Weekly Report

1 July 2022

City
Overall Risk
Tree Pollen
Grass Pollen
Weed Pollen
Mould Spores

Summary

Low temperatures with frost at night depressed the mould/fungal spore loads in some inland cities. In coastal cities with milder weather small peaks in airborne mould spores were noted. in Kimberley 40 mm rain in one day removed pollen and mould from the air so the counts were extremely low for the final three days of this sampling week. In all the sampled SA cities pollen concentrations were generally low, but signs of spring were seen in the small increases in seasonal  tree pollen in some cities. Airborne grass and weed pollen was detected in very small quantities.

Cape Town

Low levels of all pollen types were seen. Trees detected were white mulberry (Moraceae), cypress (Cupressaceae) and gum (Myrtaceae). No grass pollen was detected. Weeds included mugwort (Artemisia), the daisy family (Asteraceae) goosefoot ( Chenopodiaceae) and erica (Ericaceae). Moulds were low, with small peaks for ascospores after rain.

Calvinia:

Last week’s data are repeated due to courier delays. Extremely low pollen and mould loads were seen during this sampling period. Tree pollen included the sumac family (Anacardiaceae) and bushwillow (Combretaceae). In the category: Weeds, only goosefoot (Chenopodiaceae) and mugwort (Artemisia sp.) were detected. No grass pollen was seen.

Johannesburg

Pollen levels in the categories of trees, grasses and weeds were seen in low concentrations during this sampling period. Trees detected were cypress (Cupressaceae), oak (Quercus sp.) and elm (Ulmaceae). Weeds included pigweed (Amaranthaceae), the daisy family (Asteraceae) and ferns (Polypodiaceae). Moulds were very low.

Pretoria

Low pollen loads for trees, grasses and weeds were seen. Tree pollen included oak (Quercus sp.), gum (Myrtaceae), bushwillow (Combretaceae), cypress (Cupressaceae) plane (Platanaceae), karee (Rhus/Searsia sp.) and the flamboyant tree (Delonix sp). Weed pollen included the daisy family (Asteraceae), sedges (Cyperaceae) and erica (Ericaceae). Moulds were very low.

Bloemfontein

Low pollen counts were seen for trees, grasses and weeds, but tree pollen is increasing. Trees detected included the sumac family (Anacardiaceae), which increased to moderate levels on some days, cypress (Cupressaceae) and Australian pine (Casuarina sp.). Weeds seen were goosefoot (Chenopodiacea). Moulds were extremely low.

Kimberley

Extremely low pollen and mould loads were seen at this site. Trees detected included the sumac family (Anacardiaceae) and bushwillow (Combretaceae). Weeds identified were mallows (Malvaceae) and goosefoot (Chenopodiaceae).

Durban

Low grass levels were seen. Tree pollen was detected in low numbers and the types were the sumac family (Anacardiaceae), Australian pine (Casuarina sp.) and gum (Myrtaceae). Weeds present were mallows (Malvaceae), slangbos (Stoebe-type and knotweed (Persicaria sp.). Moulds were low.

Gqeberha

Tree, grass and weed pollen counts were low at this site. Trees included gum (Myrtaceae), the sumac family (Anacardiaceae), waxberry (Morella sp.) and cypress (Cupressaceae). Weeds detected were slangbos (Stoebe-type), goosefoot (Chenopodiaceae) and ferns (Polypodiaceae). Moulds were low, but with strong peaks for ascospores.