Weekly Report

17 January 2025

City
Overall Risk
Tree Pollen
Grass Pollen
Weed Pollen
Mould Spores

Summary

Many sites only restarted their spore traps this week, so no findings are available, Archived pollen counts from this week in January for previous years have been used where possible. Moderate grass counts were recorded in Johannesburg Central and Pretoria and moderate tree counts were seen in Johannesburg. Moderate to high mould counts were detected in Durban.

Cape Town

The spore trap clock is faulty so only one day of this sampling week was recorded. Low tree pollen concentrations included gum (Myrtaceae), waxberry (Morella), pine (Pinaceae) and the monkey puzzle tree (Araucariaceae). Low weeds were the daisy family (Asteraceae), dandelion (Taraxacum) and goosefoot (Chenopodiaceae). Moulds were low, but small spikes during the day appeared for the allergenic mould, Alternaria. 5-year averages are shown.

Johannesburg

Grass and tree pollen concentrations were moderate at times. Trees included Australian pine (Casuarina), birch (Betulaceae), beech (Fagus sylvatica), white stinkwood (Celtis), cypress (Cupressaceae), mulberry (Moraceae), gum (Myrtaceae), olive (Oleaceae), pine (Pinaceae) and elm (Ulmaceae). Low weeds were mugwort (Artemisia), lily (Liliaceae), sedges (Cyperaceae) and plantain (Plantaginaceae). Moulds were low.

Johannesburg South

No findings were received from this site.

Pretoria

Moderate to high grass counts, moderate tree counts, and low weed counts were recorded. Trees included birch (Betulaceae), Australian pine (Casuarina), cypress (Cupressaceae), ash (Fraxinus), Cape holly (Ilex ), mulberry (Moraceae), gum (Myrtaceae), olive (Oleaceae), pine (Pinaceae), oak (Quercus) and karee (Rhus/Searsia sp.). The weeds observed were the daisy family. Moulds were low. 5-year means are shown.

Bloemfontein

Pollen counts in all categories were low. Trees included mulberry (Moraceae), gum (Myrtaceae), olive (Oleaceae), poplar (Populus), karee (Rhus/Searsia) and elm (Ulmaceae). Weeds included the daisy family (Asteraceae), sedges (Cyperaceae), pigmyweeds (Crassulaceae), erica (Ericaceae), ferns (Pteridaceae) and plantain (Plantaginaceae). Fungal spores were low. 5-year means are shown.

Kimberley

Grass, tree and weed pollen was low on average but some moderate grass counts were recorded. Trees identified were waxberry (Morella) and weeds were goosefoot (Chenopodiaceae), ragweed (Ambrosia), the daisy family (Asteraceae) and nettles (Urticaceae). Moulds increased slightly after rain but remained low.

Durban

Pollen in all categories was low at this site. Tree pollen included acacia (Acacia-type), birch (Betulaceae), mulberry (Moraceae) and the monkey puzzle tree (Araucariaceae). Weeds were goosefoot (Chenopodiaceae). Nettles (Urticaceae), plantain (Plantaginaceae), the daisy family (Asteraceae) and knotweed (Persicaria). Moulds were high following rain when ascospores spiked.

Gqeberha

No findings were received from this site.

George

Pollen concentrations were low at this site. Few grass pollen grains were detected and just for trees only chestnut (Hippocastanaceae) were identified. Weeds were goosefoot (Chenopodiaceae) and the citrus/buchu family (Rutaceae) were seen. Moulds were moderate with a strong spike for the allergenic fungal spore Cladosporium and smaller spikes for ascospores and basidiospores (includes mushrooms).

Reference Range

Grass:      Low: 0-5       Moderate:      6-20         High: 21-200

Trees:      Low: 0-15     Moderate:    16-90         High: 91-1500

Weeds:   Low: 0-10      Moderate:   10-50         High: 51-500

Moulds:  Low: 0-900    Moderate:  900-2500   High 2500-25000

Unit: per cubic metre