Meliker Jaymie R, Slotnick Melissa J, Avruskin Gillian A, Kaufmann Andrew, Fedewa Stacey A, Goovaerts Pierre, Jacquez Geoffrey J, Nriagu Jerome O
BioMedware, Inc., 516 N. State St, Ann Arbor, MI 48104, USA.
Int Arch Occup Environ Health. 2007 Jan;80(3):184-97. doi: 10.1007/s00420-006-0119-2. Epub 2006 Aug 9.
A space-time information system (STIS) based method is introduced for calculating individual-level estimates of inorganic arsenic exposure over the adult life-course. STIS enables visualization and analysis of space-time data, overcoming some of the constraints inherent to spatial-only Geographic Information System software. The power of this new methodology is demonstrated using data from southeastern Michigan where 8% of the population is exposed to arsenic >10 microg/l (the World Health Organization guideline) in home drinking water.
Participants (N=440) are members of a control group in a population-based bladder cancer case-control study in southeastern Michigan and were recruited by phone using random digit dialing. Water samples were collected and analyzed for arsenic at current residence and participants were required to answer questions concerning lifetime mobility history and dietary habits. Inorganic arsenic concentrations were estimated at past residences and workplaces, and in select foods. Fluid and food consumption data were integrated with mobility histories and arsenic concentrations to calculate continuous estimates of inorganic arsenic intake over the adult life-course.
Estimates of continuous arsenic exposure are displayed, making use of both participant age and calendar year as measures of time. Results illustrate considerable temporal variability in individual-level exposure, with 26% of the participants experiencing a change in drinking water arsenic concentration of at least +/-10 microg/l over their adult lives. The average cumulative intake over the adult life-course ranges from 2.53 x 10(4)-1.30 x 10(5) microg, depending on the selected exposure metric.
The STIS-based exposure assessment method allows for flexible inclusion of different parameters or alternative formulations of those parameters, thus enabling the calculation of different exposure metrics. This flexibility is particularly useful when additional exposure routes are considered, input datasets are updated, or when a scientific consensus does not exist regarding the proper formulation of the exposure metric. These results demonstrate the potential of STIS as a useful tool for calculating continuous estimates of adult lifetime exposure to arsenic or other environmental contaminants for application in exposure and risk assessment.
介绍一种基于时空信息系统（STIS）的方法，用于计算成年人一生中无机砷暴露的个体水平估计值。STIS能够对时空数据进行可视化和分析，克服了仅空间地理信息系统软件固有的一些限制。利用密歇根州东南部的数据展示了这种新方法的效力，该地区8%的人口在家用饮用水中接触到的砷含量超过10微克/升（世界卫生组织指导标准）。
参与者（N = 440）是密歇根州东南部一项基于人群的膀胱癌病例对照研究对照组的成员，通过随机数字拨号电话招募。采集当前居住地的水样并分析其中的砷含量，参与者需要回答有关终生迁移历史和饮食习惯的问题。估计过去居住地、工作场所及特定食物中的无机砷浓度。将液体和食物消费数据与迁移历史及砷浓度相结合，以计算成年人一生中无机砷摄入量的连续估计值。
展示了连续砷暴露的估计值，同时使用参与者年龄和日历年份作为时间度量。结果表明个体水平暴露存在显著的时间变异性，26%的参与者在成年生活中饮用水砷浓度变化至少为±10微克/升。根据所选暴露指标，成年人一生中的平均累积摄入量在2.53×10⁴ - 1.30×10⁵微克之间。
基于STIS的暴露评估方法允许灵活纳入不同参数或这些参数的替代公式，从而能够计算不同的暴露指标。当考虑额外的暴露途径、更新输入数据集或在暴露指标的正确公式方面不存在科学共识时，这种灵活性特别有用。这些结果证明了STIS作为一种有用工具的潜力，可用于计算成年人一生中对砷或其他环境污染物的连续暴露估计值，以应用于暴露和风险评估。
