(Decanter) - Pesticide residues were found in the vast majority of 300 French wines tested, say researchers. A study of more than 300 French wines has found that only 10% of those tested were clean of any traces of chemicals used during vine treatments. Pascal Chatonnet and the EXCELL laboratory in Bordeaux tested wines from the 2009 and 2010 vintages of Bordeaux, the Rhone, and the wider Aquitaine region, including appellations such as Madiran and Gaillac. Wines were tested for 50 different molecules found in a range of vine treatments, such as pesticides and fungicides.