Opportunities for expanded use of soil, plant and water analysis in environmental management

Facilitated by advances in analytical chemistry, soil, plant and water analysis now play a key role in the qualitative and quantitative characterisation of the environment. Ecological and health risk assessments can predict probabilities and risks of nominated environmental outcomes from the analytical data. The accuracy of these predictions, however, is dependent on data interpretability, which is constrained by our ability to determine that fraction of the contaminant that is active in biological systems. Soil analyses, for example, are used to characterise chemically contaminated sites and determine remediation thresholds. Such decisions, though, typically are based on total analyte concentrations that often are unrelated to environmental risk. While combined ecotoxicity and chemistry tests enable quantification of soil toxicity and identification of the analytes responsible, further progress may depend on development of sequential extraction and speciation tests calibrated against bioavailability/toxicity. Similarly, while we can measure most contaminants in plant tissues and understand how they affect plant metabolism, we remain unable to identify/quantify the physiologically active fraction. There is scope to improve interpretation by linking sub-cellular chemical forms to toxicity. Substantial gains, too, have been made in water testing with the development of ambient water quality criteria related to organism-level responses. We have much to learn, though, about effects of speciation, complexation, sediment/water column interactions, and ecosystem-level responses. Solving such challenges should expand opportunities for environmental managers to use soil, plant and water analysis in the 21st Century.