swiss researchers have stated that rain falling in Europe is so full of toxic pesticides that much of it is not fit for drinking. Pesticides sprayed on crops evaporate and, in the stratosphere, they react with water vapour. Water contaminated with these toxic substances fall as rain.

Stephan Muller of the Swiss Federal Institute for Environmental Science and Technology said concentrations of dangerous substances in rain exceed the standards for drinking water set by the European Union (eu ). Muller and his colleagues analysed samples of rainwater and found it contained almost 400 nanograms per litre of the widely-used pesticide dinitrophenol. These levels quadruple the 100 nanograms limits set by the eu for any pesticide content in drinking water.