Nishijo Muneko, Suwazono Yasushi, Ruangyuttikarn Werawan, Nambunmee Kowit, Swaddiwudhipong Witaya, Nogawa Kazuhiro, Nakagawa Hideaki
Department of Public Health, Kanazawa Medical University, 1-1 Daigaku, Uchnada, 920-0293 Ishikawa, Japan.
BMC Public Health. 2014 Jul 9;14:702. doi: 10.1186/1471-2458-14-702.
The aim of the present study was to estimate the benchmark doses (BMD) for renal effects for health risk assessment of residents living in Cd-polluted and non-polluted areas in a Thai population.
The study participants consisted of inhabitants aged 40 years or older who lived in a non-polluted area (40 men and 41 women) and in the environmentally polluted Mae Sot District (230 men and 370 women) located in northwestern Thailand. We measured urinary and blood cadmium (Cd) as markers of long-term exposure and urinary β2-microglobulin (β2-MG) and N-acetyl-β-D-glucosaminidase (NAG) as renal tubular effect markers. An updated hybrid approach was applied to estimate the benchmark doses (BMD) and their 95% lower confidence limits (BMDL) of urinary and blood Cd for Cd-induced renal effects in these subjects. BMD and BMDL corresponding to an additional risk (BMR) of 5% were calculated with the background risk at zero exposure set to 5% after adjusting for age and smoking status.
The estimated BMDLs of urinary Cd for renal effect markers were 6.9 for urinary β2-MG and 4.4 for NAG in men and 8.1 for β2-MG and 6.1 for NAG μg/g creatinine (Creat) in women. These BMDLs of urinary Cd (μg/g Creat) for NAG were less than the geometric mean urinary Cd in the polluted area (6.5 in men and 7.1 in women). The estimated BMDLs of blood Cd (μg/L) were 6.2 for urinary β2-MG and 5.0 for NAG in men and 5.9 for β2-MG and 5.8 for NAG in women. The calculated BMDLs were similar or less compared with the geometric mean blood Cd (μg/L) in the polluted Thai area (6.9 in men and 5.2 in women).
The BMDLs of urinary and blood Cd for renal effects were estimated to be 4.4-8.1 μg/g Creat and 4.4-6.2 μg/L in the Thai population aged ≥ 40 years old, suggesting that more than 40% of the residents were at risk of adverse renal effects induced by Cd exposure in Thailand.
本研究旨在估算泰国人群中镉污染地区和非污染地区居民健康风险评估中肾脏效应的基准剂量（BMD）。
研究参与者包括居住在泰国西北部非污染地区（40名男性和41名女性）以及受环境污染的湄索区（230名男性和370名女性）的40岁及以上居民。我们测量了尿镉和血镉作为长期暴露的标志物，以及尿β2-微球蛋白（β2-MG）和N-乙酰-β-D-氨基葡萄糖苷酶（NAG）作为肾小管效应标志物。应用一种更新的混合方法来估算这些受试者镉诱导肾脏效应的尿镉和血镉的基准剂量（BMD）及其95%下限置信区间（BMDL）。在调整年龄和吸烟状况后，将零暴露时的背景风险设定为5%，计算对应额外风险（BMR）为5%的BMD和BMDL。
男性中，尿镉对肾脏效应标志物的估算BMDL，尿β2-MG为6.9，NAG为4.4；女性中，尿β2-MG为8.1，NAG为6.1 μg/g肌酐（Creat）。这些尿镉（μg/g Creat）对NAG的BMDL低于污染地区尿镉的几何平均值（男性为6.5，女性为7.1）。男性中，血镉（μg/L）对尿β2-MG的估算BMDL为6.2，对NAG为5.0；女性中，血镉对尿β2-MG为5.9，对NAG为5.8。计算得到的BMDL与泰国污染地区血镉的几何平均值（男性为6.9，女性为5.2 μg/L）相比相似或更低。
40岁及以上泰国人群中，尿镉和血镉对肾脏效应的BMDL估计为4.4 - 8.1 μg/g Creat和4.4 - 6.2 μg/L，这表明泰国超过40%的居民面临镉暴露引起的不良肾脏效应风险。
