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Cadernos de Saude Publica 2005Reports of poisoning and suicide attempts involving pesticides in the micro region of Dourados, Mato Grosso do Sul State, Brazil, from 1992 to 2002, were evaluated,...
Reports of poisoning and suicide attempts involving pesticides in the micro region of Dourados, Mato Grosso do Sul State, Brazil, from 1992 to 2002, were evaluated, using data from the Integrated Center for Toxicological Surveillance under the State Health Department. A total of 475 reports were made during the period, of which 261 were accidental or occupational poisonings, 203 suicide attempts, and 11 undetermined. Dourados county had the highest prevalence of pesticide poisoning and suicide attempts per 100,000 inhabitants, considering the rural population, and Fatima do Sul the second highest prevalence of suicides within the micro region. Significant correlations were found between poisoning and suicide (r = 0.60; p < 0.05) and between poisoning and temporary crop area as a percentage of the county's total area (r = 0.68; p < 0.05). Poisoning occurred predominantly in men (87.0%), but the percentage of suicide attempts by men and women were similar (53 and 47.0%, respectively). Poisonings occurred mostly from October to March and the organophosphate insecticides monocrotophos and methamidophos were the main pesticides involved.
Topics: Adolescent; Adult; Agricultural Workers' Diseases; Brazil; Child; Child, Preschool; Female; Humans; Infant; Male; Middle Aged; Occupational Exposure; Pesticides; Poisoning; Prevalence; Rural Population; Suicide, Attempted
PubMed: 15868038
DOI: 10.1590/s0102-311x2005000300014 -
Plant Disease Aug 2004Epidemics of spotted wilt caused by Tomato spotted wilt virus (TSWV) vectored by Frankliniella occidentalis and possibly other thrips species occur regularly in tomato...
Epidemics of spotted wilt caused by Tomato spotted wilt virus (TSWV) vectored by Frankliniella occidentalis and possibly other thrips species occur regularly in tomato in the southeastern United States. Field experiments were conducted to determine the effects of UV-reflective mulch, acibenzolar-S-methyl (plant activator), and insecticides on progress of tomato spotted wilt incidence and population dynamics of flower thrips (including F. occidentalis, F. tritici, and F. bispinosa). Whole plots of tomatoes grown on UV-reflective and black polyethylene mulch were divided into subplots of acibenzolar-S-methyl and no acibenzolar-S-methyl, and sub-subplots of insecticide and no insecticide for thrips control. The UV-reflective mulch was more effective than black polyethylene mulch each year in reducing colonization of thrips in May and the consequent primary infections of tomato spotted wilt. Application of acibenzolar-S-methyl further reduced tomato spotted wilt incidence in 2000 and 2002, when disease pressure was great. Reproduction of thrips on tomato was poor in these experiments, but their control in the insecticide-treated sub-subplots prevented secondary spread in both years. The combination of UV-reflective mulch, acibenzolar-S-methyl, and insecticides was very effective in reducing tomato spotted wilt incidence in tomato.
PubMed: 30812519
DOI: 10.1094/PDIS.2004.88.8.882 -
Bulletin of the World Health... 2003To assess in a developing Asian country the impact of pesticide regulation on the number of deaths from poisoning. These regulations, which were implemented in Sri Lanka...
OBJECTIVES
To assess in a developing Asian country the impact of pesticide regulation on the number of deaths from poisoning. These regulations, which were implemented in Sri Lanka from the 1970s, aimed to reduce the number of deaths - the majority from self-poisoning - by limiting the availability and use of highly toxic pesticides.
METHODS
Information on legislative changes was obtained from the Ministry of Agriculture, national and district hospital admission data were obtained from the Sri Lanka Health Statistics Unit, and individual details of deaths by pesticide poisoning were obtained from a manual review of patients' notes and intensive care unit records in Anuradhapura.
FINDINGS
Between 1986 and 2000, the total national number of admissions due to poisoning doubled, and admissions due to pesticide poisoning increased by more than 50%. At the same time, the case fatality proportion (CFP) fell for total poisonings and for poisonings due to pesticides. In 1991_92, 72% of pesticide-induced deaths in Anuradhapura were caused by organophosphorus (OP) and carbamate pesticides - in particular, the WHO class I OPs monocrotophos and methamidophos. From 1991, the import of these pesticides was reduced gradually until they were banned for routine use in January 1995, with a corresponding fall in deaths. Unfortunately, their place in agricultural practice was taken by the WHO class II organochlorine endosulfan, which led to a rise in deaths from status epilepticus - from one in 1994 to 50 in 1998. Endosulfan was banned in 1998, and over the following three years the number of endosulfan deaths fell to three. However, at the end of the decade, the number of deaths from pesticides was at a similar level to that of 1991, with WHO class II OPs causing the most deaths. Although these drugs are less toxic than class I OPs, the management of class II OPs remains difficult because they are, nevertheless, still highly toxic, and their toxicity is exacerbated by the paucity of available facilities.
