COMPARING LUNGS, LIVER AND KNEE MEASUREMENT GEOMETRIES AT VARIOUS TIMES POST INHALATION OF 239Pu AND 241Am

Abstract

In-vivo measurement of Pu/241Am in workers is carried out by placing suitable detector above lungs, liver and skeleton, as major fraction of Pu/Am is transferred to liver and skeleton, after its retention in entry organ. In this work, committed effective dose (CED) corresponding to minimum detectable activity for Type M and Type S 239Pu/241Am deposited in these organs are presented and a monitoring protocol of organ measurement giving lowest CED at different time intervals post inhalation is described. We have observed, for Type M compounds, lung measurement is most sensitive method during initial days after exposure. Liver measurement yields lowest CED between 100 and 5000 d and beyond that bone measurement gives lowest CED. For Type S compounds lung measurement remains most sensitive method even up to 10 000 d post inhalation. This study will be useful for the assessment of CED due to internally deposited 239Pu/241Am in the workers.

Binding of Cm(III) and Th(IV) with Human Transferrin at Serum pH: Combined QM and MD Investigations

“…In all the routes of entry into the human body, they are first absorbed into and then transported via blood before deposition in the target organs (e.g., thyroid, kidney, liver, bones, etc. ). − Upon entry into the blood, actinides are mainly transported to various tissues/organs by serum transferrin (sTf), − an iron carrier protein . sTf mainly binds dietary iron, transports it in the blood serum, and delivers it to cells through a process of receptor-mediated endocytosis.…”

“…Actinides, unlike some other heavy metals, have no known essential role in the normal biochemical reactions occurring in living organisms including plants and animals. Internal contamination of actinides can be monitored using direct (in vivo) or indirect (in vitro) methods. , These methods give information about the amount of radioactivity present in the body of the person and the committed effective dose received by the person. However, these methods do not give the information about the structure, speciation, and mechanism that the body uses to bind and transport actinides.…”

MD simulation reveals differential binding of Cm(III) and Th(IV) with serum transferrin at acidic pH

“…Although there are stringent safety measures during these processes, there always remains a risk that these radionuclides can enter the human body through any of the routes, namely inhalation, ingestion, and injection. Upon entry into the body they are transported to various tissues, cells via blood mainly through the iron carrier serum transferrin (sTf) protein 1,2,4‐12 . Most of the An isotopes especially, 228 Th, 238 Pu, 239 Pu, 241 Am, 242 Cm, 244 Cm, and 237 Np are mainly α emitters and are highly radiotoxic 3 .…”