CLIMATE CHANGE AND AEROALLERGENS IN SOUTH AFRICA

Climate change and its effects on aeroallergens and allergic disease have been extensively studied in the northern hemisphere, but there has been a dearth of similar studies in the southern hemisphere. Aero-allergens are extremely sensitive to certain weather parameters and changes may increase or decrease their levels in the atmosphere. Climate change projections include global warming, an increase in extreme weather events and greater volumes of rain. Alterations in the carbon dioxide levels, mean temperature, relative humidity and wetting of the nine distinct climate zones in South Africa will affect the vegetation distribution, causing shifts which will disturb the balance of their ecosystems. These changes will have a profound effect on aeroallergens such as pollen, fungal spores, house-dust mite and cockroach, each of which have specific climatic requirements. Changes to climatic conditions could extend the pollen season of allergenic plants and increase the concentration of allergenic pollen in the air. Increased relative humidity and temperature could increase the levels of house-dust mites and fungal spores. There is a concerted call by northern hemisphere researchers for greater emphasis on pollen and fungal spore testing in clinical practice and for the standardised collection of aerobiological data worldwide, in order to meet the anticipated changes.