The interaction of thermal neutrons with U results in fission with a probability of 85% and in the formation of U (t1/2 = 2.3 10 yr) with a probability of 15%. While anthropogenic U is, therefore, present in spent nuclear fuel at levels of U/U up to 10 , the expected natural ratios in the pre-anthropogenic environment range from 10 14 to 10 . At VERA, systematic investigations suggest a detecti...

Bulk analysis of environmental swipe samples taken within nuclear installations as part of routine IAEA inspections has proven to be a very sensitive analytical technique. The combination of chemical separations under very clean conditions with highly sensitive mass spectrometric measurements assists in the identification and characterization of uranium and plutonium signatures at ultratrace le...

Speciation, identification of the chemical states of elements in the environment, is indispensable in determining the environmental behavior, bioavailability, and the influence of elements on the quality of the environment. For speciation, X-ray absorption fine structure (XAFS) is a powerful tool, because it is a direct method by which we can avoid the change of the chemical state of target ele...

Poliovirus-seeded tap water, conditioned with MgCl2 and passed through virus-adsorbing filters, gave better poliovirus recovery than water identically treated but conditioned with AlCl3. Elution of several filter types with beef extract yielded higher recoveries than did elution with glycine. Seeded samples filtered through various filters and stored showed considerable virus loss in 2 days whe...

One of the critical factors for successfully conducting contamination characterization, removal, and remedial operations at hazardous waste sites is rapid and appropriate response to analyze samples in a timely fashion. Turnaround time associated with off-site analysis is often too slow to support efficient utilization of the data. Field portable X-ray fluorescence (FPXRF) techniques provide vi...

Nontuberculous mycobacteria (NTM) are a major cause of opportunistic infection in immunocompromised hosts. Because there is no evidence of person-to-person transmission and NTM have been found in drinking water, the environment is considered a likely source of infection. In this study the widespread occurrence of NTM was examined in drinking water, bottled water, and ice samples. A total of 139...

As we get into more and more analysis of environmental material, it is becoming increasingly apparent-in large part because of man's effect-that it is critical to take a look at composition as a function of size distribution of these small particles. The Duluth situation is one well known to this group, and I think it is an excellent example. It is one in which we have natural contributions of ...