Weekly Report

17 December 2021

City
Overall Risk
Tree Pollen
Grass Pollen
Weed Pollen
Mould Spores

Summary

Significant tree and weed pollen counts were seen in Cape Town and Durban. High fungal spore loads were also seen in Durban, and a peak in the allergenic fungal spore Cladosporium was observed in Pretoria. Grass counts have increased across most of the country, reaching significant levels in Cape Town, Bloemfontein and potentially also in Kimberley – based on historical data.

Cape Town

Overall high pollen counts, with moderate grasses, weeds and trees detected. The trees detected were diverse and included bushwillow (Combretaceae), cypress (Cupressaceae), mulberry (Moraceae), gum (Myrtaceae), olive (Oleaceae), waxberry (Myricaceae), pepper tree (Schinus sp.), pine (Pinaceae), monkey puzzle tree (Araucariaceae) and Cape holly (Ilex sp.). Weeds were significant due to the continued high count of bulrush (Typhaceae) pollen. Other weeds detected were ice plants (Aizoaceae), the daisy family (Asteraceae), borages (Boraginaceae), goosefoot (Chenopodiaceae), erica (Ericaceae), sedges (Cyperaceae), rushes (Juncaceae), plantain (Plantaginaceae), sorrel (Rumex sp.), the buchu or citrus family (Rutaceae) and nettles (Urticaceae). Mould levels were low.

Johannesburg

Low grass, tree and weed pollen levels were observed. The trees detected were bushwillow (Combretaceae), cypress (Cupressaceae), mulberry (Moraceae), gum (Myrtaceae) and olive (Oleaceae). Weed pollen included pigweed (Amaranthus sp.), plantain (Plantaginaceae) and sedges (Cyperaceae). Fungal spore counts were also low.

Pretoria

Significant levels of fungal spores were seen during this sampling period, with peaks in the allergenic fungal spore, Cladosporium. Low levels of grass, weed and tree pollen were detected. Tree pollen included the sumac family (Anacardiaceae), bushwillow (Combretaceae), cypress (Cupressaceae), gum (Myrtaceae), waxberry (Myricaceae), mulberry (Moraceae) and olive (Oleaceae). The weeds recorded were sedges (Cyperaceae), plantain (Plantaginaceae) and nettles (Urticaceae).

Bloemfontein

High grass counts with low tree and weed counts were seen. Tree pollen included acacia (Acacia sp.), gum (Myrtaceae), bushwillow (Combretaceae), waxberry (Myricaceae), olive (Oleaceae) and karee (Rhus / Searsia sp.). The weed pollen detected were only sedges (Cyperaceae) and pigmyweeds (Crassula sp.). Mould counts were low.

Kimberley

New data from this site will be available in January 2022. Averages of the pollen counts collected for the same dates in 2019 and 2020 are presented here.

Durban

High fungal spore counts were seen, with peaks in ascospores, basidiospores and the allergenic spore Cladosporium. Tree and grass levels were low, and weed counts were moderate. Tree pollen included the sumac family (Anacardiaceae), palm (Arecaceae), birch (Betulaceae), bushwillow (Combretaceae), cypress (Cupressaceae), mulberry (Moraceae), gum (Myrtaceae), waxberry (Myricaceae) and olive (Oleaceae). Significant weed counts were driven by plantain (Plantaginaceae) and nettles (Urticaceae). Other weed pollen seen were the daisy family (Asteraceae), sedges (Cyperaceae), bulrush (Typhaceae), goosefoot (Chenopodiaceae), fern spores (Polypodiaceae) and sorrel (Rumex sp.).

Gqeberha

Low levels of grasses, trees and weeds were seen. Tree pollen included Australian pine (Casuarina sp.) and olive (Oleaceae), with the daisy family (Asteraceae), the carnation family (Caryophyllaceae), sedges (Cyperaceae) and pigweed (Amaranthus sp.) detected in the weeds category. Fungal spore levels were also low.