1. 2. 3. 4. 5. References for Review on Oceanic Davis, W. J., "Report to the Honorable Quentin L. Kopp Re. Oceanic Weast, R. C., Ed., CRC Handbook of Chemistry and Physics, 59th Ed, CRC Joseph, A. B., "United States' Sea Disposal Operations: A Summary to National Academy of Sciences, "Radioactivity in the Marine Environment," USNRC "Evaluation of Alternative Methods for Disposal of Low-Level 6. Noshkin, V. E., et al., "Radionuclides in the Marine Environment near the 7. 8. Rodger, W. A., "Radioactive Waste Disposal," ANL 6233, September 1960. Guidelines for Sea Disposal Packages of Radioactive Waste-NEA, OECD Paris, A copy of the subject report which we shall refer to as DR-II, was received by us on September 22, 1980. Since the time available for its review has been short, a complete assessment of its contents is impossible. However, we have found enough inaccuracies, distortions and errors to discredit its validity and show that its conclusions are unjustified. A critique of specific items and other pertinent comments follows: 1) Misuse of analytical data A common characteristic of DR-I and DR-II is the misuse of available analytical data. As discussed in our first report, DR-I misused published gross beta activity measured in State analyses of fish by making the assumption that "all the measured beta emission came from Strontium 90." We pointed out that the Davis analysis was completely ridiculous since naturally occurring potassium-40 largely accounts for the observed beta activity. If the levels of beta activity were much lower than that observed, we would have a truly anomalous situation of potassium deficient fish. In DR-II, an even more serious misuse of analytical data may be found. This involves the use of the limits of analytical detectability as if they were actual measurements. The source document (EPA document #14)* for the DR-II analysis of edible fish is quite clear in its presentation of analytical data. The table (Table 2, EPA document #14) from which Davis extracts his information uses the symbol <(less than) to indicate that concentrations were below detection limits. The authors state "Because of low radionuclide concentrations and small sample sizes, the 239,240 Pu values in all other organisms collected from the disposal site were below our detection limits." They further state, "....because our detection limits are higher than those of Noshkin et al., it is possible that many of our values which are reported as less than the detection limit are in fact comparable to those of the Noshkin et al. study." As a point of comparison, EPA document #8 presents much data directly comparable with that of EPA document #14. In this document, however, the analytical results are almost invariably reported as 0.0 + LD, where LD is the limit of detectability. This alternative method of reporting that the sample contained radionuclides in concentrations below detectability limits is used to avoid confusing people who are not familiar with standard procedures of reporting scientific data. In addition to the tabular misreprestation of data (Tables 11 and 12,DR-II), there are several related statements that are patently incorrect. Key among these is the statement on page 31 of DR-II: "....the plutonium level contained within the muscle of every fish examined exceeded the level of plutonium expected in fish flesh from background fallout caused by weapons testing," and in the Summary, page 1, "Plutonium levels in the liver and flesh of edible fish species captured at the Farallon site are up to 8500 times the level expected from global fallout." This major error in DR-II by itself invalidates most of the conclusions drawn concerning plutonium content in edible fish. *References to EPA documents and other DR-II references follow the convention in DR-II where full reference citations are listed. 2) Use of weapons background as a measure of hazard Fundamental to the analysis and conclusions of DR-II is the use of weapons background as an indication of levels of environmental contamination. As detailed in our first report (Appendix A), naturally occurring radioactivity within the Farallon dumpsite far exceeds any additional contribution to total radioactivity that man has provided, due to either weapons testing or radioactive waste dumping. The levels of radioactivity from weapons testing and the resultant hazard on a worldwide average basis are so low compared to naturally occurring radioactivity that extremely sensitive techniques (such as extensive chemical preparation and alpha spectroscopy) must be used in order to even detect its presence in the environment. It is only due to the fact that radionuclides are detectable at extremely low levels (i.e. far, far below levels of health hazard) that the evaluation of weapons background contamination of the environment can be carried out. Since the levels of environmental contamination due to weapons testing are extremely low compared to naturally occurring background radiation, it is possible to have localized contamination at a dumpsite which exceeds weapons background levels by many times, but which is still totally insignificant compared to natural background levels. This is the case at the Farallons, and thus it is improper to conclude that such contamination levels in excess of weapons background present "a measurable health hazard" (DR-II). 3) Use of improper background data base Throughout DR-II, data are reported in terms of multipliers of "low," "high" and "average" weapons fallout background. Therefore, it is of great importance that the proper reference background data be used. It is apparent from our analysis of available background weapons fallout estimates that Davis attempted not to find an appropriate value to use, but rather to find the lowest values available, thereby forcing the EPA Farallon data to appear elevated. The source of Davis' background values is somewhat difficult to track. Although he cites a reference (DR-II - ref. 12) as the source of his data, these values are clearly not present in the reference. Most likely, the estimates are extracted from a different document (DR-II, ref. 4) which, in turn, are attributed to a "personal communication." Figure 1 presents data (Noshkin, 1980)* which show the most probable relationship between Plutonium concentrations in sediments and water depth for the Atlantic and Pacific Oceans. Also shown are the values used in DR-II. It is apparent from this figure that the DR-II background values are as much as a factor of 100 lower than the appropriate typical values for Pacific sediments. This misrepresentation of background information invalidates essentially every conclusion that Davis draws based on his "times background" approach. 3) Statistical treatment (or lack thereof) As is shown in Figure 1, measured levels of Plutonium in oceanic sediment normally can vary over several orders of magnitude. Although there is overlap, Pacific sediment levels are generally higher thar Atlantic. This is likely due to their closer proximity to the sites of atmospheric testing. Obviously, rather *To be published in IAEA Symposium on "Radioactivity in the Marine Environment," October 1980. |