《植物化学保护》课程教学资源（英文讲稿）Pesticide Safety and Toxicity（PPT）

Pesticide Safety & Toxicity Dave Moorhead Warnell School of Forest Resources University of Georgia

Pesticide Safety & Toxicity Dave Moorhead Warnell School of Forest Resources University of Georgia

Pesticides: Chemicals to control unwanted forms of life Pests Insecticides ·Herbicides Nurseries Nurseries Seed Orchards Plantations Plantations ·Fungicides ·Repellents Nurseries Worker use Plantations Animal use

Pesticides: Chemicals to control unwanted forms of life - Pests • Insecticides Nurseries Seed Orchards Plantations • Fungicides Nurseries Plantations • Herbicides Nurseries Plantations • Repellents Worker use Animal use

Relative Toxicity Organisms can't differentiate between "natural"and “synthetic”chemicals “Synthetic"”does not mean toxic or poisonous "Natural"does not mean safe or even low risk Chemicals must be evaluated in their biological context of behavior in organisms 。 Mode of action,not source,is the concern Pesticides should be treated with care and proper respect but so should household cleaners,gasoline and kerosene,bleaches, paints and all other chemicals Mistretta USFS R-8

Relative Toxicity • Organisms can’t differentiate between “natural” and “synthetic” chemicals • “Synthetic” does not mean toxic or poisonous • “Natural” does not mean safe or even low risk • Chemicals must be evaluated in their biological context of behavior in organisms • Mode of action, not source, is the concern • Pesticides should be treated with care and proper respect – but so should household cleaners, gasoline and kerosene, bleaches, paints and all other chemicals Mistretta USFS R-8

GARDEN SUPPLIES E GA DEN RAYS WITH VITAMIN I WANT A SPRAY THAT KILLS EVERYTHING BUT ISN'T DANGEROUS

“I WANT A SPRAY THAT KILLS EVERYTHING BUT ISN’T DANGEROUS

Relative Toxicity: Are all substances toxic? YES! >All are toxic to some quantifiable degree >Sugar has an LDs0 of 30,000 mg/kg Ethanol has an LD50 of only 13,700 mg/kg >Even water has a recognized LDs0 of slightly greater than 80,000 mg/kg

Relative Toxicity: Are all substances toxic? YES! ➢ All are toxic to some quantifiable degree ➢ Sugar has an LD50 of 30,000 mg/kg ➢ Ethanol has an LD50 of only 13,700 mg/kg ➢ Even water has a recognized LD50 of slightly greater than 80,000 mg/kg

Pesticide Toxicity Toxicity measure of ability of a chemical to injure /kill Exposure contact with chemical Hazard-degree of exposure toxicity level LDs0 lethal dose to kill 50%of test animals

Pesticide Toxicity Toxicity - measure of ability of a chemical to injure /kill Exposure - contact with chemical Hazard - degree of exposure & toxicity level LD50 - lethal dose to kill 50% of test animals

Pesticide Toxicity Acute toxicity injury/death from one exposure Chronic toxicity injury/death after long-term exposure Oral toxicity injury/death from swallowing chemical Dermal toxicity injury/death from exposure to skin

Pesticide Toxicity Acute toxicity - injury/death from one exposure Chronic toxicity - injury/death after long-term exposure Oral toxicity - injury/death from swallowing chemical Dermal toxicity - injury/death from exposure to skin

Pesticide Toxicity PPM (parts per million)-1 oz in 62,500 Ibs or 1 tbs in 3,906 gal PPB (parts per billion)-1000 times less than ppm 1 tbs in 3,906,000 gal Half-life time for 1/2 of initial concentration to be degraded Volatility ability of a liquid to evaporate

Pesticide Toxicity PPM (parts per million) - 1 oz in 62,500 lbs or 1 tbs in 3,906 gal PPB (parts per billion) - 1000 times less than ppm - 1 tbs in 3,906,000 gal Half-life - time for 1/2 of initial concentration to be degraded Volatility - ability of a liquid to evaporate

Parts per Million ppm 1 liter of water 1 kg 1 mg kg =1 ppm 1mm3 liter =1 ppm 1 mg liter =1 ppm

Parts per Million ppm 1 liter of water = 1 kg 1 mg / kg = 1 ppm 1mm3 / liter = 1 ppm 1 mg / liter = 1 ppm

One part per million is ·1 inch in 16 miles 。1 minute in two years 。1 cent in10,000 1 ounce of salt in 31 tons of potato chips 1 bad apple in 2,000 barrels of apples Mistretta USFS R-8

One part per million is • 1 inch in 16 miles • 1 minute in two years • 1 cent in $10,000 • 1 ounce of salt in 31 tons of potato chips • 1 bad apple in 2,000 barrels of apples Mistretta USFS R-8