Sulfometuron Methyl - Human Health and Ecological Risk Assessment – Final Report

with Kd values. 0.29. Not very detailed.Dickens and Wehtje1986 Kd values: 0.04-0.6 kg/L at 0-20 cmKd values: 0.019-0.036 kg/L at 65-95 cmOnce herb leaches past the top 10 cm of soil, retardation of herbicides would be slight.Contamination of ground water would depend on rate of decomposition. Composition of soils determined, but soil types not classifiedKoskinen et al.1996 Kd values [units not specified]: sandy clay loam = 0.27; loamy, sand = 0.23; clay loam =0.68; clay = 0.12 and 0.17 Kfs/mobility high lots of details.Wehtje et al. 1987 dDistribution coefficients (K values) for leached compounds in Keyport silt loam soilwere:0.121 mL/g (phenyl-labeled compound)0.114 mL/g (pyrimidine-labeled compound) dlow K values indicate that sulfometuron methyl and its eluted metabolites were mobile onwater-saturated Keyport silt loam soil.Ryan and Atkins1986MRID 41680103 lysimeters, various soil types, SM at 42.5 g a.i./ha. Mean concentration in soil water: 0.5:g/L at 10 cm and 0.4 :g/L at 20 cm. Nothing at 40 or 150 cm. p. 401: 'By 80 d post-treatment, the Cactivity was new background level, suggesting that most of the14 compound had been degraded or irreversityly sorbed into the upper soil layers.'Rainwater acidity had not effect on leaching rate in acid sand soils. Not effected by litterhumus.Stone et al. 1993 soil adsorption study. for SM, poor correlation with organic matter (r2=0.271) but abetter correlation humic matter (r2=0.729) [see Fig. 3, p. 1991.] Kd values ranging from<0.05 at <1% HM to 5-6 with >2% HM.Strek et al. 1990 Appendix 2: Laboratory and simulation studies on environmental sulfometuron methyl. Data SummaryReference Appendix 2 -6Field simulation study on percolation and runoff with comparisons to GLEAMSmodeling. Application rate of 0.6 kg/ha. Little initial runoff. Generally <1 :g/ml withmax of 2.3 :g/ml. Mostly lost from upper root zone by percolation. Rainfall on sandysoil may move most out of 0.1 m of soil quickly. Much slower percolation on clay soil -runoff will be more significant. GLEAMS modeling qualitatively similar but some quant.differences.Hubbard et al. 1989 Field simulation study. 0.4 kg/ha to 1.2x2.4 m plots. After 24 hrs, simulated rainfall of69mm/h until 2 mm runoff occured. 1-2% lost by in runoff regardless of grass cover.Runoff conc.: 0.2-0.5 mg/L max and 0.2-0.09 mg/L mean. [see Table 4, p. 123 foradditional details.] Excellent correlations with GLEAMS.Wauchope et al.1990 Soil column leaching study to determine mobility of 2-[[[[(4,6-dimethyl-2-pyrimidinyl) aminocarbonyl] amino]sulfonyl]-benzoate (DPX-5648) in four soils: Keyport silt loam, Fallsington sandy loam, Myakka sand, and Flanagan silt loam. Results indicate that DPX-5648 is mobile in sand, sandy loam, and silt loam soils. DPX-5648 shown to be least mobile in soil containing darkly-colored organic matter likeFlanagan silt loam and Myakka sand.Dulka (1981)MRID 00078702 Field study to determine residual levels of methyl 2-[[[[(4,6-dimethyl-2-pyrimidinyl) aminocarbonyl] amino]sulfonyl]-benzoate (DPX-5648) on soils in Delaware, Mississippi,and North Carolina. Residue analysis indicates a rapid breakdown of the intact herbicide under fieldconditions. In Delaware and Mississippi soils, <5% of intact DPX-5648 remained after 8weeks;Anderson 1980MRID 00078705 Preliminary data from a field simulation study indicates that methyl 2-[[[[(4,6-dimethyl2-pyrimidinyl) aminocarbonyl] amino]sulfonyl]-benzoate (DPX-5648) applied at rates of100-400 g/ha decomposes rapidly in soil with a half time of #1 month. Major metabolites included 2-(aminosulfonyl) benzoic acid and saccharin.Dulka 1980aMRID 00078706 [2-[[[[(4,6-dimethyl-2-pyrimidinyl aminocarbonyl] amino]sulfonyl] benzoate, DPX-T5648] applied at 0.2 or 1 ppm to Keyport silt loam, Flanagan silt loam, and Fallsingtonsandy loam for 1 month exposure to simulated sunlight. >50% degradation of parent compound in 1-2 weeks at each concentration on every soiltype saccharin was the major degradation product in all treated soilHardesty 1983MRID 00137864 Appendix 2: Laboratory and simulation studies on environmental sulfometuron methyl. Data SummaryReference Appendix 2 -7Photodegradation of 2-[[[[(4,6-dimethyl-2-pyrimidinyl) aminocarbonyl] amino]sulfonyl]-benzoate (sulfometuron methyl) on irradiated or non-irradiated Keyport silt loam for 33days t 1⁄2 on irradiated soil = 23 dayst 1⁄2 on irradiated soil = 34 days results indicate that photodegradation on soil is not a major decomposition pathway. Identified degradates include sulfonamide, saccharin, and pyrimidine amine, resultingfrom sulfonylurea bridge cleavage (major aerobic soil metabolism pathway).Aggregate total of minor unidentified degradation products <10.1%only in the sunlightirradiate soil samples.Ryan and Atkins1986MRID 41420601 Ryan and Atkins1987MRID 42385707[The is asupplement to Ryanand Atkins 1986] Six Brazilian (tropical) soils: dK values: 0.13-1.18 ocK values: 16-50 This study does not seem especially relevant to our RA in that the objective is to evaluate the compounds for their leaching potential to ground-water in tropical soil.Oliveira et al. 2001