[en] A review is presented of the literature through 1977 on the uses of radioactive lead isotopes in metabolic studies in man, animals, and plants. These studies have been done mainly with the naturally-occurring, long-lived (22-yr half life) ²¹⁰Pb, but a few were with 53-hr ²⁰³Pb or 10.6-hr ²¹²Pb. Such studies have made possible estimates of the metabolic parameters of lead in man and animals, such as intestinal absorption, the ratio of fecal-to-urinary excretion of endogenous lead, residence time of lead in the body and in various organs, and the distribution in the body (skeleton, liver, kidney, and blood). Subsequently, these parameters and data have been used to trace the sources of lead for man, such as those from the atmosphere, food, cigarette smoke, and automobile exhaust

[en] A review of the literature and the results of some recent measurements were presented on the levels in man's diet of the naturally-occurring radionuclides ²²⁶Ra, ²²⁸Ra, ²¹⁰Pb, and ²¹⁰Po. The mean intakes for standard U.S. diets for these nuclides are tabulated. Intakes in other countries are similar to those in the U.S., but in localized populations the ²²⁶Ra intake may be 8 or more pCi/day. The contents of ²²⁶Ra in diets chosen by individuals ranged from 0.4 to 7 pCi/day. The few data on ²²⁸Ra show intake of this nuclide to be about 80% that of ²²⁶Ra, except in monazite areas where intakes of up to 160 pCi/day ²²⁸Ra are reported, which may be 50 to 100 times that of ²²⁶Ra. Drinking water contributes less than 5% of the daily intake, except in special areas

[en] The left eye from each of two CHR cases, 01 to 144 (body burden 690 nCi) and 01-017 (body burden 1210 nCi) was analyzed for ²²⁶Ra and calcium. The total amounts in the eye were 1.80 pCi of ²²⁶Ra and 2.3 mg of Ca in case 01 to 144, and 5.4 pCi of ²²⁶Ra and 14.2 mg of calcium in case 01 to 017. For the latter case the eye was dissected and showed the highest concentrations of activity (on a wet basis) in the choroid, 3.8 pCi/g, sclera 3.4 pCi/g and iris 2.9 pCi/g. The radium content of the eye was 2.7 x 10^-4 percent to 4.7 x 10^-4 percent of the total body content at 50 to 55 yr after first exposure. The ²²⁶Ra/Ca ratios in the whole eye were ¹/₃ to ¹/₄ those in the whole body, but that for the choroid from the dissected eye was identical to that of the whole body

[en] Over a large region of Illinois, ground water of the Cambrian-Ordovician Aquifer System exceeds the US EPA drinking water standard of 5 pCi/L for the combined concentration of ²²⁶Ra and ²²⁸Ra. ²²⁶Ra concentrations range from <1 pCi/L in dilute ground water in north-central Illinois (where the aquifer is unconfined) to 25 pCi/L in highly mineralized ground water in central Illinois (where the aquifer is confined by shale bedrock). An important control on the activity of ²²⁶Ra is the geochemistry of uranium in the ground-water flow system, while the ²²⁸Ra activity in ground water which ranges from <1 to 13 pCi/L depends mainly on the primary deposition of ²³²Th-bearing minerals in the aquifer strata. The comparison of recent analyses to historical data gathered over the last 20 years indicates that, with few exceptions, ²²⁶Ra and ²²⁸Ra activities in ground water have remained constant. The combined concentrations of the two nuclides in ground water of the aquifer system ranged from <1 to 29 pCi/L. Over large regions where the ²²⁶Ra concentrations were high (greater than or equal to 10 pCi/L), those of ²²⁸Ra were low (less than or equal to 2 pCi/L), but, with few exceptions, in regions where ²²⁸Ra concentrations were high, those of ²²⁶Ra were also high. The range of values raises questions concerning the validity of the US EPA regulation which requires analysis for ²²⁸Ra only when the concentration of ²²⁶Ra exceeds 3.0 pCi/L

