PESTICIDE RESIDUES IN FOOD - 1997 Sponsored jointly by FAO and WHO with the support of the International Programme on Chemical Safety (IPCS) TOXICOLOGICAL AND ENVIRONMENTAL EVALUATIONS 1994 Joint meeting of the FAO Panel of Experts on Pesticide Residues in Food and the Environment and the WHO Core Assessment Group Lyon 22 September - 1 October 1997 The summaries and evaluations contained in this book are, in most cases, based on unpublished proprietary data submitted for the purpose of the JMPR assessment. A registration authority should not grant a registration on the basis of an evaluation unless it has first received authorization for such use from the owner who submitted the data for JMPR review or has received the data on which the summaries are based, either from the owner of the data or from a second party that has obtained permission from the owner of the data for this purpose. MEVINPHOS First draft prepared by Dr W. Erichson Environmental Fate and Effects Division US Environmental Protection Agency Washington DC, USA Identity and physical and chemical properties Sources of environmental exposure Environmental transport, distribution, and transformation Effects on nontarget organisms in the laboratory and the field Evaluation of effects on the environment Risk assessment Terrestrial organisms Aquatic environment References 1. Identity and physical and chemical properties Mevinphos is produced as a mixture of E (> 60%) and Z (< 25%) geometrical isomers. It is a pale-yellow liquid with a boiling-point of 99-103°C at 0.03 mm Hg (0.004 kPa) and a vapour pressure of 0.003 mm Hg (0.0004 kPa) at 21°C. Mevinphos is miscible in water, with an estimated solubility of 600 000 mg/L. The octanol:water partition coefficient (Kow) is 1.1-1.5. 2. Sources of environmental exposure Mevinphos is a broad-spectrum organophosphate insecticide and acaricide with both contact and systemic activity. Its mechanism of pesticidal action is direct inhibition of cholinesterase. Mevinphos was used to control aphids, mites, grasshoppers, cutworms, leafhoppers, caterpillars, and other insects, predominantly on a variety of vegetable, fruit, and field crops. All uses of mevinphos were voluntarily withdrawn in the United States from 1 December 1995 owing to concerns about workers' health. Mevinphos products have been formulated as emulsifiable concentrates, soluble concentrates, ready-to-use liquids, and dusts. Its trade names included Phosdrin, Duraphos, Apavinphos, OS-2046, Mevinox, Menite, Gesfid, Phosfene, and Compound 2046. The application rates were 0.15-3.4 kg ai/ha but were typically 0.56-1.12 kg ai/ha per application for most crops when distributed with conventional ground or aerial equipment. Multiple applications were allowed as needed. 3. Environmental transport, distribution, and transformation The available data on the environmental fate of mevinphos indicate that it dissipates rapidly in the terrestrial environment. In one field study in the San Joaquin Valley of California (USA), six applications of 0.9 kg ai/ha were made from a tractor-mounted boom sprayer at seven-day intervals, for a total application of 5.4 kg ai/ha. The residues of the E and Z isomers in the top 15 cm of soil on the day of application were reported to be < 0.01 mg/g soil; the half-lives of the isomers in soil were difficult to determine owing to the low concentrations of residues and the rapid degradation of mevinphos, but they were less than four days for both isomers (Leech & McKane, 1990). Biotic degradation appears to be a main route of terrestrial dissipation of mevinphos. The aerobic half-lives for the E and Z isomers are 1.21 and 3.83 h, respectively, under laboratory conditions at 25°C in the dark (Reynolds, 1994, 1995). The major degradation pathways appear to be the formation of methylacetoacetate followed by rapid binding to soil and mineralization to carbon dioxide. The anaerobic half-life of mevinphos (a mixture of E and Z isomers) in flooded sandy soil after 24 h of aerobic incubation is about 12 days. Both the E and Z isomers hydrolyse faster in sterile aqueous