CONCLUSION
The fall in CFP amidst a rising incidence of self-poisoning suggests that Sri Lanka's programmes of pesticide regulation were beneficial. However, a closer inspection of pesticide-induced deaths in one hospital revealed switching to other highly toxic pesticides, as one was banned and replaced in agricultural practice by another. Future regulation must predict this switching and bear in mind the ease of treatment of replacement pesticides. Furthermore, such regulations must be implemented alongside other strategies, such as integrated pest management, to reduce the overall pesticide availability for self-harm.
Topics: Acute Disease; Carbamates; Commerce; Developing Countries; Government Regulation; Health Policy; Hospitals, General; Humans; Incidence; Insecticides; Organophosphorus Compounds; Poisoning; Sri Lanka
PubMed: 14758405
DOI: No ID Found -
British Journal of Pharmacology Feb 20041. The effects of donepezil, one of the most common cholinesterase inhibitors used for treatment of Alzheimer's disease, were studied on nicotinic receptors...
1. The effects of donepezil, one of the most common cholinesterase inhibitors used for treatment of Alzheimer's disease, were studied on nicotinic receptors (nAChRs)-mediated postsynaptic currents, in dopaminergic neurons of the substantia nigra pars compacta, using the patch-clamp recording technique in slice preparations. 2. Donepezil (10-100 microM) selectively and reversibly depressed nicotine currents, induced by brief puffer pulses, through a glass micropipette positioned above the slice. 3. The peak amplitude fading of the responses generated by repeated test applications of low doses of nicotine was accelerated by donepezil, while it slowed the recovery of nicotine currents after a large, desensitising, dose of the same agonist. 4. Donepezil depressed even maximal responses to nicotine, revealing a noncompetitive mechanism of action; moreover, the inhibition of nAChRs was voltage and time independent. 5. Pretreatment with vesamicol or methamidophos did not prevent the reduction of nicotine-induced currents. The data indicated direct effect on nAChR, independent from the activity of donepezil as cholinesterase inhibitor.
Topics: Animals; Cholinesterase Inhibitors; Donepezil; Dopamine; Electrophysiology; In Vitro Techniques; Indans; Insecticides; Membrane Potentials; Neurons; Nicotine; Nicotinic Agonists; Nootropic Agents; Organothiophosphorus Compounds; Patch-Clamp Techniques; Piperidines; Rats; Receptors, Nicotinic; Substantia Nigra; Synapses; Synaptic Transmission
PubMed: 14744806
DOI: 10.1038/sj.bjp.0705660 -
Proceedings of the National Academy of... May 2003Spinal administration of nicotinic agonists can produce both hyperalgesic and analgesic effects in vivo. The cellular mechanisms underlying these behavioral phenomena...
Spinal administration of nicotinic agonists can produce both hyperalgesic and analgesic effects in vivo. The cellular mechanisms underlying these behavioral phenomena are not understood. As a possible explanation for nicotinic hyperalgesia, we tested whether nicotinic acetylcholine receptors (nAChRs) could enhance excitatory transmission onto spinal cord dorsal horn neurons. Whole-cell patch-clamp recordings were performed in neonatal rat spinal cord slices. Activation of nAChRs enhanced glutamatergic synaptic transmission in 59% of dorsal horn neurons tested, and this effect was blocked by methyllycaconitine (10 nM), suggesting a key role for alpha7 nAChRs. Inhibition of acetylcholinesterase with methamidophos also enhanced transmission, demonstrating a similar effect of endogenous acetylcholine. nAChR activation also enhanced transmission by dorsal root entry zone stimulation, suggesting that alpha7 nAChRs on the central terminals of DRG afferents mediate this effect. Paired pre- and postsynaptic stimulation induced long-term potentiation of excitatory inputs to some of the dorsal horn neurons. Long-term potentiation induction was much more prevalent when nicotine was applied during stimulation. This effect also depended on both alpha7 nAChRs and N-methyl-d-aspartate glutamate receptors. Our findings demonstrate that alpha7 nAChRs can contribute to both short- and long-term enhancement of glutamatergic synaptic transmission in the spinal cord dorsal horn and provide a possible mechanism for nicotinic hyperalgesia.
Topics: Animals; Ganglia, Spinal; In Vitro Techniques; Patch-Clamp Techniques; Rats; Rats, Sprague-Dawley; Synaptic Transmission
PubMed: 12748382
DOI: 10.1073/pnas.1131709100 -
Neuron Mar 2002A single nicotine exposure increases dopamine levels in the mesolimbic reward system for hours, but nicotine concentrations experienced by smokers desensitize nAChRs on...
