Radioiodine (I-131) is one of the large enough radioactive substances to get attention, because of its volatile nature and can damage the thyroid gland from the people health. I-131 sampling by using a charcoal device is carried out in the stack, before it is released into the environment and in the outdoor. These charcoal devices include charcoal filters, silver coated gauze and glass fiber paper filters. Charcoal filters are used to adsorb organic Iodine methyl Iodide (CH₃I). Silver coated gauze is used to adsorb elemental Iodine (I₂). Glass fiber paper filters are used to adsorb inorganic hypoiodous acid iodine (HOI). The release of I-131 activity concentrations on average from the stack and the concentration of I-131 activity in seven outdoor research locations in outdoor settlements around the isotope production facility are still below the standard level of I-131 radioactivity in the air (530 Bq/m³) based on Head regulations of Nuclear Energy Supervisory Agency (BAPETEN) No. 7/2013. Potential risk of removable dispersion radioactive iodine-131 from the stack of radioisotope production facility for the health of residential communities around radioisotope production facility does not pose a significant risk to public health (RQ <1). I-131 Dispersion from the stack to the settlement average with the north of the stack, the concentration of I-131 forms a parabolic curve starting to rise from the Sengkol settlement (0.8 km), the highest in BATAN Indah (2.6 km) and decreasing in Jaletreng (4.2 km). The activity concentration of I-131 during rain and high humidity tends to rise, while the presence of sunlight decreases the activity concentration of I-131. The activity concentrations of I-131 in stack from large to small were CH₃I (63.03%), I₂ (30,27%) and HOI (7.70%) respectively. While the activities concentration of I-131 on average in the outdoors were CH₃I (61.12%), I₂ (20.37%) and HOI (18.39%).