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EXTOXNET PIP- MANEB http://ace.orst.cdu/cgi-bin/mts/01/pips/maneb.htm and death [1,8]. • Chronic toxicity: Rat feeding trials over 2 years showed no evidence of adverse health effects at dietary doses of about 12.5 mg/kg/day [1]. Goiter(increased thyroid weight) and reduced growth rate were seen in rats fed daily doses of 62.5 mg/kg/day after 97 days [101. Dogs that received maneb orally at doses of 200 mg/kg/day for 3 or more months developed tremors, lack of energy, gastrointestinal disturbances, and incoordination. In addition, they experienced damage to the spinal cord but not the thyroid gland [1]. Rats that received 1500 mg/kg/day for 10 days showed weight loss, weakness of the hind legs, and increased mortality [I]. • Reproductive effects: Female rats that were given 50 mg/kg/day on every other day during gestation showed increased rates of embryo death and stillbirth, and decreased newborn survival [4]. In rats given a single dose of 770 mg/kg of maneb, the lowest dose tested, on the I 1 th day of gestation, early fetal deaths occurred [4]. In mice, the lowest single oral toxic dose administered during gestation which caused toxicity to the fetus was 1420 mg/kg [4]. It appears that a very high level of exposure is necessary to cause reproductive effects in humans, and this level of exposure is not likely under normal circumstances. • Teratogenic effects: Fetal abnormalities of the eye, ear, body wall, central nervous system, and musculoskeletal system were seen in rats given single doses of 770 mg/kg [4]. Maneb is metabolized to ethylenethiourea (ETU), a compound which has been shown to cause birth defects in laboratory animals such as rats, mice, and hamsters [12]. From these data and information about other EBDCs, it is likely that maneb will not be teratogenic in humans under normal circumstances. • Mutagenic effects: Several tests have shown that maneb is not mutagenic [10]. • Carcinogenic effects: In one study, maneb did not display significant carcinogenicity in laboratory tests with experimental animals [8]. In another study, malignant tumors were observed in rats which were given scrotal injections of 12.5 mg/kg body weight of 82.6% pure maneb [4]. Based on these data and evidence from other EBDCs, maneb is unlikely to cause cancer in humans [1,10]. • Organ toxicity: Target organs affected by maneb include the thyroid, kidneys, and heart. • Fate in humans and animals: Animal studies show that maneb is readily absorbed through the gastrointestinal tract, and is rapidly eliminated. In rats, 55% of an administered dose of over 300 mg/kg was eliminated within 5 days [1]. A study in mice showed that elimination was mainly through the feces. The metabolites of maneb include ethylene diamine, ethylene(bis)thiurammonosulfide, and ethylenethiourea [1]. Maneb was not found to accumulate in the tissues of rats given 125 mg/kg/day over 2 years, nor in dogs given 75 mg/kg/day for I year [1]. Ecological Effects: • Effects on birds: Maneb is practically nontoxic to birds; the 5-day dietary LC50 for maneb in bobwhite quail and mallard ducklings is greater than 10,000 ppm [34]. • Effects on aquatic organisms: Maneb is highly toxic to fish and aquatic species. The 96-hour LC50 for maneb is 1 mg/L in bluegill sunfish [34]. The reported 48-hour LC50 is 1.9 mg/L in rainbow trout, and 1.8 mg/L in carp [34]. The 72-hour LC50 is more than 40 mg/L in crayfish, and the 48-hour LC50 is 40 mg/L in tadpoles [34]. • Effects on other organisms: Maneb-treated crop foliage may be toxic to livestock [26]. The fungicide is not thought to be toxic to bees [3]. Environmental Fate: • Breakdown in soil and groundwater: Maneb is similar in its environmental fate to mancozeb [20]. Like mancozeb, maneb is of low persistence (with a reported field half-life of 12 to 36 days) but it is of 4 5/15/00 1 I:o9.-v%l