[en] Atomic absorption spectrophotometry (AAS) employing electrothermal atomization in a pyrolytic graphite tube is shown to be a precise and accurate method for analysis of 11 rare earth, or rare-earth-like elements in air filter samples taken in a thorium and rare earth refinery. The method is fairly rapid since it involves only fluoric acids. Each element was sequentially analyzed from the same resulting solution by using either the techniques of standard-curve calibration or that of standard additions. The two methods used on the same sample gave essentially identical results (composite ratio for 171 such trials being 0.9996). Matrix effects were negligible and no background correction was necessary. The average percent standard deviation for all duplicate trials (176) was 4.2%. Elements analyzed by this method were La, Nd, Sm, Eu, Gd, Dy, Ho, Tm, Yb, Gd, Sc and Y. Other rare earths such as erbium (Er), lutetium (Lu), and terbium (Tb), with comparable analytical sensitivity by AAS to Dy, Sm, and Nd, respectively, could presumably be analyzed by this method as well

[en] Because of the uncertainties in determining the separate members of the ²³¹Pa series in vivo by whole body counting, measurements of the rates at which they are excreted provide useful supplementary information for the estimation of doses to persons with long-term contamination by ²³¹Pa. A procedure is presented here for the sequential analysis of urine for ²³¹Pa and members of its decay chain, 22-yr ²²⁷Ac, 18.7-day ²²⁷Th, and 11.4-day ²²³Ra. The urine is wet-ashed with nitric acid, and the Pa is preferentially adsorbed onto silica gel, which is then separated from the supernate; the silica is removed with HF. The Pa is electrodeposited onto a stainless steel disk by the method of Talvitie. The ²²⁷Th is coprecipitated from the original wet-ashed solution with cerous fluoride, and the thorium is separated from the cerium by extraction into thenoyltrifluoroacetone (TTA) at pH 2 from a concentrated solution of Almeasurements mentsl₃. After back extraction of the Th into strong nitric acid it is electroplated as above. The ²²³Ra is coprecipitated with BaSO₄ and they are filtered out. Each of the separated nuclides is determined by counting in a proportional α-counter or in a solid-state alpha spectrometer. ²²⁷Ac, the 22-yr daughter of the ²³¹Pa, is determined by aging the aqueous supernate from the TTA extraction for several months and then analyzing for the newly grown ²²⁷Th. Cross contamination between the radioelements was less than 1 percent. Yields of added tracers were about 85 to 96 percent and were constant to +-3 percent between runs. (U.S.)

[en] The ²²⁶Ra concentration determined by the radon emanation method in a sample of NBL Reference Material No. 6-A, pitchblende ore was 192.6 +- 1.3 ng ²²⁶Ra/g ore. The weight ratio of radium to natural uranium was (3.344 +- 0.06) x 10^-7. This value is not significantly different from the value of 3.374 x 10^-7 expected if the radium were in radioactive equilibrium with its ²³⁸U parent

[en] An isotope dilution method has been incorporated into the ²¹⁰Pb-²¹⁰Po analysis. A known amount of ²⁰⁹Po is added to the sample before analysis. Then both ²⁰⁹Po and ²¹⁰Po are deposited on a silver planchet which is assayed in an alpha spectrometer to determine the activities of each isotope. The recoveries generally range from 70% to 90%

[en] The precision of the radon emanation system used in the determination of radium was 2.7 percent with a National Bureau of Standards radon emanation standard of 400 pCi and about 3.5 percent with a 10 pCi standard. The mean values of results of 12 or more measurements on each of these standards were within 0.5 percent of the NBS values. ''System'' blanks (air blank only) were 0.008 +- 0.006 (S.D.) pCi for System A and 0.006 +- 0.006 (S.D.) pCi for System B. For reagent blanks the mean was 0.015 +- 0.004 (S.D.) pCi. The errors of measurement in replicate sample measurements were consistent with those of the NBS standard samples

[en] The concentrations of ²²⁶Ra were determined in 190 samples of bone and in four teeth from a woman who had worked for two years as a radium dial painter 52 years prior to her death. The terminal body content of ²²⁶Ra was 200 nCi. The weighted mean concentration of activity in bone was 146 +- 11 pCi/g ash, with a range of 12 to 1000 pCi/g ash. The mean level in cortical bone was 116 +- 14 pCi/g ash, while that in porous bone (trabecular and eroded cortex) was 227 +- 25 pCi/g ash