glyphosate was 3.1 h (95% CI = 2.7-3.6 h).

CONCLUSIONS

Despite treatment in rural hospitals with limited resources, the mortality was 3.2%, which is lower than that reported in previous case series. More research is required to define the mechanism of toxicity, better predict the small group at risk of death, and find effective treatments.

[Dysphonia following glyphosate exposition]

Glyphosate is a commonly used nonselective herbicide which inhibits plant growth through interference with the production of essential aromatic amino acids. Toxicity for humans has been reported after suicidal ingestion. Here we describe a 26-year-old teacher who used glyphosate correctly but suffered from severe dysphonia after some hours. Laryngostroboscopy revealed decreased vocal fold mobility suggesting innervation impairment. The symptoms resolved spontaneously 6 weeks later and vocal fold mobility returned to normal. Glyphosate neurotoxicity has been discussed in the literature therefore, the dysphonia observed here may have been due to an intermittent neuropraxia of the laryngeal nerve. However, to our knowledge a similar case has not been reported in literature.

[Acute glyphosate-surfactant poisoning with neurological sequels and fatal outcome]

INTRODUCTION

Clinical picture of severe glyphosate-surfactant poisoning is manifested by gastroenteritis, respiratory disturbances, altered mental status, hypotension refractory to the treatment, renal failure, shock. Single case report indicated possible neurotoxic sequels of glyphosate-surfactant exposure with white matter lesions and development of Parkinsonism. We described a patient with massive white matter damage which led to vigil coma and lethal outcome.

CASE REPORT

A 56-year old woman ingested about 500 mL of herbicide containing glyphosate isopropylamine salt. The most prominent manifestation of poisoning included hypotension, coma, hyperkaliemia, respiratory and renal failure. The patient was treated in intensive care unit by symptomatic and supportive therapy including mechanical ventilation and hemodialysis. The patient survived the acute phase of poisoning, but she developed vigil coma. Nuclear magnetic imagining revealed extensive bilateral lesions of the brain stem white matter and pons.

CONCLUSION

The outcome of reported poisoning may be the consequence of glyphosate-surfactant neurotoxic effect or/and ischemia, especially in the episodes of marked hypotension during hemodialysis. Considering recommendation of early hemodialysis as the treatment of choice, even before renal failure development, we point out the importance of careful planning of dialysis modality in hemodynamically instable patient and recommend continuous dialysis methods.

The epidemiology of glyphosate-surfactant herbicide poisoning in Taiwan, 1986-2007: a poison center study

BACKGROUND

Glyphosate-surfactant herbicide (GlySH) is widely used in agriculture and has been associated with numerous toxicities following oral ingestion. However, there are many controversies with regard to the exact causes and determinants of developing severe/death outcome after exposure to GlySH.

METHODS

We conducted an analysis of all GlySH exposures reported to the Taiwan National Poison Control Center between 1986 and 2007. Patients' baseline characteristics and clinical data were reviewed and analyzed.

RESULTS

A total of 2,186 patients were eligible for analysis. Most of the exposures were related to oral ingestion (n = 2,023, 92.5%) and attempted suicide (n = 1,631, 74.6%). The mean age of exposure was 42.8 +/- 18.6 years. One hundred patients developed severe effects and 146 patients died following oral GlySH exposure, resulting in a case fatality rate of 7.2%. Shock (n = 85, 58.2%) and respiratory failure (n = 34, 23.3%) accounted for most fatalities. Four out of eight patients with injection exposure manifested severe (n = 3) or fatal outcome (n = 1). In a multivariate logistic regression analysis, increasing age, larger amount of exposure, longer elapsed time to presentation, attempted suicide, receipt of atropine therapy, and being exposed in certain calendar years were positively associated with the severity of poisoning following oral GlySH exposure.

CONCLUSION

Age, ingested amount, delayed presentation, and reason for exposure were likely to be determinants of the severity of GlySH exposure. Because shock is the major cause of death and usually develops early after GlySH exposure, prompt fluid replacement therapy seems critical in the initial management of such exposures. Patients' airway should also be secured to avoid aspiration and subsequent respiratory failure.

