Cytogenetic investigation of thallium-poisoned people: Pilot study

Thirteen blood samples of thallium-poisoned people were cytogenetically inv estigated. The thallium concentration in blood varied from 25 to 2700 mu g/ L. The mean frequency of chromosomal aberrations in the poisoned group sign ificantly exceeded our control level (7.08 +/- -2.19% and 2.03 +/- -0.25, p <.001). The rate of single fragments was significantly higher in poisoned group (7.77 +/- 2.68% and 1.59 +/- 0.23%, p <.001) while the frequencies of other types of chromosomal aberrations were similar in both groups. It is possible that thallium is an S-dependent clastogenic agent because the majo rity of the structural aberrations are of the chromatid type. Irrespective of mechanisms, damage to genetic material was revealed in thallium-poisoned people.