The Bacau (Romania) phosphogypsum stacks as a source of radioactive threat: a case study.

For a detailed characterization of the 5.7 10 mt phosphogypsum (PG) stack in the vicinity of Bacau city, Romania, the air dose rate (ADR) was measured in 72 points covering the stack surface, while 10 samples of stack material were collected for future analysis. Radiometric determinations showed for the ADR values varying between 364 ± 53 and 489 ± 8 nSv/h, with some extreme values of 2775 ± 734 nSv/h, significantly exceeding 90 nSv/h, the average value reported for the Romanian territory.