ENVIRONMENTAL ASSESSMENTS, MONITORING, AND STUDY DESIGN 51 



States and the world vary widely according to the local agricultural, sport fisheries and 

 wildlife, commercial fisheries, and water-use practices. Food imported or exported may 

 serve to reduce or increase the total dose of transuranics. Lx)cal gardens or small farms 

 may lead to maximization of dose to an individual through the food pathway. Dose 

 assessments have usually been calculated for a "maximum individual," i.e., one who 

 obtains all sustenance at a facility site boundary. For an actual facility where food chains 

 to man could be identified, the use of the "fence-post man" would appear to contain 

 numerous conservatisms. 



Sampling for transuranics in soils, plants, or other media in areas with existing levels 

 of radionuclides must be designed according to the particular needs of the study and must 

 include consideration of existing levels of transuranics in the environment. Methods for 

 inventory sampling may not always be adequate for defining resuspendible material 

 leading to inhalation or plant contamination. Studies must be carried out which provide 

 information about inventory mobility and the consequential effect on human health. 

 General comments throughout this section have referred to the general considerations of 

 monitoring program design with Httle reference to specific guidance. The selection of 

 sampling methods and measurement techniques for environmental media, including those 

 used to calculate radiation dose to people but also commonly used as trend indicators, 

 have been discussed in several review articles and publications; NCRP 50, the DOE guide, 

 ICRP-7, and the NRC regulatory guides are examples. As already discussed, the proper 

 selection of media samples, based on the detailed pathway analysis, is important in 

 assessing the dose to people. It would not be possible to detail these considerations here 

 for all media; therefore discussion of soil contamination is presented as an example. 



As guidance for ingestion and inhalation of transuranics in the environment was being 

 developed, consideration of soil concentration limits and resulting problems in appli- 

 cability of a soil Hmit led to the recognition that dose limits to the lung and bone are 

 most important. The calculation of this dose can be based on air measurements, in which 

 case more information on particle size and the physical parameters of the transuranics is 

 necessary than is normally developed in environmental surveillance programs. Thus the 

 need for research input and cooperation with environmental programs becomes 

 important. 



Although the air pathway is of primary concern, the environmental measurements 

 eventually must be or will be translated into soil concentrations. Thus the usual inventor>' 

 measurements and sample techniques will not provide adequate information on the 

 resuspendible and respirable fraction of transuranics in the environment. Definitions of 

 such things as resuspendible surface, sample collection methods, sample preparation, and 

 particle-size determinations are all factors in the radiological assessment of transuranic- 

 contaminated soils. Much of the necessary data is yet to be determined. SampHng 

 techniques have been reviewed by several researchers, including Bernhardt (1976). 

 Differences in techniques exist which necessitate evaluation and verification of 

 methodology used in assessing radiological impacts of transuranics in the environment. 



References 



Bernhardt, D. E., 1976, Evaluation of Sample Collection and Analysis Techniques for Environmental 

 Plutonium, Technical Note ORP/lv-76-5, U. S. Envlionmental Protection Agency, NTIS. 



Bloom, S. G., and W. E. Martin, 1916, A Model to Predict the Environmental Impact of the Release of 

 Long-Lived Radionuclides, Final Report to the U. S. Environmental Protection Agency, Battelle, 

 Columbus Laboratories, NTIS. 



