Study on origin and behavior of radionuclides and trace elements in atmospheric environment

采用电感耦合等离子体原子发射光谱、中子活化分析和γ能谱分析方法，对2002年10月至2005年1月在川崎每周采集的颗粒物(PM)样品，以及1964年和2000年至2004年在福冈、长崎、筑波和川崎每月采集的大块沉积物样品中的常量/痕量元素和放射性核素进行了测定。因此，我们在本研究中获得了以下有价值的信息：1.从被测元素浓度之间的相关系数来看，BrSb和Sc-Fe-La分别表现出良好的相关性。从PM10的粒级分布可以看出，PM10的贡献分别大于BR-Sb和Se-Fe-La的贡献。2.在各个风向的放射性平均浓度中，南风时的放射性浓度高于北风时的放射性浓度。可以看出，^…的祖先^&lt；222&>rn更多的&lt；210&gt；铅，在大陆扩散的是海洋的1000倍或更多，^7Be受到宇宙线的纬度效应的影响。此外，还发现这两种核素在这些样品中的浓度将受降雨的影响。3.可以看出，3-5月长崎沉积物中的稀土元素丰度模式与长崎的黄壤粉尘(KOSA)非常相似。这一事实表明，这几个月的长崎证词将受到科萨的强烈影响。此外，从样品中Th/Sc的比值可以看出，近几年(2000-2004年)COSA在沉积物中的贡献高于1964年。土壤中起源于土壤的元素(Si、Al、La、Th等)的时间变化与2000年夏季福冈采集的样品总量基本一致。沉积物中铀浓度、~(137)Cs和~(137)Cs放射性及U/Th比值在1964年3~5月明显高于其他月份。1964年的沉积样品似乎反映了春季平流层-对流层空气交换的活跃，并受到了1962-1963年核试验的影响。较少

In this study, major/trace elements and radionuclides in various atmospheric samples, i.e. particulate matter (PM) samples collected weekly at Kawasaki from October 2002 to January 2005 and the bulk deposition samples collected monthly at Fukuoka, Nagasaki, Tsukuba and Kawasaki in 1964 and 2000 to 2004, were determined by using ICP-AES, neutron activation analysis and γ-ray spectrometry. Consequently, we obtained some valuable information in this study as follows ;1.From the correlation coefficient between the concentrations of determined elements, Br-Sb and Sc-Fe-La showed a good correlation, respectively. Considering the size distributions in PM10, it was seen that the contribution of PM10 was higher than that of larger one in Br-Sb and Se-Fe-La, respectively.2.In the average concentrations of radioactivities of ^<210>Pb and ^7Be each direction of the wind, those when the south wind blew were higher than those when the north wind did. It could be seen that ^<222>Rn, the ancestor of ^ … More <210>Pb, was diffusing 1000 times much or more as in the continent compared with in the ocean and ^7Be was influenced by the latitude effect of cosmic rays. Furthermore, it was found that the concentrations of both nuclides in those samples would be dominated by the rainfall.3.It can be seen that the lanthanoid abundance patterns in the Nagasaki depositions from March to May are very similar to that of the yellow soil dust (Kosa) in Nagasaki. This fact shows that the Nagasaki depositions during those months would be strongly influenced by Kosa. In addition, it became clear from the Th/Sc ratios in those samples that the contribution of Kosa was higher in the depositions in recent years (2000 to 2004) than in those in 1964.4.The temporal variation of the elements (Si,Al, lanthanides, Th etc) originated in soil was almost coincided with total amounts of the samples excluding those collected at Fukuoka in summer in 2000. It was suggested that the soil dusts dominated the total amounts of the depositions.5.The concentrations of uranium, radioactivities of ^<137>Cs and the U/Th ratios in the deposition samples in 1964 were apparently higher between March and May than those in other months. It seems that the deposition samples in 1964 reflected the active stratosphere-troposphere air exchange in the springtime and were affected by the nuclear test during 1962-1963. Less