Comparative effects of the formulation of glyphosate-surfactant herbicides on hemodynamics in swine

INTRODUCTION

Most of the glyphosate-surfactant herbicides (GlySH) are formulated commercial products containing isopropylamine (IPA) salt of glyphosate (IPAG), variable amount of a surfactant, and water. Although glyphosate is only slightly toxic to rats, ingestion of GlySH may lead to severe effects, including death, in humans. We conducted a study to evaluate the cardiovascular effects of the components of GlySH.

METHODS

We used five groups of male piglets, each receiving infusion of normal saline (control), glyphosate in NaOH base, IPA, IPAG, and polyoxyethyleneamine (POEA), respectively. We chose concentrations that are similar to those in the commonly used GlySH (41% of IPAG and 15% surfactant).

RESULTS

We found that IPAG reduced the mean arterial blood pressure (MABP) and left-ventricular stroke work index (LVSWI) during the infusion, but both recovered gradually. It also decreased the cardiac index but increased the pulmonary capillary wedge pressure, central venous pressure (CVP), and mean pulmonary arterial pressure (MPAP). POEA infusion reduced the cardiac index and LVSWI, but not the MABP. It also increased the pulmonary capillary wedge pressure, CVP, MPAP, and pulmonary vascular resistance index. IPA increased the MABP, which was higher than those in the control, IPAG, and POEA groups. Glyphosate in NaOH base infusion did not affect the hemodynamics but slightly reduced the blood pH and base excess (BE) values. POEA and IPAG also resulted in metabolic acidosis, with lactate formation and decreased BE values.

CONCLUSION

We conclude that both POEA and IPAG infusion affected hemodynamics and resulted in death in piglets, whereas glyphosate (NaOH base) had no similar effects.

Rhabdomyolysis from an intramuscular injection of glyphosate-surfactant herbicide

INTRODUCTION

Glyphosate-surfactant herbicide (GlySH) is widely used as a non-selective herbicide. Most intoxicated cases are from ingestion, inhalation, and skin exposure. Intramuscular injection of GlySH has never been reported. We present a case of GlySH intoxication via intramuscular injection.

CASE REPORT

A 42-year-old woman came to the emergency department complaining of painful swelling of left upper limb for 12 h. She had performed an intramuscular injection of 6 mL of GlySH over the lateral aspect of the left elbow 15 h previously. Physical examination disclosed painful swelling over left distal arm, elbow, and forearm with three needle punctures. CT scan revealed ill-defined areas of heterogeneous high density with marked swelling at subcutaneous tissue over posterior aspect of the elbow.

DISCUSSION

The mechanism of toxicity of GlySH is complicated and surfactant was thought to play an important role in GlySH intoxication. Intramuscular GlySH poisoning is different from oral GlySH intoxication. Care should be taken when monitoring acute rhabdomyolysis and compartment syndrome, which may develop rapidly and contribute to the surfactant component of glyphosate formulation.

Severe acute poisoning due to a glufosinate containing preparation without mitochondrial involvement

Glufosinate is a non-selective herbicide widely used in domestic gardens and agriculture. Few cases of glufosinate poisoning have been reported although there has been an increase in recent years, particularly in Japan. Glufosinate toxicity is related to its capacity to inhibit glutamine synthetase and glutamate decarboxylase, which may lead to a potentially fatal multiorgan failure. We report the case of a 41-year-old woman who ingested between 30 and 50 mL of a herbicide (Finale®) containing glufosinate (14%) in a suicide attempt. One hour after ingestion, the patient attended the Emergency Department of her own volition. Her overall status was good, and the physical examination was unremarkable. Gastric lavage was carried out, 25 g of activated charcoal was administered, and the patient was admitted for observation. Seventeen hours later, the patient presented drowsiness and a sinus bradycardia of 40 bpm. Thirty-two hours after ingestion, the Glasgow Coma Score was 8, and orotracheal intubation and mechanical ventilation were begun. At 3 days, the patient presented a self-limiting episode of ventricular tachycardia. She recovered consciousness progressively and was extubated without complications. The evolution was favorable, but the sinus bradycardia persisted up to 8 days after the ingestion. A study of lymphocyte mitochondrial function showed no alteration in mitochondrial oxidative capacity or the enzymatic activity of the complexes of the electron transport chain. A small ingestion of glufosinate can cause severe poisoning, whose manifestations predominantly involve the central nervous system and heart rhythm. Signs and symptoms may not appear for several hours and may persist for several days. In spite of these multi-organ manifestations, no alteration in lymphocyte mitochondrial function has been reported.

