To eat or not to eat…organic?
  
  
Pick  just about any newspaper or journal and during the course of a year, one or  more articles will be devoted to the benefits or not of organic foods and the downsides  or not of food grown with pesticides and herbicides.  These articles are often confusing.  
    
    So how does one sort this out?
    
    Organic  food (or any food for that matter) is a combination of chemicals, most of which  our bodies need in order to function well.    However, not all chemicals in  food are useful to our body, and some of them are harmful at a certain level,  like too much aflatoxin1 ---a  natural fungal product---in peanut butter.  Organic food comes from plants grown without added  pesticides, herbicides or genetic modifications. 2
    Pesticides  are usually human-made chemicals added to growing plants and sometimes even after  the harvest to kill insects and other damaging animals, like rats.3   Herbicides are usually human-made chemicals  that are added to soil or growing plants to kill weeds and fungi. 4  But did you know the plants we grow for food  also produce pesticides and herbicides to protect themselves from insects and  weeds?  Any gardener who has tried to grow  tomatoes near a walnut tree can tell you this is true---the walnut tree’s roots  produce a herbicide that is poisonous to tomato plants.4   The use of pesticides and herbicides, whether  human-made or not, often results in small levels of these chemicals in our  food.
    
    Genetic  modification of a food crop is one way to get the crop to naturally develop yet  another pesticide and herbicide, or to give the crop a way to resist damage by  a human-made herbicide.5  
 So corn can be genetically modified to make a  protein to protect it against insect damage and at the same time to resist  damage by human-made herbicides used to kill weeks.  The use of genetically modified (GM) corn is popular  because it increases yields, increases work efficiency by reducing the need for  plowing, and protects soil by reducing erosion.  
So are  these small levels of pesticides, herbicides and genetic modifications in our  food harmful?  
Good  question!  And one that scientists in  many organizations try to answer on a daily basis.   In fact, the safety assessments for human-made  pesticides and herbicides and genetic modification are well known.  Tens of millions of dollars are spent by  competing industries on experimental animal and exposure studies.  These studies are reviewed by scientists in  government and non-government organizations to establish safe levels of these  compounds for humans and the environment.   A “safe level” means that the amount of a compound is less than the  amount that would make a sensitive person sick.   As a result, no human-made pesticide, herbicide or genetically modified  plant is used without knowing that the potential small level of these chemicals  in our food is safe. 7  
So we  can be sure that foods grown with human-made pesticides, herbicides and genetic  modifications are as safe as to eat, or maybe safer, than organically grown  food.  This is because human-made  pesticides, herbicides and genetic modifications are extensively tested to  determine safe levels, generally unlike the naturally occurring plant  chemicals.   However, other issues about either method of  growing food are important, such as farmer risk from exposures to human-made  pesticides and herbicides, nutritional differences if any,8  or  soil erosion from the extra plowing needed with organic farming. For more  information, please consider visiting the websites listed in the footnotes.9
By 
Michael  L. Dourson, Ph.D., DABT, ATS 
Board-Certified  Toxicologist with the nonprofit organization Toxicology Excellence for Risk  Assessment (TERA), dourson@tera.org 
Douglas  Lee, B.S. 
Research  Assistant with the nonprofit organization Toxicology Excellence for Risk  Assessment (TERA), lee@tera.org
1. See also http://en.wikipedia.org/wiki/Aflatoxin.
2. See also http://en.wikipedia.org/wiki/Organic farming; or http://www.usda.gov/wps/portal/usda/usdahome?navid=ORGANIC_CERTIFICATIO.
3. See also http://en.wikipedia.org/wiki/Pesticide; or http://www.epa.gov/pesticides; or http://www.epa.gov/pesticides/kids/index.htm.
6. See also http://en.wikipedia.org/wiki/Genetically_modified_food; or http://www.ers.usda.gov/data-products/adoption-of-genetically-engineered-crops-in-the-us.aspx; or http://www.ornl.gov/sci/techresources/Human_Genome/elsi/gmfood.shtml.
7. See also http://www.who.int/foodsafety/publications/biotech/20questions/en/index.html; for a listing of safe levels for chemicals from different health organization around the world see http://toxnet.nlm.nih.gov/cgi-bin/sis/htmlgen?iter; for an essay on “Is it safe?,” click here.
8. See also http://blogs.scientificamerican.com/guest-blog/2011/08/11/nutritional-differences-in-organic-vs-conventional-foods-and-the-winner-is/
9. Results were numerous for a Google query entitled “organic and conventionally grown foods, including GM foods.” Many of these websites were judged by staff of Toxicology Excellence for Risk Assessment (TERA) as too biased, not credible, or non-related. The following 3 websites were not biased, credible and related: