Inhibitor Report for: Phosalone

Between 1978 and 1986, 305 samples of apples were monitored for the residues of a wide range of pesticides used in their production. Three (1%) contained residues above the maximum residue limits (MRL) permitted under the Canadian Food and Drug Act and regulations; two involved phosalone at 5.9 and 6.2 mg/kg respectively and one involved diphenylamine at 6.7 mg/kg when the MRL was 5.0 mg/kg for both compounds. Low residues of dicofol, endosulfan, phosalone, phosmet, captan, daminozide and diphenylamine were frequently found; however they were well below the MRLs. These residue levels were correlated with survey data on the areas of the apple crop treated with specific pesticides. Residues of carbaryl, diazinon, ethion, azinophosmethyl, parathion, and dithiocarbamate fungicides were found occasionally; all were well below the MRLs and correlated with the pattern of use. No residues of PCB were found to a limit of detection of 0.01 mg/kg.

A screening method has been developed for determining organophosphorus pesticides at ng/L levels in drinking water. Sixteen organophosphorus pesticides, diazinon, diazinon-oxon, dimethoate, ronnel, beta-phosphamidon, methyl parathion, ethyl parathion, malathion, chlorpyrifos, fenitrothion, ruelene, methidathion, ethion, EPN, phosalone, and phosmet, were extracted by Amberlite XAD-2 resin from 100 and 200 L drinking water previously spiked with these pesticides. The pesticides were eluted from the XAD-2 resin with acetone-hexane (15+85). The concentrated extract was analyzed by gas chromatography using a nitrogen-phosphorus selective detector and by gas chromatography-mass spectrometry using selected ion monitoring. Recoveries at the 10 and 100 ng/L spiking levels were greater than 90%, except recoveries for dimethoate and phosphamidon were 37 and 42%, respectively. The analysis of 300 L Ottawa tap water showed no detectable amounts (less than 1 ng/L) of any of the 16 organophosphorus pesticides.

A toxicity test for organophosphates (OP) and carbamates (C) was improved with the adult ragworm Nereis diversicolor. Animals were maintained in U-shaped glass tubes of 4-mm inner diameter fixed vertically on a plastic plate and placed in glass aquaria. Each tank was covered with glass in order to reduce evaporation and heat dissipation. Temperature varied between 15 and 16 degrees C and salinity was constant (34 per thousand) during the entire length of the experiment. Experiments were performed with a fixed day length of 12 h and seawater was gently aerated. The maintenance system allowed the administration of OP and C compounds via the seawater. An acclimatization period of 48 h was not sufficient to accomodate worms to their artificial burrows; accordingly, we chose to acclimate worms for a week before beginning the exposure. Choline acetyltransferase (ChAT) activity was very low and was not significantly modified by two OP compounds: malathion and parathion-ethyl. ChAT is not a target for these pesticides and should not be used for future studies about OP and C toxicity. On the other hand, inhibitory effects on acetylcholinesterase (AChE) activity were determined at concentrations of 10(-6) M for three OP compounds-malathion, parathion-ethyl, and phosalone-and a carbamate pesticide-carbaryl. We measured only short-term effects and no cumulative effect was determined, the maximum percentage of AChE activity inhibition being between 2 (carbaryl) and 7 (OP compounds) days after exposure and then remaining stable. Mortality occured only after a period of intoxication of 14 days. N diversicolor, which can be easily maintained at the laboratory, seems to be a good candidate for future laboratory studies to test the toxicity of other pollutants.

