摘要
以中国西北地区环境中的^(239+240)Pu为例,归纳总结了全球大气核试验后环境调查的5大变化趋势,并分析了西北地区大气、土壤和湖泊等环境载体中^(239+240)Pu比活度、^(240)Pu/^(239)Pu原子比值和^(239+240)Pu存量变化的来源成因.结果表明,新疆、甘肃、青海、宁夏和陕西5省区土壤中^(239+240)Pu主要来源于全球大气核试验沉降.虽然前苏联塞米巴拉金斯克核试验(^(240)Pu/^(239)Pu=0.118~0.132)、中国西北核试验(^(240)Pu/^(239)Pu=0.158)以及青海原子城的核实验活动(^(240)Pu/^(239)Pu<0.010)导致西北地区环境中发现相对低^(240)Pu/^(239)Pu原子比值,但核试验区域沉降的影响有限.西北地区湖泊柱样沉积物中^(240)Pu/^(239)Pu原子比值垂直分布出现了突变和渐变两种模式;另外,在某些非典型柱样沉积物中^(239+240)Pu的峰值时标并非指示1963年大气沉降的高峰期.
This study was taken ^(239+240)Pu as an example,the five major trends of environmental investigation after the global atmospheric nuclear weapon tests were summarized.Meanwhile,the ^(239+240)Pu activities,^(240)Pu/^(239)Pu atom ratios and ^(239+240)Pu inventories in the environment of Northwest China were comprehensively analyzed.The results showed that ^(240)Pu/^(239)Pu atom ratios in soils from Xinjiang,Gansu,Qinghai,Ningxia and Shaanxi were mainly derived from global fallout.Although the former Soviet Union Semipalatinsk nuclear tests,China Lop Nor nuclear tests and Qinghai Atomic City nuclear testing activities may produce the relatively low ^(240)Pu/^(239)Pu atom ratio,the area of influence was limited.This study not only found the significant change of ^(240)Pu/^(239)Pu atom ratios in soils,but also found it in lake sediments.Two vertical distribution patterns of catastrophes and gradients on ^(240)Pu/^(239)Pu atom ratios were found in lake sediment cores in Northwest China.In addition,the location of ^(239+240)Pu activity in some sediment core could not indicated the 1963 peak age of global fallout.
作者
黄亚楠
吴孟孟
肖智
HUANG Ya-nan;WU Meng-meng;XIAO Zhi(School of Marine Science,Sun Yat-sen University,Zhuhai 519082,China;School of Geographic and Oceanographic Sciences,Nanjing University,Nanjing 210023,China;School of Natural Resource and surveying,Nanning Normal University,Nanning 530001,China)
出处
《中国环境科学》
EI
CAS
CSCD
北大核心
2021年第11期5334-5344,共11页
China Environmental Science
基金
广东省青年优秀人才国际培养计划博士后项目(20210616)。
