Re: Re[2]: radiopharmaceutical patient release

["J. J. Rozental" <josrozen@netmedia.net.il>]

At 06:25 AM 2/10/97 -0600, you wrote:
>     Forgive me, but I do not believe the final rule addresses continuous 
>     and occasional exposure for members of the general public [see Vol. 
>     56, No. 98, May 21, 1991]. Although ICRP-26 originally provided a 
>     differentiation of limits for long-term vs short-term transient 
>     operation, the final rule notes that the ICRP had modified it's 
>     philosophy changing the 100 mrem/year value to a primary limit.
>     
>     As I interpret 10CFR20 and the final ruling, 100 mrem/year is the 
>     limit. The 500 mrem/year limit is available to older licensees and is 
>     intended to be temporary after approval by the commission.
>     
>     Feel free to contact me with a reference for your interpretation.
>     
>     Jack McCarthy 
>
>
>______________________________ Reply Separator
_________________________________
>Subject: Re: radiopharmaceutical patient release
>Author:  radsafe@romulus.ehs.uiuc.edu at Internet
>Date:    2/7/97 6:00 PM
>
>
>100 mrem/y to a member of the general public is the limit for continuous
>exposure. 500 mrem is still the limit for occasional exposure; although I
>believe the NRC requires that the licensee request permission, in advance, to
>apply it.
>
>Chris Alston
>ccja@aol.com
>
>
According with International Recommendations, ICRP 60 and International
Basic Safety Standards, IAEA I-115, the dose limit for public, should be
considered as follow: (Data from BBS, could be from ICRP 60) 

PUBLIC EXPOSURE:

II - The estimated average doses to the relevant critical groups of members
of the public that are attributable to practices shall not exceed the
following limits:

a) an effective dose of 1 mSv in a year;

b) in special circumstances, an effective dose of up to 5 mSv in a single
year       provided that the average dose over five consecutive years does
not exceed
   1 mSv per year;

c) an equivalent dose to lens of the eye of 15 mSv in a year; and

d) an equivalent dose to the skin of 50 mSv in a year.


One example of applying the item (b) is in emergency situation. During the
Radiological Accident in Goiania, Brazil, 1987 (Health Physics, Volume 60,
Number 1, January 1991) it was adopted the following values: Inside houses
(external exposure) 1 mSv; Outside houses (pathways from contaminated soil):
4 mSv, broken down into 3 mSv due to external irradiation and 1 mSv due to
internal exposure.


Taking this opportunity it is also necessary to comment to RADSAFERS, the
situation of student of 16 to 18 years. The BSS recommend:

II-6 - For apprentices of 16 to 18 years of age who are training for
employment involving exposure to radiation and for students of age 16 to 18
who are required to uses sources in the course of their studies, the
occupational exposure shall be so controlled that the following limits be
not exceeded:

a) an effective dose  to 6 mSv in a year;
b) an equivalent dose to lens of the eye of 50 mSv in a year; and
c) an equivalent dose to the extremities or the skin of the 150 mSv in a year

The above is a typical example for practices in radiology managed by
Technical High School. So such students really should learn and understand
the basic principles for controlling doses.

Finally I would like to comment a very interesting situation on dose limit.
That's mean:  when  a dose for a worker should be considered as dose for
member of the public, the situation of  Pregnant worker
Go To 1.17 -  The notification of pregnancy shall not be considered a reason
to exclude a female from work; however, the employer of female who has
notified pregnancy shall adapt the working conditions in respect of
occupational exposure so as to ensure that the embryo  or fetus   is
afforded the same broad level  of protection a required for member of the
public. In another words. The mother is worker but the embryo member of the
public. 
Here a question, how should be considered the limitation of dose,   by the
competent authority, in case of new application,  if the female worker, for
instance, is a M.D. or RSO, in terms of project for a license?

J.J. Rozental <josrozen@netmedia.net.il>
Consultant, Radiation Safety & Regulation
for developing country