buffered solutions at pH 9 (2.8-7.5 days) than at pH 5 (50.8-84.6 days) or pH 7 (29.2-62.7 days) (Misra, 1992). At pH 5 and pH 7, both isomers hydrolysed mainly to O-des-methylmevinphos. At pH 9, both isomers produced O-des-methylmevinphos, acetoacetic acid, and acetone, but the E-isomer also produced cis-mevinphos acid. Photolysis of E-mevinphos in sterile, buffered (pH 5) aqueous solution under artificial sunlight at 25°C occurred within 27.2 days (Cohen, 1994a). After 480 h of exposure, the degradates included Z-mevinphos, O-desmethylmevinphos, methyl acetoacetate, and an unknown product. Aqueous photolysis of the Z isomer occurred within 27.8 days, with degradation to E-mevinphos, O-desmethyl-mevinphos, and an unknown product (Cohen, 1994b). Mevinphos is potentially highly mobile in soil, because of its high solubility in water (6 × 105mg/L) and low soil partition coefficient (Kads, 0.392-1.92). A study conducted in California (USA), however, showed that leaching of the E and Z isomers in the field is minimal. Residues of both isomers were detected below the soil surface (0-15 cm) in only a few instances after application of mevinphos at 0.9 kg ai/ha weekly for seven weeks. It was concluded that rapid degradation of both isomers in the top 15 cm of soil precluded leaching to greater depths (Leech & McKane, 1990). 4. Effects on nontarget organisms in the laboratory and the field The acute oral LD50 value of mevinphis in birds is 1.34-4.6 mg ai/kg for sharp-tailed grouse, ring-necked pheasant, and mallard (Table 1). When given in the diet, the LC50 was 236 mg ai/kg diet for Japanese quail and 246 mg ai/kg diet for ring-necked pheasant; it was less toxic to bobwhite quail and mallard ducks. The acute oral LD50 value in laboratory rats was 2.2 mg ai/kg. Table 1. Toxicity of mevinphos to birds Species Age End-pointa Toxicity Reference (mg ai/kg) Sharp-tailed grouse Not specified LD50 501.34 Hudson et al. (1984) (Tympanuchus phasianellus) Ring-necked pheasant 3-4 months LD50 1.37 Hudson et al. (1984) (Phasianus colchicus) 10 days LC50 246 Hill et al. (1975) Mallard (Anas platyrhynchos) 5-7 months LD50 4.63 Hudson et al. (1984) 10 days LC50 1991 Hill et al. (1975) Reproduction < 4 / 4 Beavers et al. (1992a) (NOEC/LOEC) Japanese quail 14 days LC50 236 Hill et al. (1975) (Coturnix coturnix) Bobwhite quail < 10 LC50 1000 DeWitt et al. (1963) (Colinus virginianus) Reproduction 1.5/7.1 Beavers et al. (1992b) (NOEC/LOEC) a LD50 = single oral dose; LC50 = 5-day exposure to treated food followed by 3-day exposure to untreated food The NOEC for reproductive toxicity was 1.5 mg ai/kg for bobwhite quail and < 4 mg ai/kg for mallards exposed to mevinphos in the diet for 20-22 weeks. The number of viable embryos and the eggshell thickness of bobwhite quail were significantly reduced at 7.1 mg ai/kg in comparison with the control. The body weight of mallard hens was significantly affected at 4 mg ai/kg. The LD50 values for honeybees were 0.070 mg/bee after contact and 0.027 mg/bee after oral exposure (Stevenson, 1968). Mevinphos residues were not toxic to bees 4 h after an application of 0.9 kg ai/ha (Castellon, 1989). Mevinphos applied at standard field rates was toxic to predaceous mites, parasitic wasps, and predaceous beetles in several studies (Bartlett, 1963, 1964, 1966). The toxicity of mevinphos to freshwater organisms is summarized in Tables 2 and 3. The 96-h LC50 values for technical-grade mevinphos (60% E isomer and 40% related compounds) in fish are 11.9 mg ai/L for rainbow trout and 22.5-87 mg ai/L for bluegill sunfish. The values for the formulated product (30.2-34.6% ai) are 81.4 mg ai/L for bluegill sunfish, 41.8 mg ai/L for rainbow trout, and 1.46 mg ai/L for Daphnia magna. The 48-h EC50 values for the technical-grade material are 0.18 mg ai/L for Daphnia pulex and 0.42 mg ai/L for Simocephalus serrulatus. The 96-h EC50 values for invertebrates were 2.8-130 mg ai/L for Gammarus fasciatus at water temperatures of 15-21°C, 5 mg ai/L for Pteronarcys californica, 13.5 mg ai/L for Palaemonetes kadiakensis, and 61 mg ai/L for Asellus