| The exposed concentration of chlorpyrifos in water and sediment was predicted or determined. This paper predicted the exposed concentration of fipronil in water and sediment as well.Predicting period is among 0 to 100 days after pesticides treated. Determined water samples of paddy field was collected for a full year.Result presents that the exposed concentration of chlorpyrifos in water and sediment were 2.3-20.0μg/L and 190-1240μg/kg respectively, and 2.1-5.9μg/L and 12.1-32.6μg/kg respectively for fipronil. For these result, it is according same conditions as following. The appling dose of chlorpyrifos and fipronil is 540 g/ha and 30 g/ha respectively. Amount of spray water is 600 L/ha and double spraying for one year. Crop cover rate setted about 70%. Chlorpyrifos concentration in the paddy field drainage water is 0.01-26. 1μg/L,when 40% field was sprayed with chlorpyrifos.Residue in water of chlorpyrifos and fipronil is visibly, and the maxium concentration is above 10μg/L. The concentration level got higher while fipronil sprayed, and it shows obviously mutual. Predicted Results of chlorpylifos measured exceeded the result of determined.This shows the FOCUS expose predicting model could give reference data for paddy field residue.Acute toxicity was determined for chlorpyrifos and fipronil to bees, birds, silkworm, earthworm, Trichogramma spp., frog, fish, daphnia, algae and shrimp. The toxicity values present as following. Chlorpyrifos shows extremely toxic to daphnia, with 48h LC50 0.00144mg/L, highly toxic to bee, birds and silkworm,48h LC50 1.32mg/L,7d LD50 16.9mg/kgbw,96h LC50 3.24mg/L, moderately toxic to frog and fish,48h LC50 2.40mg/L,96h LC50 1.11mg/L, Slightly toxic to earthworm,14d LC50>100mg/kg. Fipronil shows extremely toxic to bee, daphnia and shrimp,48h LC50 0.0967mg/L,48h EC50 0. 100mg/L,48h LC50 0.00282mg/L, highly toxic to birds and silkworm,7d LD5047.2mg/kgbw, moderately toxic to fish,96h LC50 1.22mg/L, slightly toxic to frog,48hLC50>100mg/L.Risk quotiety of chlorpylifos is between 55.6 to 481 for zebrfish,0.07-0.62 for daphnia,9.67-83.6 for algea,120 to 1040 for frog. The result presented the acute toxicity risk is high for daphnia, and low for other three aquatic organism. Risk quotiety of chlorpylifos is 0.00165 for bee,0.0036 for silkworm,0.00006 for Trichogramma spp.. The chlorpyrifos shows riskful to bird used as seed coating. come toRisk quotiety of fipronil is between 206 to 582 for zebrafish,16.9 to 47.7 for daphnia,0.48 to 1.35 for shrimp and shows high risk. Fipronil would has great affect to shrimp in paddy field and the aquaculture farm around the field, when fipronil was used in the paddy field. So we should select other pesticides for avoiding risk to shimp while there are aquaculture farm for shimp. Risk quotiety of fipronil is 0.0014 for bee,0.12 for silkworm. Fipronil is safe for bird.Chlorpylifos shows high acute toxicity risk to daphnia, bee, bird, silkworm and Trichogramma spp..The affect of chlorpyrifos should be avoided while daphnia playing important part in an aquatic system. Assessment result of chlorpyrifos shows high risk for bee same as fipronil,but the field risk is low. The cause should be studied later. Bird, silkworm and Trichogramma spp. should be protect when using chlorpyrifos.Fipronil shows extremely high risk to bee,and low risk to bird and silkworm. The use of fipronil was forbidden due to high risk to shrimp and bee.But fipronil could be used as referenced pesticide when we assess risk of other pesticides because of its toxicity character.
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