Time trend of the concentration of radionuclide activity in the sludge and wastewater of urban purifiers

It measures the presence of artificial radioisotopes in sludge and waste water samples (e.g. I-131, Tc-99m,..) taken from the main urban purifiers, identified on the basis of the following criteria:1. Purifiers with more than 50,000 equivalent inhabitants served (SIRAV purification plant register). 2. At least one purification plant per province (typically two for the most populous provinces): the users of the BL, RO purification plants are less than 50,000 ab.eq. 3. All the purification plants have been surveyed serving Nuclear Medicine Hospitals. Significance of the selected plants at the provincial level identified with ORAC.