title: Are Limits of Concern a useful concept to improve the environmental risk assessment of GM plants?
abstract: BACKGROUND
  The 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).
  
  
  METHODS
  We 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.
  
  
  RESULTS
  The 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.
  
  
  CONCLUSIONS
  The 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.
authors.affiliation: Environment Agency Austria, Spittelauer Laende 5, 1090 Vienna, Austria.
authors.forename: Marion
authors.identifier: 0000-0003-0037-6203
authors.initials: M
authors.lastname: Dolezel
authors.affiliation: Environment Agency Austria, Spittelauer Laende 5, 1090 Vienna, Austria.
authors.forename: Marianne
authors.initials: M
authors.lastname: Miklau
authors.affiliation: Environment Agency Austria, Spittelauer Laende 5, 1090 Vienna, Austria.
authors.forename: Andreas
authors.initials: A
authors.lastname: Heissenberger
authors.affiliation: Federal Agency for Nature Conservation, Konstantinstrasse 110, 53179 Bonn, Germany.
authors.forename: Wolfram
authors.initials: W
authors.lastname: Reichenbecher
keywords: Damage thresholds; Environmental harm; Environmental risk assessment; GMO; Genetically modified plants; Limits of Concern