I. Pesticides Definition: any chemical used to kill pests. A. In the U.S., over 700 active ingredients plus 1200 inert ingredients are mixed to make 50,000 individual pesticide products.
I. Pesticides B. Types and Usage: TYPES Targets Percent (kills) Herbicides plants 85% Insecticides insects 10% 4% Fungicides fungi
I. Pesticides B. Types and Usage: USAGE PERCENT 77% Croplands Government & 11% Industrial Lands Households 11% 1% Forests
I. Pesticides B. Types and Usage: • About 20% of pesticides are applied to lawns, gardens, parks, and golf courses. • 91% of US households use pesticides indoors. • Average homeowner uses 5X more pesticides per unit of land area than farmers.
I. Pesticides C. Pesticide Benefits 1. Disease Control a. Malaria 1) 300 million people suffer. 2) 1 million deaths each year. 3) 50 million deaths prevented over the last 50 years because of pesticide control of mosquitoes. b. Other diseases spread by biting arthropods: 1) Yellow fever (mosquitoes) 2) Encephalitis (mosquitoes) 3) West Nile virus (mosquitoes) 4) Sleeping sickness (tsetse fly) 5) River blindness 6) Elephantiasis (tiny worms transmitted by flies)
I. Pesticides C. Pesticide Benefits 2. Crop Protection – Cropland America calculates that without pesticides in the U.S. there would be: a. 21 billion $ per year loss in food and fiber. b. 67% reduction in crop yields.
II. Weed Control A. Weed: undesirable or unwanted plant.
II. Weed Control B. Weeds create numerous problems for humans. Compete for water and nutrients. Act as alternate host for insect and fungal pests. Can be toxic to range animals. Thorns can open wounds that can invite infection and/or insect pests. C. Life Cycles of Plants 1. Annual – completes life cycle in one year or less. 2. Biennial – completes life cycle sometime in second year of development. 3. Perennial – lives from year to year with varying blooming periods.
II. Weed Control D. Examples of Some Arizona Weeds 1. Types of poisonous plants a. Plants that always possess toxins. 1) Datura (Jimsonweed)
II. Weed Control D. Examples of Some Arizona Weeds 1. Types of poisonous plants a. Plants that always possess toxins. 2) Silverleaf Nightshade (Solanum elaeagnifolium)
II. Weed Control D. Examples of Some Arizona Weeds 1. Types of poisonous plants b. Plants that develop toxins under stress. 1) Johnson Grass (Sorghum halepense)
II. Weed Control D. Examples of Some Arizona Weeds 1. Types of poisonous plants b. Plants that develop toxins under stress such as HCN or nitrate accumulation. 2) Russian Thistle (tumbleweed) ( Salsola kali )
II. Weed Control D. Examples of Some Arizona Weeds 2. More pest plants. a. Examples from your backyard. 1) Prostrate spurge (Euphorbia supina)
II. Weed Control D. Examples of Some Arizona Weeds 2. More pest plants. a. Examples from your backyard. 2) Sheperd’s purse (Capsella bursa – pastoris)
II. Weed Control D. Examples of Some Arizona Weeds 2. More pest plants. a. Examples from your backyard. 3) Wild barley (Hordeum leporinum)
II. Weed Control E. Examples of common herbicides. 1. 2-4D (Weed-B-Gon) •Non-toxic, breaks down easily •Selective nature •Kills broadleaf dicots, not monocots (grass) •Economically significant for lawns and crops – monocot grains
II. Weed Control E. Examples of common herbicides. 2. Glyphosate (active ingredient) – Roundup, Doomsday, Kleen-up (trade names). •Non-selective. •Kills everything. •Contact systemic. •Useful in converting lawns to xeriscape.
II. Weed Control E. Examples of common herbicides. 3. Pre-emergants – Surflan (trade name) •Kills both seeds and seedlings.
III. Potential Problems from Pesticides Up to 90% of the pesticides never reach their targets. A. Bioaccumulation : accumulation of toxins in tissues of individual organisms. Examples: 1. 20% of all honeybees in the U.S. are destroyed by pesticides each year. 2. In 1972, a single application of the insecticide Azodrin to combat potato aphids on a farm in Dade County, Florida killed 10,000 migrating robins in 3 days.
