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Toxicology Letters Aug 2002Organophosphates (OPs) are readily absorbed through the skin and biological monitoring is an essential component of any comprehensive assessment of exposure. This paper... (Review)
Review
Organophosphates (OPs) are readily absorbed through the skin and biological monitoring is an essential component of any comprehensive assessment of exposure. This paper presents a summary of our experience in a wide range of occupational studies. Additionally, we have conducted studies of non-occupational exposure and human volunteer studies looking at the kinetics of chlorpyrifos, propetamphos, diazinon and malathion. In non-occupationally exposed people, 95% of urinary alkyl phosphates do not exceed 72 micromol/mol creatinine. In occupationally exposed people, the corresponding 95th percentile of total urinary alkyl phosphates is 122 micromol/mol creatinine. In volunteer studies with 1 mg oral doses of chlorpyifos, diazinon and propetamphos the mean peak values were 160, 750 and 404 micromol/mol creatinine, respectively, and were not associated with any reduction in blood cholinesterase activity. The levels of OP metabolites seen in urine from workers potentially exposed to OPs are generally low and unlikely to cause significant reduction in blood cholinesterase activity.
Topics: Biomarkers; Cholinesterase Inhibitors; Cholinesterases; Creatinine; Environmental Monitoring; Erythrocytes; Humans; Insecticides; Occupational Exposure; Organophosphorus Compounds
PubMed: 12191866
DOI: 10.1016/s0378-4274(02)00168-6 -
The Science of the Total Environment Aug 2004Two groups of chemicals are currently licensed for use in sheep dip products in the UK. These are organophosphate (OP) insecticides and synthetic pyrethroid (SP)...
Two groups of chemicals are currently licensed for use in sheep dip products in the UK. These are organophosphate (OP) insecticides and synthetic pyrethroid (SP) insecticides. SPs are deemed to be less toxic to human health than OPs, although they are approximately 100 times more toxic to some elements of the aquatic environment. Three insecticides were selected for experimental investigation: diazinon, propetamphos (OPs) and cis-permethrin (SP), representative of the active ingredients used in sheep dip formulations, with additional uses in insect control in crops, and for domestic control of flies, mosquitoes, cockroaches, lice, ticks and spiders. The UK Government has recently reviewed agricultural practices relating to the disposal of used sheep dip, because the constituent insecticides are frequently detected in UK watercourses and the presence of these compounds is a severe hazard to the aquatic environment. Standard batch sorption experiments were carried out to investigate insecticide partitioning from water to soil, and the relationship between sorption and soil organic carbon content is discussed. Sorption isotherms and K(d) values showed that cis-permethrin adsorption was fastest on all five soils investigated, exhibiting the greatest total partitioning to the soil phase (83.8-94.8%) and high resistance to desorption. In comparison, the OP insecticides exhibited moderately strong soil adsorption as evidenced by their K(d) coefficients (diazinon K(d) 12-35 and propetamphos K(d) 9-60), with low sorption reversibility (< 15%). Calculation of a hydrological retardation factor in a scenario representative of a typical UK environment suggested that SP insecticides such as cis-permethrin will not migrate in the soil profile due to their virtual immobility and strong soil retention, and thus waste sheep dip disposal to agricultural land should not pose a risk to aquatic life if applied with appropriate controls.
Topics: Agriculture; Animals; Biological Availability; Diazinon; Environment; Food Chain; Insecticides; Organothiophosphorus Compounds; Permethrin; Risk Assessment; Sheep; Soil Pollutants; United Kingdom; Waste Disposal, Fluid; Water Pollutants
PubMed: 15262167
DOI: 10.1016/j.scitotenv.2004.02.021 -
The Veterinary Record Oct 1982
Topics: Animals; Baths; Insecticides; Mite Infestations; Organothiophosphorus Compounds; Sheep; Sheep Diseases
PubMed: 7147660
DOI: 10.1136/vr.111.16.367-a -
Research in Veterinary Science Jan 1986Infestation of sheep with the biting louse Damalinia ovis is a potentially serious problem which can effect the quality and quantity of wool produced and may reduce... (Comparative Study)
Comparative Study
Infestation of sheep with the biting louse Damalinia ovis is a potentially serious problem which can effect the quality and quantity of wool produced and may reduce weight gains. In this trial treated sheep produced 34 per cent more wool than louse-infested controls and the wool from the treated sheep was of a better quality. The mean liveweight gain in the treated groups was 18 per cent more than that in the untreated group. Treatment with a pour-on formulation of propetamphos at 25 to 50 mg kg-1 gave more than 99 per cent control of lice and protected against reinfestation for four months.
Topics: Administration, Topical; Animals; Body Weight; Insecticides; Lice Infestations; Organothiophosphorus Compounds; Phthiraptera; Sheep; Sheep Diseases; Wool
PubMed: 3704323
DOI: No ID Found -
The Veterinary Record Mar 1990As a result of an increase in the incidence of sheep scab in Northern Ireland, the concentrations of propetamphos and diazinon were measured during 1987 and 1988 in...
As a result of an increase in the incidence of sheep scab in Northern Ireland, the concentrations of propetamphos and diazinon were measured during 1987 and 1988 in fleece and liquid dip samples from selected flocks, including some in which inadequate dipping was suspected. Sixty-five per cent and 68 per cent of the liquid dip samples contained less than the manufacturer's recommended maintenance concentrations for propetamphos and diazinon respectively. The concentrations found in fleece were also lower than those found in sheep which were dipped with the recommended concentrations of propetamphos and diazinon in a controlled experiment.
