Samples belonging to group two (II) are similar to those in
group I, but they additionally contain significant amount of barite.
Therefore, high concentration of barium in range 4.2–12.2% (the
highest concentration of barium among the investigate samples)
is well justified. Concentration of strontium is also high and varies
in range 0.13–1.6% (Tables 2 and 3) and can be explained by the
diadochy of strontium in the barite crystal lattice. Probably,
slightly enhanced, in comparison to an ordinary mudstone, concentration
of lead (35–54 mg kg1
) resulted from the same reasons.
Activity concentration of radium isotopes in these samples
is the highest among all analyzed and is a few times higher than
the limit above which such a waste should be assigned to the category
of a radioactive waste in the sense of the radiation protection
rules. The strong correlation between radium and barium is
observed.