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Fundamental Toxicological Sciences 2016The oral toxicity of phorate oxon (PHO), with emphasis on gender- and age-related effects, was characterized in the Sprague-Dawley rat. The oral LD (95% fiducial limits)...
The oral toxicity of phorate oxon (PHO), with emphasis on gender- and age-related effects, was characterized in the Sprague-Dawley rat. The oral LD (95% fiducial limits) for PHO in corn oil was 0.88 (0.79, 1.04) mg/kg in males and 0.55 (0.46, 0.63) mg/kg in females with a probit slope of 15. Females had higher baseline blood cholinesterase titers, but males were significantly more tolerant. Younger rats generally had lower absolute cholinesterase blood titers. However as PHO challenges increased, baseline-normalized cholinesterase inhibition was independent of age and gender. Butyrylcholinesterase (BChE) and especially acetylcholinesterase (AChE) in brains of younger females were affected more than that in either males or older females. In summary, while female rats, especially older females, had higher titers relative to males, female rats were more susceptible in terms of absolute cholinesterase inhibition and 24-hr lethality data, but the differences were not observed when titers were normalized to baseline levels.
PubMed: 28856079
DOI: 10.2131/fts.3.195 -
3 Biotech Jun 2016Biodegradation of the pesticides is considered as one of the safest and cheapest ways. The aim of the present study was to reveal if the inoculated Lactic acid bacteria...
Biodegradation of the pesticides is considered as one of the safest and cheapest ways. The aim of the present study was to reveal if the inoculated Lactic acid bacteria widely used in silage could provide beneficial safety to guarantee dairy feedstuffs and fresh milk. Organophosphorus pesticides (OPPs) degradation in whole corn silage was investigated. Two OPPs, chlorpyrifos and phorate, were added to the whole corn, which was inoculated with L. plantarum 1.0315, L. plantarum 1.0624, L. plantarum 1.0622 and their combination at room temperature for 10 weeks. OPPs residues in the whole corn silage at different weeks were analyzed by gas chromatography after OPPs extraction and purification. The degradation rate constants were calculated according to the OPPs residues results at different fermentation stage. The data showed that the inoculated microorganisms and strain combination exhibited obvious acceleration on OPPs degradation as the wild microorganisms did, and resulted in decreased levels of OPPs from 24.9 to 33.4 %. Strains combination brought about greater OPPs degradation than single strain or the wild microorganisms. Compared to phorate, clorpyrifos had lower degradation rate constants (0.0274-0.0381 vs. 0.0295-0.0355 week) and was more stable. The present result indicates safety benefit of lactic acid bacteria on corn silage besides lactic acid fermentation.
PubMed: 28330143
DOI: 10.1007/s13205-016-0364-3 -
The Journal of Toxicological Sciences Dec 2015Given the rapid onset of symptoms from intoxication by organophosphate (OP) compounds, a quick-acting, efficacious therapeutic regimen is needed. A primary component of...