Etiology and outcome of patients presenting for poisoning to the emergency department in Taiwan: a prospective study

Poisoning is one of the most common reasons for visiting the emergency department in many countries, and the pattern varies from countries to countries and time to time. To compare the etiology and outcome of poisoning patients in different gender and age groups, we conducted a prospective study at the emergency departments of two medical centers in southern Taiwan between January 2001 and December 2002. All cases of poisoning, excluding patients diagnosed as cases of alcohol or food poisoning, were included, and relevant information was collected. There were 1512 cases of poisoning observed with a male to female ratio of 1:1.2 (684/828). Overall, drugs (49.9%) were the main agents involved, and a suicidal attempt (66.1%) was the predominant etiology. A total of 63 fatalities (4.2%) were observed and pesticides, especially paraquat, resulted in most fatalities. Patients aged 19–30 years constituted the most cases, and significant differences in exposure agents, causes, and fatality rates were found among different age and gender groups. The results are compatible with the trend reported by other Asian countries. This study also shows important differences existing in poisoning patients of different age and gender groups. Therefore, different poisoning-prevention strategies should be applied to different groups.

The early prognostic factors of glyphosate-surfactant intoxication

BACKGROUND AND PURPOSE

The purpose of this study was to establish an early prognostic model of patients with glyphosate-surfactant (GlySH) herbicide intoxication.

METHODS

A case-control study was conducted. Data of GlySH-intoxicated patients were collected from 2 hospitals. Patients were admitted to the emergency departments (EDs) of Chang Gung Memorial Hospital from April 1996 to March 2003 and Taichung Veterans General Hospital from April 2000 to October 2003. Collected variables such as age, sex, estimated amount of ingestion, symptoms/signs including first vital signs, chest x-ray (CXR), and biochemical studies were analyzed for their role in the prognostic model of GlySH intoxication mortality. Univariate and odds ratio analyses were then performed. The prognostic model was then established by using logistic regression analysis and further stratified analysis.

RESULTS

Fifty-eight patients (19 men and 39 women; age, 48.8 +/- 15.8 years; P = .38) were enrolled in our study. Forty-one patients survived from GlySH intoxication and 17 died. After univariate analysis, 5 variables (respiratory distress needing intubation, metabolic acidosis, tachycardia, elevated creatinine (Cr) level, and hyperkalemia) were found to be highly associated with poor outcome and mortality. Then a multiple logistic regression model was established as follows: log(p/q) = -6.13 + 3.43 (abnormal CXR) + 2.53 (metabolic acidosis) + 2.55 (Cr) + 2.4 (tachycardia) + e.

CONCLUSION

GlySH poisoning is multiorgan toxicity. Pulmonary toxicity and renal toxicity seem to be responsible for its mortality. Metabolic acidosis, abnormal CXR, tachycardia, and elevated Cr level are useful prognostic factors for predicting GlySH mortality.

Presentations of patients of poisoning and predictors of poisoning-related fatality: findings from a hospital-based prospective study

BACKGROUND

Poisoning is a significant public health problem worldwide and is one of the most common reasons for visiting emergency departments (EDs), but factors that help to predict overall poisoning-related fatality have rarely been elucidated. Using 1512 subjects from a hospital-based study, we sought to describe the demographic and clinical characteristics of poisoning patients and to identify predictors for poisoning-related fatality.

METHODS

Between January 2001 and December 2002 we prospectively recruited poisoning patients through the EDs of two medical centers in southwest Taiwan. Interviews were conducted with patients within 24 hours after admission to collect relevant information. We made comparisons between survival and fatality cases, and used logistic regressions to identify predictors of fatality.

RESULTS

A total of 1512 poisoning cases were recorded at the EDs during the study period, corresponding to an average of 4.2 poisonings per 1000 ED visits. These cases involved 828 women and 684 men with a mean age of 38.8 years, although most patients were between 19 and 50 years old (66.8%), and 29.4% were 19 to 30 years. Drugs were the dominant poisoning agents involved (49.9%), followed by pesticides (14.5%). Of the 1512 patients, 63 fatalities (4.2%) occurred. Paraquat exposure was associated with an extremely high fatality rate (72.1%). The significant predictors for fatality included age over 61 years, insufficient respiration, shock status, abnormal heart rate, abnormal body temperature, suicidal intent and paraquat exposure.

