FWD: OEM reply to post previously forwarded

[liselin@planetx.bloomu.edu (Louis H Iselin)]

Since Dr. de Silva's 2nd post in this thread was recently forwarded, I decided 
to let the RadSafers see what his original post was.  At least in the 2nd post 
Dr. de Silva suggested that a health physicist be consulted.

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In reply to:
>From: CJMARTIN@PHS.Med.UAlberta.CA
>Subject: OEM: Carcinoid tumour of thymus and radioisotope exposure

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>Message-Id: <9609051751.AA04846@aehafs1.apgea.army.mil>
>Date: Thu, 05 Sep 96 14:10:30 -0700
>From: "Shirin R. de Silva, MD, MPH" <sdesilva@aeha1.apgea.army.mil>
>Organization: USA-CHPPM
>To: occ-env-med-L@list.mc.duke.edu

>(1)  With respect to the cluster, remember that cancers are common - one 
>out of every four U.S. residents develop some form of cancer during their 
>lifetimes - and that the different cancers are different diseases.  
>However, if you have three or more uncommon cancers of a specific 
>type, and if that type is known to be associated with radiation exposure, 
>then the population should get worked up.  Your Department of Labor 
>may take care of this.  In particular, the folks with thyroid 
>abnormalities should get checked out, given the use of radioactive iodine 
>in this population.

>(2)  Does the worker has any other risk factors?

>(3)  In addition to looking through the literature, I would call the 
>manufacturer of the radioactive isotopes used in the injection process, 
>describe the situation to their safety personnel, and ask for safety data 
>on this product.  They should have information on the inhalation hazard 
>of the isotopes under standard conditions of use.  

>(4)  The manufacturer is unlikely to have information on ingestion 
>hazards, as that would not be a standard condition.  However you can 
>guestimate the ingestion hazard of each of the isotopes used as follows:

>Hazard Equation:

>Annual Isotope Specific 
>Ingestion Hazard          =   M    x   250 days/year  x     R    x     F

>                                                          
>where 

>M represents the amount of dust consumed daily by the workers.  If the 
>employer has no data on this point, and if Canada has no specific 
>numbers, I would use 100 mg, which  is U.S. EPA's default value for daily 
>adult dust ingestion, and assume that 100% of dust consumption occurs at 
>the worksite.  If the radioactive contamination is limited to work sites, 
>and the interior of the vehicles are not contaminated, according to the 
>sampling information which you gather, then I would modify this figure by 
>multiplying it by the number of minutes spent in a contaminated 
>environment, / divided by the number of minutes in the workday.  That is, 
>M = 100 mg   x  (minutes spent in contaminated area per day/ (60 minutes 
>per hour x number of hours exposed per day))  The default for "number of 
>hours exposed per day" is 8 hours, but you would have to modify this if 
>there is take home exposure, or the worker works different hours.

>250 days/year is U.S. Occupational Safety and Health Administration's 
>default value for annual working days.  If the workers work more or less 
>days each year, or if you suspect take-home contamination you would need 
>to modify this figure.

>R represents the geometric mean radiation level of the dust in the 
>contaminated areas.  You need sampling information for this.  Your 
>Department of Labor should be getting it.

>F  represents the proportion of dust contaminated with the isotopes used. 
>This value must also be determined from environmental sampling data.    

>The Annual Ingestion Hazards for each isotope which you calculate using 
>the equation listed above should be 50 X lower than their corresponding 
>isotope specific Annual Limits on Intake for Radiation Workers, as laid 
>out in U.S. EPA's Federal Guidance Report No. 11.  EPA-520/1-88-020 
>September 1988.  The reason you need to divide the EPA's numbers by 50 is 
>that the worker does not sound like he fits into the category of 
>radiation worker, and therefore gets categorized as a member of the 
>general population.

>References:

>U.S. EPA Office of Radiation Programs, Limiting Values of Radionuclide 
>Intake and Air Concentration and Dose Conversion Factors for Inhalation, 
>Submersion, and Ingestion.  Federal Guidance Report No. 11. 
>EPA-520/1-88-020.  September 1988.

>U.S. EPA, Office of Solid Waste and Emergency Response, Risk Assessment 
>Guidance for Superfund, Volume I: Human Health Evaluation Manual, 
>Supplemental Guidance: Standard Default Exposure Factors.  Directive 
>9285.6-03; Interim Final.   March 25, 1991.

>J. Konz, K. Lisi, and E. Friebele, Exposure Factors Handbook, U.S. EPA, 
>Office of Health and Environmental Assessment, EPA/600/8-89/043; March 
>1989.

>Sincerely,

>Shirin R. de Silva, MD, MPH
>Occupational and Environmental Medicine Program
>U.S. Army Centers for Health Promotion and Preventive Medicine
>Aberdeen Proving Ground - Edgewood Area, 
>Maryland, USA
>----------------------------------------------------------------------
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_____________________________________________________________________
Louis H. Iselin, Ph.D.           * Go Gators! *                   <*>
Assistant Professor of Physics (Health Physics Program)
Bloomsburg University of Pennsylvania
Bloomsburg PA  17815-1399                          liselin@bloomu.edu