Allergen Update
Calgary, Alberta (South-west foothills)
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 described here try to cover the time when each can occur.
Acer sp.- Maple season varies from year to year slightly due to weather. Significant counts are observed from the end of April to the end of May.The amount of pollen from the maples varies from one part of the City to the other. THe amount of pollen collected at the two sites varies a great deal.
Alnus sp.- Alder season starts from April to mid-June and the counts vary from low to moderate due to the number of species present.
Betula sp.- The birch season is from the end of April to nearly the end of May with mostly moderate counts. The season for birch varies from year to year due to the effect of weather. Birch look-alikes' season is short around mid-May and the counts are low.
Populus sp.- The poplar and aspen season is from April to early May. Some of the counts are very high and may cause allergic reactions.
Juniperus- The cedars, junipers and yews produce some moderate counts from mid-April to mid-May. Probably of no significance in causing allergic reactions except in individuals who are highly sensitized.
Fraxinus sp.- The ash pollination season is short in May. Moderate counts are observed. Considered to be allergenic only in highly sensitized individuals.
Pinaceae- This includes the spruce, fir and pine trees. Very high counts are observed from late May to late July. The pollen season can occur between early May to the end of July. The season varies from year to year due to weather.
Quercus sp.- The oaks flower for a short period, with low counts, in early May. There is a second season with low counts from mid-May to early June. Oaks can be highly allergenic.
Ulmus sp.- The elm are important allergens. The season can start between late March to early May and can end late April to late May. The counts are low to moderate and can create allergic reactions.
Salix- The willows pollen season can occur from late April to mid-June. The season usually lasts at least a month. There is some variation in the season from year to year and low to moderate counts are observed.
Gramineae- The grasses produce significant counts, from low to high range, from early June to early August. The grass season starts late May and ends early September.
Ambrosia sp.- Ragweed season is from the mid-August to mid-September with only very sporadic low counts observed.
Artemisia sp.- The main sagebrush season is from late July to mid-September with low and moderate counts observed.
Plantago sp.- The plantains pollinate from late June to early September. The counts are in the low range but may cause allergic reaction in highly sensitized individuals.
Predominant spores:
Diatrypaceae sp.- The counts are sporadic throughout the whole counting season. Very high counts can be observed from late March to mid-October.
Erysephe (Oospora)- Powdery mildew - The main season is from May to mid-October. The counts can get very high. Allergenic properties unknown.
Leptosphaeria sp. & Leptosphaeria look-alikes- These two are grouped together since they are in the same class of fungi and are similar microscopically. The season starts mid-May to the end of September. The counts vary from day to day, which is probably due to the effect of weather. Very high counts are observed from May to mid-October.
Boletus sp.- The season for this spore is very sporadic with some high counts observed. It may be of significance in causing allergic reactions. The season, with significant counts, is July to the end of September.
Coprinus sp.- This mushroom produces moderate and high counts from the end of May to mid-October. It is considered an important allergen.
Ganoderma sp.- The bracket fungus produces moderate and high counts from mid-June to the end of September. It is considered an important allergen.
Uredinales- The rusts produce mostly moderate counts in the main season, but not enough is known about their significance in causing allergic reactions at these levels. The season is from mid-June to mid-October.
Ustilaginales- The allergenic properties of the smuts are unknown. The season, with significant counts, is from June to mid-October with some very high counts from July to the end of September.
Alternaria sp.- The counts are mostly in the moderate range with a few high counts and some species are known to cause allergic reactions. The main season is from Mid-June to mid-October.
Penicillium & Aspergillus sp.- These spores are found throughout the whole counting season and are probably present in significant numbers beyond that. There are significant counts from early March to late fall. Probably significant in causing allergic reactions.
Botrytis sp.- This may be a significant allergen, with very sporadic counts from May to early October.
Cladosporium sp.- The most abundant spore found throughout the whole season. This spore exists all year round but very high counts are known to occur from March to well into late fall. Some species are known to cause allergic reactions.
Epicoccum sp.- Some species are known to cause allergic reactions. The season is from May to mid-October with only low counts. May not be a significant allergen at these levels.
Helicomyces sp.- Season is very sporadic from June to the end of September producing moderate counts. Allergenic properties unknown.
Drechslera sp.- The counts are mostly in the low range. This is a summer and fall spore, June to September. There are other related genera, which are also found in air samples, that can cause respiratory problems. One example is Bipolaris sp.
Myxomycetes- Moderate counts are observed from April to mid-October. Allergenic properties are not well known.
Last Updated: 06-March-2006
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