I am interested in knowing more about the presence of heavy metals and other pollutants in urban or peri-urban soils used for growing food. Are these allotments (in the UK) so old that no polluting activity was ever carried out on them before they were turned into allotments? Are polluted urban spaces unknowingly turned into food growing lots? Does urban soil pollution actually pose a serious health risk to urban food eaters?
In Berlin, Germany, air pollution is a problem (who knew, in such a green city): food grown near roads have nefarious deposits that pushed the city to warn the citizen to wash their harvest thoroughly. Ancient train tracks and right-of-ways have a history of heavy herbicide use (in the Netherlands, in Canada) and polluted run-off accumulation.
The story of the birth of the allotments told by Peronne in this podcast (privatisation of the commons over time, 2m 55s) has bits of information on the activities carried out on these lands before they were turned into food growing spaces. I understand the process took place early during the industrialisation of the country, making me think the soils of these allotments are not heavily polluted. But that may not bne the case for allotments in and around cities of other regions/countries.