Topics: Animals; Diazinon; Insecticides; Mite Infestations; Northern Ireland; Organothiophosphorus Compounds; Sheep; Sheep Diseases; Wool
PubMed: 2327045
DOI: No ID Found -
Activated transformations of organophosphorus insecticides in the case of non-AChE inhibitory oxons.Pest Management Science Nov 2002Many organophosphorus (OP) compounds are of the thiono form and in insects or animals are converted by microsomal mixed function oxidases (MFO) into the oxon forms which... (Review)
Review
Many organophosphorus (OP) compounds are of the thiono form and in insects or animals are converted by microsomal mixed function oxidases (MFO) into the oxon forms which inhibit acetylcholinesterase (AChE) and give toxic activity. However, certain S-alkyl phosphorothiolates (RS-P(O) <) such as methamidophos, profenophos and prothiophos oxon are strongly insecticidal, but very poor inhibitors of AChE in vitro. Their oxons are converted further to the S-oxides, which either inhibit AChE or decompose, depending on the alkyl substituents on the sulfur atom. It is also inferred in the case of prothiophos oxon that its S-oxide not only inhibits AChE but also conjugates with glutathione (GSH) by the action of glutathione S-transferase (GST), and the conjugate inhibits AChE. Certain phosphoramidates (R2N-P(O) <) such as isofenphos oxon, schradan and propetamphos oxon are weak AChE inhibitors, but strongly insecticidal. It is well known that isofenphos oxon is converted into the stable N-desalkyl form (H2N-P(O) <) by oxidative dealkylation to inhibit AChE. The authors have studied activation of phosphoramidates using 2,4-dichlorophenyl methyl N-alkylphosphoramidates as model compounds using various approaches including computational chemistry, and these studies indicated that the O-aminophosphate structure (R2N-O-P(O) <) is an activated form.
Topics: Acetylcholinesterase; Amides; Animals; Cattle; Chlorobenzoates; Cholinesterase Inhibitors; Erythrocytes; Fenitrothion; Glutathione Transferase; Houseflies; Inhibitory Concentration 50; Insecticides; Lethal Dose 50; Molecular Structure; NADP; Organothiophosphates; Organothiophosphorus Compounds; Oxidation-Reduction; Phosphoric Acids
PubMed: 12449529
DOI: 10.1002/ps.546 -
The Veterinary Record Feb 1987
Topics: Animals; Female; Nematode Infections; Organothiophosphorus Compounds; Sheep; Sheep Diseases
PubMed: 3604036
DOI: 10.1136/vr.120.7.167 -
Australian Veterinary Journal May 1993
Comparative Study
Topics: Animals; Diptera; Disease Susceptibility; Ectoparasitic Infestations; Female; Insecticides; Male; Organothiophosphorus Compounds; Sheep; Sheep Diseases; Tail; Wound Healing
PubMed: 8343093
DOI: 10.1111/j.1751-0813.1993.tb06132.x -
CDR (London, England : Weekly) Oct 1991
Topics: Agricultural Workers' Diseases; Animals; Chlorfenvinphos; Diazinon; Environmental Monitoring; Insecticides; Occupational Exposure; Organothiophosphorus Compounds; Risk Factors; Sheep; Sheep Diseases; United Kingdom
PubMed: 1669884
DOI: No ID Found -
Journal of Mass Spectrometry : JMS Nov 2022Lanolin, also known as wool wax, is derived from sheep and has diverse applications in food, cosmetic, textile and lubricant industries. Owing to its direct contact with...
Lanolin, also known as wool wax, is derived from sheep and has diverse applications in food, cosmetic, textile and lubricant industries. Owing to its direct contact with human, there is a need of studying pesticide residues as contaminants in lanolin. The present study describes a single novel hyphenated gas chromatography-tandem mass spectrometry (GC-MS/MS) technique for the quantification of 14 organophosphorus (OP) pesticides (tecnazene, propetamphos, diazinon, dichlofenthion, chlorpyrifos methyl, fenchlorphos, malathion, chlorpyrifos, pirimiphos ethyl, bromophos ethyl, tetrachlorvinphos, ethion, phosalone, and coumaphos) in lanolin using electrospray ionization (EI) with multiple reaction monitoring (MRM) acquisition mode. The method is simple in terms of sample preparation steps based on matrix solid-phase dispersion (MSPD). The method was found to be linear over the analytical range of 0.05-2.0 μg/g, with acceptable coefficient of determination (r ≥ 0.99) for all the 14 pesticides. The limit of detection (LOD) and limit of quantification (LOQ) of the method were found to be less than 0.05 and 0.1 μg/g, respectively, for all the 14 OP pesticide residues. The precision and accuracy of the method were found to be within the acceptable limits, that is, recoveries in the range of 83.5%-104.1% with less than 12.5% of relative standard deviation for all the pesticides. The multiresidue method for estimating pesticide residues employing GC-MS/MS technique will be useful for OP pesticide levels in large number of lanolin samples.
Topics: Sheep; Animals; Humans; Pesticides; Pesticide Residues; Tandem Mass Spectrometry; Lanolin; Organophosphorus Compounds; Gas Chromatography-Mass Spectrometry; Chlorpyrifos
PubMed: 36369744
DOI: 10.1002/jms.4894