A single nicotine exposure increases dopamine levels in the mesolimbic reward system for hours, but nicotine concentrations experienced by smokers desensitize nAChRs on dopamine neurons in seconds to minutes. Here, we show that persistent modulation of both GABAergic and glutamatergic synaptic transmission by nicotine can contribute to the sustained increase in dopamine neuron excitability. Nicotine enhances GABAergic transmission transiently, which is followed by a persistent depression of these inhibitory inputs due to nAChR desensitization. Simultaneously, nicotine enhances glutamatergic transmission through nAChRs that desensitize less than those on GABA neurons. The net effect is a shift toward excitation of the dopamine reward system. These results suggest that spatial and temporal differences in nicotinic receptor activity on both excitatory and inhibitory neurons in reward areas coordinate to reinforce nicotine self-administration.
Topics: Acetylcholinesterase; Action Potentials; Adolescent; Animals; Atropine; Cholinergic Antagonists; Cholinesterase Inhibitors; Dopamine; Electrophysiology; Excitatory Amino Acid Antagonists; Ganglionic Stimulants; Glutamic Acid; Humans; In Vitro Techniques; Insecticides; Mice; Muscarinic Antagonists; Neurons; Nicotine; Organothiophosphorus Compounds; Patch-Clamp Techniques; Quinoxalines; Rats; Rats, Sprague-Dawley; Receptors, Nicotinic; Reward; Smoking; Synaptic Transmission; Ventral Tegmental Area; gamma-Aminobutyric Acid
PubMed: 11906697
DOI: 10.1016/s0896-6273(02)00625-6 -
American Journal of Public Health Nov 1993The purpose of this study was to demonstrate the usefulness of the Northwestern Nicaraguan Ministry of Health surveillance system for detecting pesticide poisonings.
OBJECTIVES
The purpose of this study was to demonstrate the usefulness of the Northwestern Nicaraguan Ministry of Health surveillance system for detecting pesticide poisonings.
METHODS
Cases were reported to the regional department of epidemiology through daily telephone reports and through monthly consolidated reports from each of the 18 health centers of the National Health Service. Reporting forms were also distributed to the four area hospitals.
RESULTS
During June and July 1987, an epidemic of 548 pesticide poisoning was detected in northwestern Nicaragua. Seventy-seven percent of the poisonings were caused by carbofuran or methamidophos. Of the work-related cases (91% of reported poisonings), more than 80% occurred among maize farmers and on small to medium land holdings (fewer than 140 hectares). Nineteen percent of the work-related cases involved children under 16 years of age.
CONCLUSIONS
Unsafe working conditions such as manual application of pesticides and the use of backpack sprayers, the introduction of a hazardous powdered formulation of carbofuran highly restricted in the developed world, and agricultural subsidies that encouraged the use of hazardous pesticides all contributed to the epidemic.
Topics: Adolescent; Adult; Agrochemicals; Cholinesterase Inhibitors; Developing Countries; Disease Outbreaks; Female; Humans; Insecticides; Male; Nicaragua; Occupational Diseases; Poisoning; Registries
PubMed: 8238678
DOI: 10.2105/ajph.83.11.1559 -
Archives of Toxicology 1992It has been recently reported that phenylmethanesulfonyl fluoride (PMSF) when given to hens after a neuropathic organophosphate (OP) promotes organophosphate-induced...
It has been recently reported that phenylmethanesulfonyl fluoride (PMSF) when given to hens after a neuropathic organophosphate (OP) promotes organophosphate-induced delayed polyneuropathy (OPIDP). Chicks are resistant to OPIDP despite high inhibition/aging of neuropathy target esterase (NTE), the putative target of OPIDP initiation. However, when PMSF (300 mg/kg s.c.) is given to chicks after di-butyl 2,2-dichlorovinyl phosphate (DBDCVP, 1 or 5 mg/kg s.c.), OPIDP is promoted. Inhibition/aging of at least 30% of NTE was thought to be an essential prerequisite for promotion to be elicited in adult hens. However, we observed in hens that when NTE is maximally affected (greater than 90%) by phenyl N-methyl N-benzyl carbamate (40 mg/kg i.v.), a non-ageable inhibitor of NTE, and then PMSF is given (120 mg/kg/day s.c. x 3 days) clinical signs of neuropathy become evident. Methamidophos (50 mg/kg p.o. to hens), which produces in vivo a reactivatable form of inhibited NTE, was shown either to protect from or promote OPIDP caused by DBDCVP (0.45 mg/kg s.c.), depending on the sequence of dosing. Because very high doses of methamidophos cause OPIDP, we considered this effect to be a "self-promoted" OPIDP. We concluded that NTE inhibitors might have different intrinsic activities for producing OPIDP once NTE is affected. Aging might differentiate highly neuropathic OPs, like DBDCVP, from less neuropathic OPs, like methamidophos, or from the least neuropathic carbamates, which require promotion in order for neuropathy to be expressed.(ABSTRACT TRUNCATED AT 250 WORDS)
Topics: Aging; Animals; Carboxylic Ester Hydrolases; Chickens; Female; Hexanones; Peripheral Nervous System Diseases; Phenylmethylsulfonyl Fluoride
PubMed: 1316117
DOI: 10.1007/BF02307272 -
British Journal of Industrial Medicine Feb 1991To assess the exposure response relation of pyrethroids in spraymen, 50 adult male cotton growers were selected and divided into three groups, one group to spray...
