Abstract:
BACKGROUND : Pollen 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.
METHODS : Daily 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.
RESULTS : The 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.
CONCLUSIONS : Differences 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.
Description:
CONFLICT OF INTEREST STATEMENT :
The authors declare that this research was made possible by the
following funders and industry affiliations: NE was funded by a UCT
Lung Institute Postdoctoral Research Fellow award (2019–2022); RG
and JJ were supported by a CSIR Parliamentary Grant for the
duration of the project; The University of the Free State team
received funding in 2020/2021 from the Interdisciplinary Funding
provided by the UFS; This project was supported by Zeiss South
Africa which sponsored light microscopes for aeropalynology at the
University of Cape Town and the University of the Witwatersrand.
The Real Pollen Count received industry sponsorship from Clicks, Dr.
Reddy's, Thermo Fisher Scientific, Novartis, Glenmark, SA Natural
Products, and Twinsaver.
DATA AVAILABILITY STATEMENT :
The data that support the findings of this study are available from the
corresponding author upon reasonable request.
