2Pesticides -Pros and Cons Kill unwanted pests that carry disease (rats, mosquitoes, Tse-Tse flies)Increase food suppliesMore food means food is less expensiveEffective and fast-actingNewer pesticides are safer, more specificReduces labor costs on farmsFood looks betterAgriculture is more profitableAccumulate in food chainPests develop resistance – 500 species so farResistance creates pesticide treadmillEstimates are $5-10 in damage done for $1 spent on pesticidePesticide runoffDestroy bees - $200 millionThreaten endangered speciesAffect egg shell of birds5% actually reach pest~20,000 human deaths/year
3Types of Pesticides Biological – Ladybugs, parasitic wasps, etc. Carbamates effect nervous system of pests more water soluble than chlorinated hydrocarbonsAldicarb, aminocarb, carbaryl (Sevin), carbofuran, MirexChlorinated Hydrocarbons affect nervous system –Aldrin, Chlordane, DDT, dieldrin, kepone and toxaphene
4Fumigants are used to sterilize soil and prevent grain infestation Organophosphates – extremely toxic, rapidly absorbed, low persistenceMalathion, parathion
5Types of Pesticides Inorganic – arsenic, copper, lead, mercury Highly toxic and bioaccumulationOrganic or natural – derived from plants such as tobacco and chrysanthemum
6Chlorinated Hydrocarbons (organochlorines) DDT, aldrin, dieldrine, chlordane and toxapheneAffect the nervous system of pestRemain in ecosystem 15+ yearsHighly persistent, fat soluble, and subject to biomagnificationNearly all have been banned
7Carbamates Are used as insecticides, herbicides and fungicides effect nervous system of pestsMore water soluble than chlorinated hydrocarbons – which means greater risks of dissolving in surface water or percolating into groundwater100 grams has the same effect as 2,000 grams chlorinated hydrocarbonsExamples: Aldicarb(Temik), aminocarb, carbaryl (Sevin), carbofuran, Mirex
8AldicarbPotato growers on eastern Long Island used Aldicarb from 1975 – 1979 to control the Colorado potato beetle and the golden nematode. In 1979, Aldicarb residues were detected in well water. Subsequent testing found more than 2,000 wells with very high concentrations. It was banned in New York. In 1984 areas with deep wells were found to have increased levels from 1979 levels wells are still contaminated above state guidelines. Aldicard has been found in groundwater in 26 other states.
9Gaseous pesticides use to sterilize soil and prevent pest infestation of stored grains. Used on grain weevils, beetles and moth catepillars. Comparable to “mustard gases” used in WWII. Phosphine is the most popular today – others are carbon tetrachloride and methyl bromideFumigantsMethyl Bromide was banned in 2005 due to it’s damage to the ozone layer.
10InorganicBroad-based pesticides. Includes arsenic, copper, lead, mercury. Highly toxic and accumulates in the environment.
11Organic or Natural Pesticides Natural poisons derived from plants such as tobacco or chrysanthemum.NeemIngredients: Contains 2 ingredients, azadirachtin (AZA0 and liminoids, both from the seed kernels of the neem tree fruit.Application: Sprayed onto plant leaves.How It Works: Upsets the insects hormonal system and prevents it from developing to its mature stage. Most effective on immature insects and species that undergo complete metamorphosis.Pros: Non-toxic to humansCons: Washes away in rain. Slow acting. Breaks down in sunlight Indiscriminate pesticidePrecautions: Keep pets from treated leaves until they dry.
12Organic Pesticides Pyrethrins Ingredients: Derived from Chrysanthemum cinerariifoliumApplication: Generally found in powder form and dusted on leaves.How It Works: Poisons the insect, causing a quick deathPros: Quick acting. Low toxicity to animals. Degrades within a day.Cons: Broad spectrum insecticide. Kills any insect. Very toxic to honeybeesPrecautions: Use cautiously, only when you have a major problem with hard-to-kill insects.
13Organic or Natural Pesticides RotenoneIngredients: Derived from the roots of tropical legumes (derris plant)Application: Dust onto plant – originally used to kill fish. Kills potato beetles and cabbage worms. Used on chickens to kill mitesHow It Works: Inhibits a cellular process, depriving insects of oxygen in their tissue cells.Pros: Low residual effect. Breaks down quickly in sunlight.Cons: Broad spectrum pesticidePrecautions: Apply in the evening, when bees are less active.
14Malathion and Parthion OrganophosphatesMalathion and ParthionExtremely toxic but only remains in the environment for a brief amount of time.Effects the central nervous system by interfering with the enzyme cholinesterase.
15Biological Pest Control A knowledgeable gardener knows that each of those cocoons will hatch into a beneficial parasitic wasp - an organic control for more than just horn worms.
16Major Kinds of Herbicides Selective HerbicidesKill only certain types of plantsCan be classified to the type of plant they killBroad-leaf herbicidesGrass herbicidesEx: 2,4-DDichlorophenoxyacetic acidcommon systemic pesticide / herbicide used in the control of broadleaf weeds
17Risk of Pesticides to Human Health Short-term Effects of PesticidesHandling food with pesticide residueMild case: nausea, vomiting, headachesSevere case: damage to nervous system,
18Risk of Pesticides to Human Health Long-term Effects of PesticidesCancer- lymphomaBreast cancerSterilityMiscarriageBirth defectsDecreases body’s ability to fight infectionPotential connection to Parkinson’s disease
19Laws Controlling Pesticide Use Food, Drug, and Cosmetics Act (1938)Pesticide Chemicals Amendment (1954)Delaney Clause (1958) (a zero cancer risk standard)Federal Insecticide, Fungicide, and Rodenticide Act (1947) federal control of pesticide distribution, sale, and useFood Quality Protection Act (1996)