Weekly Report

4 March 2022

City
Overall Risk
Tree Pollen
Grass Pollen
Weed Pollen
Mould Spores

Summary

Grass levels remain significant in the summer rainfall areas, with very high counts recorded in Kimberley. Tree pollen counts approached significance in Cape Town and the weed pollen in Bloemfontein was also above the moderate threshold. Mould counts likely remained high in Durban (no new data) and peaks for the allergenic spores, Cladosporium and Alternaria, were seen in Kimberley.

Cape Town

Grass and weed pollen counts were low, and tree pollen levels were approaching significance. Trees found included the ebony family (Ebenaceae), waxberry (Myricaceae), gum (Myrtaceae), mulberry (Moraceae), olive (Oleaceae), pine (Pinaceae), karee (Rhus/Searsia sp.), buckthorns (Rhamnaceae) and elm (Ulmaceae). The weeds detected were the aloe family (Asphodelaceae), the daisy family (Asteraceae), the carnation family (Caryophyllaceae), goosefoot (Chenopodiaceae), sedges (Cyperaceae), erica (Ericaceae), plantain (Plantaginaceae), the rose family (Rosaceae), bulrush (Typhaceae) and nettles (Urticaceae). Mould counts were low.

Calvinia

Tree, grass and weed pollen were seen in small quantities. Trees included elm (Ulmaceae) only. Weeds detected were goosefoot (Chenopodiaceae) and the daisy family (Asteraceae). Few grass pollen grains were observed and moulds were sparse.

Johannesburg

Grass counts were significant. Low tree pollen included palm (Arecaceae), gum (Myrtaceae), pine (Pinaceae) and elm (Ulmaceae). Weeds were also low and included pigweed (Amaranthus sp.), the daisy family (Asteraceae), sedges (Cyperaceae), erica (Ericaceae), bulrush (Typhaceae) and fern spores (Polypodiaceae). Fungal spore counts were low.

Pretoria

Significant grass counts with low tree and weed counts were found during this sampling period. Tree pollen included cypress (Cupressaceae), mulberry (Moraceae), pine (Pinaceae), poplar (Populus sp.) and oak (Quercus sp.). The weed pollen detected were the daisy family (Asteraceae), the carnation family (Caryophyllaceae), goosefoot (Chenopodiaceae), sedges (Cyperaceae), erica (Ericaceae) and plantain (Plantaginaceae). Fungal spore counts were not significant.

Bloemfontein

Significant grass and weed pollen counts were seen, with low tree and mould counts. The tree types detected were acacia (Acacia sp.), birch (Betulaceae), hackberry (Celtis sp.), waxberry (Morella sp.) and olive (Oleaceae). Weeds were dominated by sedges (Cyperaceae) and also included the daisy family (Asteraceae), goosefoot (Chenopodiaceae), pigmy weeds (Crassulaceae), plantain (Plantaginaceae) and fern spores (Pteridaceae).

Kimberley

High grass counts were seen during this sampling period. Tree pollen was low and included the sumac family (Anacardiaceae), hackberry (Celtis sp.), bushwillow (Combretaceae), cypress (Cupressaceae), Australian pine (Casuarina sp.), the pea family (Fabaceae), gum (Myrtaceae) and karee (Rhus/Searsia sp.). Weeds were diverse but also found in low amounts. This included the daisy family (Asteraceae), goosefoot (Chenopodiaceae), the carnation family (Caryophyllaceae), sedges (Cyperaceae), erica (Ericaceae), the iris family (Iridaceae), pelargoniums (Geraniaceae), mallows (Malvaceae) and figworts (Scrophulariaceae). Mould levels were significant and high counts were found for the allergenic fungal spores, Alternaria and Cladosporium.

Durban

Courier delays meant that no new data were available for this site. Results from last week are repeated. Grass pollen was detected in small quantities. Trees were not significant and included gum (Myrtaceae), bushwillow (Combretaceae) and mulberry (Moraceae). Weeds were equally sparse, and the types detected were ragweed (Ambrosia sp.), the daisy family (Asteraceae), ferns (Polypodiaceae), bulrush (Typhaceae) and nettles (Urticaceae). Fungal spores were high and included large spikes for ascospores throughout the week, possibly owing to high humidity levels.

Gqeberha

Pollen and fungal spore counts were very low. No tree pollen was detected. Weeds included pigweed (Amaranthus sp.), katstert (Anthospermum sp.), the carnation family (Caryophyllaceae) and sedges (Cyperaceae).