A rapid procedure has been developed that allows a single-step, selective extraction and cleanup of organophosphate (OP) pesticide residues from milk dispersed on solid-matrix diatomaceous material filled into disposable cartridges by means of light petroleum saturated with acetonitrile and ethanol. Recovery experiments were carried out on homogenized commercial milk (3.6% fat content) spiked with ethanolic solutions of 24 OP pesticides, viz., ethoprophos, diazinon, dimethoate, chlorpyrifos-methyl, parathion-methyl, chlorpyrifos-ethyl, malathion, isofenphos, quinalphos, ethion, pyrazophos, azinphosethyl, heptenophos, omethoate, fonofos, pirimiphos-methyl, fenitrothion, parathion, chlorfenvinphos, phenthoate, methidathion, triazophos, phosalone, azinphos-methyl, at levels ranging for the different OP pesticides from 0.02 mg/kg to 1.11 mg/kg. Average recoveries of four replicates were in the range 72-109% for the different OP pesticides, with relative standard deviations (R.S.D.) from ca. 1 to 19%, while dimethoate and omethoate were not recovered. Coextracted fatty material amounted to an average of about 4.0 mg/ml of milk. The extraction procedure requires about 30 min. The main advantages are that extraction and cleanup are carried out in a single step, emulsions do not occur, several samples can be run in parallel by a single operator, reusable glassware is not needed and simple operations are required.

Dehydrated fruits and vegetables, which may well be used in baby foods, must be of excellent bacteriological quality with an absence of contamination. In order to define the effects of the industrial dehydration process, according to the 'Hatmacker' drying method, on an organophosphorus pesticide, we have studied phosalone in Golden Delicious apples as an example. The technological process undertaken leads to a reduction in phosalone levels on the apples of more than 80%, whatever the initial dose between 0 and 4.29 micrograms/kg. Washing brings about a reduction of 30-50%, probably by the dissolution of the phosalone in the water. The cooking and especially the filtration of the pured apple mechanically eliminates, without notable deterioration, 40-70% of the phosalone. However, drying, which takes place at the end of the process, does not lead to significant variations in phosalone levels. Consequently, the reduction in phosalone residue levels in dehydrated apple products manufactured by this process provides the consumer with a greater degree of security with respect to this contaminant. In addition, we have presented several possibilities to add to the quality of dehydrated products.

The effect of an organophosphorus pesticide-phosalone on some parameters of humoral and cellular immunologic response in mice was investigated. Haematological and morphological examinations were made parallelly. It was found that immunotropic effect of phosalone was a reversible process.

The multiple sublethal doses of phosalone induced changes in haemodynamics, maximum absorption spectra, oxygen equilibrium curves (OEC), half saturation tension (P50), degree of interaction (n), pH of blood, Bohr factor and circulatory gases of blood in rat, Rattus norvegicus. The results have obviously shown that increase the activation of pyridoxal phosphate, shift of OEC to right and decrease in the affinity of haemoglobin for oxygen at tissue level.

The influence of multiple sublethal concentrations of phosalone on whole animal and kidney oxygen consumption, haem synthesis and blood gases of rat, were carried out over a 90 day dosed period. The results indicate the existence of hypoventilation and a hypoxic condition in the animals which lead to the disruption of neuromuscular transmission in respiratory muscles and increase of erythropoiesis and haemoglobin synthesis. The changes were most pronounced when animals were exposed for the 90 day dosed period.

Organophosphorus compounds and carbamates are pesticides which inhibit acetylcholinesterase activity. The toxicity of phosalone and carbaryl was studied for 29 days in the adult common prawn (Palaemon serratus). Induction thresholds for inhibitory effects were determined and the toxicity of these two pesticides was investigated. For monitoring purposes, several methods of assessing the effects of these two pesticides in the marine environment are considered and discussed.

The level of acetylcholinesterase (AChE) in brain regions of O. mossambicus at different intervals showed the extent of phosalone toxicity. Significant inhibition of AChE at the end of 96 hr in the brain regions was observed. In contrast to AChE inhibition, the monoamine oxidase (MAO) activity showed significant increase in the regions of cerebral hemispheres, dien/mesencephalon, cerebellum and medulla oblongata. The increase of MAO activity in the brain regions under phosalone toxicity is considered to be one of the mechanisms to maintain the amines level in O. mossambicus.

