Impact of Technologies on Biosphere

1
Impact of Technologies on Biosphere

• Deforestation, Toxins, GMO, Food Radiation, Food
  Additives, Nuclear Radiation

2
Risks Associated with Food Technologies?

• Genetically altered food products may have risks
  that are as yet unidentified
• Safety of some food additives has been questioned
• Using ?-radiation to kill bacteria may produce
  carcinogenic radiolytic products

3
Biological Magnification

• If a pollutant or toxic is in the producers and
  then the primary consumers eat it, it spreads to
  their bodies and so on up through all levels of
  the ecosystem
• Eventually, many species have ingested the toxin
  with the highest animals in the food chain (often
  humans) ending up with the most toxin in their
  bodies

4
Biomagnification of a Lipid Soluble Pesticide
(DDT)
Nebel/Wright, Environmental Science, 7th,
Prentice Hall, NJ, 2000, 415
5
Absorption, Distribution and Elimination of Toxic
Substances in Humans
6
Deforestation in the Tropics
Millions of acres of tropical rain forest are
being cut down each year to make room for
agricult-ure. Called slash-and-burn agricult-ure
Nebel/Wright, Environmental Science,
7th,Prentice Hall, NJ, 2000, 146
7
Locations of the Tropical Rain Forests
Between 1960 and 1990, 20 of the tropical
forests ( 1.1 B acres ? two-fifths of the land
area of the U.S.) have been converted to other
uses. Between 1990-1995, another 160 M acres
have been lost. Current rate of deforestation is
41.8 million acres/yr or about 1 football
field/second
Raven et al, Environment, Saunders, NY, 1995, 378
8
Exposure and Risk for Nuclear Radiation

• External exposure - minimum risk unless to
  radiation from nuclear bomb or core of nuclear
  reactor
• Internal exposure from ingested radioactive
  materials - high risk since vital organs receive
  direct radiation

9
Measuring Exposure
McMurray/Fay, "Chemistry", Prentice Hall, NJ,
1995,804
10
McMurray/Fay, "Chemistry", Prentice Hall, NJ,
1995,806
11
Tro, 197
12
Joesten/Wood, "World of Chemistry,2nd,
Saunders,PA, 1996,122
13
Radon
14
Buell/Girard, "Chemistry", Prentice Hall,
NJ,1994, 164
15
Tro, 199
16
5730 y
McMurray/Fay, "Chemistry", Prentice Hall, NJ,
1995,885
17
Ionizing Radiation and Free Radicals
Brady/Russel/Holum, Chemistry, 3rd, Wiley,NY,
2000, 1011.
18
Smoke Detector
Am-241 emits alpha radiation which ionizes oxygen
and nitrogen molecules of air completing
electrical circuit. Smoke breaks circuit and sets
off alarm.
Radel/Navidi, Chemistry, West, NY, 1990, 971.
19
Society's Response
20
Chemtech, August, 1992,482