What are the concerns associated with GMO crops?

Answer 1

Though some claim they are not harmful, genetically modified foods allow crops to withstand herbicides being sprayed directly on them. Herbicides are harmful to the environment and the use of herbicides used on genetically modified crops has increased since GMO crops were introduced. Insecticide use has decreased, but Bt crops are modified to produce an insecticide in the plant itself. Thus, Bt crops may be harmful to friendly insects. There is also the issue of horizontal breeding (mixing the genes from one species with those of another species) and whether those changes will spread to species in the environment. Weeds developing resistance to herbicides used on GMO crops much faster than they would without GMO crops is also a concern, as is the need to use more herbicides to produce the same results after a number of years.

Answer 2

While some claim they do no harm to the environment, usage of glyphosate (Round up), which is the most widely used herbicide for transgenic crops up to this time (2014), has doubled since the introduction of GMO crops. At the same time, other herbicide use has not been reduced enough to offset the increased use of glyphosate. Herbicide use is not good for the environment. It is not known what effect the use of horizontal breeding and introducing forced genetic changes and breeding between species will have on the environment. Weed resistance to glyphosate has escalated since the introduction of GMO crops. While weed resistance to herbicides occurs when using non-GMO crops, its increase has been faster and more severe with the use of GMO crops.

Answer 3

There is no way to know what effects transgenics (GMOs) will have on the environment over the long term (50 years or longer). Since they have been grown commercially (1996), overall herbicide use has dropped slightly in the U.S. while the use of Round-up (glysophate) has doubled. Weeds have developed resistance, so new GMO varieties that are resistant to more toxic herbicides have been developed and at this time, are waiting for approval by the regulating agencies. Though the cause of bee colony collapse is not known, bT varieties (engineered to produce an insecticide within the plant itself) may be at least partially responsible for it. Though the toxin produced by bT varieties is supposed to be targeted to certain insects, it is not known if it kills other insects or has an effect on human health. In addition, it is suspected that insects are becoming resistant to it. The use of herbicides also have negative effects on soil and runoff can pollute the water, so unless the use of GMO varieties significantly reduce pesticide use, pollution continues to be as much as a factor as using non-GMO varieties. It is also not known if the transgene that was inserted artificially into GMO varieties will transfer horizontally to other plants, though many say it is no different than vertical breeding, which is how breeding occurs in nature.

Answer 4

Some concerns associated with GMO crops are:

• Unexpected damage to the genetics that could cause genes to turn on or off that are not intentional.
• The effects of horizontal gene transfer may have on the environment and that if negative effects occur, it might be impossible to control them.
• Possible harm being done to non-targeted insects by Bt technology.
• Herbicide resistant varieties causing more herbicides to be needed over the course of a few years.
• Development of weeds that are resistant to the herbicide, which require other types of herbicides which might be more damaging to the environment.
• Insects becoming resistant to the insecticide producing Bt varieties, causing the use of more insecticides.
• Health effects on animals and humans.
• GMO contamination of Non-GMO and organically-grown crops through cross pollination.
• Eventual lack of choice to eat non-GMO foods, which is actually already happening.

Answer 5

Plants as food impacts the environment because certain plants are edible while others are not. Also, some species need more plants as food than others do.