Evaluation of a previously published gel permeation chromatographic (GPC) procedure was undertaken to determine whether it can be used for additional organochlorine pesticides. After repeatability studies of many pesticides, the following compounds were approved for inclusion in the U.S. Department of Agriculture Domestic Residue Monitoring Program: coumaphos-S, stirophos, chlorpyrifos, ronnel, carbophenothion, chlorfenvinphos, phosalone, kepone, captan, linuron, and endosulfan I and II. Recoveries ranged from 54% for captan to 123% for ronnel. Ranges of CVs varied from 0-9.5% for carbophenothion to 7.1-47.7% for kepone. Although the minimum acceptable recovery of 50% was attained for all 12 pesticides, the anticipated CV of 20% was waived to include chlorpyrifos, endosulfan I and II, and kepone. For a multiresidue procedure involving approximately 40 compounds, these results were within the acceptable criteria.

Effect of multiple sublethal concentrations of Phosalone on whole animal and kidney oxygen consumption, haematological indices and serum enzymes of freshwater fish, Oreochromis mossambicus, were carried out over a 90 day exposure period. Significant changes were observed which have been indicating that the presence of hypoxic condition in the biosystem, gradual increase in the rate of synthesis of haemoglobin and disruption of liver function during the toxicity of phosalone.

Zinc chloride-diphenylamine reagent, whose use has been reported for the detection of organochlorine insecticides by thin layer chromatography, was further studied for its ability to detect the organophosphorus insecticides phorate, phosphamidon, DDVP, and phosalone and the carbamate insecticide carbaryl and aldicarb. These insecticides give intense blue-green spots with this reagent. The procedure can be applied to the detection of the insecticides in biological materials and thus has a potential use in forensic toxicology.

An illness characterized by weakness, dizziness, and gastrointestinal symtoms was identified among a crew of 30 migrant field-workers employed by a grape grower in Madera County, California, during August 1987. The onset of symptoms occurred between August 24 and August 30 and a median of 9 days from the date of first employment. The first crew member sought medical treatment on August 26, and 10 crew members were admitted to hospital between August 27 and August 30. For most workers, gastrointestinal and constitutional symptoms resolved shortly after admission, but 4 patients had episodes of severe sinus bradycardia persisting for several days. On the day of admission, transient atrioventricular dissociation developed in 2 persons. Interviews with 16 crew members not admitted to the hospital identified only 1 additional worker ill with gastrointestinal symptoms, but all 16 had moderate to severe inhibition of both plasma and red blood cell cholinesterase. Four other workers who were tested but not interviewed also had cholinesterase depression. The crew had had exposure since August 19 to the organophosphate insecticide phosalone, which was last applied to the vineyard on July 21, or 29 days earlier. Although this is the first report unequivocally linking phosalone to field-worker poisoning, the delayed onset and nonspecific nature of the symptoms associated with subacute poisoning may have hindered the recognition of previous similar episodes.

Brain cholinesterase (ChE) activities of songbirds collected in pecan groves 6 to 7 hr after separate applications of the organophosphorus pesticides, phosalone and disulfoton, were compared to mean ChE activities of controls (normals) as a measure of insecticide exposure. In general, reduction of brain ChE activity greater than or equal to 2 standard deviations below the control mean indicates exposure to an anticholinesterase compound. Phosalone had little effect on brain ChE activity of birds from treated groves; only slight to moderate (21 to 38%) ChE inhibition was detected in blue jays (Cyanocitta cristata) and red-bellied woodpeckers (Melanerpes carolinus). However, 11 of 15 blue jays from disulfoton-treated groves had moderate to severe ChE depression, ranging from 32 to 72%. Inhibition greater than or equal to 50% of normal may be diagnostic for cause of death. Direct mortality was not observed, but studies have shown that bird carcasses disappear rapidly from agricultural areas, many within 24 hr. We recommend additional field studies of the effects of disulfoton to wildlife, since large wheat-growing areas in the western United States are being considered for disulfoton treatment to control the Russian wheat aphid (Diuraphis noxia).

