Multiple chemical sensitivity

Of the 200 or so recent publications on MCS in the biomedical literature, only about 30 relate to original research. In almost all cases, the validity and precision of the research leave much to be desired. This is related to the fact that there is no unambiguous definition of MCS, and hence, a priori, there is considerable vagueness concerning both the possible causes and effects of the phenomenon. If MCS is to be researched in a more scientific manner, there is need for hypotheses that are both reasonable and testable (Dye97). Researchers should agree on the measurable characteristics of MCS, as well as its possible causes.