Weekly Report

15 October 2021

City
Overall Risk
Tree Pollen
Grass Pollen
Weed Pollen
Mould Spores

Summary

High pollen alert for Cape Town with high grass counts, high tree levels (cypress, eucalyptus, pine) and moderate weed counts due to a spike in sorrel. Grasses are still low in the other cities, which are all situated in summer rainfall regions. Tree pollen has decreased in most cities across South Africa, but significant counts are still detected in Bloemfontein and Johannesburg. High mould / fungal spore counts were seen in Durban.

Cape Town

Overall high pollen alert for Cape Town. Grasses were high, with moderate to high levels of tree and weed pollen seen. The dominant tree pollens detected were cypress (Cupressaceae), gum (Myrtaceae) and pine (Pinaceae), with lower levels of palm (Arecaceae), birch (Betulaceae), hackberry (Celtis sp.), Australian pine (Casuarina sp.), bushwillow (Combretaceae), the pea family (Fabaceae), ash (Fraxinus sp.), mulberry (Moraceae), waxberry (Myricaceae), olive (Oleaceae), plane (Platanaceae), yellowwood (Podocarpaceae), poplar (Populaceae), oak (Quercus sp.), linden (Tiliaceae), syringa (Melia sp.) and karee (Rhus sp. / Searsia sp.) also seen. Sorrel (Rumex sp.) dominated the weed count, with moderate levels of nettles (Urticaceae) and English plantain (Plantaginaceae) present. Low levels of pollen from the daisy family (Asteraceae), borages (Boraginaceae), goosefoot (Chenopodiaceae), the carnation family (Caryophyllaceae), sedges (Cyperaceae), erica (Ericaceae), spurges (Euphorbiaceae), stork-bills (Erodium sp.), knotweeds (Polygonaceae), the rose family (Rosaceae), the mezereum family (Thymelaeaceae) and protea (Proteaceae) were also recorded.  Moulds were low, but spikes for the allergenic fungal spore Alternaria were seen.

Johannesburg

Low to moderate tree counts, with low weed and grass counts were seen during this sampling period. Tree pollen included hackberry (Celtis sp.), bushwillow (Combretaceae), cypress (Cupressaceae), ash (Fraxinus sp.), mulberry (Moraceae), gum (Myrtaceae), pine (Pinaceae), plane (Platanus sp.), oak (Quercus sp.) and karee (Rhus sp. / Searsia sp.). The weed pollen detected were the carnation family (Caryophyllaceae), goosefoot (Chenopodiaceae) and spurges (Euphorbiaceae). Mould levels were low.

Pretoria

Tree, grass and weed pollen concentrations were low. Trees detected were the sumac family (Anacardiaceae), birch (Betulaceae), bush willow (Combretaceae), cypress (Cupressaceae), mulberry (Moraceae), gum (Myrtaceae), yellowwood (Podocarpaceae), poplar (Populaceae), wild syringa (Burkea sp.) and karee (Rhus/Searsia). The only weed found was nettle (Urticaceae). Moulds were low.

Bloemfontein

Moderate tree counts, but low weed and grass counts were seen during this sampling period. Tree pollen was dominated by karee (Rhus sp. / Searsia sp.) and included lower levels of bushwillow (Combretaceae), waxberry (Morella sp.), gum (Myrtaceae), olive (Oleaceae), mulberry (Moraceae), plane (Platanus sp.) and pine (Pinaceae). The weed pollen detected were mugwort (Artemisia sp.), the daisy family (Asteraceae), goosefoot (Chenopodiaceae) and pigmyweeds (Crassula sp.). Mould counts were low.

Kimberley

Trees, grasses and weeds were all very low. Tree pollen included bushwillow (Combretaceae), pine (Pinaceae), yellowwood (Podocarpaceae) and oak (Quercus sp.). Weeds detected were goosefoot (Chenopodiaceae), English Plantain (Plantaginaceae) and protea (Proteaceae). Moulds were low.

Durban

High mould levels were seen as large spikes for ascospores and Cladosporium occurred. Grasses, trees and weeds were low. Trees included ash (Fraxinus sp.), hackberry (Celtis sp.), acacia (Acacia sp.), mulberry (Moraceae), pine (Pinaceae), yellowwood (Podocarpaceae), Australian pine (Casuarina sp.) and bushwillow (Combretaceae). Low weed levels included sedge (Cyperaceae), nettle (Urticaceae), the daisy family (Asteraceae) and knotweed (Polygonaceae).

Gqeberha

Tree, grass and weed pollen levels were low. Trees detected included acacia (Acacia sp.), Australian pine (Casuarina sp.), cedar (Cedrus sp.), cypress (Cupressaceae), waxberry (Morella sp.) and olive (Oleaceae). Weeds included pigweed (Amaranthus sp.), katstert (Anthospermum sp.), heath/erica (Ericaceae) and the mezereum family (Thymelaeaceae). Moulds were also low.