Table 5.

Comparison of Phased Approaches for Stressor-Based and Effects-Based Cumulative Risk Assessment as described by Menzie et al. [61].

Phase	Stressor-Based Approach	Effects-Based Approach
Step 1	- develop conceptual model describing stressors and ways they cause effects - identify receptors and end points affected by stressors individually and in combination - establish common denominators for evaluation by identifying common receptors and end points	- develop conceptual model describing important stressors and the ways they cause critical effects - establish common denominators for evaluation by identifying common receptors and end points
Step 2	- screen stressors of interest to determine which need to be included in the assessment and which may act in combination	- screen potential stressors to identify an appropriate and manageable number to characterize the problem adequately
Step 3	- appraise individual effects of stressors along with combinations of other stressors as part of the conceptual model - determine how the combined effects of multiple stressors affect end point - incorporate psychosocial stressors by characterizing the environmental and cultural and socioeconomic attributes of exposed groups	- appraise the individual effects of individual stressors to determine whether one or a few stressors are predominant
Step 4	- assess the combined effect of stressors, taking into account potential interactions among the stressors and effects	- assess the combined effects of stressors without considering the potential for interactions
Step 5	- not applicable	- gauge the combined effect of stressors, taking into account potential interactions among the stressors and effects