Weekly Report

8 April 2022

City
Overall Risk
Tree Pollen
Grass Pollen
Weed Pollen
Mould Spores

Summary

Significant grass levels were seen in Bloemfontein and on sunny days in Kimberley, where frequent rain removed some pollen from the air. A greater variety of tree pollen was detected in Cape Town during this sampling period, but tree and weed levels were generally low at all the sites. High mould (fungal spore) concentrations were recorded in Durban and moderate mould levels were seen in Bloemfontein and Pretoria.

Cape Town

Tree pollen levels approached significance, and included the sumac family (Anacardiaceae), birch (Betulaceae), waxberry (Morella sp.), gum (Myrtaceae), pine (Pinaceae), the ebony family (Ebenaceae) and elm (Ulmaceae). Grass, weed and mould counts were low. The weeds detected were the daisy family (Asteraceae), goosefoot (Chenopodiaceae), sedges (Cyperaceae), plantain (Plantaginaceae), fern spores (Polypodiaceae) and nettles (Urticaceae).

Calvinia

Grass and weed counts approached significance. Waxberry (Morella sp.) was the only tree pollen found at very low levels. The weed pollen included the daisy family (Asteraceae), goosefoot (Chenopodiaceae), the carnation family (Caryophyllaceae), erica (Ericaceae) and nettles (Urticaceae). Mould counts were low.

Johannesburg

Tree, grass and weed pollen categories were consistently low. Trees detected included Australian pine (Casuarina sp.), gum (Myrtaceae), pine (Pinaceae), oak (Quercus sp.) and elm (Ulmaceae). Weeds were erica (Ericaceae) and ferns (Polypodiaceae). Moulds were very low.

Pretoria

Grasses were moderate. Tree pollen concentrations were low and the trees detected were cypress (Cupressaceae), gum (Myrtaceae), poplar (Populaceae), oak (Quercus sp.) and birch (Betulaceae). Weeds were represented by the daisy family (Asteraceae), the carnation family (Caryophyllaceae), goosefoot (Chenopodiaceae), mallows (Malvaceae), ferns (Polypodiaceae) and slangbos (Stoebe-type). Moulds were moderate as ascospores, basidiospores (includes mushrooms) and the allergenic spore Cladosporium increased.

Bloemfontein

Significant grass and mould counts, with moderate tree and low weed pollen levels were seen during this sampling period. Tree pollen included the sumac family (Anacardiaceae), birch (Betulaceae), mulberry (Moraceae), waxberry (Morella sp.), gum (Myrtaceae), pine (Pinaceae), yellowwood (Podocarpaceae) and elm (Ulmaceae). The weeds detected were the daisy family (Asteraceae), the carnation family (Caryophyllaceae), goosefoot (Chenopodiaceae) and nettles (Urticaceae).

Kimberley

Grasses were moderate overall, but high on days without rain. Low tree concentrations included waxberry (Morella sp.) and the sumac family (Anacardiaceae). Low weeds were detected including ragweed (Ambrosia sp.), goosefoot (Chenopodiaceae), the daisy family (Asteraceae) and nettles (Urticaceae). Moulds fluctuated from low to moderate when rain was followed by sunshine. Spikes were noted for ascospores and the allergenic mould, Cladosporium.

Durban

Moulds reached high levels as strong spikes were recorded for ascospores and basidiospores. Pollen in all three categories was insignificant. Tree pollen detected included cypress (Cupressaceae), waxberry (Morella sp.), gum (Myrtaceae), birch (Betulaceae), the sumac family (Anacardiaceae) and karee (Rhus/Searsia sp.). Weeds included ragweed (Ambrosia sp.), ferns (Polypodiaceae), the daisy family (Asteraceae), goosefoot (Chenopodiaceae), protea (Proteaceae), sedges (Cyperaceae)and nettles (Urticaceae).

Gqeberha

Tree, grass and weed pollen concentrations were low. Trees detected include the sumac family (Anacardiaceae), Australian pine (Casuarina sp.) and waxberry (Morella sp.). Weeds included the daisy family (Asteraceae), erica (Ericaceae), sedges (Cyperaceae) and slangbos (Stoebe-type). Moulds were very low.