Pesticide resurrection

The actual health risk and associated diseases induced by the presence of pesticides and other organic pollutants in most environmental media worldwide are largely underestimated because current analytical methods measure only the extractable fraction of the pollutant, whereas there is now ample evidence that a large part of pollutants are trapped as bound residues in complex organo-mineral matrixes, and are thus unanalyzable by current tools. Once trapped, pollutants can be stored for long periods, then released in the biosphere upon suitable conditions such as soil erosion and climate change. This 'resurrection' and underlying mechanisms of trapping, storage and release are poorly known. Here we discuss the limit of knowledge on bound pollutants and their later release, with examples of organochlorines in glaciers, vineyards and banana plantations. Unexpectedly, soil application of a modern pesticide such as glyphosate, can lead to the resurrection of ancient, actually banned pesticides such as chlordecone and dichlorodiphenyltrichloroethane.