To assess the exposure response relation of pyrethroids in spraymen, 50 adult male cotton growers were selected and divided into three groups, one group to spray pyrethroids for one day, two groups to spray for three days. Deltamethrin, fenvalerate, and a deltamethrin methamidophos mixture were sprayed by appropriate subgroups for five hours a day. Exposure levels were evaluated by measuring the air concentration, dermal exposure concentration, and urinary content of pyrethroids by gas chromatography. Air concentrations of deltamethrin at the breathing zone were 0.01-0.89 microgram/m3 in the deltamethrin exposed group. For fenvalerate, air concentrations were 0.06-1.98 micrograms/m3. Dermal exposure, particularly on the legs, feet, and hands was appreciable and indicated that this was the main route of absorption. In those spraying for one day, urinary deltamethrin was not detectable by 12 hours after the beginning of exposure whereas fenvalerate was still detectable up to 24 hours after first exposure. Both pyrethroids could be detected two days after the end of three day spraying. Health effects were investigated by interview and physical examination. Twenty nine spraymen complained of abnormal facial sensations that developed mostly two to three hours from the start of pyrethroid spraying and that disappeared by 24 hours after exposure ceased. Some had dizziness, headache, and nausea, but no subject was diagnosed as having acute pyrethroid poisoning. The symptoms showed no significant correlation with urinary pyrethroid excretion. Blood cholinesterase activity of spraymen using the pyrethroid methamidophos mixture did not change.
Topics: Acute Disease; Adolescent; Adult; Agricultural Workers' Diseases; Air Pollutants, Occupational; Environmental Monitoring; Gossypium; Humans; Male; Middle Aged; Nitriles; Occupational Exposure; Organothiophosphorus Compounds; Poisoning; Pyrethrins
PubMed: 1998612
DOI: 10.1136/oem.48.2.82 -
Zeitschrift Fur Naturforschung. C,... 1987The cytogenetic effect of the insecticide methamidophos (0,S-dimethylphosphoroamidothiolate) was studied in mouse bone marrow and mouse spleen cells in culture. In vivo...
The cytogenetic effect of the insecticide methamidophos (0,S-dimethylphosphoroamidothiolate) was studied in mouse bone marrow and mouse spleen cells in culture. In vivo the ability of methamidophos to induce micronuclei and sisterchromatid exchange in mouse bone marrow was investigated. In vitro mouse spleen cells in culture were used to assess the ability of the insecticide to induce chromosomal aberrations and sister chromatid exchange. Three different routes of application for the pure insecticide were tested so as to cover the different possibilities for human exposure to the insecticide. Intraperitoneal, oral and dermal treatment with methamidophos caused toxicity to marrow as indicated by a significant increase in the percentage of polychromatic erythrocytes (PEs) over that of the control. Methamidophos showed mutagenic potential as evidenced by a positive response in the micronucleus and chromosomal aberrations assays. Thus, single and multiple i.p. injections at 6 and 4.5 mg methamidophos/kg body wt., oral administration of the insecticide for 14 consecutive days at a dietary level of 100 ppm and multiple dermal treatments (total 4) with 24 mg/kg body wt. induced a statistically significant increase in the frequency of PEs with micronuclei in mouse bone marrow. Moreover, the tested concentrations of methamidophos as low as 0.25 microgram/ml induced a high percentage of metaphases with chromosomal aberrations in cultured mouse spleen cells. Methamidophos is a weak inducer of SCEs in mouse bone marrow and cultured mouse spleen cells.
Topics: Animals; Bone Marrow; Bone Marrow Cells; Cell Nucleus; Cells, Cultured; Insecticides; Karyotyping; Lymphocytes; Mice; Organothiophosphorus Compounds; Polyploidy; Sister Chromatid Exchange; Spleen
PubMed: 2953131
DOI: 10.1515/znc-1987-1-205