Study reaffirms importance of developing nationwide pollen-monitoring system

Results from a ground-breaking pollen-monitoring study, focused on various regions in South Africa, has revealed the importance of developing a formal, nationwide pollen-monitoring system, to assist clinicians as they treat patients with asthma, hayfever and eczema.

Led by Professor Jonny Peter in the University of Cape Town’s (UCT) Division of Allergology and Immunology, the two-year study kicked off in 2019 and monitored multiple biomes in the country. Titled: “The South African pollen monitoring network (SAPNET): Insights from two years of national aerospora sampling”, the study is the country’s first-ever aerospora (pollen and fungal spores) monitoring system and measured daily airborne pollen concentrations in seven cities. To get this message across to their audience, researchers consolidated the data and provided weekly pollen count reports to healthcare providers and allergy sufferers via the Real Pollen Count website.

Prior to developing the SAPNET, Cape Town was the only region in the country that provided updated information on its pollen levels, while provinces like Gauteng’s and KwaZulu-Natal’s available monitoring information was patchy and outdated. Some of the other newly monitored areas had never been sampled before.

“Previously, South Africa had no published data that indicated the pollen profiles or most abundant pollen taxa in our nine biomes.”

“Previously, South Africa had no published data that indicated the pollen profiles or most abundant pollen taxa in our nine biomes. It was important for us to define the similarities and differences found between the pollen catch in the biomes to better manage patients with seasonal allergies triggered by pollen, and understand the pollen differences in the country,” said co-researcher, Dr Dilys Berman.

Importance of understanding pollen levels

The SAPNET aimed to plug this gap and help clinicians understand the pollen and fungal taxa driving respiratory allergies among allergy sufferers.

Since its inception, the network has closely monitored airborne pollen and fungal spores in some of the major cities in South Africa with diverse climates, topographies and vegetation types. Dr Dilys said monitoring processes were primarily conducted in Cape Town, Johannesburg, Pretoria, Bloemfontein, Kimberly, Durban and Gqeberha. An eighth site in the Northern Cape was added to the network in 2021, but its results remain inconclusive.

The pollen and spore counts were calculated daily, and the results were shared on the website to provide the public and healthcare providers with an accurate allergy risk guide.

“Allergologists urgently need up-to-date pollen counts to facilitate treatment and to manage allergy symptoms. This network is especially useful because it creates awareness on the seasonal patterns of pollen in different biomes, which is crucial for healthcare workers as they develop treatment regimens for their patients,” she said.

The largest dataset of aerobiological monitoring

According to Dr Dorra Gharbi, a postdoctoral research fellow at the Lung Institute, South Africa has approximately nine distinct biomes that contain numerous vegetation units. Each biome comprises a unique climate and suite of plant species. The pollen monitoring study provided extensive details on each biome and matched this data with a significant array of pollen exposure.

The main pollen types uncovered during the research process emanated from exotic vegetation. And the leading pollen aeroallegens identified in the study included grass and trees, specifically cypress trees, mulberry plants and false olive trees. While these tree species were largely similar nationally, Dr Gharbi said grass species were widely different across the biomes.

While monitoring and comparing the data across the multiple regions, she said one thing is clear: the country’s weather patterns are shifting, and climate change is to blame – and this could have serious implications for allergy sufferers. The change in weather patterns will increase the amount of pollen in the air and extend the pollen season, which is now expected to start sooner and end later.

“Climate change could also alter the amount of pollen released into the environment, which is likely to make the pollen season more intense for allergy sufferers.”

“Climate change could also alter the amount of pollen released into the environment, which is likely to make the pollen season more intense for allergy sufferers,” she said. “We wouldn’t know any of this without the SAPNET, which is now officially the largest-ever dataset of aerobiological monitoring in the history of the African continent.”

Developing pollen calendars

As this work continues, Gharbi said keeping clinicians and the public updated on national pollen levels, especially as they fluctuate, is of utmost importance. To achieve this, pollen-monitoring calendars have been developed to provide healthcare workers and allergy sufferers with the information they require. These calendars are updated on a weekly basis for each city.

In addition, developing a strong network of clinicians, establishing improved healthcare practices, communicating risk levels accurately and making recommendations to the public on how to reduce their exposure to pollen and fungal spores to reduce allergic symptoms are also priorities. The goal, she added, is to develop an early warning system to alert the public to high pollen days, and to encourage them to be aware of current changes in the environment to help establish effective mitigation strategies. The SAPNET has also partnered with the South African Weather Service to expand its monitoring and introduce automated pollen monitoring.

“This is a gamechanger because automatic pollen sampling techniques are easier to standardise, identify targets in real- or near-real time and carry information to allergy sufferers and healthcare workers much faster,” she said.

Adopting new approaches to green spaces

Having identified the problem-causing trees, Gharbi said what’s left is to adopt new approaches to green spaces. This, she said, starts with identifying and selecting appropriate, alternative tree species that cause less harm to allergy sufferers.

“We hope the impact of this work will set the foundation we need towards working together to improve the quality of life for allergy sufferers across the country.”

“It would be valuable for policymakers and urban planners to assess the implementation of concrete frameworks, consider concerns about the pollution and allergenicity of urban spaces in South Africa and extend the use of indigenous tree species with insignificant allergenic risk that also require less water,” she said.

“We hope that the impact of this work will set the foundation we need towards working together to improve the quality of life for allergy suffers across the country, and to simplify the treatment processes for clinicians.”