Between 1978 and 1986, 305 samples of apples were monitored for the residues of a wide range of pesticides used in their production. Three (1%) contained residues above the maximum residue limits (MRL) permitted under the Canadian Food and Drug Act and regulations; two involved phosalone at 5.9 and 6.2 mg/kg respectively and one involved diphenylamine at 6.7 mg/kg when the MRL was 5.0 mg/kg for both compounds. Low residues of dicofol, endosulfan, phosalone, phosmet, captan, daminozide and diphenylamine were frequently found; however they were well below the MRLs. These residue levels were correlated with survey data on the areas of the apple crop treated with specific pesticides. Residues of carbaryl, diazinon, ethion, azinophosmethyl, parathion, and dithiocarbamate fungicides were found occasionally; all were well below the MRLs and correlated with the pattern of use. No residues of PCB were found to a limit of detection of 0.01 mg/kg.

An HPLC method for the simultaneous detection of six organophosphorus pesticides (Dimethoate, Ethion, Malathion, Phorate, Phosalone and Parathion) on a Zorbex ODS column using methanol + water (80:20) as solvent is described.

Phosalone, O,O-diethyl-S-(6-chloro-1,3-benzoxazol-2(3H)-onyl)methyl phosphorodithioate, was field-applied by ground equipment to cotton (Gossypium hirsutum L.) at the rates of 1050 and 2100 g a.i./ha, respectively, to determine its dissipation on leaves and soils and the residues in seeds at harvest. The insecticide concentrations on cotton leaves and soils were measured periodically for 14 days following its application. It was found that the half lives of the insecticide on cotton leaves at the dosages of 1050 and 2100 g a.i./ha were 6.8 and 6.3 days, respectively. And the half lives on soils for the 2 dosages were 7 and 5.8 days, respectively. The residues remaining in soils at harvest time were 0.072 and 0.121 mg/kg 14 days post-application and the residues in cotton seeds were relatively low (less than 0.02-0.12 mg/kg).

Presence of insecticide-endosulfan, phosalone or permethrin in the growth medium caused concentration dependent inhibition in the vegetative growth of Chlamydomonas reinhardtii algal cells. The rate of inhibition produced by endosulfan was two-fold higher than that of phosalone or permethrin. Endosulfan affected the cell growth completely at 100 times less concentration as compared to that of phosalone or permethrin. Non-dividing cell populations encountered significant losses in cells during their exposure (2 h) to endosulfan and did not show further loss in the 72 h post-treatment period. The populations treated with phosalone exhibited losses of considerable magnitude in the post-treatment period. Permethrin treated non-diving cell populations did not lower the cell number, either after the treatment period (2 h) or the post-treatment period (72 h). However, these populations showed reduced levels of chlorophyll following the exposure of the insecticide and did not display recovery or further reduction in the levels in the post-treatment period. The chlorophyll levels of endosulfan or phosalone treated cell populations remained unaffected. The cells remaining intact after the treatment (2 h) of endosulfan or phosalone exhibited significant decreases in their post treatment vegetative growth abilities. The growth ability of such permethrin exposed cells was similar to that of untreated cells.

In developing countries, extensive use of pesticides to meet with increased agricultural needs is inevitable and the indiscriminate use has led to several toxicological implications in humans. The toxic effects, however, to a large extent depend on the nutritional status of the individuals. In the present work, the hepatic susceptibility to pesticide toxicity has been studied in experimental animals maintained on diets containing different levels of protein for a period of 3 weeks. Along with protein deprivation, the rats were also exposed to three organophosphorus pesticides, viz., parathion, malathion, and phosalone, individually at various doses for the same time period. Phosphatases, the functionally important enzymes of the liver, were estimated and the results obtained indicated that protein deprivation further aggravated the pesticide-induced effects on the hepatic phosphatases.