CONCLUSION

In addition to well-recognized risk factors for fatality in clinical settings, such as old age and abnormal vital signs, we found that suicidal intent and ingestion of paraquat were significant predictors of poisoning-related fatality. Identification of these predictors may help risk stratification and the development of preventive interventions.

Glyphosate herbicide formulation: a potentially lethal ingestion

Glyphosate surfactant herbicide (GlySH) toxicity is an uncommon poisoning. We report two fatalities involving suicidal ingestion of this herbicide. Both deaths occurred despite early recognition of the serious nature of the poisoning and aggressive treatment. The deaths in this series are analysed in the context of a review of existing literature. Although traditionally regarded as minimally toxic, many deaths have been reported following suicidal ingestion. Severe GlySH toxicity may be refractory even to the most intensive supportive care. The triad of pulmonary oedema, metabolic acidosis and hyperkalaemia portends poor outcome. While containing a carbon phosphorus moiety, GlySH does not exhibit organophosphate toxicity. A clinical guide to assessing severity of GlySH toxicity is proposed and treatment modalities discussed.

Glyphosate poisoning

Glyphosate is used extensively as a non-selective herbicide by both professional applicators and consumers and its use is likely to increase further as it is one of the first herbicides against which crops have been genetically modified to increase their tolerance. Commercial glyphosate-based formulations most commonly range from concentrates containing 41% or more glyphosate to 1% glyphosate formulations marketed for domestic use. They generally consist of an aqueous mixture of the isopropylamine (IPA) salt of glyphosate, a surfactant, and various minor components including anti-foaming and colour agents, biocides and inorganic ions to produce pH adjustment. The mechanisms of toxicity of glyphosate formulations are complicated. Not only is glyphosate used as five different salts but commercial formulations of it contain surfactants, which vary in nature and concentration. As a result, human poisoning with this herbicide is not with the active ingredient alone but with complex and variable mixtures. Therefore, It is difficult to separate the toxicity of glyphosate from that of the formulation as a whole or to determine the contribution of surfactants to overall toxicity. Experimental studies suggest that the toxicity of the surfactant, polyoxyethyleneamine (POEA), is greater than the toxicity of glyphosate alone and commercial formulations alone. There is insufficient evidence to conclude that glyphosate preparations containing POEA are more toxic than those containing alternative surfactants. Although surfactants probably contribute to the acute toxicity of glyphosate formulations, the weight of evidence is against surfactants potentiating the toxicity of glyphosate. Accidental ingestion of glyphosate formulations is generally associated with only mild, transient, gastrointestinal features. Most reported cases have followed the deliberate ingestion of the concentrated formulation of Roundup (The use of trade names is for product identification purposes only and does not imply endorsement.) (41% glyphosate as the IPA salt and 15% POEA). There is a reasonable correlation between the amount ingested and the likelihood of serious systemic sequelae or death. Advancing age is also associated with a less favourable prognosis. Ingestion of >85 mL of the concentrated formulation is likely to cause significant toxicity in adults. Gastrointestinal corrosive effects, with mouth, throat and epigastric pain and dysphagia are common. Renal and hepatic impairment are also frequent and usually reflect reduced organ perfusion. Respiratory distress, impaired consciousness, pulmonary oedema, infiltration on chest x-ray, shock, arrythmias, renal failure requiring haemodialysis, metabolic acidosis and hyperkalaemia may supervene in severe cases. Bradycardia and ventricular arrhythmias are often present pre-terminally. Dermal exposure to ready-to-use glyphosate formulations can cause irritation and photo-contact dermatitis has been reported occasionally; these effects are probably due to the preservative Proxel (benzisothiazolin-3-one). Severe skin burns are very rare. Inhalation is a minor route of exposure but spray mist may cause oral or nasal discomfort, an unpleasant taste in the mouth, tingling and throat irritation. Eye exposure may lead to mild conjunctivitis, and superficial corneal injury is possible if irrigation is delayed or inadequate. Management is symptomatic and supportive, and skin decontamination with soap and water after removal of contaminated clothing should be undertaken in cases of dermal exposure.

