ABSTRACT
Environmental Risk Assessment (ERA) is a method to evaluate the probability that adverse effects on the environment or human health occur, or may occur, as a consequence of exposure to physical, chemical, or biological agents. There are generally four key steps to conducting a risk assessment, which include hazard identification, exposure assessment, dose-response assessment and, finally, risk characterization for human health and ecological exposure. In its essence, risk assessment, itself, is a tool used to organize, structure and compile scientific information in order to help identify existing hazardous situations, anticipate potential problems, establish priorities and provide a basis for regulatory controls and/or corrective actions. ERAs can actually involve the evaluation of both human health impact risks and ecological (i.e. environmental) impact risks. For both types of assessments, the step of hazard identification involves recognizing and documenting the adverse effect that a substance has an inherent capacity to cause. Exposure assessment involves the estimation of the concentrations/doses to which human populations (i.e., workers, consumers and individuals exposed indirectly via the environment) or environmental compartments (aquatic environment, terrestrial environment and air) are or may be exposed. Dose-response assessment is used to estimate the relationship between dose, or level of exposure to a substance, and the incidence and severity of an effect. Lastly, risk characterization involves estimation of the incidence and severity of the adverse effects likely to occur in a human population or environmental compartment due to actual or predicted exposure to a substance, i.e., the quantification of that likelihood.
