EN 
DE 
The chemical factory of Eugen de Haën was located in the List district of Hanover from 1861 to 1902. Products for photochemistry, pharmacy, electroplating and dyeing were produced there. The resources used included radioactive materials (uranium and thorium ores) as well as various chemicals and elements.
In the course of numerous investigations by various specialist offices, a number of sites were located where radiologically contaminated production waste had been deposited.
Contaminated areas were remediated depending on the risk to human health and/or groundwater.
Due to hundreds of years of urban development in the List district, not all contaminated soil layers can be "reached" equally by a remediation measure. Some areas have been built over by multi-storey residential buildings or are firmly sealed.
To identify soil contamination by the radioactive component from decay series of compounds containing thorium and uranium, measurements of the local dose conduction are carried out at the ground surface. The results of the most recent precautionary investigations are published on the homepage of the City of Hannover: Precautionary radiological investigations of city-owned land | Contaminated Sites Programme | Waste & Soil Protection | Environment | Living in the Hannover Region