How are asthmatics included in the derivation of guideline values for emergency planning and response?

Guideline values for emergency planning and response are aimed to protect the general public, including asthmatics and other susceptible groups, during sudden airborne releases of chemicals. A precondition of asthma may increase the individual susceptibility to acute exposures. This paper studies to what extent experimental data on asthmatics are included in the rationale and derivation of guideline values. An analysis of the Technical Support Documents (TSDs) of the Acute Exposure Guideline Levels (AEGLs) shows that only 23 of the 176 TSDs include references to experimental studies on asthmatics, 30 include a statement on asthmatics but no reference to experimental data, and 123 lack any explicit statement on asthmatics. The TSDs were further compared with the support documents of nine other programs for acute or occupational short-term values. All programs were incomplete with respect to experimental data on asthmatics. Omission of asthmatics may interfere with trustful and efficient health protective actions. We suggest that the availability of data on asthmatics should be carefully examined in the development of guideline values, and that the lack of such data should be explicitly noted. In the latter case, available data for other irritants may be used to justify an appropriate assessment factor.