Today’s programme is chock full of environmental chemistry, including a few sessions on pharmaceuticals in the environment. In the last few decades chemistry has given us more and better drugs, and we have not been shy about taking them. One graph of pharmaceutical consumption in France from 1970 to the present was hair-raisingly steep. All those drugs that aren’t broken down by our bodies are, well, let’s be scientific here, excreted and enter the waste-treatment stream. Some end up in rivers and lakes.