低硒环境的健康损失评估及其对环境变化的响应研究

Low selenium is associated with multiple health consequences. In the natural environment of China, there exists an obvious low-selenium belt stretching from northeast to southwest. People living in this belt generally have insufficient selenium intake. The low-selenium environment has caused serious health problems to local residents. This project intends to explore a health evaluation index attributable to low selenium by the method of burden of disease, to comprehensively and quantitatively evaluate the health loss caused by low- selenium sensitive diseases under low-selenium environment. On this basis, two typical regions in the Tibetan Plateau and Loess Plateau low-selenium landscape areas were selected, to study the spatial-temporal changes and regional differences of health loss under different types of low-selenium environment. Through the environmental and human sample collection and the questionnaire investigation, the spatial-temporal correlation between health loss caused by low-selenium sensitive diseases and selenium level changes in environment and population will be studied. By the method of chemical analysis and GIS spatial analysis, the response mechanism of low-selenium related health loss to the complex natural and social environment changes will also be discussed. The findings will provide scientific basis and new ideas for evaluation, prevention and control of low-selenium diseases, as well as rational allocation of health resources in low-selenium areas. It will also expand and deepen the health geographical research of selenium in China.

低硒与人体多种健康后果相关，我国自然环境中自东北至西南方向存在着一条明显的低硒带，带内人群普遍硒摄入不足，低硒环境对当地居民健康造成了极大的危害。本项目拟借助归因疾病负担的研究方法，探索一种针对低硒的健康评价指标，用以综合定量评估低硒环境下低硒敏感疾病所造成的人群健康损失；并在此基础上，选择我国青藏高原和黄土高原两大低硒景观区的典型地区，研究不同生态类型区低硒敏感疾病健康损失的时空变化与区域差异特征；通过典型区环境-人体样品采集和问卷调查，综合运用室内实验分析、GIS空间分析等技术方法，探讨低硒敏感疾病健康损失与环境-人群硒变化的时空关联性，及其对复杂自然和社会环境变化的响应机制。本研究可为低硒地区低硒疾病的评价、防控及卫生资源的合理配置提供科学依据和新思路，同时拓展和深化硒的健康地理学研究。

低硒与心血管疾病、肌肉退行性疾病和认知能力下降等人体多种健康后果相关，其中严重缺硒可引发大骨节病和克山病，给人群健康造成极大危害。本项目以大骨节病为研究对象，通过引入健康寿命损失年这一指标，定量评估低硒敏感疾病所致伤残对人群生命质量造成的隐性后果和健康寿命损失，并以青藏高原和黄土高原典型地区为研究区，重点研究不同低硒景观区大骨节病健康损失的时空分异特征及影响机制，探讨其与环境-人群硒的关系和对社会经济环境变化的响应。取得的主要进展包括：①健康寿命损失年与患病率等传统评价指标呈现出不同的病情估计结果，前者因综合考虑了疾病患病率和病情程度，更有助于致畸致残类疾病对患者生命质量影响的综合评价；②青藏高原和黄土高原低硒景观区的大骨节病健康损失均呈显著空间集聚特征，且表现出与自然环境硒水平更为密切的关系，青藏高原病区居民对当地自然低硒环境的依赖度相对更高，90.5%的大骨节病健康寿命损失变异可由耕作土壤硒和青稞硒解释，而黄土高原病区大骨节病健康损失的空间分异受土壤中有机结合态硒的影响更大；③大骨节病健康损失与人群发硒水平、食物消费模式均呈较好对应关系，即膳食结构越均衡，人均发硒水平越高，大骨节病健康寿命损失越小；④人口结构对大骨节病健康寿命损失的影响不同地区表现较为一致，50岁以上年龄组健康损失最高，对历史重病区而言，人口老龄化程度越高，大骨节病健康损失越严重；⑤不同低硒景观区大骨节病健康损失的时空集聚特征均受自然、社会、政策等因素的综合影响，空间分异上受自然环境影响更明显，土壤环境是最主要的影响因子，气候、地形与土壤、人口质量与人口结构的交互作用进一步增强了影响程度；随时间的集聚变化主要取决于病区社会环境的改变，青藏高原病区受政策导向的农牧业产业结构调整影响较大，黄土高原病区受区域经济发展水平影响较大。研究的开展为高原地方病的可持续防控和大骨节病患病情况的科学评估、精准施策提供了科学依据。