Weekly Report

14 March 2025

City
Overall Risk
Tree Pollen
Grass Pollen
Weed Pollen
Mould Spores

Summary

Significant grass concentrations were seen at all the inland sites. Trees and weeds have waned and moulds were low at all sites except Vandebijlpark, south of Johannesburg.

Cape Town

All pollen concentrations are low at this site at this time of the year. Trees would include pine (Pinaceae), waxberry (Morella), olive (Oleaceae), gum (Myrtaceae) and elm (Ulmaceae). Weeds are the daisy family (Asteraceae), goosefoot (Chenopodiaceae), erica (Ericaceae), ferns (Polypodiaceae), mallow (Malvaceae) and nettles (Urticaceae). Moulds are low. 5-year means are given.

Johannesburg Central

Grasses were moderate. Low trees included false olive (Buddleia), Australian pine (Casuarina), cypress (Cupressaceae), white stinkwood (Celtis) and mulberry (Moraceae). Weeds were pigweed (Amaranthaceae), mugwort (Artemisia), the daisy family (Asteraceae) and sedges (Cyperaceae). Moulds were low.

Johannesburg South

Grasses are high. Low tree concentrations included gum (Myrtaceae), karee (Rhus/Searsia) and birch (Betulus). Weeds were pigweed (Amaranthaceae), ragweed (Ambrosia), the daisy family (Asteraceae) and sedges (Cyperaceae). Moulds were low.

Pretoria:

Grasses are moderate and tree and weed concentrations are typically low at this site in March. Trees would include mulberry (Moraceae), gum (Myrtaceae), karee Rhus/Searsia), cypress (Cupressaceae), birch (Betulus), ash (Fraxinus) and Australian pine (Casuarina). Weeds are ragweed (Ambrosia) and the daisy family (Asteraceae). Moulds are low. 5-year means are shown.

Bloemfontein

Grasses are high at this time of the year. Low tree concentrations include acacia (Acacia-type), olive (Oleaceae), false olive (Buddleia), (Euphorbiaceae), pine (Pinaceae), birch (Betulus) and white stinkwood (Celtis). Weeds would be the daisy family (Asteraceae), goosefoot (Chenopodiaceae), pigweed (Amaranthaceae) and spurges. Moulds are typically low. 5-year means are given.

Kimberley

Grass concentrations were high and degranulating grasses were seen. No tree pollen was detected and weed pollen was goosefoot (Chenopodiaceae) and plantain (Plantaginaceae). A strong spike is noted for plantain on 8 + 9 March. Moulds were low but small spikes for the allergenic fungal spore, Alternaria were frequent.

Durban

Rain removed pollen and fungal spores from the air at this site so that all concentrations were low. Trees included gum (Myrtaceae), karee (Rhus/Searsia), birch (Betulus) and mulberry (Asteraceae). Weeds were the daisy family (Asteraceae), knotweed (Persicaria), goosefoot (Chenopodiaceae), ferns (Polypodiaceae), plantain (Plantaginaceae) and lily (Liliaceae). Moulds were low.

Gqeberha

Tree, grass and weed pollen was low at this sampling site. Trees included cypress (Cupressaceae), Guarri (Euclea), waxberry (Morella), gum (Myrtaceae) and olive (Oleaceae). Weeds were pigweed (Amaranthaceae), katstert (Anthospermum), sedges (Cyperaceae), erica (Ericaceae), the daisy family (Asteraceae) and mugwort (Artemisia) and spurges (Euphorbiaceae). Moulds were low.

George

Tree, grass and weed pollen was low at this sampling site. Trees included cypress (Cupressaceae), Guarri (Euclea), waxberry (Morella), gum (Myrtaceae) and olive (Oleaceae). Weeds were pigweed (Amaranthaceae), katstert (Anthospermum), sedges (Cyperaceae), erica (Ericaceae), the daisy family (Asteraceae) and mugwort (Artemisia) and spurges (Euphorbiaceae). Moulds were low. Findings for the same time period in 2024 re shown.

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