Liquid discharges from patients undergoing 131I treatments

This work discusses the production and management of liquid radioactive wastes as excretas from patients undergoing therapy procedures with (131)I radiopharmaceuticals in Spain. The activity in the sewage has been estimated with and without waste radioactive decay tanks. Two common therapy procedures have been considered, the thyroid cancer (4.14GBq administered per treatment), and the hyperthyroidism (414MBq administered per treatment). The calculations were based on measurements of external exposure around the 244 hyperthyroidism patients and 23 thyroid cancer patients. The estimated direct activity discharged to the sewage for two thyroid carcinomas and three hyperthyroidisms was 14.57GBq and 1.27GBq, respectively, per week; the annual doses received by the most exposed individual (sewage worker) were 164muSv and 13muSv, respectively. General equations to calculate the activity as a function of the number of patient treated each week were also obtained.