Explains the technical base of recent palaeolimnology, indicates how diatom analysis in particular is, and can be, used for environmental reconstruction. Stresses that the study of the present and recent past is critical, not just to enhance understanding of the impact of pollution, but for the further development of palaeolimnology in general. Themes Palaeolimnology (Ontogeny and recent human impact); Sediment sampling and dating; Sediment accumulation rates; The information content of lake sediments; Environmental reconstruction from diatom analysis; Evaluation and hypothesis. Interest in the impact of pollution, especially acidification, has led to a marked increase in research, and the development of improved techniques in recent decades. -K.Clayton