1. Pesticide, Bioaccumulation and Biomagnification

2. A. Pesticides A1. Pesticides are chemicals that kill pests
A million tonnes of pesticides used yearly
A3. 75% used in agriculture

3. B-Types of pesticides
B1. Insecticides: kill insects by attacking their nervous system
B2. Herbicides: kill undesirable
plants (weeds)
B3. Bateriocides: kill bacteria.
B4. Fungicides: kill fungi, mold

4. C-Benefits of using pesticides?
C1- Protect, thus protecting industries’ and farmers’ profits
C2- Prevent epidemic outbreak
Discuss in pair

5. D- Problems with Pesticides
Let’s brainstorm in pairs, with whiteboard

6. D- Problems with Pesticides?
D1. Mutation randomly occur allows pest to develop resistance to pesticides
D2. Costs lots of time and resources to constantly develop new poisons
D3. They are often toxic substances and can accumulate and magnify in the food chain

8. FOOD FOR THOUGHT ACTIVITY
You are what you eat!!!
FOOD FOR THOUGHT ACTIVITY
Due Monday Sep

9. E-Bioaccumulation
E1. refers to an increase in the concentration of a chemical in an organism over time.

10. F- Biomagnification (=bioamplification)
F1. Biomagnification is the increase concentration of toxic chemicals, such as pesticides as it is passed upwards and maximized to the top predator of the food chain
Bioaccumulation worsens biomagnification

11. TROPHIC LEVEL
Trophic level is the position that an organism occupies in a food chain - what it eats, and what eats it.

12. G- Meet a pesticide DDT: (stands for Dichlorodiphenyltrichloroethane)
- First produced in 1939
a highly potent,
fat soluble insecticides
Tobacco extract (i.e. nicotine sulfate) as insecticides
Plants themselves developed chemicals that can kill animals that graze on them
a DDT molecule

13. H- Case study 1: DDT and the bald eagle
Bald eagles feed on fish
They disappear for many reasons:
H1. Loss of habitat (industrialization, deforestation)
H2. Hunting
H3.Toxins in lake
in lake

14. I-DDT in the Great Lakes
I1. How DDT enter the Great Lakes?
I2. In this food chain, what type of consumer is the bald eagle?
I3. tertiary (top) consumer
I4.How could DDT end up in the bald eagle with highest concentration?

15. J-Impacts of DDT on birds
double-crested cormorant
DDT was banned in Canada in 1971
Egg shell thinning

16. K-DDT and Human Health
K1. Concentration of 6-10 mg/kg leads to such symptoms as headache, nausea, vomiting
K2. Lethal (=deadly) dose :236 mg DDT per kg of body weight

17. L-Discussion
L1.There still countries haven’t banned DDT. Why would this be of concern to Canadians?
L2. Breast milk contains fat. How breast-feeding might affect the concentration of DDT in a mother and in her baby?
Throw in questions of scavenger (vulture)

18. M-Recent pesticide development
-Water soluble pesticides
-animals can remove them in livers
-break down quickly
-therefore need to apply them more frequently

19. R- Mercury Poisoning- Minamata disease
Choose the most correct statement(s)
The residents of Minamata have bioaccummulated mercury in their body
The residents of Minamata have biomagnified mercury in their body
The residents of Minamata display both bioaccummulation and biomagnification
The residents of Minamata have also suffered from lead poisoning