Presentation is loading. Please wait.

Presentation is loading. Please wait.

SACCONE POWERPOINT Chapter 22 The Pesticide Dilemma

Similar presentations


Presentation on theme: "SACCONE POWERPOINT Chapter 22 The Pesticide Dilemma"— Presentation transcript:

1

2 SACCONE POWERPOINT Chapter 22 The Pesticide Dilemma http://smccd.net/accounts/snitovsky/bio215/Labs/bioins.html

3 SACCONE POWERPOINT Pesticides Pesticides: toxic chemicals used to control pests (weeds, rodents, insects, bacteria, fungi…)Pesticides: toxic chemicals used to control pests (weeds, rodents, insects, bacteria, fungi…) Herbicides  weedsHerbicides  weeds Rodenticides  rats, mice, moles, volesRodenticides  rats, mice, moles, voles Insecticides  insects, arachnidsInsecticides  insects, arachnids Fungicides  fungi, molds, yeastsFungicides  fungi, molds, yeasts http://www.epa.gov/ebtpages/pollchemicals.html

4 SACCONE POWERPOINT

5 Narrow-Spectrum These pesticides would kill only the target organism.These pesticides would kill only the target organism. It would biodegrade into C, H, & O.It would biodegrade into C, H, & O. It also would not move throughout the environment.It also would not move throughout the environment. However this “perfect pesticide” does not exist.However this “perfect pesticide” does not exist.

6 SACCONE POWERPOINT Broad-Spectrum These pesticides kill a wide variety of organisms, including beneficial ones.These pesticides kill a wide variety of organisms, including beneficial ones. They do not readily break down but they turn into secondary pollutants.They do not readily break down but they turn into secondary pollutants. They also move easily through ecosystems & biomes (mobile).They also move easily through ecosystems & biomes (mobile).

7 SACCONE POWERPOINT Pesticides 1 st Generation Pesticides: produced prior to 1940 (before synthetics) & include inorganics, organics, & botanicals.1 st Generation Pesticides: produced prior to 1940 (before synthetics) & include inorganics, organics, & botanicals. Botanicals are plant derived pesticides that are produced as a natural plant defense.Botanicals are plant derived pesticides that are produced as a natural plant defense. Ex: nicotine (tobacco), pyrethrin (chrysanthemum), rotenone (Derris plant)Ex: nicotine (tobacco), pyrethrin (chrysanthemum), rotenone (Derris plant)

8 SACCONE POWERPOINT Pesticides 2 nd Generation Pesticides: synthetic (man-made) pesticides mostly used after the 1940’s. Ex: DDT dichloro-diphenyl-trichloroethane was the first of the 2 nd generation pesticides (1939). http://www.epa.gov/pesticides/about/types.htm

9 Major Groups of Insecticides Chlorinated hydrocarbons: Organic compounds that contain Cl.Chlorinated hydrocarbons: Organic compounds that contain Cl. These are mostly broad-spectrum pesticides. Slow degradation & remain in the environment & within organisms.These are mostly broad-spectrum pesticides. Slow degradation & remain in the environment & within organisms. Still in use; endosulfan, lindane, & methoxychlor.Still in use; endosulfan, lindane, & methoxychlor. 1963 author Rachel Carson brought pesticides to the public attention in Silent Spring.1963 author Rachel Carson brought pesticides to the public attention in Silent Spring.

10 SACCONE POWERPOINT

11 Major Groups of Insecticides Organophosphates: These contain phosphates & were developed based upon nerve gas..; These are more poisonous than other insecticides. They are toxic to birds, bees, & aquatic organisms.Organophosphates: These contain phosphates & were developed based upon nerve gas..; These are more poisonous than other insecticides. They are toxic to birds, bees, & aquatic organisms. These don’t persist in the environment as long as the Hydrocarbons. Have replaced commercial use of hydrocarbons. These don’t persist in the environment as long as the Hydrocarbons. Have replaced commercial use of hydrocarbons. Ex: Methamidophos, dimethoate, & malathion.Ex: Methamidophos, dimethoate, & malathion. http://www.crisny.org/not-for-profit/nycap/mosquitopaper.htm

12 SACCONE POWERPOINT Major Groups of Insecticides Carbamates: derived from carbamic acid. Are broad-spectrum pesticides. Not as toxic to mammals as organophosphates. Ex: carbaryl & aldicarb

