Broad experience in characterization of contaminated sites and waste products, contaminant behavior especially in soil and groundwater, risk evaluation, determining natural background concentrations and proposing critical values. Working in the 'gap' between science and soil practice, I promote a more statistical view on data resulting in advice that distinguishes uncertainties and not denying them.Broad experience in analyzing complex systems, not only soils (see above) but also ecosystems, village communities and medical databases.You can contact me at vries.spek@hetnet.nlSpecialties: gasworks, tar, cyanides, implementing probabilities in soil characterization, vitality of rural communities, statistical analysis