Grass pollen in the air is decreasing but moderate amounts are still present and hay fever sufferers will still be experiencing symptoms. Tree pollen is diminishing and weed pollen remains low. Fungal spores (mould) increased in the last week due to slight rain and moderate temperatures. Increases were seen for Alternaria, Cladosporium and Epicoccum. Alternaria concentrations were high for most of the week. Alternaria is the most allergenic aeroallergen in the Western Cape.
The rain during this sampling period depressed the pollen and fungal spore concentrations in the atmosphere but moderate levels of grass pollen were still seen. Weed pollen is increasing and tree pollen concentrations are decreasing. Fungal spores retreated in response to the rain and low temperatures, but will increase shortly with warmer weather. Alternaria, the dry air spore is likely to increase during this month (November).
The high grass concentrations seen in the first half of October were repeated during this sampling week in response to a five day heat wave in Cape Town with temperatures above 30’C. Tree pollen is declining although pine pollen is still moderate. Pine is a weak allergen. Weed pollen is slowly increasing and includes English Plantain, goosefoot grass, erica and protea. Fungal spores were uniformly low.
Although grasses are starting to dry due to the very hot weather, the grass pollen counts are still very high. Tree pollen has declined to moderate levels and includes, oak, plane, olive Rhus, pine, gum and Poplar. Weed pollen level is consistently low, but a large variety of weed pollen is in the air at present. Fungal spore levels are low except for Alternaria which is high and will increase in November.
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.