Laserfiche WebLink
EXTOXNET PIP- DIAZINON Page 2 of 4 <br /> more toxic forms. This transformation may occur in air,particularly in the presence of moisture, and by ultraviolet <br /> radiation. Most modem diazinon formulations in the U.S. are stable and do not degrade easily[8]. The symptoms <br /> associated with diazinon poisoning in humans include weakness, headaches, tightness in the chest,blurred vision, <br /> nonreactive pinpoint pupils, salivation, sweating, nausea, vomiting, diarrhea, abdominal cramps, and slurred speech. <br /> Death has occurred in some instances from both dermal and oral exposures at very high levels [2,8]. The LD50 is <br /> 300 to 400mg/kg for technical grade diazinon in rats (2,13). The inhalation LC50 (4-hour) in rats is 3.5 mg/L [13]. <br /> In rabbits, the dermal LD50 is 3600 mg/kg [13]. <br /> • Chronic toxicity: Chronic effects have been observed at doses ranging from 10 mg/kg/day for swine to 1000 <br /> mg/kg/day for rats. Inhibition of red blood cell cholinesterase, and enzyme response occurred at lower doses in the <br /> rats. Enzyme inhibition has been documented in red blood cells, in blood plasma, and in brain cells at varying doses <br /> and with different species [2]. <br /> • Reproductive effects: No data are currently available. <br /> • Teratogenic effects: The data on teratogenic effects due to chronic exposure are inconclusive. One study has <br /> shown that injection of diazinon into chicken eggs resulted in skeletal and spinal deformities in the chicks. <br /> Bobwhite quail born from eggs treated in a similar manner showed skeletal deformities but no spinal abnormalities. <br /> Acetylcholine was significantly affected in this latter study [56]. Tests with hamsters and rabbits at low doses <br /> (0.125 0.25 mg/kg/day) showed no developmental effects, while tests with dogs and pigs at higher levels (1.0 10.0 <br /> mg/kg/day)revealed gross abnormalities [57]. <br /> • Mutagenic effects: While some tests have suggested that diazinon is mutagenic, current evidence is inconclusive <br /> [2]• <br /> • Carcinogenic effects: Diazinon is not considered carcinogenic. Tests on rats over a 2-year period at moderate <br /> doses (about 45 mg/kg) did not cause tumor development in the test animals [2]. <br /> • Organ toxicity: Diazinon itself is not a potent cholinesterase inhibitor. However, in animals, it is converted to <br /> diazoxon, a compound that is a strong enzyme inhibitor [2]. <br /> • Fate in humans and animals: Metabolism and excretion rates for diazinon are rapid. The half-life of diazinon in <br /> animals is about 12 hours. The product is passed out of the body through urine and in the feces. The metabolites <br /> account for about 70%of the total amount excreted. Cattle exposed to diazinon may store the compound in their fat <br /> over the short term [8]. One study showed that the compound cleared the cows within 2 weeks after spraying <br /> stopped. Application of diazinon to the skin of cows resulted in trace amounts in milk 24 hours after the application <br /> [8]. <br /> Ecological Effects: <br /> • Effects on birds: Birds are quite susceptible to diazinon poisoning. In 1988, the EPA concluded that the use of <br /> diazinon in open areas poses a "widespread and continuous hazard" to birds. Bird kills associated with diazinon use <br /> have been reported in every area of the country and at all times of the year. Canadian geese and mallard ducks may <br /> be exposed to LC50 concentrations in very short periods of time after application (from 15 to 80 minutes depending <br /> on the application rate of the pesticide). Birds are significantly more susceptible to diazinon than other wildlife. <br /> LD50 values for birds range from 2.75 mg/kg to 40.8 mg/kg [8]. <br /> • Effects on aquatic organisms: Diazinon is highly toxic to fish. In rainbow trout, the diazinon LC50 is 2.6 to 3.2 <br /> mg/L [13]. In hard water, lake trout and cutthroat trout are somewhat more resistant. Warm water fish such as <br /> fathead minnows and goldfish are even more resistant with diazinon LC50 values ranging up to 15 mg/L [8]. There <br /> is some evidence that saltwater fish are more susceptible than freshwater fish. Bioconcentration ratios range from <br /> 200 in minnows to 17.5 for guppies. These studies show that diazinon does not bioconcentrate significantly in fish <br /> [12]. <br /> • Effects on other organisms: Diazinon is highly toxic to bees [13]. <br /> Environmental Fate: <br /> hftp://extoxnet.orst.edtVpips/diazinon.htm <br />