This is a difficult time of the year for those who have seasonal allergy. Hay fever, rhinitis (runny nose) and itchy eyes can cause great discomfort. Many airborne allergens are around this spring. Late tree pollen levels (oak, plane, pine, cypress) are still in the air in significant amounts and olive pollen is entering its flowering cycle. Moulds are also high in response to warmer temperatures and moist air.
The heavy rains at the end of winter followed by unusually warm weather for early October with temperatures exceeding 30’C have resulted in very high grass and tree concentrations during the past sampling week. Tree pollen consisted of birch, cypress, oak gum, pine, plane Rhus, poplar and willow. Cypress and pine tree concentrations were very high, plane, oak and gum were high and acacia, poplar and willow were low. Fungal spore loads increased and significant Alternaria levels were seen. Weed pollen was low, but a large variety of weed pollen was trapped and included. erica, protea, goosefoot, fern, and daisy.
Despite the rain, High pollen concentrations were recorded for grasses in the past week. Tree pollen concentrations remain high as cypress, pine, oak and Rhus continue to flower. Fungal spores were low in response to the low temperatures and weed pollen concentrations were below the threshold.
The tree pollen concentrations are very high now on warm dry days. Cypress and pine counts are peaking and plane tree pollen is increasing. Grass pollen is moderate on sunny days. Weed and fungal spores are consistently low. The pollen count fluctuates with the weather and rain should relieve sufferers with allergic rhinitis, hay fever and conjunctivitis as it washes pollen from the atmosphere. Cyclists and runners should take note of the pollen count before exercising or competing.
Pollen sampling in Cape Town has ceased due to lack of funding.
All pollen and fungal spore concentrations are currently low, but tree pollen is increasing in the atmosphere, as oak, pine, cypress and olive trees begin their pollen release spring cycle.
The fungal spore concentrations fluctuate between moderate levels on warm days and very low levels on days that are rainy or have very low temperatures. Ascospores and basidiospores increase after rain and Cladosporium levels increase on warm sunny days after rain. Pollen concentrations are generally low, but cypress trees are beginning their pollen release cycle, so Cupressaceae are a constant low presence in the atmosphere, together with occasional pine and oak pollen grains.
We are in the months of the year with the lowest pollen concentrations in Cape Town. Despite this, Cupressus pollen is appearing in the atmosphere in low concentrations as it begins its pollen release cycle. Fungal spores soar on sunny days following rain, but are composed largely of basidispores (includes mushrooms) and ascospores.
Fungal spore levels are moderate as ascospores increase after rain. Small spikes for basidiospores (includes mushrooms) and Cladosporium were seen during the past week. Tree and grass pollen concentrations were low but moderate concentrations were observed again for weed pollen as Parietaria completed its pollen release cycle.
Parietaria is a weed from the family Urticaceae. Parietaria concentrations are steadily rising in Cape Town. Current heavy rain will have washed this pollen from the air, but it will reach its highest concentrations in the last week of May and decrease in early June. Tree and grass pollen concentrations were low. Fungal spore levels were similarly low, despite small peak on sunny days for basidiospores, ascospores and Cladosporium.