Assessment of ecological risks during manufacturing, use, transport, and disposal are becoming increasingly important as planning tools during development of new products. The objective of this study was to establish the potential ecotoxicological hazard associated with two polycarboxylate polymers in water, sludge, sediment, and soil. The concentrations of both polymers were quantified using 14C-radiolabeled synthesis and liquid scintillation counting (LSC). The program included water column acute and chronic exposures with Ceriodaphnia dubia, Pimephales promelas, and Selenastrum capricornutum, sediment exposures with Chironomus riparius, and soil exposures with Eisenia foetida. Sludge treated with either polymer, from a semicontinuous activated sludge unit, was used to evaluate the effect on growth of five plants. The hazard assessment program for both polymers indicated a very low order of toxicity as defined by the U.S. EPA and OECD. Very small fractions of each polymer may not be removed by waste treatment and could accumulate in sediments, but should not pose a significant risk because of their low toxicity to benthic organisms. Terrestrial testing demonstrated that soil needs to be saturated with these chemicals to produce adverse effects. Bioaccumulation potential for both polymers was extremely low. Use of these polymers does not appear to pose a significant risk to the environment, based on their low inherent toxicity.

The mineral content of stationary bone samples can be quantified by 31P nuclear magnetic resonance (NMR) spectroscopy. The assay can be performed in regions of the anatomy that pose problems for absorptiometric techniques, because the mineral content is measured within a selected volume without concern for the geometry of the bone. In vivo 31P NMR spectra of the bones in human fingers and wrist are reported. Soft tissue such as marrow and skeletal muscle contributes little to the 31P NMR spectra of human fingers and wrist and thus should not seriously affect the accuracy of the mineral assay. 31P NMR spectrometry should prove helpful for confirming rapid bone mineral loss in those at risk and for monitoring response to treatment.

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The mineral content of bone can be quantified by recording a 31P NMR spectrum while the bone is stationary. The quantity of mineral in the bone is determined from the spectrum with a reference standard by comparison of relative peak areas. The phosphate of bone mineral is readily distinguished from inorganic phosphate and phosphorylated metabolites dissolved in cytosol and from the head groups of phospholipids in membranes. The technical feasibility of constructing a cost-effective instrument for analysis of bone mineral content in the extremities is demonstrated. The possible utility of such a noninvasive assay for detecting osteoporosis and for monitoring the progress of treatment is discussed.

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