Given the rapid onset of symptoms from intoxication by organophosphate (OP) compounds, a quick-acting, efficacious therapeutic regimen is needed. A primary component of anti-OP therapy is an oxime reactivator to rescue OP-inhibited acetylcholinesterases. Male guinea pigs, clipped of hair, received neat applications of either VR, VX, parathion, or phorate oxon (PHO) at the 85(th) percentile lethal dose, and, beginning with presentation of toxicosis, received the human equivalent dose therapy by intramuscular injection with two additional follow-on treatments at 3-hr intervals. Each therapy consisted of atropine free base at 0.4 mg/kg followed by one of eight candidate oximes. Lethality rates were obtained at 24 hr after VR, VX and PHO challenges, and at 48 hr after challenge with parathion. Lethality rates among symptomatic, oxime-treated groups were compared with that of positive control (OP-challenged and atropine-only treated) guinea pigs composited across the test days. Significant (p ≤ 0.05) protective therapy was afforded by 1,1-methylene bis(4(hydroxyimino- methyl)pyridinium) dimethanesulfonate (MMB4 DMS) against challenges of VR (p ≤ 0.001) and VX (p ≤ 0.05). Lethal effects of VX were also significantly (p ≤ 0.05) mitigated by treatments with oxo-[[1-[[4-(oxoazaniumylmethylidene)pyridin-1-yl]methoxymethyl]pyridin-4-ylidene]methyl]azanium dichloride (obidoxime Cl2) and 1-(((4-(aminocarbonyl) pyridinio)methoxy)methyl)-2,4-bis((hydroxyimino)methyl)pyridinium dimethanesulfonate (HLö-7 DMS). Against parathion, significant protective therapy was afforded by obidoxime dichloride (p ≤ 0.001) and 1,1'-propane-1,3-diylbis{4-[(E)-(hydroxyimino)methyl]pyridinium} dibromide (TMB-4, p ≤ 0.01). None of the oximes evaluated was therapeutically effective against PHO. Across the spectrum of OP chemicals tested, the oximes that offered the highest level of therapy were MMB4 DMS and obidoxime dichloride.
Topics: Animals; Guinea Pigs; Humans; Male; Nerve Agents; Organophosphate Poisoning; Oximes; Pesticides
PubMed: 26558457
DOI: 10.2131/jts.40.759 -
Toxicology and Applied Pharmacology Dec 2014The currently fielded pre-hospital therapeutic regimen for the treatment of organophosphorus (OP) poisoning in the United States (U.S.) is the administration of atropine... (Comparative Study)
Comparative Study
The currently fielded pre-hospital therapeutic regimen for the treatment of organophosphorus (OP) poisoning in the United States (U.S.) is the administration of atropine in combination with an oxime antidote (2-PAM Cl) to reactivate inhibited acetylcholinesterase (AChE). Depending on clinical symptoms, an anticonvulsant, e.g., diazepam, may also be administered. Unfortunately, 2-PAM Cl does not offer sufficient protection across the range of OP threat agents, and there is some question as to whether it is the most effective oxime compound available. The objective of the present study is to identify an oxime antidote, under standardized and comparable conditions, that offers protection at the FDA approved human equivalent dose (HED) of 2-PAM Cl against tabun (GA), sarin (GB), soman (GD), cyclosarin (GF), and VX, and the pesticides paraoxon, chlorpyrifos oxon, and phorate oxon. Male Hartley guinea pigs were subcutaneously challenged with a lethal level of OP and treated at approximately 1 min post challenge with atropine followed by equimolar oxime therapy (2-PAM Cl, HI-6 DMS, obidoxime Cl₂, TMB-4, MMB4-DMS, HLö-7 DMS, MINA, and RS194B) or therapeutic-index (TI) level therapy (HI-6 DMS, MMB4-DMS, MINA, and RS194B). Clinical signs of toxicity were observed for 24 h post challenge and blood cholinesterase [AChE and butyrylcholinesterase (BChE)] activity was analyzed utilizing a modified Ellman's method. When the oxime is standardized against the HED of 2-PAM Cl for guinea pigs, the evidence from clinical observations, lethality, quality of life (QOL) scores, and cholinesterase reactivation rates across all OPs indicated that MMB4 DMS and HLö-7 DMS were the two most consistently efficacious oximes.
Topics: Animals; Antidotes; Atropine; Chemical Warfare Agents; Cholinesterase Inhibitors; Cholinesterase Reactivators; Cholinesterases; Drug Administration Schedule; Drug Monitoring; Drug Therapy, Combination; Guinea Pigs; Injections, Intramuscular; Injections, Subcutaneous; Male; Muscarinic Antagonists; Organophosphate Poisoning; Oximes; Pesticides; Pyridinium Compounds; Random Allocation
PubMed: 25448441
DOI: 10.1016/j.taap.2014.10.009 -
Journal of Natural Science, Biology,... Jul 2014A vast majority of Indian population are engaged in agriculture. While pesticides help in increasing crop production, inappropriate pesticide storage practice and...
