Allergen Update
St. John's, Newfoundland
Predominant pollen:
Due to extreme variations in the weather at this site, the tree pollen season fluctuates significantly from year to year. The pollen seasons for some trees can occur in two to three days. We try to cover the time when each can occur.
Alnus sp.- Alder season is from early April to the end of June. The counts fluctuate due to the number of species present and the effect of weather. The alders can cause allergic reactions in sensitized individuals. The season, with moderate and high counts, can start from early May to early June and end from late May to late June.
Betula sp.- Birch pollination season varies a great deal from year to year. There is a short season, lasting less than a week, which can occur from early to mid-May. The main season, with low to high counts, lasts approximately three to four weeks and can occur from early May to late June. Birch counts are very unpredictable and sporadic due to the effect of weather.
Pinaceae group- The season for the pine, spruce and firs can vary both in pollen counts and pollination occurance. Counts fluctuate a great deal throughout the season from low to high levels. The main season can start from mid-May to early June and end mid-June to early July. May be of significance in causing allergic reactions in individuals who are sensitized.
Cupressaceae group- The cedars, junipers and yews' produce low to high counts. There are two pollinating seasons: the first one occuring from mid-April to early May. The second season can occur from late May to early July. Both seasons last approximately one to two weeks. May not be of any significance in allergies.
Populus sp.- Pollination season for poplar and aspen can vary drastically. Generally it occurs from mid-April to late May. There are usually just a few days where relevant counts are observed at this collection site. This has to do with the great fluctuations in temperature and the abundance of rain during the season.
Rumex sp.- Sorrel or Dock - Season starts early June to mid-August with mostly low and the occasional moderate counts.
Ambrosia sp.- Ragweed counts are always low and very sporadic. Season is from mid-August to mid-October.
Gramineae- The grass season starts mid-May and ends late September with the highest counts observed from mid-June to early August.
Compositae- A group of weeds which are similar microscopically and can be wind or insect pollinated. Some of the weeds in this group can cause allergic reactions and moderate counts are observed in June.
Plantago- The plantains produce low counts from early July to mid-September. May cause allergic reactions in individuals who are highly sensitized.
Predominant spores:
Diatrypaceae sp.- Very sporadic counts are observed throughout all of our collecting season, and the highest numbers are found in cool wet weather. Clinical significance in unknown.
Leptosphaeria sp. & Leptosphaeria look-a-likes- These two are grouped together since they are in the same class of fungi and are similar microscopically. The season is May to mid-October with great fluctuations in counts from day to day which is probably due to the effect of weather.
Erysephe (Oospora)- Powdery mildew - The season is from May to mid-October.
Boletus sp.- Spore counts for this mushroom can reach very high numbers from the end of July well into October. Can be a significant allergen.
Coprinus sp.- The majority of the season is from July to well into October. Considered an important allergen.
Ganoderma sp.- This fungus can produce very high spore numbers and the majority of the season is from mid-June to mid-October. Can be a significant allergen.
Uredinales sp.- The season with significant counts is from mid-June to mid-October. Allergenicity at these levels is not well understood.
Ustilaginales sp.- High counts occur from June to mid-October. Allergenicity at these levels is not well understood.)
Aspergillus sp. & Penicillium sp.- These two genera can occur throughout our counting season from March to the end of October. Highest counts are from August to early October. They are considered important allergens.
Cladosporium sp.- Very high numbers are recorded. Occurs throughout the year with significant counts occuring from March to well into October. The highest counts occur from June to mid-October.
Fusarium sp.- Counts fluctuate a lot throughout the counting season which is normal for this fungus. Majority of the season is June to mid-October.
Helicomyces sp.- Very high counts are observed. Most of the season is from May to early October. Medical significance is unknown.
Botrytis sp.- This fungal spore is considered to be a significant allergen. Season is from early June to early October.
Pithomyces sp.- Moderate counts are observed from August to the end of September. Medical significance is unknown.
Polythrincium sp.- Moderate counts are observed from late July to early October. Medical significance is unknown.
Epicoccum sp.- Moderate counts are observed in July and August. May not play a significant role in allergies except to those individuals who are highly sensitized.
Myxomycetes- Moderate counts are observed from May to early October. Allergenicity is not well understood.
Last Updated: 21-March-2006
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