Department of Epidemiology and Biostatistics, Institute of Basic Medical Sciences Chinese Academy of Medical Sciences, School of Basic Medicine, Peking Union Medical College, Beijing, China.
Center of Environmental and Health Sciences, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing, China.
BMJ Open. 2018 Jun 27;8(6):e021470. doi: 10.1136/bmjopen-2017-021470.
The International Agency for Research on Cancer classifies hexavalent chromium (Cr(VI)) as a human carcinogen. As reported, cancer mortality was higher in Cr(VI)-contaminated areas. Scientists have recommended studying its health impact on people living in contaminated areas. This study aims to evaluate the health risk for people living in Cr(VI)-contaminated areas.
We conducted a cross-sectional study in rural areas of north-eastern China. Malondialdehyde (MDA), glutathione peroxidase (GSH-Px), superoxide dismutase (SOD) and catalase (CAT) were used as oxidative stress parameters, and 8-hydroxy-2 deoxyguanosine (8-OHdG) as a DNA damage biomarker. We collected information on demographics, lifestyles and length of residence from all participants using a questionnaire. Biological specimens and environmental media samples were collected on the same day as the survey was done. We used t-test, χ test, Wilcoxon rank-sum test and multivariate linear regression analysis.
The study included 319 participants exposed to Cr(VI) and 307 unexposed participants, with 447 women and 179 men. These participants met the following criteria: (1) living in the areas for more than 10 years; (2) age older than 18 years; and (3) without occupational chromium exposure.
Our study revealed that serum concentration of MDA (p<0.001), serum activities of CAT (p<0.001) and GSH-Px (p<0.001), as well as urine concentration of 8-OHdG (p=0.008) in the exposed group were significantly higher than those in the unexposed group. However, serum SOD activity was significantly lower in the exposed group, compared with that in the unexposed group (p<0.001). Cr(VI) exposure and smoking have an interaction effect on GSH-Px activity (p<0.05). Cr(VI) exposure and alcohol drinking also have an interaction effect on GSH-Px activity (p<0.05). Longer residence in the exposed areas increased the oxidative levels (p<0.05).
The findings of this study showed elevated oxidative stress and DNA damage in people exposed to Cr(VI).
国际癌症研究机构将六价铬（Cr(VI)）归类为人类致癌物。据报道，Cr(VI)污染地区的癌症死亡率更高。科学家们建议研究其对污染地区居民的健康影响。本研究旨在评估居住在 Cr(VI)污染地区的人群的健康风险。
我们在中国东北地区的农村地区进行了一项横断面研究。丙二醛（MDA）、谷胱甘肽过氧化物酶（GSH-Px）、超氧化物歧化酶（SOD）和过氧化氢酶（CAT）被用作氧化应激参数，8-羟基-2-脱氧鸟苷（8-OHdG）作为 DNA 损伤生物标志物。我们使用问卷收集了所有参与者的人口统计学、生活方式和居住时间信息。生物标本和环境介质样本在调查当天采集。我们使用 t 检验、卡方检验、Wilcoxon 秩和检验和多元线性回归分析。
该研究包括 319 名接触 Cr(VI)的参与者和 307 名未接触的参与者，其中女性 447 名，男性 179 名。这些参与者符合以下标准：（1）在该地区居住 10 年以上；（2）年龄大于 18 岁；（3）无职业性铬暴露。
我们的研究表明，暴露组的血清 MDA 浓度（p<0.001）、血清 CAT（p<0.001）和 GSH-Px（p<0.001）活性以及尿 8-OHdG 浓度（p=0.008）明显高于未暴露组。然而，暴露组的血清 SOD 活性明显低于未暴露组（p<0.001）。Cr(VI)暴露和吸烟对 GSH-Px 活性有交互作用（p<0.05）。Cr(VI)暴露和饮酒对 GSH-Px 活性也有交互作用（p<0.05）。在暴露地区居住时间较长会增加氧化水平（p<0.05）。
本研究结果表明，接触 Cr(VI)的人群存在氧化应激和 DNA 损伤升高。
