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&section=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

Gas Chromatography Video

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?