Objectives: Environmental clinics are frequented by patients with fears and complaints related to environmental triggers. A dose-independent overreaction to small doses of widely used and generally non-toxic chemicals is referred to as multiple chemical sensitivity (MCS), but no clearly defined clinical syndrome with objective physical findings has been delineated so far. We aimed to obtain information about symptoms, supposed environmental triggers, the frequency of self-reported chemical sensitivity, and of the diagnosis MCS in Germany.
Methods: We conducted a representative survey among 2032 adult Germans.
Results: We found self-reported chemical sensitivity in 9% and physician-diagnosed MCS in 0.5% of our representative sample. Physical complaints were common in the whole study population and in chemically sensitive individuals, but there was no clear-cut symptom constellation among the latter. The most common complaints were headache, fatigue, sleep disturbances, joint pain, mood changes and nervousness. A subjective connection between complaints and environmental triggers was denied by 67% of the whole group and by 35% of the self-reported chemically sensitive. Factor analysis of environmental triggers suggested that a specific exposure situation rather than chemical similarity is the basis for individual trigger combinations.
Conclusions: The prevalence of subjective sensitivity towards chemicals is similar to such rates reported from other countries. There is a relatively low awareness of the MCS-concept, and it appears to be diagnosed less frequently than, e.g., in the USA. Since symptoms and triggers in chemically sensitive individuals did not differ from the general population, our data do not suggest the existence of a widespread new syndrome related to chemical sensitivities in Germany. We outline the limitations of self-reported chemical sensitivity as the major criterion for such a contentious diagnosis as MCS.