1. October 12, 1999: 6 billion!
December, 2012: 7 billion!
Now doubling every 61 years

4. Pesticides and the
GREEN REVOLUTION
can we feed the planet?
Since 1950 food grew
faster than population:
population growth: 1.7% per year
food growth: 3% per year
0% per year
land growth:

5. 10% of Earth’s surface produces food
37% of Earth’s land produces food
Total surface area of earth  5.1  1014 m2
Land  25%  1.3  1014 m2  13 Gha
10%  4.8 Gha
(1 hm = 102 m; 1 ha = 1 hm2 = 104 m2)
pastures: 3.3 Gha
cropland: 1.5 Gha

6. The Earth's Land Total Area: 13 Billion Hectares
Other land" includes barren
and developed land.
Source: Food and Agriculture Organization
from Committee for the National Institute for the Environment

7. [1] development of high yield strains of grains
The green revolution:
[1] development of high yield
strains of grains
[2] increased use of inorganic fertilizers
[3] irrigation
[4] synthetic pesticide use
increase production
eliminate competition

8. environmental impacts?
3 times more food
being produced
than in 1950
Are there
any
environmental impacts?

9. Glyphosate (G) is the largest selling herbicide worldwide; the most common formulations
(Roundup, R) contain polyoxyethyleneamine as main surfactant.
Recent findings indicate that G exposure may cause DNA damage and cancer in humans.
Arch Toxicol Feb 14. Epub 2012 Feb 14. PMID: 

10. Glyphosate kills EPSP
Plant cannot make
Aromatic aminoacids

11. 2,4-D = 2,4-Dichlorophenoxyacetic acid
Enlist

13. Dow Chemical (the main manufacturer of DDT) and the Velsicol Chemical Company
were the first to respond to the publication of Silent Spring.
They threatened legal action against the publishers as well as the magazines
publishing excerpts, and then they began publishing their own brochures,
documentaries, books and articles promoting the safety of pesticides while
attacking Carson and her book.
Staunch critics claimed that if we followed the advice of this “Doomsayer”
that we’d return to the Dark Ages and insects would inherit the earth.
Some attacked Carson’s scientific credentials (she was only a marine biologist),
while others labeled her “a fanatic defender of the cult of the balance of nature.”
Finally there were those who called her a Communist.

14. Metabolic breakdown product, DDE:

17. Properties of DDT and other
organic compounds
very stable
low stability in water
high stability in hydrocarbon solvents
high toxicity to tissues
relatively low toxicity to humans

18. The idea of
BIOMAGNIFICATION

19. Fish are
living separatory funnels
They ingest water containing DDT
The DDT dissolves in the fatty tissues of their bodies

20. Biomagnification in Long Island Sound [DDT] in sea water 0.000003 ppm
[DDT] in plankton ppm
[DDT] in minnows 0.5 ppm
[DDT] in needle fish 2 ppm
[DDT] in cormorants 25 ppm

22. Polychlorine biphenols = PCBs

26. © 2012 W. H. Freeman & Co.

27. © 2012 W. H. Freeman & Co.

28. © 2012 W. H. Freeman & Co.

30. LD50 A measure of toxicity
Feed DDT to rats (spike their food)
Continue upping their dose until half of the die
Measure concentration of DDT in the rats
LD50 = (mass of DDT in rats) # Kg of rat

32. © 2012 W. H. Freeman & Co.

33. © 2012 W. H. Freeman & Co.

34. © 2012 W. H. Freeman & Co.