Weekly Report

20 August 2021

City
Overall Risk
Tree Pollen
Grass Pollen
Weed Pollen
Mould Spores

Summary

Across the country most sites report low pollen concentrations. The exceptions are Cape Town and Johannesburg where the trees have begun their springtime pollen release cycles. In Cape Town tree levels have breached the significant threshold and daily averages >200/cu metre are occurring. Cypress is the dominant tree pollen at this site, while low to moderate levels of gum tree, pine, mulberry, Australian pine, oak and karee have been detected. In Johannesburg several trees are flowering and so moderate daily tree concentrations include acacia, birch, Australian pine, cypress, ash, mulberry, gum and karee. Grasses and weeds are low at all the sites, as are moulds.

The tree pollen cycle is relatively short, but athletes sensitized to tree pollen should try to exercise (walk, run, cycle) in flat areas where the tree cover is sparse.

Cape Town

Grass and weed pollen counts were low. Tree pollen levels were high, with cypress (Cupressaceae) as the dominant pollen type detected. Other tree pollen present in lower concentrations were acacia (Acacia sp.), Australian pine (Casaurina sp.), pine (Pinaceae), mulberry (Moraceae), gum (Myrtaceae), oak (Quercus sp.) and karee (Rhus sp. / Searsia sp.). Weed pollen detected included the daisy family (Asteraceae), the carnation family (Caryophyllaceae), goosefoot (Chenopodiaceae), ericas (Ericaceae), knotweed (Polygonaceae) and nettles (Urticaceae). Mould levels were low.

Johannesburg

Grass and weed pollen counts were low. Tree pollen was moderate and included acacia (Acacia sp.), birch (Betula sp.), Australian pine (Casaurina sp.), cypress (Cupressaceae), ash (Fraxinus sp.), mulberry (Moraceae), gum (Myrtaceae), pine (Pinaceae), plane (Platanus sp.), poplar (Populus sp.), oak (Quercus sp.), karee (Rhus sp. / Searsia sp.) and willow (Salix sp.). Weed pollen detected was the daisy family (Asteraceae sp.), amaranths (Amaranthus sp.), the carnation family (Caryophyllaceae), goosefoot (Chenopodiaceae), ericas (Ericaceae), spurges (Euphorbiaceae), mallows (Malvaceae), ferns (Polypodiaceae), sorrel (Rumex sp.) and the mezereum family (Thymelaceae). Mould levels were low.

Pretoria

The pollen findings were not received by The Lung Institute in Cape Town in time for posting so the previous week’s findings are repeated here. Tree, grass and weed pollen levels were low. Trees included birch (Betula sp.), karee (Rhus sp. / Searsia sp.), cypress (Cupressaceae) and pine (Pinaceae). Weeds included the carnation family (Caryophyllaceae) and the spurge family (Euphorbiaceae). Moulds were low.

Bloemfontein

Grass, tree, weed and mould levels were low during this sampling period. Karee (Rhus sp. / Searsia sp.) was the only tree pollen detected. Weed pollen included the daisy family (Asteraceae) and goosefoot (Chenopodiaceae).

Kimberley

Tree, grass and weed pollen levels were very low. Only cypress (Cupressaceae) pollen was detected. The only weed seen was slangbos (Stoebe-type). Moulds were low. Geophytes and charcoal from grass burning was seen in moderate quantities.

Durban

Tree, grass and weed pollen levels were low. Trees detected included birch (Betulaceae), cypress (Cupressaceae), mulberry (Moraceae) and pine (Pinaceae). Weeds seen were the daisy family (Asteraceae) and nettle (Urticaceae). Moulds were generally low with a spike for ascospores following rain.

Gqeberha

Grass, tree and weed pollen counts were low. Tree pollen included acacia (Acacia sp.), cedar (Cedrus sp.), Australian pine (Casaurina sp.), cypress (Cupressaceae), gum (Myrtaceae), pine (Pinaceae) and olive (Oleaceae). Spurges (Euphorbiaceae) and sedges (Cyperaceae) were the two weed pollens detected. Mould levels were low.

 

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