Studies on the epidemiology (water birds) for the multiple contaminations by various toxic heavy metals and the effects of the metals on gene.

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1.Epidemiological study : Contents of Cr, Mo, Ti, Tl, Cd, V and Cu were investigated for the livers and kidneys of the 74 water birds ; 58 dabbling ducks and 16 diving ducks. The contents for these elements were distributed in wide ranges from ND(not detect value) to more than 10μg/g dry weight except for Cu. Cu contents were very high in many livers of these ducks (more than 100μg/g dry weight), and the contents were also distributed in wide range but had no ND value. Further, several mean values for element contents were largely different from the median values such as Tl contents in the kidneys of widgeons, Ti and V contents in the kidneys and livers of spotbill ducks, respectively. However, we could not jump to a conclusion as the contamination by these metal contents because of no information for the normal range (control) of the metal contents in these ducks. It is generally very difficult to know the exact age, feeding habit and/or living area of each bird species, and therefore … More , it is also difficult to grasp the exact contamination of living area. Thus, we selected Cd pollution having many data, and tried to make a new indicator (an integrated control) for birds and mammals to evaluate of the pollution.2.A new indicator : Cd contents in kidney and liver (83 data) were first obtained from references for wildlife that any special contamination was not written, and then, a Cd standard regression line(CSRL) was made as an integrated control line. The CSRL was verified from the relation between the Cd burdens of normal human and Itai-Itai disease patients, and from the relation between the contents in the organs of normal animals and the experimental animals Cd exposed. The results suggested the availability of CSRL as an integrated control line. Further, this CSRL suggested that 74 water birds investigated in the present study included several contaminated birds.3.Effects of toxic metals on the chromosomal DNA : Effects of Na_3V_4,CdCl_2 and SnCl_2 on chromosomal DNA were investigated using E.coli (K-12 strain) and Lmonocytogenes (L.m ; L98-82B1 strain). The results showed the possibilities that several different mutation sites are located on the chromosomal DNA depending on the metals, and that the mutations occur within short times when the elements exist in the environment. These points are important for the analysis of genomic structures and pathogenicity between the different strains. Thus, further investigation would be needed for these points.4.Conclusion : A part of these results has already published as next page and all results have been summarized in the report submitting with this paper. Less