Watershed, risk assessment

Hall, L.W., Jr., M.C. Scott, and W.D. Killen. 1998. Ecological risk assessment of copper and cadmium in surface waters of Chesapeake Bay watershed. Environ. Toxicol. Chem. 17 1172-1189. 

Golet EM, Alder AC, Giger W (2002) Environmental exposure and risk assessment of fluoroquinolone antibacterial agents in wastewater and river water of the Glatt Valley Watershed, Switzerland. Environ Sci Technol 36 3645-3651... 

Diamond, J. M. Serveiss, V. B. 2001. Identifying sources of stress to native aquatic fauna using a watershed ecological risk assessment framework. Environmental Science and Technology, 35, 4711-4718. 

The purpose of this paper Is to (1) clarify the distinction between traditional risk assessments involving single species and assessments that integrate effects among species, including both direct and indirect effects (2) show the kinds of Information needed for ecosystem assessments at the forest watershed level and (3) review the recommendations of the National Research Council Committee in terms of the type of information needed and its availability for herbicides and forestry. 

The cotton landscape example presented above reveals that landscape-level risk assessment can be conducted by investigating the influence of the surrounding landscape on the emission of insecticides to the water bodies of concern in order to characterize more realistically actual exposure concentrations. This relatively simple approach addresses variability within the landscape, but pays less attention to the interactions between water bodies. A more complex approach is to assess the fate and effects of a chemical (or combination of stressors) for the entire watershed and to consider this watershed as a true continuum. The latter approach may include all water bodies within a watershed and addresses their interdependence, for example, by studying the flow of water, chemicals, matter, and organisms between these systems. An example of such a watershed approach is the study of Pandovani et al. (2004). They used a landscape-level approach to assess aquatic exposure via spray drift of chlorpyrifos-methyl in the watershed of the Simeto River in Sicily (Italy). 

Wurbs, A. Kersebaum, K. C. Merz, Ch. (1999) Quantification of leached pollutants into the groundwater caused by agricultural land use - scenarios as a method for - quantitative risk assessment of groundwater pollution. In Integrated Watershed Management in the Global Ecosystem, CRC, Boca Raton, Florida, 239-250. 

This gives an example of fate modeling in which the risks of an insect growth inhibitor, CGA-72662, in aquatic environments were assessed using a combination of the SWRRB and EXAMS mathematical models.. Runoff of CGA-72662 from agricultural watersheds was estimated using the SWRRB model. The runoff data were then used to estimate the loading of CGA-72662 into the EXAMS model for aquatic environments. EXAMS was used to estimate the maximum concentrations of CGA-72662 that would occur in various compartments of the defined ponds and lakes. The maximum expected environmental concentrations of CGA-72662 in water were then compared with acute and chronic toxicity data for CGA-72662 in fish and aquatic invertebrates in order to establish a safety factor for CGA-72662 in aquatic environments. 

Hall Jr., L.W., R.D. Anderson, J. Kilian, and D.P. Tierney (1999). Concurrent exposure assessments of atrazine and metolachlor in the mainstem, major tributaries and small streams of the Chesapeake Bay watershed Indicators of ecological risk. Environ. Monit. Assess., 59 155-190. 

In a chemically disturbed landscape unit, exposure concentrations, as well as population and community responses, may show clear spatial patterns. Assessing risks at a landscape scale (e.g., watershed), however, requires the development of a... 

When studying the ecological status of watersheds and landscapes, monitoring techniques and indicators are widely used tools. The diagnostic indicators comprise indicator species and community metric approaches. To improve the interpretation of monitoring programs and ecosystem health indicators to assess risks of... 

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