13 SACCONE POWERPOINT

14 Nonselective: Kill all vegetation.Nonselective: Kill all vegetation. Selective herbicides: kill only certain types.Selective herbicides: kill only certain types. A) Broad-leaf herbicides: Kill broad-leafed plant but no grasses. B) Grass Herbicides: kill grass but safe for most other plants. Major Groups of Herbicides

15 SACCONE POWERPOINT Use of Herbicides in Vietnam

16 12 million gallons of herbicides to expose hiding places & destroy crops of Vietcong.12 million gallons of herbicides to expose hiding places & destroy crops of Vietcong. Agent White, Agent Blue, and Agent Orange. Agent Orange is made of:Agent Orange is made of: (2,4,-D) 2,4 dichlorophenooxyacetic acid & (2,4,5-T) 2,4,5 trichlorophenooxyacetic acid as well as dioxins. as well as dioxins. Birth defects, stillbirths, cancer in Vietnam Agent orange Syndrome in Vietnam Vets.

17 SACCONE POWERPOINT Benefits of Pesticides Disease control (malaria, west Nile)Disease control (malaria, west Nile) Crop protection (increase yields)Crop protection (increase yields)

18 SACCONE POWERPOINT

19 Problems with Pesticides Genetic resistanceGenetic resistance Imbalance in the ecosystemImbalance in the ecosystem Persistence of pesticidesPersistence of pesticides Bioaccumulation in organismsBioaccumulation in organisms Biological magnification in food webBiological magnification in food web Mobility in the environmentMobility in the environment Risks to human health (short-term & long-term)Risks to human health (short-term & long-term)

20 Problems with Pesticides Genetic resistance: inherited characteristics (natural selection) that decrease the effect of the pesticide on the pest.Genetic resistance: inherited characteristics (natural selection) that decrease the effect of the pesticide on the pest. Resistance Management: a technique employed to delay the evolution of genetic resistance in a population to maximize the effectiveness of a pesticide.Resistance Management: a technique employed to delay the evolution of genetic resistance in a population to maximize the effectiveness of a pesticide. http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5233a4.htm Methicillin-Resistant Staphylococcus aureus Infections

21 Problems with Pesticides Imbalance in the ecosystemImbalance in the ecosystem http://www.indiana.edu/~bradwood/eagles/ddt2.htm

22 SACCONE POWERPOINT

23 Problems with Pesticides DDE (dichlorodiphenyldichloroethylene) and DDD (dichlorodiphenyldichloroethane) are chemicals similar to DDT that contaminate commercial DDT preparations. DDE has no commercial use. DDT  Eagles  DDE DDD was also used to kill pests, but its use has also been banned. One form of DDD has been used medically to treat cancer of the adrenal gland. DDD was also used to kill pests, but its use has also been banned. One form of DDD has been used medically to treat cancer of the adrenal gland.

24 SACCONE POWERPOINT Imbalance in the ecosystem

25 Problems with Pesticides Persistence: resistance to degradation into less toxic forms.Persistence: resistance to degradation into less toxic forms. http://www.epa.gov/pbt/pubs/accomp99.htm

26 Biological magnification Bioaccumulation

27 Problems with Pesticides Bioaccumulation: the build up of a persistent chemical (pesticide)within an organism.Bioaccumulation: the build up of a persistent chemical (pesticide)within an organism.

28 Biological magnification: an increase in the chemical (pesticide) concentration of a pollutant as it passes through successive trophic levels of a food web.Biological magnification: an increase in the chemical (pesticide) concentration of a pollutant as it passes through successive trophic levels of a food web.

29 SACCONE POWERPOINT

30 Problems with Pesticides Mobility in the environmentMobility in the environment

31 SACCONE POWERPOINT Pesticide Mobility in the environment

32 Problems with Pesticides Risks to human health  Short-term: Poisoning & irritation Long-term:Cancers Endocrine disruption Mental/physical retardation

33 SACCONE POWERPOINT

34 Solutions to the Pesticide Dilemma Using cultivation to control pestsUsing cultivation to control pests Biological controlsBiological controls Pheromones & hormonesPheromones & hormones Genetic controlsGenetic controls Bt & its potential & problemsBt & its potential & problems QuarantineQuarantine Integrated Pest ManagementIntegrated Pest Management Irradiating FoodsIrradiating Foods

35 Solutions to the Pesticide Dilemma Using cultivation to control pestsUsing cultivation to control pests Aphid infestation of Wheat & Barley Infestation was stopped by a local resistant variety of these plants (not a monoculture.)Infestation was stopped by a local resistant variety of these plants (not a monoculture.)

