Effects of donor age and contamination level of dioxins and related chemicals on frequency of sister chromatid exchanges in human lymphocytes cultured in vitro

Frequencies of sister chromatid exchanges (SCEs) of human lymphocytes in control (DMSO treated) and 7,8-benzoflavone (ANF) treated cultures were measured in 39 healthy Japanese people and examined in connection with donor age. Both the control (baseline) and ANF induced SCE rates were significantly enhanced with age and highly positive correlation was observed between them. Therefore, in vivo aging seemed to have some effects on the frequencies of SCEs in human lymphocytes cultured in vitro. Concentrations of PCDDs, PCDFs and Co-PCBs in the blood and sebum of face were determined in the same Japanese subjects. Significantly positive correlation was observed between the blood and sebum in their total TEQ levels. Hence, PCDDs, PCDFs and Co-PCBs, which have been contaminating human bodies, are considered proportionally excreted from the sebum of face or body. Their total TEQ concentrations were also meaningfully increased with donor age in the sebum of face as well as in the blood. Either the baseline or ANF induced SCE frequencies was not enhanced with the total TEQ levels in the blood. Therefore, background levels of their contamination seem not to affect the SCE rates of the lymphocytes in the control and ANF treated cultures.