ALLERGENIC IMPLICATIONS OF AIRBORNE LEPTOSPHAERIA ASCOSPORES

In order to investigate potential aeroallergens of the Auckland region , a quantitative and qualitative study of the air spora was conducted at three different sites over the 12-month period, September 1979 to A ugust 1980. Burkard volumetric spore traps were operated simultaneousl y at each of the three sites viz. Mt. Eden, Henderson and Waitakeres, located on a 20-km axis extending westward from Auckland City and enco mpassing residential, horticultural, agricultural, commercial and fore sted contexts. In the individual category of ascomycetous fungi, Lepto sphaeria ascospores were recorded as an important component of air spo ra of the two non-forested sites. Ascospores concentration displayed a seasonal peak in late summer (February) and early autumn (March) and a diel periodicity with a distinct nocturnal maxima at all sites, conf irming Leptosphaeria to be a component of the ''rising air'' or ''damp -air spora''. The maximum concentration exceeded 4430 m-3 of air aroun d midnight (24/25 March, early autumn). A comparison of the results fr om the three sites showed that 61% of the total Leptosphaeria ascospor es were trapped at Henderson (a satellite town in a rural setting) 29% at Mt. Eden (commercial/residential area) and 10% at Waitakeres (main ly forest site). Our data for Leptosphaeria ascospores combined with a high regional incidence of respiratory allergic diseases particularly bronchial asthma in late summer and autumn, indicate that a thorough investigation of the role of Leptosphaeria as a potential aeroallergen is warranted.