III. Potential Problems from Pesticides B. Biological magnification/amplification : bioconcentration of fat soluble toxins that concentrate in the bodies of predators such as: • Porpoises • Whales • Polar bears • Tuna • Raptors (eagles, etc.) • Humans
III. Potential Problems from Pesticides B. Biological magnification/amplification : bioconcentration of fat soluble toxins that concentrate in the bodies of predators:
III. Potential Problems from Pesticides B. Biological magnification/amplification : Examples: 1. In 1999, researchers found p,p’DDE (a DDT breakdown byproduct in the amniotic fluid of 30% of a sample of pregnant L.A., California women. DDT was banned in the U.S. and Canada in the late 1970’s!! 2. Other biomagnified toxins: a. Persistent Organic Pollutants (POP’s) – Examples: • PCB’s (polychlorinated biphenyls) • Dioxins • Dieldrin • Aldrin
III. Potential Problems from Pesticides B. Biological magnification/amplification : Examples: 2. Other biomagnified toxins: b. Toxic Metals – Examples: Lead •
III. Potential Problems from Pesticides B. Biological magnification/amplification : Examples: 2. Other biomagnified toxins: b. Toxic Metals – Examples: Lead • Mercury • Nickel • Beryllium • c. Halogens – Examples: Fluorine • Chlorine • Bromine • Iodine •
III. Potential Problems from Pesticides 3. Increase in pesticide resistance. The Worldwide Institute reports that at least 1000 insect pest species and 550 weeds and plant pathogens worldwide have developed chemical resistance. Compound Bollworm Tobacco Budworm 1960 1965 1960 1965 DDT 0.03 1000+ 0.13 16.51
III. Potential Problems from Pesticides F. Some potential problems from pesticides. 3. Increase in pesticide resistance.
III. Potential Problems from Pesticides 4. Synergy. • Relatively harmless compounds that form hazardous combinations after release. • Examples: (Widely used pesticide.) (Banned pesticide that lingers.) Endosulfan Dieldrin Endosulfan/Dieldrin (160 – 1600 X the estrogen potential.)
IV. Toxins & Your Health: Endocrine Disruptors Endocrine disrupters A. _______________ are ____________ that may ___________ with the chemicals interfere body’s endocrine system and produce adverse ________ , _________ , neural immune ___________, and ____________________in both humans & wildlife. A reproductive effects developmental wide range of substances, both natural and man-made, are thought to cause endocrine disruption, including: 1. Parabens : preservatives in foods & cosmetics)
IV. Toxins & Your Health: Endocrine Disruptors Endocrine disrupters A. _______________ are ____________ that may ___________ with the chemicals interfere body’s endocrine system and produce adverse ________ , _________ , neural immune ___________, and ____________________in both humans & wildlife. A reproductive effects developmental wide range of substances, both natural and man-made, are thought to cause endocrine disruption, including: 1. Parabens : preservatives in foods & cosmetics)
IV. Toxins & Your Health: Endocrine Disruptors chemicals interfere Endocrine disrupters A. _______________ are ____________ that may ___________ with the neural immune body’s endocrine system and produce adverse ________ , _________ , developmental ___________, and ____________________in both humans & wildlife. A reproductive effects wide range of substances, both natural and man-made, are thought to cause endocrine disruption, including: 1. Parabens : preservatives in foods & cosmetics) 2. Plasticizers: such as Bisphenol A(BPA), found even in dental sealants. 3. Pharmaceuticals: such as Prozac found in bass in Texas lakes. 4. Pesticides: DDT, atrazine, and other organophosphates. 5. Phthalates: used in cars, clothing, food packaging, medical devices.
IV. Toxins & Your Health: Endocrine Disruptors B. Endocrine disruptors may be found in everyday products: 1. Plastic bottles 2. Metal food cans 3. Detergents 4. Flame retardants 5. Foods 6. Toys 7. Cosmetics 8. Pesticides
IV. Toxins & Your Health: Endocrine Disruptors C. The NIEHS (National Institute of Environmental Health Services) supports studies to determine whether exposure to endocrine disruptors may result in human health effects lowered fertility including: _________________ , and an increased incidence of cancers ______________, and some _____________. Research shows endometriosis that endocrine disruptors may pose the greatest risk during prenatal and early postnatal development when organ and neural systems are forming.
IV. Toxins & Your Health: Endocrine Disruptors
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