brevicaudus. The toxicity of mevinphos to estuarine and marine organisms is summarized in Tables 2 and 3. The 96-h LC50 values for sheepshead minnows are 0.81 mg ai/L for total mevinphos and 0.67 mg ai/L for its E isomer, and those for mysid shrimp are 1.3 and 1.08 mg ai/L, respectively. The 96-h EC50 value for shell deposition in eastern oysters is > 1 mg ai/L. Longer studies are not appropriate, given the rapid degradation of the compound. Deaths have been reported among wildlife exposed to mevinphos in Scotland, but all of the incidents involved misuse (Hamilton et al., 1981). The US Environmental Protection Agency (personal communication) has received only one documented incident of acute poisoning of birds with mevinphos. In that incident, 120 starlings and blackbirds were found dead near treated cole crops in California. The cause of death was confirmed to be mevinphos on the basis of a mean concentration of 1.3 mg/kg residues in the gizzard contents. Although mevinphos dissipates rapidly and exposure may be brief, its high acute toxicity clearly poses a danger to exposed wildlife. Table 2. Toxicity of mevinphos to fish Species Mean Test material Static/ End-point Toxicity Reference size/age (% ai) Flow (mg ai/litre) Freshwater species Bluegill (Lepomis macrochirus) 0.9-1.3 g 60 Static 96-h LC50 22.5-87 Mayer & Ellersieck (1986) 0.45 g 34.6 Flow 96-h LC50 81.4 Ward (1992a) Rainbow trout 0.9 g 60 Static 96-h LC50 11.9 Mayer & Ellersieck (1986) (Oncorhynchus mykiss) 0.51 g 34.6 Flow 96-h LC50 41.8 Ward (1992b) Largemouth bass 0.8 g 60 Static 96-h LC50 115 Mayer & Ellersieck (Micropterus salmoides) (1986) Estuarine and marine species Sheepshead minnow Juvenile 100 Flow 48-h LC50 640 Mayer (1986) (Cyprinodon variegatus) 0.33g 74.48 E-isomer, Flow 96-h LC50 670-810 Yurk (1991) 15.09 Z-isomer Table 3. Toxicity of mevinphos to aquatic invertebrates Species Mean Test material Static/ End-point Toxicity Reference size/age (% ai) Flow (mg ai/litre) Freshwater species Water flea (Daphnia magna) < 24 h 30.2 E-isomer Flow 96-h EC50 1.5 Lintott (1992) Water flea (Daphnia pulex) 1st instar 60 Static 48-h EC50 0.18 Mayer & Ellersieck (1986) Simocephalus serrulatus 1st instar 60 Static 48-h EC50 0.42-0.49 Mayer & Ellersieck (1986) Gammarus fasciatus Immature 60 Static 96-h EC50 2.8-130 Mayer & Ellersieck (1986) Pteronarcys californica 1st year 60 Static 96-h EC50 5 Mayer & Ellersieck (1986) Palaemonetes kadiakensis Immature 60 Static 96-h EC50 13.5 Mayer & Ellersieck (1986) Asellus brevicaudus Early instar 60 Static 96-h EC50 61 Mayer & Ellersieck (1986) Estuarine and marine specie Mysid shrimp < 24 h 74.48 E-isomer, Flow 96-h LC50 1.03 Vaishnav et al. (Mysidopsis bahia) 15.09 Z-isomer (1991) Eastern oyster Juvenile 100 Flow EC50 (shell > 1000 Mayer (1986) (Crassostrea virginica) deposition) Brown shrimp (Penaeus aztecus) Juvenile 100 Flow 48-h EC50 150 Mayer (1986) Residues resulting from application of 0.9 kg ai/ha were not toxic to bees 4 h after application (Castellon, 1989), but mevinphos applied at standard field rates was highly toxic to predaceous mites, parasitic wasps, and predaceous beetles in several studies (Bartlett, 1963, 1964, 1966). The US Environmental Protection Agency Office of Pesticides Program uses the 'generic expected environmental concentration' to estimate the aquatic PEC values for use in preliminary risk assessments. Acute risk is assessed on the basis of peak PEC values from single and/or multiple applications. Chronic risk is assessed from 21-day average PECs for invertebrates and 56-day average PECs for fish; however, as chronic toxicity is not applicable to mevinphos, the chronic risk to aquatic organisms was not assessed. In this calculation, the soil:water partition coefficient, the degradation half-lives, and information given on the label are used to estimate runoff from a 10-ha field into a 1-ha, 2-m deep pond. It accounts for reductions in dissolved pesticide concentrations due to adsorption to soil or sediment, soil incorporation, degradation in soil before washoff into the pond, and degradation of the pesticide