Studied was the effect of the preparations phenitrothion (Agria-1050) and phosalon (Agria-1060) on the immunologic reactivity of sheep through following up the phenomena of agglutination and phagocytosis at the injection of a Salm. gallinarum antigen. An unknown property of these preparations was established, consisting in the stimulation of some defense immunobiologic processes in the body of animals, at their application in minimum doses per os, simultaneously with the injection of a bacterial antigen. Phenitrothion applied orally to sheep at the rate of 50 mg per kg body mass daily, seven times in the course of sixty days, with the injection of a suspension of a killed Salmonella gallinarum culture (containing 10(7) microbial cells per 1 cm3-3 cm3 i/v, and 5 cm3 four days later, s/c per animal) stimulated agglutinin production, increasing it from 9 to 17 times; it raised the phagocytic number by 2.5 to 3 times, and the phagocytic index--by 1.7 to 2.14 times. With control animals the increase was 3-4, 1.4-1.5, and 1.10-1.19 times, respectively. Phosalon applied to sheep in following the same pattern at the rate of 13 mg per kg body mass led to a rise of the agglutinintiter from 22 to 26 times; the phagocytic number was raised by 2.6 to 4.3 times, and the phagocytic index--by 1.6-2.3 times.

The effects of oral ingestion of different pesticides (lindane, phosalone, carbaryl) and of a polychlorinated biphenyl (pyralene) on nonreaginic antibody production in BALB/c mice and also on the duration of Giardia muris infection have been studied using the animal model of this disease. Only lindane and carbaryl produced significant effects on systemic antibody production following oral immunization with sheep red blood cells (SRBC). Lindane ingestion led to a twofold increase in IgG2b antibody titer to SRBC (P less than 0.05) and carbaryl significantly increased both IgG1 and IgG2b titers. No reduction was seen in the synthesis of any antibody class. The effect of feeding with lindane was to increase the duration of giardiasis significantly (P less than 0.002), and these mice developed systemic anti-Giardia antibodies more frequently than Giardia-infected mice on normal diets. These results suggest that in the doses used these pesticides may increase systemic antibody responses to orally ingested antigens, and by inference that spontaneous elimination of giardiasis is independent of the systemic nonreaginic antibody response to the parasite.

The zolone PM (phosalone) insecticide in the suspensions used destroys parts of the hypostome, ruins many buds and budless hydras. In the insecticide suspension a hydra shrinks and assumes the smallest surface. It is due to this that the surface mucous layer thickens and epidermal and gastrodermal cells become highly squeezed together. The insecticide penetrates the hypostomal opening and destroys hypostomal cells but does not act specifically upon a certain type of cells. Gradually, other cells replace the destroyed ones. They arrive from the gastrodermal region. Among them, zymogen cells, capable of differentiation und dedifferentiation into other types of cells, play the most significant part.

A single oral dose of DDT (60.0 mg/kg), malathion (687.5 mg/kg), phosalone (60.0 mg/kg) and elsan (175.0 mg/kg) to adult male albino rats produced significant impairment in acid and alkaline phosphatase activities within 1 h of dosing. Renal and hepatic alkaline phosphatase activity was significantly inhibited in all cases, while treatment with malathion and phosalone resulted in an increase in intestinal alkaline phosphatase activity. Elsan induced an increase in acid phosphatase activity in liver, kidney and intestine whereas the response to DDT, malathion and phosalone was variable.

Four sprays of 0.05 and 0.10% phosalone were given on chilli (Capsicum annuum Linn.) crop at an interval of 15 days starting from 21 days after transplanting. Residues were determined in the green chilli fruits by GLC after cleanup of extract on multiband thin-layer plate. The half-lives of residues were 1.55 and 1.68 days on chilli fruits from the crop treated with four sprays of 0.05 and 0.10% phosalone respectively. The time required to reach the tolerance limit of 1 ppm after last spray with 0.05 and 0.10% emulsion was 4.75 and 7.62 days respectively. Washing of fruits under tap water was found effective in bringing down the level of phosalone residue by 21.64 to 75.11%.

