Modifying factor Risk index

The modifying factor in the risk index represents any considerations of importance to waste classification other than those that are directly incorporated in the calculated risk from disposal and the specified allowable risk. The modifying factor can take into account, for example, the probability of occurrence of assumed exposure scenarios used in classifying waste, uncertainties in the assessment of risk from disposal and in the data required to evaluate the risk index, levels of naturally occurring hazardous substances in surface soil and their associated health risks to the public, and the costs and benefits of different means of waste disposal. The modifying factor is discussed further in Section 6.3.3. 

The modifying factor in the risk index in Equation 6.2 or 6.3 represents any factors deemed important in classifying waste other than those explicitly accounted for in the calculated risk or dose from waste disposal in the numerator or the allowable risk or dose for the waste class of concern in the denominator. The modifying factor generally can be substance- or waste-specific. 

NCRP notes that the modifying factor in the risk index should be applied independently of the requirement to achieve a negligible risk or dose for exempt waste or an acceptable (barely tolerable) risk or dose for nonexempt waste, in order to provide regulatory flexibility in classifying particular wastes. NCRP believes that such flexibility is highly desirable to promote cost-effective management and disposal of waste, provided it is applied in a transparent manner. 

As in the case of the risk index for mixtures of substances that cause stochastic responses discussed in the previous section, the modifying factor (F) in Equation 6.5 generally can be substance-specific, but its value often would be the same for all substances in a given waste that cause deterministic responses. 

For the purpose of illustrating how the composite risk index in Equation 6.6 would be used to classify a hypothetical waste, it is helpful to simplify Equations 6.4 and 6.5. This is done by assuming that the summation over all responses (index r) has been calculated, that only one waste classification boundary represented by the index j is being considered (i.e., the boundary between exempt and low-hazard waste, based on a negligible risk, or the boundary between low-hazard and high-hazard waste, based on an acceptable risk), and that the modifying factor (F) is unity. Further, the calculated dose in the numerator of the risk index is denoted by D and the allowable dose in the denominator is denoted by L. Then, the composite risk index for all hazardous substances in the waste, expressed in the form of Equation 6.6, can be written as ... 

New-onset DM prevention consists mainly of identifying patients at risk before transplantation and controlling modifiable risk factors both before and after transplantation.74 The major modifiable risk factors are choice of immunosuppressive therapy and body mass index (BMI). For example,... 

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