Five thousand years of atmospheric Ni, Zn, As, and Cd deposition recorded in bogs from NW Iberia: prehistoric and historic anthropogenic contributions

► Iberian bogs have recorded the start of some trace metals geochemical cycles forcing. ► A significant excess flux of trace metals in Iberian bogs was detected by 3500 cal BP. ► Between 2350 and 2150 years ago the excess fluxes of some elements were >80%. ► Phases of metal enrichment coincide with forest clearance during prehistoric times. ► The results are in agreement with the development of prehistoric cultures in Europe.