Weekly Report

29 October 2021

City
Overall Risk
Tree Pollen
Grass Pollen
Weed Pollen
Mould Spores

Summary

Tree pollen decreased in all cities except Pretoria where a spike for the allergenic mesquite tree (Prosopis sp.) was detected.  Grass levels were moderate in Cape Town, but low at all the other sampling sites. Moulds / fungal spore levels were moderate in Durban, but low in the other cities. Weed pollen was low across the country.

Cape Town

Pollen levels declined further in response to rain and strong wind. Grasses were moderate, while trees and weeds were low. Trees detected were pine (Pinaceae), cypress (Cupressaceae), gum (Myrtaceae), oak (Quercus sp.), mulberry (Moraceae), olive (Oleaceae) and elm (Ulmaceae). Weeds observed were reeds (Juncaceae), sedges (Cyperaceae), English plantain (Plantaginaceae), the mezereum family (Thymelaeaceae), erica (Ericaceae), knotweeds (Polygonaceae), the daisy family (Asteraceae) and ferns (Polypodiaceae). Moulds were low.

Johannesburg

Grass, tree and weed pollen levels were low during this sampling period. Tree pollen included the sumac family (Anacardiaceae), bushwillow (Combretaceae), cypress (Cupressaceae), ash (Fraxinus sp.), mulberry (Moraceae), gum (Myrtaceae), pine (Pinaceae), plane (Platanus sp.), poplar (Populus sp.), oak (Quercus sp.) and karee (Rhus sp. / Searsia sp.). The weeds detected were sedges (Cyperaceae), the daisy family (Asteraceae), the carnation family (Caryophyllaceae), spurges (Euphorbiaceae) and fern spores (Polypodiaceae). Mould counts were low.

Pretoria

Grass and weed pollen levels were low, while tree pollen was moderate. Significant levels were seen for mesquite (Prosopis sp.) – an allergenic tree. Low tree pollen levels were detected for acacia (Acacia sp.), hackberry (Celtis sp.), bushwillow (Combretaceae), jacaranda (Jacaranda sp.), mulberry (Moraceae), gum (Myrtaceae) and olive (Oleaceae). Weed types detected included nettle (Urticaceae) and sedges (Cyperaceae). Moulds were low.

Bloemfontein

Grass, weed and tree pollen counts were low. Tree pollen included acacia (Acacia sp.), bushwillow (Combretaceae), waxberry (Morella sp.), gum (Myrtaceae), mulberry (Moraceae), plane (Platanus sp.) and karee (Rhus sp. / Searsia sp.). The weed pollen detected were the daisy family (Asteraceae), goosefoot (Chenopodiaceae) and pigmyweeds (Crassula sp.). Mould levels were low. Charcoal particles from the recent fires around Bloemfontein were still observed.

Kimberley

Very low pollen and fungal spore counts were found in this sampling period. Tree pollen included pecan (Carya sp.), bushwillow (Combretaceae), pine (Pinaceae) and karee (Rhus sp. / Searsia sp.). The weed pollen detected were the daisy family (Asteraceae), spurges (Euphorbiaceae), sorrel (Rumex sp.) and mezereum (Thymelaeaceae). Grasses were low.

Durban

Low grass, weed and tree pollen levels were detected during this sampling period. Tree pollen included pecan (Carya sp.), Australian pine (Casuarina sp.), cedar (Cedrus sp.), mulberry (Moraceae), gum (Myrtaceae) and pine (Pinaceae). The weed pollen detected were the carrot family (Apiaceae), the daisy family (Asteraceae), goosefoot (Chenopodiaceae), geraniums (Geraniaceae), sedges (Cyperaceae), spurges (Euphorbiaceae), fern spores (Polypodiaceae), English plantain (Plantaginaceae) and sorrel (Rumex sp.). Mould counts were moderate.

Gqeberha

Pollen levels in all three categories: Trees, grasses and weeds were low during this sampling period. Tree pollen included cedar (Cedrus sp.), gum (Myrtaceae), pine (Pinaceae), waxberry (Morella sp.), olive (Oleaceae) and yellowwood (Podocarpaceae). Weeds detected were the daisy family (Asteraceae), slangbos (Stoebe-type), katstert (Anthospermum sp.) and pigweed (Amaranthus sp.). Moulds were low.