within the pond. The model also accounts for direct deposition of spray drift into the pond (1% of the application rate assumed for ground application and 5% for aerial spray applications), the number of applications, and the interval between applications. The model assumes that runoff from a single, large rainstorm is sufficient to remove 10% of the pesticide two days after the final application. The environmental fate values used in the model are soil KOC = 1, solubility = 6 × 105mg/L, aerobic soil metabolism half-life = 1 day, hydrolytic half-life = 16 days, and water photolytic half-life = 27 days. The PEC values for single aerial and ground sprays at application rates of 1.12 kg ai/ha and 0.56 kg ai/ha are presented in Table 4. The peak PEC is 16 mg ai/L for a single aerial application. The TER values, ranging from < 0.01 to 0.08, indicate that mevinphos applied Table 4. Predicted environmental concentrations (PECs) after single aerial and ground spray applications of mevinphos Application ratea Method of Peak PEC (kg ai/ha) application (µg ai/litre) 1.12 Aerial spray 16 Ground spray 14 0.56 Aerial spray 8 Ground spray 7 a Based on the product label for Phosdrin 4 EC (US Environmental Protection Agency registration no. 5481-412, accepted 16/5/94) at a typical rate of 1.12 kg ai/ha presents 'very large' acute risks to freshwater, estuarine, and marine invertebrates (Table 5). The acute risk to freshwater fish is classified as 'large' on the basis of the TER value of 0.74, but that to estuarine and marine fish is low (TER = 50.6). Although no incidents of fish kills due to mevinphos have been reported, overspray of fresh water should be avoided. 5. Evaluation of effects on the environment Mevinphos is a broad-spectrum organophosphate insecticide and acaricide with both contact and systemic activity. It is a mixture of E (> 60%) and Z (< 25%) geometrical isomers. Its pesticidal action is due to direct inhibition of cholinesterase activity. It is used (except in the United States) to control aphids, mites, grasshoppers, cutworms, leafhoppers, caterpillars, and other insects on a variety of vegetable, fruit, and field crops. The available formulations include emulsifiable concentrates, soluble concentrates, ready-to-use liquids, and dusts. Mevinphos dissipates rapidly in the terrestrial environment. The half-lives of both isomers in soil are less than four days. Biotic degradation is the major means of terrestrial dissipation. The main degradation pathway appears to be the formation of methylacetoacetate, followed by rapid binding to soil, and mineralization to carbon dioxide. Under laboratory conditions at 25°C in the dark, the aerobic half-lives of the E and Z isomers are 1.21 and 3.83 h, respectively. The half-lives for hydrolysis of the isomers in sterile aqueous buffered solution are related to the pH: pH 9, 2.8-7.5 days; pH 5, 50.8-84.6 days. O-Desmethylmevinphos is the major product. The photolysis half-life in aqueous solution was about 27 days for both isomersœ Mevinphos is potentially very mobile in soils because of its high solubility in water (6 × 105 mg/L) and low soil partition coefficients (Kads, 0.392-1.92), but rapid degradation of both isomers in the top 15 cm of soil prevents further leaching. Mevinphos is toxic to birds, with acute oral LD50 values ranging from 1.34-4.6 mg ai/kg bw for sharp-tailed grouse, ring-necked pheasants, and mallards The dietary LC50 values were 236 mg/kg diet for Japanese quail and 246 mg/kg diet for ring-necked pheasants. In bobwhite quail and mallards exposed to mevinphos in the diet for 20-22 weeks, the NOEC values for reproductive toxicity were 1.5 ppm ai and < 4 ppm ai, respectivelyœ The number of viable embryos and the eggshell thickness of bobwhite quail were significantly reduced at 7.1 ppm ai and the body weights of mallard hens were significantly affected at 4 ppm ai. The oral LD50 value for laboratory rats was 2.2 mg ai/kg bw. Mevinphos is toxic to a number of insect species. In the laboratory, the LD50 values for honeybees were 0.070 µg/bee for contact and 0.027 µg/bee for oral