~
VIII
5]
=
Summary of Recommendations
Tne following recommendations apply to alpvha-emitting
hot particles where a hot particle is defined as a particle
that contains sufficient activity to deliver at least 10060
rem/yr to the surrounding lung tissue.
For isotopes having
hali-lives greater than one year, this would correspond to
particles containing at least 0.07 oCi of alpha activity. ®?
& is recommended that:
l.
For occupational exposure
MPEP?B = 2 not particles
MPCa for Pu-239 = 3.3x10-16 uciyn1®?
--2.
For non-occuvational exposure
MPLP3 = 9.2 hot particles
MPCs Zor Pu-239 = 9xl0-18 uci/mi®?
87/
These varvticulates would consist of compeunds of Pu and
tne other actnises which fall into Class Y material in the ICR
Task Group Lung Mocel.
These materials wouis be retained for
years in the lung.
See for example, ICRP Publication 19, O95. cit.,
3. 6.
Since oniy sarticles in the size ranca of 5 u and Dalaw in
Giameter woulc be deposited in the @een ressiratoryv tissue, this
in eliact saris an unoer limit for tne particle size of interest
here
Ef the nalf-life is less than or clss2 to l year the Limit
of 9.97 3Ci can be adjusted usoward through .asprovriate calculations.
fi/ Tails MPa asolies for sarticles containing 0.07 sci of
Dy-233.
For garcticles containing more than 9.97 oCi the
Mrln Could na insraasad sropertionately.
For particles
Tontaining less than 0.07 voCi the existins s2Cysaxlo7li cCi/n}
would apply.
The MPCqa for hot garticlas of otner isotopes
and mixtures af isotoses shoulda be astablisnad on a similar
bisis with considaration given to the half-lifa of the isotope.
a9/
Tate
\,