chemicals in my food? how do people know for sure?
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Chemicals in my food?How do people know for sure?
The Dirty Dozen
“Dirty Dozen” and “Clean Fifteen”
Dirty Dozen• Celery• Peaches• Apples• Strawberries• Blueberries• Nectarines• Sweet bell peppers• Spinach, Kale, Collard greens • Cherries• Potatoes• Grapes• lettuce
Clean Fifteen• Onions• Avocadoes• Sweet corn• Pineapples• Mangos• Sweet peas• Asparagus• Kiwi fruit• Cabbage• Eggplant• Cantaloupe• Watermelon• Grape fruit• Sweet potatoes• Sweet onions
Who is telling me what foods are dirty and clean?
• The Environmental Working Group– States that, “choosing to buy certain organic food
can significantly lower residue exposure by as much as 90%”.
– The outer shell, or protective layer, of food determines how much residue it repels and absorbs.
• U.S. Department of Agriculture– Non-organic fruits and vegetables are 3 to 4 times
more likely to have chemical residues than organic food and…
– 8 to 10 times more likely to contain multiple pesticide residues.
http://en.wikipedia.org/w/index.php?title=Pesticide_residue&action=edit§ion=17
HTTP://WWW.YOUTUBE.COM/WATCH?V=1P5ALC8JRPS
Not everyone says organic is better…
What do you think?
• Is organic better?• Have you ever worried about chemicals
on your food?• Have you ever had food poisoning?• Why do you think you got that food
poisoning?• Are you interested to find out more about
organic, conventional, and maybe even genetically monitored organisms [food], GMOs?
What are some of the types of chemicals that farmers actually put on
their crops?
Pesticides
Meant to stop and/or kill insects and other
pests, like mice or rats
Fungicides
Prevent and kill fungi and their spores.
Herbicides
Prevent and kill the growth of unwanted plants, like weeds.
OrganophosphatesCarbamatesOrganochlorinePyrethroidSulfonylureaBiopesticides – Organic
Each type also has subtypes.
A few facts…Crop Acres (million) $ Profit (billions)
Corn 72.7 15.1
Soybeans 72.7 12.5
Hay 59.9 3.4
Wheat 53.0 5.5
Cotton 13.1 4.6
Rice 3.0 1.2
http://www.epa.gov/agriculture/ag101/printcrop.html - major
Also, According to agricultural chemical usage statistics from USDA, herbicides were applied to 98% of corn acreage and 96% of soybean acreage
in 2001.
What about animals?
• Hormones• Antibiotics• The Federal Drug Administration
(FDA), does monitor the feeds that are given to livestock and poultry for future human consumption.
• But you will research more on animals later…
So how are these chemicals in fruits and vegetables measured?
• ECD - Electron Capture Detector • ELCD - Electrochemical Detector Con -
Conductivity Detector• FID - Flame Ionization Detector • FLD - Fluorescence Detector • FPD - Flame Photometric Detector • FPD (S or P) - Flame Photometric Detector
(Sulfur or Phosphorus Mode) • GFAA - Graphite Atomic Absorption
SpectrophotometerHALL - Hall Electrolytic Conductivity Detector
• MS - Mass Spectrometer • MS (NCl) - Mass Spectrometer (Negative
Chemical Ionization Mode) • NPD - Nitrogen Phosphorus Detector • NST - Nitrogen Selective Thermionic
Detector• PCD - Photoconductivity Detector • RADI - RadioassayRIS - Radiographic
Imaging System
• SPEC –Spectrophotometer• TSD - Thermionic Specific Detector • UV - Ultraviolet Absorption Detector • XSD - Halogen Specific Detector• AA - Atomic Absorption• CE - Capillary Electrophoresis Col.switch
- Column Switching Technique • GC - Gas Chromatograph• HPLC - High Performance Liquid
Chromatograph • HPTLC - High Performance Thin Layer
Chromatography• IC - Ion ChromatographImmunoassay -
Immunoassay Kit • LSC - Liquid Scintillation Counter• TLC - Thin Layer Chromatography• UV SPEC - Ultraviolet
Spectrophotometer Wet - Wet Chemistry
http://www.epa.gov/pesticides/methods/glossary.htm
We’ll focus on one common detection method.
• FDA analyzed an average of 2,243 domestic samples and 4,870 import samples annually in its pesticide residue monitoring program.
• Multi-residue methods (MRMs) • MRMs can determine about half of the
approximately 400 pesticides approved by the Environmental Protection Agency (EPA).
• GAS CHROMOTOGRAPHYhttp://www.fda.gov/Food/FoodborneIllnessContaminants/Pesticides/ucm125183.htm
Here’s a few chemicals that might be found in food around Knox
county:• Extrazine Herbicide for corn• Bicep Herbicide for corn• Canopy Herbicide for soybeans• Lorsban Insecticide for alfalfa or corn
http://www2.kenyon.edu/projects/farmschool/types/fert.htm
Review and Reflection
Review• There are many arguments for
and against conventional foods, including GMOs.
• There are more steps and materials involved in growing non-organic foods.
• There are many ways to measure chemicals in food; gas chromatography is a common method.
• Basically, foods are liquified and ions are measured in the machine. Different ions signify different chemicals.
Reflection for your Journal
• What areas of food production has this presentation made you have questions about?– Organic, conventional, GMOs?– Pesticides, fungicides, and
herbicides?– Chemical measuring methods?
• Write one detailed and specific question about this presentation that you would like for the teacher to answer?
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