exposure. Mevinphos applied at standard field rates was toxic to predaceous mites, parasitic wasps, and predaceous beetles. Table 5. Risks to aquatic organisms after single exposures Risk category Toxicity value PECa Toxicity:exposure Risk (µg ai/litre) (µg ai/litre) ratio (TER) classification Freshwater fish 11.9 16 0.74 Large Freshwater invertebrates 0.18 16 0.01 Very large Estuarine and marine fish 810 16 50.6 Low Estuarine and marine invertebrates 1.3 16 0.08 Very large a Calculated from the 'generic expected environmental concentration' model of the US Environmental Protection Agency; acute exposure is based on peak PEC values for a single aerial application of 1.12 kg ai/ha b Value for toxicity divided by the PEC Mevinphos is toxic to fish. The 96-h LC50 values for technical-grade mevinphos (60% E isomer and 40% related compounds) were 11.9 µg ai/L for rainbow trout and 22.5-87 µg ai/L for bluegill sunfish. The 96-h LC50 values for the formulated product (30.2-34.6% ai) were 81.4 µg ai/L for bluegill sunfish, 41.8 µg ai/L for rainbow trout, and 1.46 µg ai/L for Daphnia magna. The 48-h LC50 values for the technical- grade material were 0.18 µg ai/L for Daphnia pulex and 0.42 µg ai/L for Simocephalus serrulatus. The 96-h LC50 values for other invertebrates include 2.8-130 µg ai/L for Gammarus fasciatus in water temperatures of 15-21°C, 5 µg ai/L for Pteronarcys californica, 13.5 µg ai/L, for Palaemonetes kadiakensis, and 61 µg ai/L for Asellus brevicaudus. For estuarine and marine organisms, the 96-h LC50 values were 0.81 mg ai/L for total mevinphos and 0.67 mg ai/L for its E isomer in sheepshead minnows, and 1.3 and 1.08 µg ai/L in mysid shrimp, respectively. The 96-h EC50 for shell deposition in eastern oysters was > 1 mg ai/L. Longer studies are not appropriate in view of the rapid degradation of the compound. Risk assessment (a) Terrestrial organisms Terrestrial organisms may be exposed to mevinphos by consuming contaminated foods and/or by dermal contact with contaminated soil and vegetation. The risk posed by foliar sprays is assessed by comparing the dietary LC50 values with the predicted environmental concentrations (PECs) of mevinphos on potential avian food items (grass, insects, and seeds). The PEC values are based on the Kenaga nomogram (Hoerger & Kenaga, 1992) as modified by Fletcher et al. (1994). The maximum PECs immediately after a single, direct application of mevinphos at 1.12 kg ai/ha are 240 mg ai/kg for short grasses, 135 mg ai/kg for small insects, and 15 mg ai/kg for seeds. For birds, the toxicity:exposure ratios (TERs), based on comparisons of the PECs with the lowest LC50 value seen in dietary tests for acute risk, are given in Table 6. This analysis indicates that mevinphos applied at a typical rate of 1.12 kg ai/ha presents 'very large' to 'present' acute risks to herbivorous (TER = 1.0) and insectivorous (TER = 1.7) birds, wheres that to granivores is expected to be 'low' (TER = 15.7)œ Deaths due to exposure to mevinphos have been reported, but most of the incidents involved misuse. Although mevinphos dissipates rapidly and exposure may be brief, its high acute toxicity clearly poses a danger to exposed wildlifeœ Table 6. Toxicity:exposure ratios (TERs) for birds Toxicitya PECb TERc Risk classification LC50 = 236 240 (short grass) 1.0 Very large (Japanese quail) 135 (small insects) 1.7 Present 15 (seeds) 15.7 Low a For the most sensitive species tested b Maximum PECs after a single application of 1.12 kg ai/ha c Value for toxicity divided by value for exposure (i.e. PEC) The hazard ratios for honeybees exposed after application at a rate of 1120g ai/ha, based on the LD50 values, were 16 000 for contact and 37 333 for oral exposure, indicating a high risk. Mevinphos should not be applied or allowed to drift onto blooming crops or weeds while bees are visiting the treated area. Mevinphos applied at standard field rates was highly toxic to predaceous mites, parasitic wasps, and predaceous beetles in several studies. (b) Aquatic organisms Aquatic organisms may be exposed to mevinphos from surface water