Risk assessment

In accordance with the GenTG the JKI delivers a scientific opinion on applications for releases into the environment, and placing on the market of GMO. This opinion which is based on scientific principles and criteria laid down in a control scheme is drafted by SG.

Since gene technology allows to transfer, in an asexual manner, genes as isolated nucleic acid segments between any organisms, animals, plants, microorganisms and viruses may carry characteristics which never before were tested under the new biological and ecological conditions. When evaluating an application for release into the environment, the GMO concerned are assessed, under the aspects of potential and hypothetical risks, according to the following questions:

• Do the organisms possess critical mutations of their metabolism and new characteristics which are an unintended result from the genetic modification?
  In the case of plants, this refers to sensitivity to pathogenic viruses, microorganisms, and fungi, as well as to tolerances towards climatic stresses (cold, aridness, salt, etc.). Unexpected gene expression may have unintended effects, e.g., an unfavourable selection pressure on pests or non-target organisms due to constitutive expression of plant protection substances. Unexpected toxicity or pathogenicity present hypothetical risks to be considered in the product authorisation process. Unexpected new traits may result from unforeseen expression patterns of the introduced genes, and from the interactions of the gene products with the metabolism of the organism. This necessitates analysing the stability of the new genes and their expression in the new chromosomal context.
  
  
• To which extent can the organisms transfer their new genes to other organisms? In case of plants the gene transfer to related wild species and neighboured crops must be observed while a transfer of genes to microorganisms is regarded as hypothetical. It is not known to which extent a natural horizontal gene transfer between microorganisms does exist, hence, detection limits have to be taken into account. If possible recombination between introduced virus genes and plant viruses and their heterologous encapsidation may have the potential to result in an extended virus host range should be considered.
  
  
• Which effects have organisms released into the environment on the balance of nature? Is their uncontrolled dispersion possible, thus expelling other organisms, or can they spread as an unwanted weed? Can they unintentionally persist and disturb ecological balances, or can they serve as a reservoir of pathogens? In the case of plants, resistance to herbicides must be taken into account because of its agricultural importance, whereas in the case of microorganisms, their resistance to antibiotics must be judged with regard to therapeutical implications.

Plants are regarded as being retrievable. Small-scale releases of GMP are performed under ‘monitoring’ in a way that allows to recognise possible effects, and thus to gain experience for their application in agricultural practice. In the case of first releases of a GMO into the environment, isolation distances according to the conventional farming practice are maintained. This helps to limit the spread of pollen able to cross with wild plants or neighbouring crops. Once released, microorganisms are regarded to be non-retrievable. That is why the risk assessment should concentrate on the kind of genes that were introduced. It is not possible to completely prevent gene transfer between microorganisms. Organisms and traits which exist ubiquitously in the environment usually do not contribute substantially to changes of the ecological balance. Applications for the release of new GMO are generally subject to a case-specific evaluation. The total range of characteristics of the GMO is decisive for the assessment of the risks which may possibly result from a release.