In article <5843kv$ru0 at newsstand.cit.cornell.edu> aq12 at cornell.edu (Antonio Quiñones) writes:
>From: aq12 at cornell.edu (Antonio Quiñones)
>Subject: Mineral neutron activation
>Date: 4 Dec 1996 14:59:43 GMT
>It's my understanding that, upon irradiation of humans with neutrons
>(purposefully or by accident), the minerals in the body (Ca2+, for
>example) will be activated and will emit radiation in their decay
>process.
>(if this is incorrect please do correct me. I am also assuming that
>neutron activation is the only way to activate minerals by
>irradiation).
>My questions:
>Q.1.) Does anyone have a list of the predominant minerals in
>the human body that would become activated upon irradiation with
>neutrons?
The principal ones are: (stable isotope, natural abundance, neutron reaction,
product, half-life)
sodium-23 (100%) (n,gamma) -> Na-24 (15 hr)
chlorine-37 (24%) (n,gamma) -> Cl-38 (37 min)
calcium-48 (0.2%) (n,gamma) -> Ca-49 (8.7 min)
phosphorus-31 (100%) (n,gamma) -> P-32 (14.3 d)
nitrogen-14 (99.64%) (n,2n) -> N-13 (10 min)
iodine-127 (100%) (n,gamma) -> I-128 (25 min)
All of the products are gamma emitters and can be detected from outside the
body using a whole-body counter or equivalent. See for example Kennedy N et
al: Normal levels of total body sodium and chlorine by neutron activation
analysis. Phys. Med. Biol. 1983: 28:215-221, or Leroy Booth's chapter on NAA
in Henkin RE et al [eds]: Nuclear Medicine. Mosby, 1996, pp 156-158.
>Q.2.) What are the half-lives of these activated minerals? (see above)
>Q.3.) Could these internal emissions (from the activated
>minerals in decay) be detected at the surface of the individual's
>skin? (see above)
>Many thanks
>Antonio Quiñones
>aq12 at cornell.edu
Dennis D. Patton MD
Division of Nuclear Medicine
University of Arizona, Tucson
