Dietary habits that expose populations to potential toxicants as well as protective agents simultaneously are a realistic scenario where a meaningful assessment of the interactions and net benefit or damage can be made. A group of Inuit from Salluit, Northern Canada are exposed to high levels of PCBs and selenium, both present in the Inuit traditional foods such as blubber from sea mammals and fatty fish. Blood samples were collected from 83 Inuit, 22-70years old. Blood selenium and PCB levels were determined previously and ranged from 227 to 2069μg/L and 1.7 to 143μg/L, respectively. DNA isolated from white blood cells were analyzed by modified 32P-postlabeling adductomics technology that detects a multitude of highly polar to lipophilic adducts. The levels of 8-oxodG adducts ranged from 470 to 7400 adducts/109 nucleotides. Other as yet unidentified polar adducts showed a 30 to 800-fold inter-individual variability. Adduct levels were negatively associated with PCB and selenium levels. The subjects were classified into high and low ratio groups, with respect to selenium/PCB. In the high ratio group, the coefficient of selenium is significantly negatively correlated with 8-oxodG (r=-0.38, p=0.014) and total adducts (r=-0.41, p=0.009) while there was no correlation within the low selenium/PCB group. This study suggests that increasing selenium has mitigating effect in reducing DNA adducts and therefore, possible negative effects of PCB were not seen. A protective effect of selenium is highlighted.
|Number of pages||7|
|State||Published - Nov 2010|
Bibliographical noteFunding Information:
This work was supported by USPHS grants ES 07380 , CA-77114 , P30ES 014443 ES 013661 and, in part, from the Agnes Brown Duggan Endowment Funds.
- DNA adducts
ASJC Scopus subject areas
- Environmental Science (all)