36 Solutions to the Pesticide Dilemma Biological controls: utilizes naturally occurring disease organisms, parasites,, or predators to control pests.Biological controls: utilizes naturally occurring disease organisms, parasites,, or predators to control pests. Sterile Male technique: reduces population by “tricking” the females into thinking their eggs have been fertilized (sterile male can’t)Sterile Male technique: reduces population by “tricking” the females into thinking their eggs have been fertilized (sterile male can’t)

37 biological controls Aphids and Ladybeetles www.ces.ncsu.edu/.../notes/ Fruits/NoteS-1.html

38 www.eap.mcgill.ca/Publications/ EAP53.htm

39 biological controls

40 Solutions to the Pesticide Dilemma Hormones: chemical messengers produced by organisms.Hormones: chemical messengers produced by organisms. Pheromones: reproductive hormones used to lure in the opposite sex.Pheromones: reproductive hormones used to lure in the opposite sex. Both are used to lure pests into traps or to confuse pests to prevent mating.Both are used to lure pests into traps or to confuse pests to prevent mating.

41 Solutions to the Pesticide Dilemma Scientists will use pheromones to kill sea lamprey

42 Solutions to the Pesticide Dilemma Genetic controls: using genetic variation to produce species that are resistant to pests.Genetic controls: using genetic variation to produce species that are resistant to pests. Selective breeding (genetic diversity)Selective breeding (genetic diversity)Or Genetic engineering: the ability to take one gene from an organism & place it into an unrelated organism where it is expressed.Genetic engineering: the ability to take one gene from an organism & place it into an unrelated organism where it is expressed.

43 Solutions to the Pesticide Dilemma http://www.bt.ucsd.edu/crop_refuge.html Case in Point: Bt, Its Potential & Problems

44 Solutions to the Pesticide Dilemma Quarantine: restricting the importation of exotic plant & animal material that might harbor pests.Quarantine: restricting the importation of exotic plant & animal material that might harbor pests.

45 Solutions to the Pesticide Dilemma Integrated Pest ManagementIntegrated Pest Management

46

47 SACCONE POWERPOINT

48 Solutions to the Pesticide Dilemma Irradiating Foods: http://www.storewars.org/flash/index.html

49 Irradiating Foods www.ext.vt.edu/pubs/foods/ 458-300/458-300.html

50 Pesticide Dilemma: Laws, Laws, Laws FDCA Food, Drug, and Cosmetics Act:FDCA Food, Drug, and Cosmetics Act: enacted in 1938 it recognized the need to regulate pesticides in food (no means for regulation) The Miller Amendment: passed in 1954, required standards for levels of pesticides in food (acceptable & unacceptable) Who decides? Criteria? The Delaney Clause: 1958, no known carcinogens (lab animals or humans) would be permitted in processed foods. (based upon 1978 standards) Prior?

51 Pesticide Dilemma: Laws, Laws, Laws FIFRA: Federal Insecticide, Fungicide, & Rodenticide Act:FIFRA: Federal Insecticide, Fungicide, & Rodenticide Act: 1947, required testing & registration of the active ingredients of pesticides. 1988 version targeted older pesticides and new for ED 50 and LD 50 testing.

52 Pesticide Dilemma: Laws, Laws, Laws The Food quality Protection Act:The Food quality Protection Act: 1996, amended both the FDCA and the FIFRA. Set pesticide residue limits. Revised The Delaney Clause to include raw & processed foods.

53 Pesticide Dilemma: Laws, Laws, Laws Stockholm Convention on Persistent Organic Pollutants: eliminate the production and use of P.O.P’s (persistent organic pesticides).Stockholm Convention on Persistent Organic Pollutants: eliminate the production and use of P.O.P’s (persistent organic pesticides). DDT falls into this category but will still be used BY SOME.DDT falls into this category but will still be used BY SOME.

54 External

55 External

56 Internal

57 SACCONE POWERPOINT Gene Splicing GENE for Nicotine production

58 SACCONE POWERPOINT Biotechnology

59 SACCONE POWERPOINT Biotechnology

60 SACCONE POWERPOINT Biotechnology Each bacterial cell can now make nicotine. Each bacterial cell has the gene for making nicotine.


Download ppt "SACCONE POWERPOINT Chapter 22 The Pesticide Dilemma"

Similar presentations


Ads by Google