BACKGROUND
A vast majority of Indian population are engaged in agriculture. While pesticides help in increasing crop production, inappropriate pesticide storage practice and inadequate protective measures frequently causes accidental poisoning among farmers.
OBJECTIVE
The present study was conducted to explore the pattern of pesticide use among farmers in a district of India with an attempt to identify the lacunae in their knowledge and awareness level on risks and hazards of pesticides use.
MATERIALS AND METHODS
A cross-sectional questionnaire based study was conducted in the district of Burdwan, West Bengal, to address the study objective. Data analysis was performed by using descriptive statistical methods: Frequency, percentage, mean, standard deviation.
RESULTS
In the present study alpha-cypermethrin (46%) was the most commonly used pesticide followed by methyl parathion (25.6%), imidacloprid (16.4%), dichlorvos (7.8%) and phorate (4.2%). The farmers used to store pesticides mostly in cowshed (48.4%) followed by storeroom (29.6%). During spraying of pesticides, farmers experienced headache (29.8%) followed by nausea (26%), burning sensation in eyes (9.8%), cough (9.2%), muscle cramps (2%). Regarding the personal protective measures taken by the farmers for spraying, covering nose, mouth with cloth combined with bath after spraying was the most common practice (27%). When asked about suggested actions to be taken if anybody becomes sick following exposure to pesticides, 86% of farmers prefer consulting a doctor.
CONCLUSION
The study suggested that farmers of Burdwan were exposed to highly hazardous, restricted and banned pesticides, with insufficient protection. In this situation, educational and training interventions on pesticide handling and safety precautions are urgently needed.
PubMed: 25097405
DOI: 10.4103/0976-9668.136173 -
Occupational and Environmental Medicine Sep 2014To estimate associations between use of specific agricultural pesticides and incident diabetes in women.
OBJECTIVE
To estimate associations between use of specific agricultural pesticides and incident diabetes in women.
METHODS
We used data from the Agricultural Health Study, a large prospective cohort of pesticide applicators and their spouses in Iowa and North Carolina. For comparability with previous studies of farmers, we limited analysis to 13 637 farmers' wives who reported ever personally mixing or applying pesticides at enrolment (1993-1997), who provided complete data on required covariates and diabetes diagnosis and who reported no previous diagnosis of diabetes at enrolment. Participants reported ever-use of 50 specific pesticides at enrolment and incident diabetes at one of two follow-up interviews within an average of 12 years of enrolment. We fit Cox proportional hazards models with age as the time scale and adjusting for state and body mass index to estimate HRs and 95% CIs for each of the 45 pesticides with sufficient users.
RESULTS
Five pesticides were positively associated with incident diabetes (n=688; 5%): three organophosphates, fonofos (HR=1.56, 95% CI 1.11 to 2.19), phorate (HR=1.57, 95% CI 1.14 to 2.16) and parathion (HR=1.61, 95% CI 1.05 to 2.46); the organochlorine dieldrin (HR=1.99, 95% CI 1.12 to 3.54); and the herbicide 2,4,5-T/2,4,5-TP (HR=1.59, 95% CI 1.00 to 2.51). With phorate and fonofos together in one model to account for their correlation, risks for both remained elevated, though attenuated compared with separate models.
CONCLUSIONS
Results are consistent with previous studies reporting an association between specific organochlorines and diabetes and add to growing evidence that certain organophosphates also may increase risk.
Topics: Adolescent; Adult; Aged; Aged, 80 and over; Agricultural Workers' Diseases; Diabetes Mellitus; Female; Humans; Incidence; Iowa; Middle Aged; North Carolina; Occupational Exposure; Organophosphates; Pesticides; Proportional Hazards Models; Spouses; Young Adult
PubMed: 24727735
DOI: 10.1136/oemed-2013-101659