An analysis of glyphosate data from the California Environmental Protection Agency Pesticide Illness Surveillance Program

Glyphosate is among the pesticides most frequently reported to the California EPA Pesticide Illness Surveillance Program. We analyzed glyphosate-related calls to the Pesticide Illness Surveillance Program in order to assess the number of reports involving systemic symptoms and to better understand the nature and severity of reported cases. Data on glyphosate and other pesticides are available for the years 1982-1997 including: type of exposure (agricultural/other); target organ(s) affected (skin/eye/respiratory/systemic); exposure(s); an assessment of causal relationship (possible, probable, or definite); and limited medical text. Of 815 total glyphosate calls, most involved topical irritation of the eye (n = 399), skin (n = 250), upper airway (n = 7), or combinations of these sites (n = 32) without systemic symptoms. Of the 187 systemic cases, only 22 had symptoms recorded as probably or definitely related to glyphosate exposure alone. The reported symptoms were not severe, expected to be limited in duration, and frequently inconsistent with the route of exposure and/or previous experience with glyphosate. We conclude that call volume is not a reliable indicator of the actual incidence or severity of glyphosate-related incidents in California.

Safety evaluation and risk assessment of the herbicide Roundup and its active ingredient, glyphosate, for humans

Reviews on the safety of glyphosate and Roundup herbicide that have been conducted by several regulatory agencies and scientific institutions worldwide have concluded that there is no indication of any human health concern. Nevertheless, questions regarding their safety are periodically raised. This review was undertaken to produce a current and comprehensive safety evaluation and risk assessment for humans. It includes assessments of glyphosate, its major breakdown product [aminomethylphosphonic acid (AMPA)], its Roundup formulations, and the predominant surfactant [polyethoxylated tallow amine (POEA)] used in Roundup formulations worldwide. The studies evaluated in this review included those performed for regulatory purposes as well as published research reports. The oral absorption of glyphosate and AMPA is low, and both materials are eliminated essentially unmetabolized. Dermal penetration studies with Roundup showed very low absorption. Experimental evidence has shown that neither glyphosate nor AMPA bioaccumulates in any animal tissue. No significant toxicity occurred in acute, subchronic, and chronic studies. Direct ocular exposure to the concentrated Roundup formulation can result in transient irritation, while normal spray dilutions cause, at most, only minimal effects. The genotoxicity data for glyphosate and Roundup were assessed using a weight-of-evidence approach and standard evaluation criteria. There was no convincing evidence for direct DNA damage in vitro or in vivo, and it was concluded that Roundup and its components do not pose a risk for the production of heritable/somatic mutations in humans. Multiple lifetime feeding studies have failed to demonstrate any tumorigenic potential for glyphosate. Accordingly, it was concluded that glyphosate is noncarcinogenic. Glyphosate, AMPA, and POEA were not teratogenic or developmentally toxic. There were no effects on fertility or reproductive parameters in two multigeneration reproduction studies with glyphosate. Likewise there were no adverse effects in reproductive tissues from animals treated with glyphosate, AMPA, or POEA in chronic and/or subchronic studies. Results from standard studies with these materials also failed to show any effects indicative of endocrine modulation. Therefore, it is concluded that the use of Roundup herbicide does not result in adverse effects on development, reproduction, or endocrine systems in humans and other mammals. For purposes of risk assessment, no-observed-adverse-effect levels (NOAELs) were identified for all subchronic, chronic, developmental, and reproduction studies with glyphosate, AMPA, and POEA. Margins-of-exposure for chronic risk were calculated for each compound by dividing the lowest applicable NOAEL by worst-case estimates of chronic exposure. Acute risks were assessed by comparison of oral LD50 values to estimated maximum acute human exposure. It was concluded that, under present and expected conditions of use, Roundup herbicide does not pose a health risk to humans.

Acute poisoning with a herbicide containing imazapyr (Arsenal): a report of six cases

BACKGROUND

Acute pesticide poisoning is a major cause of morbidity and mortality in Taiwan and herbicides are most frequently implicated. Imazapyr [2-(4-isopropyl-4-methyl-5-oxo-2 imidazoline-2-yl)nicotinic acid] is a new herbicide, recently registered in Taiwan under the tradename "Arsenal" (Imazapyr 23.1%, Cyanamid Taiwan Corporation, Taipei). Imazapyr is also marketed as Assault, Chopper, Contain, and Pivot. To the best of our knowledge, there is no information in the literature concerning acute toxicity in humans after ingestion of herbicides containing this compound.

