Are Limits of Concern a useful concept to improve the environmental risk assessment of GM plants?

Abstract

BackgroundThe European Food Safety Authority (EFSA) has introduced a concept for the environmental risk assessment of genetically modified (GM) plants which foresees the definition of ecological threshold values defining acceptable adverse effects of the GM plant on the environment (Limits of Concern, LoC).MethodsWe analysed the LoC concept by scrutinising its feasibility with regard to important aspects of the environmental risk assessment. We then considered its relationship with protection goals, the comparative safety assessment and the stepwise testing approach. We finally discussed its usefulness for assessing long-term effects, effects on non-target organisms and species of conservation concern.ResultsThe LoC concept is a possible approach to introduce ecological thresholds into environmental risk assessment in order to evaluate environmental harm. However, the concept leaves many important aspects open. Thresholds for environmental harm for protection goals need spatial and temporal differentiation from LoCs used for ERA indicators. Regionalisation of LoCs must be provided for as biodiversity levels and protection goals vary across the EU. Further guidance is needed with respect to the consequences, in case LoCs are exceeded and a link needs to be established between environmentally relevant results from the comparative safety assessment and the LoC concept. LoCs for long-term effects have to be evaluated by long-term monitoring. LoCs for non-target organisms need to be discriminated according to the species and parameters assessed.ConclusionsThe overall LoC concept is considered useful if LoCs are further specified and differentiated. Although LoCs will finally be determined by political decisions, they should be based on scientific grounds in order to increase confidence in the conclusions on the safety of GM plants.

Limits of Concern: suggestions for the operationalisation of a concept to determine the relevance of adverse effects in the ERA of GMOs

“…It is generally questionable what role LoCs should have for laboratory studies. General shortcomings of applying LoCs for laboratory toxicity testing are outlined by Dolezel et al [22]. In addition EFSA acknowledges that “ standardised methods and models used at tier 1 levels do not measure the specific protection goals directly ” [12].…”

“…Against this background and to harmonise protection goals for ERA purposes as required by EFSA, effects by GM crops on non-target lepidopteran species in off-field areas need to be small to negligible. Clearly, for endangered or protected Lepidoptera occurring in protected sites or biodiversity hotspots within the agro-environment [133–135], no additional adverse effects due to Bt maize cultivation should be tolerated at all (see also [22]).…”

“…A general appraisal of the LoC concept as well as suggestions for its operationalisation for ERA use has already been provided [22]. One of the basic elements of the ERA of genetically modified plants (GMP) is the comparative safety assessment [6, 9].…”

“…For the food and feed risk assessment, so-called “equivalence limits”, composed of values from commercial plant varieties with a history of safe use, are used to put any differences found into the context of harm [23, 24]. For the ERA and the establishment of environmental safety of a GMP, a similar claim does not exist when using conventional comparators (for further discussion see [22]). Using LoCs is, therefore, necessary to define whether observed differences between the GMP and the non-genetically modified (GM) comparator are biologically relevant and may cause environmental harm [6, 9, 24].…”

Annual report of the EFSA Scientific Network for Risk Assessment of GMOs for 2017

“…Limits of concern in environmental risk assessment Marion Dolezel, delegate from Austria to the GMO Network (ERA), gave a presentation on the results of a study on Limits of Concern for the environmental risk assessment of GM plants carried out by the Environment Agency Austria (Dolezel et al, 2017). Since the concept of Limits of Concern (hereafter referred to as 'LoCs') for the ERA of GMPs has been introduced by EFSA in its Guidance Document in 2010 it has so far not been implemented by applicants.…”