Human Severe Effect Estimates for CK IH

From Section 9.6.1.1, the ratio of the ECtjo (severe) to LCtso for CK has been found experimentally to equal 0.60. Thus, the 2 min ECtjo (severe) for a healthy subpopulation equals 4100 x 0.6 or 2460 mg min m , which was rounded to 2500 mg min m for the final estimate. Severe effects (for the purpose of this estimate) are defined as unconsciousness/collapse. This follows the approach of Short et al. (1944) (see Section 9.5.1) and medical opinion. Since severe effects and lethality result from the same toxic mechanism, the lethality PS (12) was adopted for severe effects. Using a PS of 12, the ETLxx (severe) can be expressed as  

SSSThe critical Crosier parameters of 5,- and % equal 0.900 and 0.744, respectively, for a single truncation subpopulation. This assumes that the healthy subpopulation comprises 30% of the general population. 

For the general population, the lethality PS (9) was adopted for severe effeets. Using the Crosier model (with the same inputs as were used for lethality), the ECtjo (severe) was found to equal 1982 mg min m, which was rounded to 2000 mg min m for the final value. Using a PS of 9, the ETL x-can be expressed as  

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