[en] An aerial radiological survey was performed over the area surrounding the Three Mile Island Nuclear Station during October 26 to 30, 1982. The survey covered an 82-square-kilometer area centered on the nuclear plant and encompassed the communities of Middletown, York Haven, Goldsboro and Royalton, Pennsylvania. The highest radiation exposure rates, up to a maximum of 200 microroentgens per hour (μR/h), were inferred from data measured directly over the TMI facilities. This detected radiation was due to the presence of cobalt-58, cobalt-60 and cesium-137, which was consistent with normal plant operations. Similar activity is routinely observed in aerial surveys over nuclear power plants which have been or are presently in an operational mode. For the remainder of the survey area, the inferred radiation exposure rates varied from 6 to 14 μR/h. The reported exposure rate values include an estimated cosmic ray contribution of 3.7 μR/h. Ground-based measurements, conducted during the time of the aerial survey, were compared to the aerial results. Pressurized ionization chamber readings and a group of soil samples were acquired at several locations within the survey area, along the river banks upstream and downstream of the survey area, and at the ground-based locations used for a previous aerial survey which was conducted in 1976. The exposure rate values obtained from these measurements were in agreement with the corresponding aerial data. With the exception of the activity observed within the TMI facilities, no evidence of any contamination which might have occurred as a result of past reactor operations or the 1979 TMI Unit 2 accident was detected from the aerial survey data. This was further supported by the results of the soil sample analyses and the comparison with the 1976 aerial survey data. 7 references, 12 figures, 4 tables