runoff and soil erosion and/or drift from treated sites into water bodies. The risk posed by mevinphos is assessed on the basis of the 'generic expected environmental concentration'. Acute risk is assessed from peak PECs after single and/or multiple applications. Because chronic toxicity is not relevant for mevinphos, the chronic risk to aquatic organisms was not assessed. The environmental fate values used in the assessment of mevinphos are soil KOC = 1, solubility = 6 × 105 mg/L, aerobic soil degradation half-life = 1 day, hydrolytic half-life = 16 days, and water photolytic half-life = 27 days. The PEC values after single aerial and ground spray applications of mevinphos at rates of 1.12 and 0.56 kg ai/ha are shown in Table 4. The TERs for mevinphos in aquatic invertebrates are 0.01-0.08 (Table 5), indicating that mevinphos applied at a typical field application rate of 1.12 kg ai/ha presents 'very large' acute risks to freshwater, estuarine, and marine invertebrates. The acute risk to freshwater fish is classified as 'large' on the basis of the TER of 0.74, but that to estuarine and marine fish is low (TER = 50.6). Although no incidents of fish kills due to mevinphos have been reported, overspray of freshwaters should be avoided. References Bartlett, B.R. (1963) The contact toxicity of some pesticide residues to hymenopterous parasites and coccinellid predators. J. Econ. Entomol., 56, 694-698. Bartlett, B.R. (1964) The toxicity of some pesticide residues to adult Amblyseius hibisci, with a compilation of the effects of pesticides upon phytoseiid mites. J. Econ. Entomol., 57, 559-562. Bartlett, B.R. (1966) Toxicity and acceptance of some pesticides fed to parasitic hymenoptera and predatory coccinellids. J. Econ. Entomol., 59, 1142-1149. Beavers, J.B., Ross, T., Smith, G.J., Lynn, S.P. & Jaber, M.J. (1992a) Mevinphos: A one-generation reproduction study with the mallard (Anas platyrhynchos). Unpublished study from Wildlife International Ltd, Easton, Maryland, USA. Submitted to US Environmental Protection Agency by Amvac Chemical Corp., Los Angeles, California, USA. Beavers, J.B., Ross, T., Smith, G.J., Lynn, S.P. & Jaber, M.J. (1992b) Mevinphos: A one-generation reproduction study with the bobwhite (Colinus virginianus). Conducted by Wildlife International Ltd., Easton, Maryland, USA. Submitted to US Environmental Protection Agency by Amvac Chemical Corp., Los Angeles, California, USA. Castellon, A. (1989) Residual toxicity of mevinphos to honey bees (Apis mellifera). Unpublished study from Pan-Agricultural Laboratories, Inc., Madera, California, USA. Submitted to US Environmental Protection Agency by Amvac Chemical Corp., Los Angeles, California, USA. Cohen, S.P. (1994a) Photodegradation of alpha-mevinphos in an aqueous pH 5 buffered solution under artificial sunlight. Unpublished study from Pittsburgh Environmental Research Laboratory, Inc., Pittsburgh, Pennsylvania, USA. Submitted to US Environmental Protection Agency by Amvac Chemical Corp., Los Angeles, California, USA. Cohen, S.P. (1994b) Photodegradation of beta-mevinphos in an aqueous pH 5 buffered solution under artificial sunlight. Unpublished study from Pittsburg Environmental Research Laboratory, Pittsburg, Pennsylvania, USA. Submitted to US Environmental Protection Agency by Amvac Chemical Corp., Los Angeles, California, USA. DeWitt, J.B., Stickel, W.H. & Springer, P.F. (1963) Wildlife studies, Patuxent Wildlife Research Center, 1961-1962 (US Fish and Wildlife Service Circular 167), Washington DC, US Fish and Wildlife Service. Fletcher, J.S, Nellessen, J.E. & Pfleeger, T.G. (1994) Literature review and evaluation of the EPA food-chain (Kenaga) nomagram, an instrument for estimating pesticide residues on plants. Environ. Toxicol. Chem., 13, 1383-1391. Hamilton, G,A., Ruthven, A.D., Findlay, E., Hunter, K. & Lindsay, D.A. (1981) Wildlife deaths in Scotland resulting from misuse of agricultural chemicals. Biol. Conserv., 21, 315-326. Hill, E.F., Heath, R.G., Spann, J.W. & Williams, J.D. (1975) Lethal dietary toxicities of environmental pollutants to birds (US Fish and Wildlife