Weekly Report

10 September 2021

City
Overall Risk
Tree Pollen
Grass Pollen
Weed Pollen
Mould Spores

Summary

Trees are flowering at most sites now and significant tree counts were seen in Johannesburg, Pretoria and Cape Town. Cypress, plane, mulberry and birch have been detected in significant numbers and a variety of other trees are entering their pollen release cycle. Weed and grass levels are low at all the sites. Remember that seasonal symptoms include ocular allergy (itchy eyes) if you are sensitive to tree pollen, so avoid forested areas when hiking.

Cape Town

Grasses were low during a week with continual rain and low temperatures. Despite this, trees were high due to the contribution of cypress (Cupressaceae). Other tree types detected were birch (Betulaceae), cedar (Cedrus sp.), gum (Myrtaceae), plane (Platanaceae), pine (Pinaceae), ash (Fraxinus sp.), oak (Quercus sp.) and yellowwood (Podocarpaceae). Weeds were very low and only the daisy family (Asteraceae), English plantain (Plantaginaceae) and nettle (Urticaceae) were detected. Moulds were low.

Johannesburg

Significant tree pollen counts were detected. Plane tree was the dominant pollen type recorded, with notable counts of mulberry (Moraceae) and birch (Betula sp.) also seen. Other tree pollen found in lower levels were acacia (Acacia sp.), cypress (Cupressaceae), ash (Fraxinus sp.), gum (Myrtaceae), pine (Pinaceae), plane (Platanus sp.), oak (Quercus sp.) and willow (Salix sp.). Low levels of weed pollen were seen, including the daisy family (Asteraceae sp.), the carnation family (Caryophyllaceae), goosefoot (Chenopodiaceae), ericas (Ericaceae) and spurges (Euphorbiaceae). Mould counts were also low.

Pretoria

Tree pollen levels were high, with mulberry (Moraceae) being the dominant pollen type detected. Other tree pollen present in moderate amounts were birch (Betulaceae) and plane (Platanus sp.), whereas acacia (Acacia sp.), hackberry (Celtis sp.), cypress (Cupressaceae), ash (Fraxinus sp.), jacaranda (Jacaranda sp.), gum (Eucalyptus sp.), pine (Pinus sp.), oak (Quercus sp.) and karee (Rhus sp./ Searsia sp.). Weed pollen counts were low and only included the carnation family (Caryophyllaceae) and the daisy family (Asteraceae). No grass pollen was detected, and mould levels were low.

Bloemfontein

Pollen and mould levels were low during this sampling period. Tree pollen included pine (Pinus sp.), plane (Platanus sp.) and karee (Rhus sp. / Searsia sp.). The weed pollen detected were the daisy family (Asteraceae), nettles (Urticaceae), knotweed (Polygonaceae) and goosefoot (Chenopodiaceae).

Kimberley

Grass levels were low. Trees were low but some moderate levels were seen as cypress (Cupressaceae) levels increased. Other flowering trees were pine (Pinaceae), mulberry (Moraceae) and hackberry (Celtis sp.). Weed levels were low and only nettle (Urticaceae) was detected in the atmosphere. Moulds were low.

Durban

Grasses, trees and weeds were low. Tree pollen types included birch (Betulaceae), cypress (Cupressaceae), mulberry (Moraceae), gum (Myrtaceae), hackberry (Celtis sp.), pecan (Carya sp.) and oak (Quercus sp.). Weeds identified were the daisy family (Asteraceae) and nettle (Urticaceae). Moulds were generally low, but significant spikes for Cladosporium were detected following rain.

Gqeberha

All pollen counts and mould levels were low. The tree pollen detected were cedar (Cedrus sp.), Australian pine (Casuarina sp.), pine (Pinaceae), waxberry (Myricaceae), gum (Myrtaceae) and olive (Oleaceae). Weed pollen included the carnation family (Caryophyllaceae), ericas (Ericaceae) and sedges (Cyperaceae).