Ozone increases allergy potential of rye

(Vienna, 23 August 2010) - Higher ozone levels may increase the allergy potential of plants. Scientists from the Medical University of Vienna and the Austrian Institute of Technology (AIT) have now been able to prove this connection for rye anyway. The work was supported by the Austrian Science Fund (FWF) and has been published in the scientific magazine "Journal of Allergy Clinical Immunology".

The team headed by Rudolf Valenta from the Centre for Pathophysiology, Infectiology and Immunology at MedUni Vienna grew two different types of rye under controlled environmental conditions here. For one group of plants the ozone concentration was at times increased to 79 ppb (parts per billion). This figure corresponds with the top levels in the national capital on hot days. For comparison, normal ozone levels at ground level are around 22 ppb.

After maturation of the pollen this was analysed for its content of proteins, considered as a trigger of allergies. Not only were the general protein contents of the plants with high ozone levels increased here. It was also demonstrated in particular that known allergens were found in higher concentrations than in the types of rye without high ozone levels.

Since "more allergens" does not automatically mean "more allergies", however, the researchers made further investigations and exposed the protein extracts of the different plants to so-called IgE antibodies of allergy patients. IgE antibodies are relevant for the development of allergies in the human body.

With these experiments the result was also clear: the protein extracts of the plants stressed with ozone showed a stronger reaction with the IgE antibodies than those of the control group. From this the scientists conclude that the rising ozone content of the soil air may be one of the reasons for the increasing number of allergic diseases in recent years.