The goal of this study was to evaluate the selenium mass fraction in toenail clippings taken from random inhabitants living
in various areas of the Pomeranian (Northern Poland) and Lubuskie (Western Poland) Districts. Toenail clippings were analyzed
by instrumental neutron activation analysis (INAA) giving means of 0.57±0.10 and 0.60±0.16 mg·kg−1 for the two areas, respectively, but the difference was statistically not significant. In additional, it was found that gender,
age, body mass index (BMI), smoking, and selenium supplementation are factors with apparent effects to the selenium levels
in toenail clippings.