He made the comments after de-classified Government documents revealed that two consignments of hospital waste were disposed of at the municipal dump in Culmore between 1977 and 1982.
Total activity amounted to 170 microcuries.
At another local authority site at Duncrue Street in Belfast “a number of controlled burials of hospital/university waste of short half-life, together with small amounts of industrial waste were arranged.”
Hospitals, fertiliser plants, the University of Ulster and the Queen’s University were all authorised to dispose of radioactive waste by controlled burials at the two sites.
Environment Minister Mark H. Durkan has now asked for a report in relation to radioactive material being dumped at landfill sites over 30 years ago.
He said: “Following the release of these papers I have asked officials in the NI Environment Agency to provide a report on the dumping of the waste in Belfast and Derry.”