Weekly Report

18 February 2022

City
Overall Risk
Tree Pollen
Grass Pollen
Weed Pollen
Mould Spores

Summary

Grass levels continue to be significant in the summer rainfall cities of Johannesburg, Pretoria and Kimberley. Tree pollen remained low across the country and weed counts approached significance only in Pretoria and Bloemfontein. Pretoria and Durban both had significant fungal spore levels.

Cape Town

Grass counts were insignificant. Tree pollen included the sumac or cashew family (Anacardiaceae), gum (Myrtaceae), karee (Rhus/Searsia sp.), waxberry (Morella sp.) and elm (Ulmaceae). English plantain (Plantaginaceae) and ferns (Polypodiaceae) were detected in the weeds category. Moulds were low.

Calvinia

A technical issue prevented new data collection in this sampling period. Results from the previous week are repeated. Grass, tree and weed levels were not significant. Tree pollen included karee (Rhus/Searsia sp.) and the pea family (Fabaceae). The weeds identified were sedges (Cyperaceae), the mustard or cabbage family (Brassicaceae), goosefoot (Chenopodiaceae), nettles (Urticaceae) and the daisy family (Asteraceae). Moulds were found in low amounts.

Johannesburg

Grass counts were significant, but trees and weeds remained low. The tree pollen detected included cypress (Cyperaceae), the pea family (Fabaceae), gum (Myrtaceae) and pine (Pinaceae). Weeds included pigweed (Amaranthus sp.), sedges (Cyperaceae) and erica (Ericaceae). Mould counts were low.

Pretoria

Grass counts were high and pollen from maize (Zea mays) was detected. Weed and mould counts were also significant during this sampling period, with high levels of the allergenic spore Cladosporium found. Weed pollen included pigweed (Amaranthus sp.), the carnation family (Caryophyllaceae), sedges (Cyperaceae) and slangbos (Stoebe-type). Tree counts were low and included palm (Arecaceae), birch (Betulaceae), mulberry (Moraceae), gum (Myrtaceae), olive (Oleaceae), plane (Platanus sp.) karee (Rhus/Searsia sp.) and star apple (Sapotaceae).

Bloemfontein

Grass and weed counts were moderate, with tree pollen and fungal spores found at insignificant levels. Trees included only olive (Oleaceae). In the weeds category, mugwort (Artemisia sp.), the daisy family (Asteraceae), goosefoot (Chenopodiaceae), sedges (Cyperaceae), plantain (Plantaginaceae), fern spores (Polypodiaceae), bulrush (Typhaceae) and nettles (Urticaceae) were seen.

Kimberley

Grass levels were significant. Tree and woody shrub pollen was detected in small quantities and included elm (Ulmaceae) and protea (Proteaceae). Few weeds were detected and these included nettles (Urticaceae), the carnation family (Caryophyllaceae), sedges (Cyperaceae) and the daisy family (Asteraceae). Moulds were generally insignificant but small spikes were seen for basidiospores (a group that includes mushrooms) and the allergenic spore, Cladosporium.

Durban

Tree, grass and weed levels were insignificant. Tree taxa included mulberry (Moraceae), bushwillow (Combretaceae), elm (Ulmaceae) Australian pine (Casuarina sp.) and birch (Betulaceae). Weeds detected were ragweed (Ambrosia sp.), ferns (Polypodiaceae), and nettles (Urticaceae). Mould levels exceeded the significance threshold and large spikes were seen for ascospores.

Gqeberha

Pollen and fungal spore levels were low during this sampling period. Tree pollen included only Australian pine (Casuarina sp.) and olive (Oleaceae). The weeds detected were the carnation family (Caryophyllaceae) and sedges (Cyperaceae).