Low Level Radiation Research Laboratory, Radiation Biology and Health Science Division, Bhabha Atomic Research Centre, Kollam-691 001, Kerala, India.
Radiat Res. 2012 May;177(5):643-50. doi: 10.1667/rr2681.1. Epub 2011 Dec 16.
Inhabitants of the high-level natural radiation areas (>1 mSv year(-1)) of Kerala in southwest India were evaluated for basal damage (spontaneous DNA strand breaks and alkali-labile sites) by the alkaline comet assay and oxidative DNA damage (ENDO III- and hOGG1-sensitive sites) by the enzyme-modified comet assay. Of the 67 adult male subjects studied, 45 were from high-level natural radiation areas and 22 subjects were from a nearby normal-level natural radiation area (≤1 mSv year(-1)). Basal damage due to the age and residential area (normal-level natural radiation area/high-level natural radiation areas) of the donors showed significant interaction (P < 0.001) when all subjects were analyzed using a general linear model (GLM). In subgroup analysis, basal damage increased with age in subjects from the normal-level natural radiation area (P = 0.02), while a significant negative correlation (P = 0.002) was observed in subjects from high-level natural radiation areas. Further, basal damage in elderly subjects from high-level natural radiation areas was significantly (P < 0.001) lower compared to the subjects from the normal-level natural radiation area. Oxidative DNA damage was not influenced by age, smoking habit or residential area in the entire sample. However, in a subgroup analysis, hOGG1-sensitive sites showed a significant increase with age in subjects from high-level natural radiation areas (P = 0.005). ENDO III-sensitive sites increased with natural radiation exposure in subjects from high-level natural radiation areas (P = 0.02), but when stratified according to smoking, a significant increase was observed only in smokers (P = 0.01). To the best of our knowledge, this is the first study on basal and oxidative DNA damage in healthy adults of this population. However, our findings need more validation in a larger study population.
印度西南部喀拉拉邦（Kerala）高水平自然辐射区（>1 mSv 年(-1)) 的居民，采用碱性彗星试验评估其基础损伤（自发 DNA 链断裂和碱不稳定位点），采用酶修饰彗星试验评估其氧化 DNA 损伤（ENDO III 和 hOGG1 敏感位点）。在研究的 67 名成年男性中，45 名来自高水平自然辐射区，22 名来自附近的低水平自然辐射区（≤1 mSv 年(-1))。当使用一般线性模型（GLM）分析所有受试者时，供体的年龄和居住区域（低水平自然辐射区/高水平自然辐射区）导致的基础损伤显示出显著的相互作用（P < 0.001）。在亚组分析中，低水平自然辐射区的受试者的基础损伤随年龄增长而增加（P = 0.02），而高水平自然辐射区的受试者则观察到显著的负相关（P = 0.002）。此外，高水平自然辐射区的老年受试者的基础损伤明显低于低水平自然辐射区的受试者（P < 0.001）。在整个样本中，氧化 DNA 损伤不受年龄、吸烟习惯或居住区域的影响。然而，在亚组分析中，高水平自然辐射区的受试者的 hOGG1 敏感位点随年龄增长呈显著增加（P = 0.005）。ENDO III 敏感位点随高水平自然辐射区受试者的自然辐射暴露增加而增加（P = 0.02），但按吸烟分层时，仅在吸烟者中观察到显著增加（P = 0.01）。据我们所知，这是对该人群健康成年人基础和氧化 DNA 损伤的首次研究。然而，我们的发现需要在更大的研究人群中进行更多验证。
