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EXTOXNET PIP - MOLIN"...E ..1 Page 2 of 3 [6]. Their symptoms, which were apparently quite rapid in onset, included abdominal and gastrointestinal disorders, fever, weakness, and conjuntivitis [6]. These symptoms disappeared following the use of an alternative water source, and there were no reports of long-term complications or lingering effects due to this exposure [6]. The concentration of the well water sampled 15 days following the first reported symptoms was 6 ug/L; it is not known what the initial concentration was [6]. • Reproductive effects: Administration of molinate to young male rats at a dose of 3.6 mg/kg/day for 2 months caused changes in spermatozoa but did not decrease sperm fertility [6]. When these rats were mated to normal females, many of the embryos were resorbed and postnatal mortality was increased [6]. It is unlikely that such effects will occur in humans at expected exposure levels. • Teratogenic effects: Reports on the teratogenicity of molinate are conflicting,with one suggestion that it is teratogenic [35] and another that it is not [7]. Thus, its teratogenicity is unknown. • Mutagenic effects: No data were located regarding the potential mutagenic effects of molinate although it has been reported to be nongenotoxic [4,7]. • Carcinogenic effects: In a 2-year assay in rats, no carcinogenic activity was reported at doses up to 2 mg/kg/day [6]. • Organ toxicity: The primary target organ affected by molinate is the thyroid. • Fate in humans and animals: Molinate is only fairly well absorbed through oral, dermal, and inhalation exposure [4]. It is metabolized in the rat liver, and rapid excretion occurs primarily through the urine (88% of the applied dose) with a small amount lost in the feces (11% of the applied dose). Excretion by rats was practically complete within 48 hours [6]. Ecological Effects: • Effects on birds: Molinate appears to be practically nontoxic to birds. The reported 5-day dietary LC50 in Japanese quail is greater than 5000 ppm, and that in mallards is greater than 13,000 ppm [4,13]. • Effects on aquatic organisms: The reported toxicity to fish varies greatly, from slightly to highly toxic. One source reports the 96-hour LC50 values at 0.21 mg/L in rainbow trout and 0.32 mg/L in bluegill sunfish [16], while another reports tham as 1.3 and 29 mg/L, respectively [3]. A 96- hour LC50 value of 30 mg/L in goldfish has also been reported [4]. Fish kills of carp due to molinate were observed in Japan. The pesticide caused an anemia-like condition in these fish [4]. Reported 96-hour LC50 values in aquatic invertebrates such as Daphnia and stoneflies are about 0.3 to 0.6 mg/L, indicating that molinate is highly toxic to these invertebrates [4,16]. • Effects on other organisms: No data are currently available. Environmental Fate: • Breakdown in soil and groundwater: Molinate is of low persistence in the soil environment, with a field half-life of 5 to 21 days [20]. It is poorly bound to soils, soluble in water, and thus may be mobile [20] and present a risk to groundwater contamination. Soil microorganisms are responsible for most molinate breakdown [4]. Molinate may rapidly volatilize if not plowed into the soil, and may undergo breakdown by sunlight [4]. • Breakdown in water: Molinate may be degraded by hydrolysis (reaction with water). • Breakdown in vegetation: Molinate is rapidly taken up by plant roots and transported to the leaves. In the leaves, molinate inhibits leaf growth and development. It is rapidly metabolized to carbon dioxide and other naturally occurring plant products such as amino acids and organic acids in nonsusceptable plants. http.//extoxnet.orst.edu/pips/molinate.htm 9/21/2004