Effects of 90Sr and 137Cs administered continuously and through Generations upon Mice

Abstract

and Sakiko IKEGUCHI Mice of NA-2 strain were administered continuously and through generations with 90Sr and 137Cs contained in drinking water. Concentration of the isotopes was divided into three levels; Group I: (90Sr and Group IV (Control) was fed with noncontaminated water. Abnormality of growth, life-span and reproduction in these groups were summed up till 10th generation. Group I showed shortening of lifespan and lost reproductive function already in 2nd generation. Group II showed injury of growth and reproduction and shortening of life-span, but kept proceeding of the generations. In Group III we could not observe such injury as seen in Group I and II, but there appeared increase in reproductive function and lengthening of life-span. It can be concluded that Group I and II were obviously in state of radiation injury, but Group III was in some excited state by 90Sr and 137Cs. Another remarkable character of Group III is that tolerance against whole body irradiation of 700 R was aquired not by genetic mutation or selection but by effect of the isotopes after birth and that the tolerance was more intence in female than in male mice. This tendency was found also in Group II, but the tolerance was weaker. RadiationCenter of Osaka Prefecture

Co-exposure to internal and external radiation alters cesium biokinetics and retention in mice

“…Experimental data on combined internal contamination plus external radiation exposures are very sparse, and are mainly limited to very early studies with a combination of 137Cs and 90Sr, but without any comparison with single radionuclide exposure (Nishio, 1968(Nishio, , 1969(Nishio, , 1971Nishio et al, 1968). It is thus difficult to compare our study of combined exposures with work from others, even with the study by Calvi et al (Calvi et al, 2019).…”

“…The studies demonstrated a reduced life expectancy and a reduction of reproductive efficiency. However, in these studies there was no comparison between exposure with a single radionuclide and the mixture of the two radionuclides (Nishio et al 1968, Nishio 1968, 1969, 1971. This absence of study on the effect of combined exposure is probably linked to the hypothesis of additivity of health effects, as the absorbed dose is considered as additive, too.…”

“…For instance, laboratory studies using a mixed exposure, both internal and external, are very sparse. A series of studies was conducted at the end of the 60s by Nishio (Nishio et al 1968, Nishio 1968, 1969, 1971) in a mouse model of 137 Cs+ 90 Sr chronic, long-term internal exposure. The studies demonstrated a reduced life expectancy and a reduction of reproductive efficiency.…”

“…This author demonstrated a reduced life expectancy and a reduction of reproductive efficiency. However, in these studies, there was no comparison between exposure with a single radionuclide and the mixture of the two radionuclides (Nishio, 1968(Nishio, , 1969(Nishio, , 1971Nishio et al, 1968).…”

Co-contaminations radiologiques et chimiques en situation post-accidentelle : données récentes et perspectives

“…Les recherches sur les effets biologiques de co-contaminations de radionucléides restent très limitées. Pour l'essentiel, il existe une série de travaux réalisées durant les années 1960 par une équipe japonaise sur 20 générations de souris contaminées via l'eau de boisson (Nishio, 1968 ;Nishio et al, 1968 ;Nishio, 1969 ;Nishio, 1971 90 Sr a été calqué sur ce qui a été retrouvé dans l'environnement à la suite des essais nucléaires aériens des années 1960 dans les îles du Pacifique. Il a été montré une altération de la durée de vie dans tous les groupes, avec un déficit de reproduction dans le premier groupe tel que l'expérience n'a pu être menée que jusqu'à la 8 e génération (Nishio, 1969).…”