METHOD

Six cases of acute poisoning with Arsenal occurred during the period 1993-1997 in a single hospital. Emergency room records and medical charts were reviewed.

RESULTS

Of 6 cases, 5 were suicide attempts and 1 was an act of violence inflicted on a child. Three of the 6 patients (50%) presented with severe symptoms, including impairment of consciousness and respiratory distress requiring intubation. Other presentations included metabolic acidosis (2), hypotension (2), leukocytosis (3), fever (2), mild elevation of hepatic transaminase and creatinine (2), unconjugated hyperbilirubinemia (2), oral ulceration (2), pharyngolaryngitis (2), and chemical burns of the cornea (1). All cases had copious vomiting after ingestion of Arsenal. No mortality occurred.

CONCLUSION

According to our observations, it appeared the toxic syndrome that results from a large quantity (> 100 mL) of Arsenal herbicide ingestion consists of hypotension, pulmonary dysfunction, oral mucosal and gastrointestinal irritation, and transient liver and renal dysfunction. However, the existence of a dose-response relationship, with increasing amounts of ingestion resulting in more severe symptoms, needs further observation and studies that include a larger series.

Herbicide (Roundup) pneumonitis

A case of acute intoxication presented as toxic pneumonitis after exposure to Roundup (glyphosate) (Solaris Group, Monsanto; San Ramon, CA) herbicide in an agriculture worker. The correct etiologic factor causing this specific clinical picture was identified only 2 weeks later, after a thorough occupational history was taken and meticulous delineation of the working conditions and exposures of the involved worker were made. As a rule, occupational related diseases are not readily elucidated by nonoccupational physicians. However, most acute intoxication events are first encountered by such physicians. In these situations, rapid and comprehensive evaluation is necessary in order to clearly identify the causative agent(s) and to initiate the appropriate treatment. Consulting occupational physicians at this early stage may facilitate early and accurate diagnosis.

Risk factors for occupational illnesses associated with the use of paraquat (1,1'-dimethyl-4,4'-bipyridylium dichloride) in California

This study was conducted to identify risk factors for paraquat-related occupational illnesses. Pesticide-related illness is a reportable disease in California. A total of 231 skin (26.0%), eye (32.0%), local respiratory (3.5%), and systemic (38.5%) paraquat-related cases were reported to the Worker Health and Safety Branch, California Department of Food and Agriculture, during 1971 through 1985. Following paraquat exposure, we found no cases of pulmonary fibrosis. Annual numbers of cases ranged between 1 and 33 (median = 14 cases/y). Information on illnesses reported during 1981 through 1985 (n = 62) was merged with detailed information on paraquat use in agricultural settings (111,716 applications) for the same years. We found that crop treated, method of application, and season of application all contributed independently to the risk of reported illness. Hand application was associated with a higher risk of illness, compared with air application (RR = 99.1, 95% CI = 22.16-443.47); summer application was associated with a higher risk of illness than was winter application (RR = 4.1, 95% CI = 1.91-8.61); and fruit trees were associated with higher risk of illness than were other crops (mainly cotton) (RR = 3.6, 95% CI = 1.18-11.21).

Glyphosate herbicide poisoning: use of a routine aminoacid analyzer appears to be a rapid method for determining glyphosate and its metabolite in biological fluids

Glyphosate containing herbicides are an alternative to paraquat and are widely used throughout the world. Despite animal studies showing a low mammalian toxicity, human fatalities are reported after suicidal ingestions of glyphosate. Among the numerous analytical methods proposed, the reference method is the HPLC Monsanto procedure which is available in very few laboratories. The Monsanto procedure consists of a pre-column derivatization with detection of the resulting chromophore by HPLC with a variable wavelength UV/VIS detector. We propose a simple and rapid method for the diagnosis and monitoring of glyphosate poisoning. This method uses an aminoacid analyzer (Beckman 6300) with the program for biological fluids. With this procedure the glyphosate and amino methyl phosphoric acid retention times are respectively 1.75 and 3.54 min. This method gives a rapid result. The time between collecting the sample and completing the result is 45 min. This method may be useful for the diagnosis and monitoring of glyphosate poisoning and is easy to perform with an apparatus usually available in every laboratory involved in aminoacid analysis.