Weekly Report

17 March 2023

City
Overall Risk
Tree Pollen
Grass Pollen
Weed Pollen
Mould Spores

Summary

There is a moderate risk for grass pollen allergy in Pretoria and Bloemfontein and mould spores were significant in Durban and Pretoria.

Cape Town

Pollen in the atmosphere was scanty. Trees detected were elm (Ulmaceae), gum (Myrtaceae), birch (Betulaceae), white mulberry (Moraceae), Australian pine (Casuarina spp.) and waxberry (Morella spp.). Small spikes were seen for waxberry on some days. Weeds were goosefoot (Chenopodiaceae), erica (Ericaceae) and plantain (Plantaginaceae). Moulds were low.

Calvinia

The pollen strip did not reach the laboratory in time for processing so last week’s findings are repeated. Very low pollen concentrations were detected in the atmosphere during this sampling period for grasses, trees and weeds. Trees identified were waxberry (Morella spp.) and bushwillow (Combretaceae). Weeds were goosefoot. Moulds were very low.

Johannesburg

Pollen in the categories of trees, grasses and weeds had low concentrations in the ambient air. Trees detected were birch (Betulaceae), false olive Buddleja spp.), mulberry (Moraceae), gum (Myrtaceae), poplar (Populaceae), karee (Rhus/Searsia spp.), olive (Oleaceae) and elm (Ulmaceae). Weeds included pigweed (Amaranthaceae), mugwort (Artemisia spp.), the daisy family (Asteraceae),  the carnation family (Caryophyllaceae), sedge (Cyperaceae), erica (Ericaceae) and plantain (Plantaginaceae). Mould spores were low.

Pretoria: Grass pollen increased to moderate levels during this sampling period. Trees detected were acacia (Acacia spp.), birch (Betulaceae), cypress (Cupressaceae), Cape holly (Ilex spp.), mulberry (Moraceae), gum (Myrtaceae), the daisy family (Asteraceae), goosefoot (Chenopodiaceae) and sedge (Cyperaceae). Moulds were moderate with peaks for ascospores.

Bloemfontein

Grass pollen reached moderate concentrations in the air during this sampling period. Low tree pollen included Australian pine (Casuarina spp.), gum (Myrtaceae), pine (Pinaceae) and elm (Ulmaceae). Weeds were mugwort (Artemisia spp.), the daisy family (Asteraceae), the carnation family (Caryophyllaceae), ferns (Polypodiaceae) and bulrush (Typhaceae). Mould spores were present in low quantities.

Kimberley

Very little tree pollen was detected during this sampling period and only pine (Pinaceae) was seen in the tree category. No significant grass concentrations were observed during a week with three days of rain. Weed pollen was similarly sparse as the carnation family (Caryophyllaceae), ragweed (Ambrosia spp.) and plantain (Plantaginaceae) appeared in the atmosphere fleetingly. Mould spores fluctuated but were consistently low.

Durban

No significant tree, grass or weed concentrations occurred during this sampling week. Trees detected were white mulberry (Moraceae), gum ) Myrtaceae), poplar (Populaceae), elm (Ulmaceae) and birch (Betulaceae). Weeds were ragweed (Ambrosia spp.), the daisy family (Asteraceae), nettles (Urticaceae), ferns (Polypodiaceae), sedges (Cyperaceae), moss (Bryophtes), sun dew (Droseraceae) and plantain (Plantaginaceae). Mould spores were high with strong spikes for ascospores.

Gqeberha

Pollen concentrations in the atmosphere of this city were low. Tree pollen detected was gum (Myrtaceae) and waxberry (Morella spp.). Weeds were pigweed (Amaranthaceae), goosefoot (Chenopodiaceae), sedge (Cyperaceae), lily (Liliaceae) and reed (Restionaceae). Mould spore loads were slight.

Potchefstroom

All pollen concentrations in Potchefstroom were low during this sampling period. Trees detected were cypress (Cupressaceae), bushwillow (Combretaceae), pine (Pinaceae), oak (Quercus spp.) and elm (Ulmaceae). Weeds were pigweed (Amaranthaceae), the daisy family (Asteraceae), sedges (Cyperaceae), buckwheat (Polygonaceae), nettle (Urticaceae), ragweed (Ambrosia spp.) and ferns (Polypodiaceae). Mould spore were very low.