Understanding the impact of GMOs on the environment

 

By definition, a genetically modified organism (GMO) is one where genetic characteristics of one specie is modified by insertion of an altered organism gene of the same species or a gene from other organisms using genetic engineering. When the gene is taken from the same species it is called intragenic modification where as a gene from a different organism is called transgenic modification. The major criticisms of genetic engineering in food production have been in the areas of potential human health effects, environmental and other possible socioeconomic effects.

Genetically modified foods first appeared in the food market in the 1960s (Uzogara, 2000). In 1967, a new potato variety called Lenape Potato was bred for its high solids which made it appropriate for making potato chips. Two years later, the Lenape potato developed a toxin called solanine and it was withdrawn from the market by the United States Department of Agriculture. The development of toxin in the Lenape potato variety showed an important lesson that genetic engineering in plants and animals can have unexpected effects.

Although the global debate on GMOs has usually allied disparate groups concerned about food safety and the environment, environmental risks are perceived to differ from food safety risks in several ways. Experience built up through decades of environmental impact studies suggests that the impact of new biological elements in ecosystems may take years or decades to be understood. The environmental impacts of introduced GMOs can be either ecological or genetic and may include:

·         Unintended effects on the dynamics of populations in the receiving environment as a result of impacts on non-target species, which may occur directly by predation or competition, or indirectly by changes in land use or farming practices;

·         Unintended effects on biogeochemistry, especially through impacts on soil microbial populations that regulate the flow of nitrogen, phosphorus and other essential elements;

·         the transfer of inserted genetic material to other domesticated or native populations, generally known as gene flow, through pollination, mixed mating, dispersal or microbial transfer.

Because these potentially adverse effects have been documented in the field with non-GMO species, and because the consequences of these effects could be serious, it is important to regulate and monitor all introductions of GMOs effectively.

Some of the arguments raised in favor of genetically modified crop technology in agriculture includes the promise that the technology might be more suitable to control some problematic species of pests when compared to conventional ways resulting in less pollution from pesticide toxins.

However, arguments against genetically modified crops include concerns that herbicide and pest resistant genetically modified crops might lead to an increase in herbicide application and that toxins produced may enter and disturb the food web and thus affecting non-targeted organisms.

The  potential risk on the food web is most likely to have huge impacts on animal species, ecosystems and humans mostly because these effects may be irreversible primarily because the majority of GM crops are those that are engineered to be herbicide (weed-killer) resistant.

Roundup ready soya, for example, produced by Monsanto and grown extensively in north and South America, allows farmers to spray soya plants with Roundup - a toxic cocktail of glyphosate and other chemicals. This may not harm the genetically engineered crop but the treatment creates chemical residues and run off, making it disastrous for surrounding ecosystems.

Another GMO downside is that it encourages the development of super weeds which are resistant to glyphosate, such as the giant pig weed, which grows over 2m tall, or Morning Glory. The latter has evolved a reproductive system which ensures its tolerance of glyphosate. I bet this was not something predicted by the genetic engineers.

Regarding its environmental effects, toxicity is a huge issue concerning GM crops. One particular example is the Bt corn (Bacillus Thuringensis Corn), which is widely known for its pest controlling ability.

Bacillus thuringensis is a soil bacterium that has a gene that produces certain protein toxins that effectively destroy pests and insects, like larval caterpillars. This gene is then inserted into the corn to make it more resistant to pests.

While such characteristic is helpful in controlling pests, it may result into releasing the said toxin to the soil. Too much toxins in the soil prevents the growth of bacteria essential for plant growth and as a result, the soil becomes void of all necessary nutrients. And you know what happens next? Poor soils and poor food production means hunger and food insecurity.

Even though GMOs present some upside as far as increased production is concerned, the introduction of GMO in crop production bears more costs than benefits to the environment mainly because of the fact that confirmed environmental costs pose huge threats to the natural ecosystems on which the majority of the population in Africa derive their livelihoods from.

Preserving the earth’s bio-integrity must constrain genetic engineering in sectors such as agriculture because prioritizing the earth’s bio-integrity in vital sectors such as agriculture saves the ecosystems which contribute to decent livelihoods  for  millions of people while  providing  clean  air  and  water,  conserving  biodiversity and mitigating climate change.

In the end, the introduction of GMO technology in food production bears high costs associated with destruction of natural habitats, which may be extreme (especially in Africa) where a significant proportion of the population depends on natural and semi-natural ecosystems for their survival which in itself puts pressure on the resources.