Service Special Scientific Report: Wildlife No. 191), Washington DC, US Fish and Wildlife Service, 61 pp. Hoerger, F. & Kenaga, E.E. (1992) Pesticide residues on plants: Correlation of representative data as basis for estimation of their magnitude in the environment. In: Coulston, F. & Korte, F., eds, Environmental Quality and Safety: Chemistry, Toxicology, and Technology, Stuttgart, Georg Thieme Publishers, pp. 9-28. Hudson, R.H., Tucker, R.K. & Haegele, M.A. (1984) Handbook of Toxicity of Pesticides to Wildlife (US Fish and Wildlife Service Resource Publication 153), Washington DC, US Fish and Wildlife Service, 90 pp. Leech, G.N. & McKane, E.B. (1990) Terrestrial dissipation of mevinphos in California soil in the San Joaquin Valley. Unpublished study from Pan-Agricultural Laboratories, Madem, California, USA. Submitted to US Environmental Protection Agency by Amvac Chemical Corp., Los Angeles, California, USA. Lintott, D.R. (1992) Phosdrin 4 EC insecticide: acute toxicity to the water flea, Daphnia magna, under flow-through test conditions. Unpublished study from Toxikon Environmental Sciences, Jupiter, Florida, USA. Submitted to US Environmental Protection Agency by Amvac Chemical Corp., Los Angeles, California, USA. Mayer, F.L., Jr (1986) Acute Toxicity Handbook of Chemicals to Estuarine Organisms (USEPA/OPTS, EPA/ 600/X-86/231), Washington DC, US Environmental Protection Agency, 274 pp. Mayer, F.L., Jr & Ellersieck, M.R. (1986) Manual of Acute Toxicity: Interpretation and Data Base for 410 Chemicals and 66 Species of Freshwater Animals (US Fish and Wildlife Service Resource Publication 160), Washington DC, US Fish and Wildlife Service, 506 pp. Misra, B. (1992) Hydrolysis of alpha and beta isomers of mevinphos in buffered aqueous solutions. Unpublished study from Center for Hazardous Materials Research, Pittsburgh, Pennsylvania, USA. Submitted to US Environmental Protection Agency by Amvac Chemical Corp., Los Angeles, California, USA. Reynolds, J.L. (1994) Aerobic soil metabolism of 14C-mevinphos (beta isomer). Unpublished study from XenoBiotic Laboratories, Inc., Plainsboro, New Jersey, USA. Submitted to US Environmental Protection Agency by Amvac Chemical Corp., Los Angeles, California, USA. Reynolds, J.L. (1995) Aerobic soil metabolism of 14C-mevinphos (beta isomer). Unpublished study from XenoBiotic Laboratories, Inc., Plainsboro, New Jersey, USA. Submitted to US Environmental Protection Agency by Amvac Chemical Corp., Los Angeles, California, USA. Stevenson, J.H. (1968) Laboratory studies on the acute contact and oral toxicities of insecticides to honeybees. Ann. Appl. Biol., 61, 467-472. Vaishnav, D.D., Yurk, J.J. & Wade, B.A. (1991) Mevinphos: Acute toxicity to mysid (Mysidopsis bahia) under flow-through conditions. Unpublished study from Toxikon Environmental Sciences, Jupiter, Florida, USA. Submitted to US Environmental Protection Agency by Amvac Chemical Corp., Los Angeles, California, USA. Ward, G.S. (1992a). Phosdrin 4 EC insecticide: Acute toxicity to bluegill, Lepomis macrochirus, under flow-through test conditions. Unpublished study from Toxikon Environmental Sciences, Jupiter, Florida, USA. Submitted to US Environmental Protection Agency by Amvac Chemical Corp., Los Angeles, California, USA. Ward, G.S. (1992b) Phosdrin 4 EC insecticide: Acute toxicity to rainbow trout, Oncorhynchus mykiss, under flow-through test conditions. Unpublished study from Toxikon Environmental Sciences, Jupiter, Florida, USA. Submitted to US Environmental Protection Agency by Amvac Chemical Corp., Los Angeles, California, USA. Yurk, J.J. (1991) Mevinphos: acute toxicity to sheepshead minnow (Cyprinodon variegatus) under flow-through conditions. Unpublished study from Environmental Science & Engineering, Inc., Gainesville, Florida, USA. Submitted to US Environmental Protection Agency by Amvac Chemical Corp., Los Angeles, California, USA.
See Also: Toxicological Abbreviations Mevinphos (FAO Meeting Report PL/1965/10/1) Mevinphos (WHO Pesticide Residues Series 2) Mevinphos (Pesticide residues in food: 1996 evaluations Part II Toxicological)