Look at the PLU code on your produce. If it has 4 digits it is conventionally grown. 5 digits beginning with a 9 means it is organically grown. 5 digits beginning with an 8 means it is genetically modified which means, "made with techniques that alter the biology of an organism by means that are not possible under natural conditions" as defined by the Organic Trade Association. The eventual impact on our health remains to be seen, but the jury is out...It doesn't look good.
Also, avoid purchasing 'Round-Up' which is the worlds #1 herbicide. Buying this product contributes to the financial motivation of Monsanto to continue altering our food until we all eventually evolve into chemivores. Did somebody say, McCancer?...Not lovin' it!