Further research is required to ensure that pollen from genetically modified crops does not contaminate natural plants, says a new report from the European Environment Agency. The paper considers six GM crops that are close to commercial release in the European Union: oilseed rape, sugar beet, potatoes, maize, wheat and barley, assessing the risk of them contaminating natural fields, above the European Commission's 1% recommended threshold for GM free-status for foodstuffs.