Navas-Acien Ana, Umans Jason G, Howard Barbara V, Goessler Walter, Francesconi Kevin A, Crainiceanu Ciprian M, Silbergeld Ellen K, Guallar Eliseo
Department of Environmental Health Sciences, Johns Hopkins Bloomberg School of Public Health, 615 North Wolfe Street, Baltimore, MD 21205, USA.
Environ Health Perspect. 2009 Sep;117(9):1428-33. doi: 10.1289/ehp.0800509. Epub 2009 May 7.
Arsenic exposure in drinking water disproportionately affects small communities in some U.S. regions, including American Indian communities. In U.S. adults with no seafood intake, median total urine arsenic is 3.4 microg/L.
We evaluated arsenic exposure and excretion patterns using urine samples collected over 10 years in a random sample of American Indians from Arizona, Oklahoma, and North and South Dakota who participated in a cohort study from 1989 to 1999.
We measured total urine arsenic and arsenic species [inorganic arsenic (arsenite and arsenate), methylarsonate (MA), dimethylarsinate (DMA), and arsenobetaine] concentrations in 60 participants (three urine samples each, for a total of 180 urine samples) using inductively coupled plasma/mass spectrometry (ICPMS) and high-performance liquid chromatography/ICPMS, respectively.
Median (10th, 90th percentiles) urine concentration for the sum of inorganic arsenic, MA, and DMA at baseline was 7.2 (3.1, 16.9) microg/g creatinine; the median was higher in Arizona (12.5 microg/g), intermediate in the Dakotas (9.1 microg/g), and lower in Oklahoma (4.4 microg/g). The mean percentage distribution of arsenic species over the sum of inorganic and methylated species was 10.6% for inorganic arsenic, 18.4% for MA, and 70.9% for DMA. The intraclass correlation coefficient for three repeated arsenic measurements over a 10-year period was 0.80 for the sum of inorganic and methylated species and 0.64, 0.80, and 0.77 for percent inorganic arsenic, percent MA, and percent DMA, respectively.
This study found low to moderate inorganic arsenic exposure and confirmed long-term constancy in arsenic exposure and urine excretion patterns in American Indians from three U.S. regions over a 10-year period. Our findings support the feasibility of analyzing arsenic species in large population-based studies with stored urine samples.
饮用水中的砷暴露对美国一些地区的小社区影响尤为严重，其中包括美国印第安社区。在美国不摄入海鲜的成年人中，尿总砷中位数为3.4微克/升。
我们使用1989年至1999年参与队列研究的来自亚利桑那州、俄克拉何马州以及北达科他州和南达科他州的美国印第安人随机样本中在10年期间收集的尿液样本，评估砷暴露和排泄模式。
我们分别使用电感耦合等离子体质谱法（ICPMS）和高效液相色谱/ICPMS测量了60名参与者（每人三个尿液样本，共180个尿液样本）的尿总砷和砷形态[无机砷（亚砷酸盐和砷酸盐）、甲基胂酸（MA）、二甲基胂酸（DMA）和砷甜菜碱]浓度。
基线时无机砷、MA和DMA总和的尿浓度中位数（第10、90百分位数）为7.2（3.1，16.9）微克/克肌酐；亚利桑那州的中位数较高（12.5微克/克），达科他州居中（9.1微克/克），俄克拉何马州较低（4.4微克/克）。无机砷、MA和DMA在无机和甲基化形态总和中的平均百分比分布分别为10.6%、18.4%和70.9%。10年期间三次重复砷测量的组内相关系数，无机和甲基化形态总和为0.80，无机砷百分比、MA百分比和DMA百分比分别为0.64、0.80和0.77。
本研究发现美国印第安人无机砷暴露水平低至中等，并证实了来自美国三个地区的美国印第安人在10年期间砷暴露和尿排泄模式的长期稳定性。我们的研究结果支持在基于人群的大型研究中使用储存尿液样本分析砷形态的可行性。
