Highly Allergenic Weed Detected in KZN for the First Time.

By Jan 31, 2020 No Comments

The discovery was made by Dr Dilys Berman, an aerobiologist at UCT and Prof Jonny Peter, who heads up the UCT Lung Institute’s Allergy Unit. Palynologist, Dr Frank Neumann, based at Wits University whose research focuses on the impact that climate change has on vegetation, also confirmed that the pollen grains indeed belong to the invasive Ambrosia species.
Prof Peter says while the threat of allergic plants, such as ragweed migrating southward, because of climate change, has always been a concern, little did they know it was going to show up so soon.
“Ragweed is incredibly invasive, and its potent pollen has been problematic in the US for many decades. In recent years, allergy sufferers in Europe and South America have also come under threat as ragweed started to invade these areas.
“For now, KwaZulu-Natal residents are most at risk as ragweed pollen has recently been detected at the Durban monitoring site over the last few days. The counts are relatively low at this stage, but we are monitoringthem daily to detect any sudden spikes. A small population of ragweed has also been found on the banks of the Vaal River near Heidelberg – about 50km away from Johannesburg, while the Eastern and Western Cape still remain ragweed-free.
“Based on historical data, ragweed thrives in hot, dry environments and produces more pollen when CO2 levels are high,” he says.
UCT aerobiologist, Dilys Berman warns that ragweed poses a serious implication for human health.
“It’s been one of the most loathed weeds in the US, causing misery for 23 million Americans and it’s estimated that ragweed allergy rates in Europe will increase from 33 to 77 million in the next two decades. While we haven’t reported sensitisation in SA yet, it is a cause for concern.
“Increasing amounts of fine-powder ragweed in SA could exacerbate hay fever symptoms and asthma for the estimated 17 million South Africans who suffer from allergies.
“Given that its highly allergenic, people who normally don’t suffer from pollen allergies, may develop a sensitivity to it in the future as the weed proliferates.”