Allergen Update
Calgary, Alberta (City-centre)
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 significantly from year to year due to weather. Low and Moderate 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 this site is much lower than at the South West Foothills location.
Alnus sp.- Alder season starts late March and ends late 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 low and moderate counts. The season for birch varies from year to year due to the effect of weather. Birch look-alikes' season lasts around two weeks and occurs between late April to early June and the counts are mostly low.
Populus sp.- The poplar and aspen season can occur between late March to mid-May. Some of the counts are very high and may cause allergic reactions.
Juniperus- The cedars, junipers and yews produce some moderate counts from late March to mid-May. Probably of no significance in causing allergic reactions except in individuals who are highly sensitized.
Fraxinus sp.- The ash pollination season lasts approximately two weeks and usually occurs sometime in May. Low, moderate and some high 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 and the season occurs from early May to late July. The season start and finish varies from year to year.
Quercus sp.- The oaks flower for a short period in May or early June. Only low counts are observed. Oaks can be highly allergenic.
Ulmus sp.- The elm are important allergens. Very little pollen is collected at this site. The season lasts approximately two weeks and occurs in the month of April.
Salix- The willows pollinate mostly in May. There is some variation in the season from year to year and low to moderate counts are observed.
Gramineae- The grasses produce significant counts, mostly in the moderate range, from mid-June to early August. Low counts are observed throughout the whole season from late May to early October.
Ambrosia sp.- Ragweed season is from the end of July to late September with only sporadic low counts observed.
Artemisia sp.- The sagebrush season is from late July to late September with low and moderate counts observed.
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 season is from May to mid-October. The counts are mostly in the low and moderate ranges with some high counts observed. May not be significant in causing allergic reactions.
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 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 July to early October. They could cause allergic reactions.
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 is from late June to the end of September.
Coprinus sp.- This mushroom produces moderate and high counts from late May to early October. It is considered an important allergen.
Ganoderma sp.- The bracket fungus can produce high counts from mid-June to the end of September. It is considered an important allergen.
Uredinales- The rusts do occur in very high numbers but not enough is known about their significance in causing allergic reactions at these levels. The season is from early June to mid-October. The counts are mostly low to moderate with some in the very high range.
Ustilaginales- The allergenic properties of the smuts are unknown. The season is from June to mid-October with some very high counts from July to the end of September.
Alternaria sp.- The counts are in the low to moderate ranges and some species are known to cause allergic reactions. The season is from mid-April to mid-October.
Penicillium & Aspergillus sp.- These spores are found throughout the whole counting season and are probably present in significant numbers beyond that. The counts are significant from March to late fall.
Botrytis sp.- This may be a significant allergen, with low to moderate counts. The season is June to the end of September.
Cladosporium sp.- Some species are known to cause allergic reactions. 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.
Epicoccum sp.- Some species are known to cause allergic reactions. The season is from late May to the end of September with only low counts. May not be a significant allergen at these levels.
Helicomyces sp.- Season is very sporadic from May to the end of September producing low to high counts.
Drechslera sp.- The counts are mostly in the low range with some moderate counts in July and August. 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: 07-March-2006
Copyright (c) 2000 Aerobiology Research Laboratories, All Rights Reserved
Contact info@aerobiology.ca for more information