Legacy of war: Pedogenesis divergence and heavy metal contamination on the WWI front line a century after battle

In Europe, the First World War left a legacy on the environment due to the extensive and intense use of artillery during this period. This study examined a small wooded area in the Pas-de-Calais region in France which was subject to considerably less intense fire than previously studied WWI battlefields. In a process named "bombturbation," significant physical changes have occurred to the landscape subject to artillery fire, resulting in a divergent soil development in craters. Cratering led to higher organic matter and electrical conductivity values, but-unlike other studies-no significant difference in soil pH. Soil heavy metal concentrations did not differ within craters compared to the flat landscape. However, lead (Pb) and copper (Cu) enrichment was observed above the baseline values for the region. Despite the average concentrations of Cu and Pb being within legal limits for soils in the UK and European Union, it is likely that enrichment of Cu and Pb in the concentrations observed has caused detrimental ecotoxicological and human health effects. Highlights Few studies investigate the legacy of WWI on soil, particularly from low intensity fighting. WWI bomb craters alter soil development, resulting in changes to organic matter and salinity. Cu and Pb enrichment of soil from WWI may lead to ecotoxicological and human health impacts.