广东省某地区不同年龄段人群镉负荷水平研究

Cadmium Burden of Residents in High and Low Age Groups in a District of Guangdong

目的探究广东省某地区不同年龄段人群镉负荷水平,利用基准剂量法评估不同年龄段人群尿NAG及尿β2MG相应的尿镉参考剂量,以此对不同年龄段人群尿镉可接受阈值进行研究。方法对该地区开展基于大样本人群调查的环境流行病学研究,采集当地常住居民的尿液样本,共获得872例(男性375例,女性497例)有效样本。并以我国环境镉污染健康危害区判定标准值为肾功能损害发生临界值,应用BMDS软件对不同年龄段人群进行尿镉基准剂量估算。结果以尿NAG为效应指标的BMDL值为低年龄组4.25μg/g肌酐,高年龄组4.05μg/g肌酐;以尿β2MG为效应指标的BMDL值为低年龄组1.70μg/g肌酐,高年龄组1.58μg/g肌酐。结论在镉污染健康风险评价中,尿β2MG比尿NAG更为敏感,高年龄组人群尿镉可接受阈值低于低年龄组。在长期镉暴露过程中,高年龄组人群可能比低年龄组人群更容易发生肾功能损害。

Objectives The aim of this study was to evaluate the cadmium burden level of residents in a district of Guangdong province by using a benchmark dose method to evaluate the relevance of urinary cadmium with urinary β2 -microglobulin （MG） and N-acetyl-β-glucosaminidase （NAG）, and to investigate the acceptable threshold for urinary cadmium level of residents in high （ 〉50 years） and low （ ≤50 years） age groups. Methods An environmental epidemiology study was conducted in a district of Guangdong province. The total number of valid subjects was 872 （375 men and 497 women）. The cut-off value for renal dysfunction was defined as a discriminant standard for health hazard caused by environmental cadmium pollution. The benchmark dose was estimated by a BMDS software. Results The BMDL for NAG was 4. 25μg/g creatinine in low age group and 4. 05 μg/g creatinine in high age group. The BMDL for β2 MG was 1.70 μg/g creatinine in low age group and 1.58μg/ g creatinine in high age group. Conclusions In the risk assessment of renal dysfunction caused by cadmium, β2 MG would be a more sensitive biomarker than NAG, and the acceptable threshold for urinary cadmium in high age group was lower than that in low age group. The rate of renal dysfunction in high age group might be higher than that in low age group, which might be the result of long-term cadmium exposure.