Weekly Report

10 October 2019

City
Overall Risk
Tree Pollen
Grass Pollen
Weed Pollen
Mould Spores

Kimberley

There has been very little rain at this site so all tree, grass and weed pollen and mould levels are consistently low.

Gqeberha

Pollen and fungal spore levels were low and little changed from the preceding week but days with rain and few pollen grain/mould spores were followed by days with higher numbers of pollen and mould spores. There was a small spike for basidiospores (mushrooms) on 6 October. Grass, sedge grass, pine, plane and poplar pollen was detected and weed/herbaceous shrub pollen: Erica and English Plantain.

Cape Town

Grass counts increased and exceeded 10 grains/cu M on some days. Tree pollen decreased to low levels but cypress, eucalyptus, oak, elm, pine, olive and mulberry are still completing their pollen release cycle. Weed pollen is low, but daisy, erica, rumex and English Plantain pollen was present in the atmosphere. A huge spike of 302 spores/cu M was seen for Alternaria on 1 October. This is a significant score. Fungal spore loads were generally low.

Bloemfontein

Very low fungal spore and low pollen counts were seen during this hot, dry sampling week. Grass counts declined further and tree pollen included Combretum (bush willow) buddleja, rhus/searsia, casuarina,  pine, eucalyptus and white stinkwood. Weed pollen was low and only daisy pollen was seen.

Johannesburg

All fungal spores, trees, grasses and weed pollen concentrations were low during this sampling week. Tree pollen included, birch, bush willow, ash, white mulberry, eucalyptus, olive, pine, yellowwood, plane, oak and willow. Weed/herbaceous shrub pollen included Caryophyllaceae (carnation family), chenopod (goosefoot) and daisy.

Pretoria

All pollen and fungal spore counts were low during this sampling week. Tree pollen included birch, cypress, bush willow, white mulberry, eucalyptus, olive, pine, plane, yellowwood, oak and willow. Only daisy pollen appeared in the weed/herbaceous shrub category.

Durban

All pollen and fungal spores were low during this sampling period but more tree taxa were seen than in previous weeks: Acacia, birch, white mulberry, oak, pine and white stinkwood. Weed/herbaceous shrubs included daisy, ferns and English Plantain. Spikes for ascospores (immature spores seen after rain) were noted.

Overall report

The grass season is about to start, beginning with Cape Town, the only winter rainfall region where significant grass pollen concentrations are already being detected in the air. Gqeberha and Durban have had several rainy days which have washed pollen and mould spores from the air, but rain is followed by spikes in fungal/mould spores, especially the allergenic spores. Tree pollen counts are waning but a variety of trees are still flowering in Cape Town, Johannesburg, Pretoria and Bloemfontein. The highest fungal/mould spores are consistently found in subtropical Durban. The counts are low in Kimberley, but despite little rain, there is more variation in the mould and pollen found in the atmosphere.