Abstract

This study analyzes uncertainties in the ecological toxicology paradigm to expedite the reduction of overall uncertainty in policy decisions. To facilitate this analysis, ecological toxicology is developed both in theory and in an applied case of discharge regulation, i.e., assessment of biological impacts due to effluent discharge in Skeleton Creek, Enid, Oklahoma. ;There are both objective and subjective sources of uncertainty affecting each of the three stages in ecological risk assessment/management, i.e., research, risk assessment, and risk management. Objective sources in research and risk assessment, including uncertainties due to incomplete data bases, inaccurate measurements, and statistical extrapolations, culminate in risk assessment uncertainty associated with estimated risks. Uncertainty in estimated risks is then propagated to risk management in the development of policy options. Chronic 7-day Ceriodaphnia toxicity tests following current EPA methods are performed to provide a thorough examination of the most fundamental sources of objective uncertainty. ;The most important subjective sources examined are value uncertainties associated with both instrumental and intrinsic values. These uncertainties have direct effects on expert judgments and policy decisions and indirect effects on research. Examining these sources involves developing underlying paradigm assumptions, e.g., that humans are separate from nature, and then establishing connections between uncertainties in these assumptions, value uncertainties, and the effects that these uncertainties have on policy decisions. The influence that uncertainties in risk communication and perception have on public values are also examined. ;This analysis shows that value uncertainties are the most significant sources of uncertainty in the entire paradigm due to their underlying effects on all processes in ecological toxicology. The majority of time and resources, however, have been allocated to reducing objective uncertainties, with little effort expended on reducing subjective sources . The result of prioritizing objective sources has been slight reductions in overall policy uncertainty. However, significant reductions will remain elusive until value uncertainties are properly reduced, which may require modifying some very basic assumptions that have direct effects on environmental values