Quantitative characterization of trace levels of PFOS and PFOA in the Tennessee River.

Although there is evidence of widespread distribution of organic fluorochemicals such as perfluorooctane sulfonate and perfluorooctanoate, in the environment, the versatility of these compounds in industrial and commercial applications complicates characterization of pathways into the environment. A solid-phase extraction method coupled with HPLC-negative-ion electrospray tandem mass spectrometry was developed to quantitatively measure trace levels of organic fluorochemicals in drinking water and surface water. Using this method, certain fluorochemicals can be quantitatively measured in water samples down to 25 ppt, a level well below calculated drinking water advisory levels. To assess fluorochemical distribution in a localized geography and to ascertain whether fluorochemical manufacturing facilities contribute to environmental levels of fluorochemicals, 40 water samples were collected on an 80-mi stretch of the Tennessee River, near a fluorochemical manufacturing site in Decatur, AL. Low levels (ppt) of perfluorooctane sulfonate were determined throughout the stretch of river sampled. Concentrations of the measured fluorochemicals increased downstream of the fluorochemical manufacturing facility, indicating that effluent from manufacturing is one likely source of organic fluorochemicals into the river.

Transfer of 137Cs and 60Co in a waste retention pond with emphasis on aquatic insects.

The objectives of this research were (1) to analyze the transfers of 137Cs and 60Co in a retention pond, with emphasis on aquatic insects and (2) to determine if detectable concentrations of these radionuclides are exported by emerging aquatic insects. We analyzed the radionuclide concentrations in the following components: water solution, bottom sediments, suspended particulate matter, plankton, floating mats of filamentous algae, benthic macroinvertebrates, and emerging aquatic insects. Samples were collected quarterly from June 1981 to April 1982. The lowest concentrations (in picocuries per milliliter) occurred in solution (range: 1.4 X 10(2) to 3.2 X 10(2) for 137Cs and 8.1 X 10(-1) to 2.2 X 10(0) for 60Co). The highest concentrations (in picocuries per gram dry weight) occurred in the sediments (range: 1.5 X 10(4) to 1.1 X 10(8) for 137Cs and 1.0 X 10(2) to 4.3 X 10(6) for 60Co). The primary producers and aquatic insect consumers had concentrations of both radionuclides that were two to four orders of magnitude higher than the respective concentrations dissolved in water but two to three orders of magnitude lower than the concentrations in the sediments. The concentrations of both radionuclides decreased successively at higher trophic levels. There were considerable temporal variations as the radionuclides cycled among the abiotic and biotic components of the pond. Emerging adult aquatic insects had lower concentrations of both radionuclides than the immature stages that lived in the pond (adult/immature ratio about 0.25). Because the emerging adult insects contain detectable concentrations of radionuclides, have relatively long life spans, and disperse away from the aquatic habitat, we conclude that adult aquatic insects would be effective biological monitors.

Radioactive pollutant determinations using gamma-ray spectroscopy.

Qualitative and quantitative determination of radionuclide contamination in environmental samples is often complicated by the presence of uranium- and thorium-series radioelements as well as 40K. High resolution gamma-ray spectroscopy with lithium-drifted germanium detectors provides a method for the determination of man-made radio-nuclide contaminants in many matrices with a minimum of chemical separation. Methods have been studied for increasing the efficiency of such determinations by using large samples in reentrant beakers ("Merinelli beakers") and small samples inside the well of a recently developed Ge(Li) well detector. Specific examples for the determination of 129I(16 m.y. half-life) in the well detector and recent fall-out in grass samples are presented.

Primordial radioelements and cosmogenic radionuclides in lunar samples from apollo 15.

Two basalts, two breccias, and two soils from Apollo 15 were analyzed by nondestructive gamma-ray spectrometry. The concentrations of potassium, thorium, and uranium in the basalts were similar to those in the Apollo 12 basalts, but the potassium: uranium ratios were somewhat higher. Primordial radioelements were enriched in the soils and breccia, consistent with a two-component mixture of mare basalt and up to 20 percent foreign component (KREEP). The abundance patterns for cosmogenic radionuclides implied surface sampling for all specimens. The galactic cosmic-ray production rate of vanadium-48 was determined as 57 +/- 11 disintegrations per minute per kilogram of iron. Cobalt-56 concentrations were used to estimate the intensity of the solar flare of 25 January 1971.

Elemental compositions and ages of lunar samples by nondestructive gamma-ray spectrometry.

A gamma-ray spectrometry system with low background was used to determine the radioactivity of crystalline rocks, breccias, and fine material. Nuclides identified were (40)K, (232)Th, (238)U, (7)Be, (22)Na (26)A1, (44)Ti, (46)Sc, (48)V, (52)Mn, (54)Mn, and (56)Co. Concentrations of K, Th, and U ranged between 480 and 2550, 1.01 and 3.30, and 0.26 and 0.83 parts per million, respectively. Concentrations of thorium and uranium were those of terrestrial basalts, while the potassium concentrations were near values for chondrites. Products of low-energy nuclear reactions showed pronounced concentration gradients at rock surfaces. Concentrations of K and of (22)Na determined here were combined with concentrations of rare gases to estimate gas-retention ages and cosmic-ray exposure ages with ranges of 2200 to 3200 and 34 to 340 million years, respectively, for three rocks.

Meteorite fail at pueblito de allende, chihuahua, Mexico: preliminary information.

Specimens from the meteorite fall at 1:05 a. m., on 8 February 1969 at Pueblito de Allende, Chihuahua, Mexico, have been recovered. The meteorite is a chondrite (C3 and C4) with both opaque and microcrystalline matrices. Specimens were brought to a low background gamma counter less than 4 (1/2) days after the fall, and gamma rays from short-lived isotopes have been observed.