While soil pollution can stem from various sources, the French seem particularly concerned about diffuse pollution, whether it results from the deposition of air pollutants—especially those emitted by transportation or industry—or from the use of pesticides. The risks posed by pesticides are very much on the minds of the French but are difficult to describe. Indeed, pesticides are composed of over a thousand molecules; their effects depend on their physical and chemical properties and on how they bind to and degrade in the soil. Numerous reports have indeed shown that pesticides constitute a form of diffuse pollution that can contaminate inland waters: rivers, groundwater, and coastal areas. Major sources of pesticide contamination can also be attributed to negligence, such as storage under poor conditions, faulty application techniques, failure to adhere to dosage guidelines, the careless disposal of residues or excesses, or accidental pollution. Respondents, however, have less knowledge of local soil pollution resulting from past industrial activities, which are subject to specific monitoring by government agencies. Generally speaking, soil pollution is among the environmental concerns of the French population as assessed by the 2007 IRSN Barometer: the risk is perceived as fairly significant, just like those associated with pesticides. Trust in the authorities to protect the public is very low, as is the belief that the truth is being told about the risk. [excerpt from chapter]