The South African Pollen Monitoring Network: Insights from 2 years of national aerospora sampling (2019–2021)

Abstract

BackgroundPollen monitoring has been discontinuously undertaken in South Africa, a country with high biodiversity, a seasonal rainfall gradient, and nine biomes from arid to subtropical. The South African Pollen Monitoring Network was set up in 2019 to conduct the first long‐term national aerospora monitoring across multiple biomes, providing weekly reports to allergy sufferers and healthcare providers.MethodsDaily airborne pollen concentrations were measured from August 2019 to August 2021 in seven cities across South Africa. Updated pollen calendars were created for the major pollen types (>3%), the average Annual Pollen Index over 12 months was calculated, and the results were compared to available historical data.ResultsThe main pollen types were from exotic vegetation. The most abundant taxa were Poaceae, Cupressaceae, Moraceae and Buddleja. The pollen season start, peak and end varied widely according to the biome and suite of pollen taxa. The main tree season started in the last week of August, peaked in September and ended in early December. Grass seasons followed rainfall patterns: September–January and January–April for summer and winter rainfall areas, respectively. Major urban centres, for example, Johannesburg and Pretoria in the same biome with similar rainfall, showed substantive differences in pollen taxa and abundance. Some major differences in pollen spectra were detected compared with historical data. However, we are cognisant that we are describing only 2 years of data that may be skewed by short‐term weather patterns.ConclusionsDifferences in pollen spectra and concentrations were noted across biomes and between geographically close urban centres. Comparison with historical data suggests pollen spectra and seasons may be changing due to anthropogenic climate change and landscaping. These data stress the importance of regional and continuous pollen monitoring for informed care of pollinosis.

Allergic rhinitis: Review of the diagnosis and management: South African Allergic Rhinitis Working Group

“…• Cladosporium has been removed from the ARDWG panel, and Plane and Cypress trees (Figure 2) included as early pollen monitoring data from across SA suggest these are the commonest allergenic tree pollens. 33 However, pollen data are not yet comprehensive for all areas across SA, and other allergenic pollens (trees and weeds) may be relevant in certain areas 33 (updated pollen data can be found at https:// pollencount.co.za/). • Specific tree panels should be considered based on clinical history, and where available, local sensitisation and pollen data (https://pollencount.co.za/).…”