Many of the readers will be questioning my authority on this matter; I hold a Master’s degree in Molecular Biology, specializing in GMO biosafety, and work in a routine diagnostics laboratory testing for the presence of genetic modification in seed and food products. I am solely writing this article to hopefully shed some light on GMOs. I shall try to keep the information as simple as possible.
The difference between public perceptions and scientific knowledge on the development and safety of genetically modified organisms (GMO) appears to be vast. There are numerous surveys that have been conducted to determine what the public understanding and perceptions of genetically modified (GM) food and crops are. Generally, there is little understanding of GM crop production and safety, and GM foods are perceived to be potentially harmful. Hence, the aim of this article is to deliver a concise description of GM crop production and safety to the News24 readers.
GM crops have been deliberately altered through the use of recombinant DNA technology to develop plant varieties with improved traits. Two methods are used in the recombination process, namely Agrobacterium transformation and particle bombardment. The first method, Agrobacterium transformation, utilizes the ability of Agrobacterium to transfer a desired piece of DNA, which contains the recombinant gene, into the plant genome. The second method, particle bombardment, inserts the desired gene into the plant genome by bombarding plant tissue with tungsten or gold particles which have been coated with the DNA segment. Both methods result in the random insertion of DNA into the plants genome. This implies that native DNA is interrupted by the recombination process. This means that each recombination event, using the same gene, will result in a different insertion point. The legislature in the USA regulates the genes used and not each GM event, where as the EU regulates each GM event, despite if the same gene is used. Majority of the GM crops that are commercially grown were developed using particle bombardment.
Before a GM event can be released for commercial use, a risk assessment is conducted. The risk assessment includes safety to humans and animals, and the environment. The seed company is responsible to conduct the risk assessment before applying for commercial release of the GM event. Generally, the legislature will make provision for a government review of the risk assessment with the help of individuals from other government departments, academia and private bodies. In addition, the release of a GMO will include the notification to the public and allow their opinion to be heard. However, it is up to the government to notify the public about the release of new GM events. Thus, before a GM event is released, there are numerous bodies and individuals that provide input into the approved release of a GM event.
In South Africa, GM cotton, soybean and maize have been approved for commercial production (James, 2010). In 2010, approximately 2.2 million hectares of GM crop was cultivated in South Africa. It is estimated that 100% (15,000 hectares) of cotton, 85.0% (331,500 hectares) of soybean and 76.9% (1.9 million hectares) of maize grown in South Africa is GM. The GM events that have been released in South Africa for cotton include MON15985 (insect resistant (IR)), MON531/757/1076 (IR), MON1445/1698 (herbicide tolerant (HT)) and MON88913 (HT). Only one GM event has been released for soybean, namely GTS 40-3-2 (HT). The GM maize events that have been released are MON810 and Bt11 (IR), NK603 and GA21 (HT), and stacked event MON89034 (IR) (DAFF, 2011). Currently, the majority of insect resistant maize grown in South Africa is MON810, which was introduced into local maize varieties through conventional breeding.
The high production percentage of GM crops in South Africa is also reflected by the high percentage of GM detected in off the shelf food products. A study by Viljoen et al (2006) found that majority of off the shelf food products were positive for the presence of GM maize and/or soybean. The possibility of the average person in South Africa consuming a food product that contains GM appears to be high.
Up to now, this article has just given a brief overview of what a GMO is, basic regulation, and GMO production and presence in South Africa. The real question is “Are GMOs safe?!!” The answer is quite simply, we do not know! First, I will address GMO safety in relation to humans, followed to by GMO safety to the environment.
First, human risk to health, we know: There appears to be a possible risk, although that risk doesn’t appear to be biologically significant. Insect resistant GM crops have been transformed to produce an endotoxin that originates from the soil bacterium Bacillus thirengiensis, which has insecticidal properties. A study by Finamore et al (2008) found that there was an immune response in mice fed GM maize compared to mice fed non-GM maize. However, the immune response was not statistically significant. Which raises the question of what impact does a non-statistically significant response have on a biological level? Another study did find that rats fed IR potato did show a negative response. The negative response was only observed when the rats were fed the equivalent to that of a person eating over a 100 kg of GM potato per day. In respect to insect resistant GM crops, the long term effects are unknown. Herbicide tolerant GM crops is more complicated than insect resistant GM crops, as all negative impacts to human health are due to the RoundUp Ready herbicide and not the GM plant itself. Since herbicide tolerant crops are not affected by the glyphosate based RoundUp Ready herbicide, farmers can spray HT crops more regularly. This result in a greater build up of herbicide on the crops, which is then consumed (stressing the importance of washing your fresh produce before consumption). In respect to herbicide GM crops, the herbicide itself appears to have a negative impact on human health.
Second, environmental risk: There are a few reported cases of field resistance to insect resistance GM crops and herbicide tolerant GM crops. In the case of the development of resistance in the target insect to GM crops have all been due to a lack of proper management practice by the farmer. Suggesting that better enforcement of insect resistance crop management by the government is required. In the case of the development of herbicide tolerant weeds in fields where herbicide tolerant GM crops are grown, was attributed to the increased use of herbicides. This allowed the weeds to adapt and evolve resistance to the herbicide. Again, over use of the herbicide by the farmers resulted in resistance development.
To put the concern of risk to human/animal health and the environment from GM crops into perspective – the first GM crop was commercially grown in 1996, only 16 years ago. The long term effects are unknown, the same if you compare it to cigarette smoking many years back, just note that I am comparing not knowing the long term effects and NOT the actual effects in this comparison. It appears that studies have to be reviewed on a case by case basis, and that there are so many factors contributing to the understanding of risk potential in a GM event. I have not even mentioned the unknown risks of the transformation process, to field variation in mRNA and protein expression, substantial equivalence in terms of chemical composition, ect. This is just a basic article to give the reader the understanding behind GMO development and production, including a very basic risk assessment to human/animal health and the environment. I advise readers to rather search for scientific articles on Google Scholar rather than reading NGO paranoia articles. GM crops are a reality, you are eating them already!! If you want to know if Gm crops and food are safe, here is the answer, the long term effects are still unknown.
If you have any comments or questions, feel free to ask!
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