Question

A risk assessment is performed by a team representing various technical disciplines. The air dispersion modeler has estimated his uncertainty as a factor of 1.3 for “modeling”, 1.6 for “statistics”, and 1.4 for “others”. What is the uncertainty range for a best estimate concentration of 3.8 µg/m3?

Answer 1

Solution )

Given uncertainty factor for modelling = 1.3

Uncertainty factor for statistics = 1.6

Uncertainty factor for others = 1.4

Overall factor of uncertainty = 1.3*1.6*1.4 = 2.91

Given concentration to be estimated

= 3.8 micrograms/m3

Lower limit after uncertainty = 3.8/2.91

= 1.305 micrograms/m3

Higher limit after uncertainty = 3.8*2.91 = 11.06

Uncertainty range for the estimated concentration of 3.8 micrograms/m3 is between

1.305 microgms/m3 to 11.06 microgms/m3