The absorption of malathion and phosalone was followed in occupationally exposed workers by determination of residues excreted in the urine. Because of the high concentrations found in the morning urine samples, the rates of excretion of phosalone metabolites in the urine of a volunteer experimentally exposed to phosalone during one and then again during three subsequent working days were investigated. The urinary excretion of phosalone metabolites was most intense 4--5 hours after exposure. At the beginning of the next day, the metabolites were still well measureable in the urine. Blood and plasma cholinesterase activities were only slightly reduced during exposure. The analyses of 24-hour urine samples, or of urine samples taken 4--5 hours after exposure, are not suitable for the routine control of occupationally exposed persons because of sampling difficulties. Instead, analyses of samples taken immediately before and after work hours have to be performed. A systematic increase in the concentrations of pesticide residues in the morning urine should initiate more efficient and well-timed protection measures.

A screening method has been developed for determining organophosphorus pesticides at ng/L levels in drinking water. Sixteen organophosphorus pesticides, diazinon, diazinon-oxon, dimethoate, ronnel, beta-phosphamidon, methyl parathion, ethyl parathion, malathion, chlorpyrifos, fenitrothion, ruelene, methidathion, ethion, EPN, phosalone, and phosmet, were extracted by Amberlite XAD-2 resin from 100 and 200 L drinking water previously spiked with these pesticides. The pesticides were eluted from the XAD-2 resin with acetone-hexane (15+85). The concentrated extract was analyzed by gas chromatography using a nitrogen-phosphorus selective detector and by gas chromatography-mass spectrometry using selected ion monitoring. Recoveries at the 10 and 100 ng/L spiking levels were greater than 90%, except recoveries for dimethoate and phosphamidon were 37 and 42%, respectively. The analysis of 300 L Ottawa tap water showed no detectable amounts (less than 1 ng/L) of any of the 16 organophosphorus pesticides.

The intestinal dipeptidase and disaccharidase activities were investigated in 120 male albino rats of the Wistar strain after administration of 21 mumol.kg-1 body weight phosalone, 14.8 mumol.kg-1 body weight lindane and 10.5 mumol.kg-1 body weight phosalone combined with 7.4 mumol.kg-1 body weight lindane. The dipeptidase activity under the effect of these comparatively low doses of pesticides reveals slightly to moderate changes. The activity of intestinal disaccharidases after a 90-day phosalone and lindane treatment is markedly decreased, particularly that of sucrase. The mechanism of these changes remains unknown.

The study on the embryotrophic action of phosalon insecticide preparation is conducted against the background of its comprehensive and thorough hygiene-toxicologic assay. Pregnant white rats undergo treatment per os with 1/10 and 1/100 LD50 throughout the entire gravidity period. Recordings are made of the quantity of corpora lutea, pre- and postimplantation lethality; the pedigree development is traced up to the end of the second postnatal month with readings being made of weight and length in the first postnatal day, presence or not of external malformations, weight increase and survival up to the end of the lactation period, day of eye cleft opening and hairing, and sex ratio. The presence of phosalon and phosalon-oxone in whole embryo homogenates is estimated. Enzyme activity of GOT, GPT, catalase, LDH, G-6-PD, RNA and DNA quantity are studied in the liver of newborns on the second postnatal day. Within 21 days of birth, the peripheral blood picture and visceral weight coefficient are also studied. Investigation of the peripheral blood picture, activity of catalase, GOT and GPT in the liver and serum, alkaline and acid phosphatase, and peroxidase in the serum is performed at the end of the second month. The results point to the presence of an embryotoxic effect at the level of the investigated hepatic indicators, detected on the 2nd day of the postnatal period, only at 1/10 LD50 dose.