Distribution of 241 Americium in Soft Tissues and Bones of Monkey

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Distribution of 241 Americium in Soft Tissues and Bones of Monkey

Introduction

A by-product named as Americium- 241 denoted by Am is created from Uranium-238. Wastes of U.S separated defense has about 5.6 x 1015 Bq of Americium-241. 50 time more than this amount is found in U.S power reactors. Potential intake risk of Americium isotope is almost equal to long lived fission product which is about 100y after removal from the reactor. Americium kinetic studies in monkeys were started in 1960 because of lack of metabolic data available.

241 Am solution

In 1960 a stock solution was obtained from Actinide chemistry group. It was stored in volumetric flask at 4oc. some amount of the solution was diluted with isotonic sodium in a bottle so that it could be injected in monkeys. Some amount of solution was transferred into calibrated syringe after 1967 in order to measure the exact amount delivered syringes were weighted filled and empty. In order to provide counting standards for monkeys in a day additional syringe containing measured solution was put into a flask containing 2NHN03. NBS standard was followed to conduct this activity.

Animals

Species Used: MACACA was the type used which included 12 species having different body size (1.5kg-18kg).

Cage: All the animals lived in separate cage after the arrival. They lived in LBL colony. These cages were metabolic constructed from the iron sheet. After 1970 animals were transferred into different cages according to their sizes.

Diet: monkeys were given fresh vegetables and fruits, iron and vitamins, dry biscuits and reconstituted milk fortified. From 1960 to 1970 infant monkeys were given enriched bread and biscuits.

Health Care and Colony management: initially before 1963 monkeys were brought to us in bulk quantity and were sent to buyers without complete isolation. Initially when monkeys were brought to LBL they were housed in a quarantine room and were treated for intestinal worms with oral vermifuges. After 1963 monkey were imported in smaller quantity and were held in isolation for several months so that they could be brought in good health to LBL. As the time passed housing standards, cleanliness and care was improved.

Anaesthesia: Macaques are stubborn and physically strong despite their sex. From 1960 to 1966 Nembutal (barbiturates) was used it was occasionally supplemented by ethyl ether gas. Later from 1960-1973 Sernylan was used and from 1973-1983 Ketelar was used. In addition Acepromazine was used as muscle relaxant.

Injections: there were two type of injection used. blood samples were taken from superficial vein of calf and ankle with the help of Intravenous. Other injection was Intramuscular injections.

Health records: each animal was given certain number. There was medical history of each monkey which included results of TB tests body weights, surgical procedures, hemograms, and treatment of infections etc.

Collection of Excreta

Schedule: after a nuclide injection separated sheet was extracted almost daily or every other day for almost a week and twice a week thereafter.

Collection Procedure: At LBL excreta was collected from the ...