Cytogenetic status of healthy children assessed with the alkaline comet assay and the cytokinesis-block micronucleus cytome assay

In the present study the alkaline comet assay and the cytokinesis-block micronucleus cytome (CBMN Cyt) assay were used to evaluate the baseline frequency of cytogenetic damage in peripheral blood lymphocytes (PBLs) of 50 healthy children from the general population in Croatia (age, 11.62 ± 1.81 years). Mean values of tail length, tail intensity and tail moment, as comet assay parameters, were 12.92 ± 0.10, 0.73 ± 0.06 and 0.08 ± 0.01, respectively. The mean frequency of micronuclei (MN) for all subjects was 2.32 ± 0.28 per 1000 bi-nucleated cells, while the mean frequency of nucleoplasmic bridges (NPBs) was 1.72 ± 0.24 and of nuclear buds (NBUDs) 1.44 ± 0.19. The mean nuclear division index (NDI) was 1.70 ± 0.05. When comet-assay parameters were considered, higher mean values for all three were found for the female population. According to the Mann–Whitney U test applied on the results of the comet assay, the only statistically significant difference between the male and female populations was found for tail length. Similar to the results obtained by the comet assay, girls showed higher mean values of all three measured parameters of the CBMN Cyt assay. This difference was statistically significant for total number of NPBs only. In the case of the NDI, a higher mean value was also obtained in girls, but this difference was not statistically significant. The results obtained present background data that could be considered as normal values for healthy children living in urban areas, and can later on serve as baseline values for further toxicological monitoring. Additionally, the usefulness of both techniques in measuring cytogenetic damage during bio-monitoring of children is confirmed.

► Baseline frequency of cytogenetic damage in healthy children was assessed.
► This was done with the alkaline comet and the cytokinesis-block micronucleus assay.
► Results present background data that could be considered as normal values.
► Usefulness of both techniques in child biomonitoring is confirmed.