Paracelsus got it wrong

The contemporary interpretation of Paracelsus's famous declaration “the dose makes the poison”, for which he is often called the father of toxicology, is that dose and effect move together in a predictably linear fashion, and that lower exposures to a hazardous compound will therefore always generate lower risks. This idea is not just a philosophical abstraction; it is the core assumption underlying the system of chemical-safety testing that arose in the mid-twentieth century. Risk assessors typically look for adverse effects of a compound over a range of high doses and, from there, extrapolate downwards to establish health standards — always assuming, like Paracelsus, that chemicals toxic at high doses are much less risky at lower, real-world levels. But what if the Paracelsian presumption is wrong? On the basis of conventional high-dose testing, regulators have set maximum acceptable levels for each of them that assume all doses below that level are safe. But academic researchers who have studied a wider range of doses, including very low ones found in the everyday environment, say that their experiments usually do not generate the tidy, familiar 'ski-slope' dose-response graphs of classic toxicology.

Source: Nature, 24 October 2012
http://www.nature.com/news/toxicology-the-learning-curve-1.11644

Please read:
http://www.boerenlandvogels.nl/content/toxicity-neonicotinoid-insectici…