Allergen Update
Toronto, Ontario (Brampton area)
Predominant pollen:
The tree pollen seasons can fluctuate from year to year by as much as two to three weeks at this site. The pollen seasons described here try to cover the time when each can occur.
Acer sp.- Maple season varies due to the number of species present and the effect of weather. Significant counts, in the moderate range, are observed from the end of March to early June. Occasional high count is observed.
Alnus sp.- Alder season occurs from the end of March to early June and the counts vary from low to moderate with the occasional high counts. The fluctuation in the season is due to the number of species present and the effect of weather.
Betula sp.- The birch season can occur from mid-April to mid-June with some very high counts observed. The birch look-a-likes' season has significant counts for approximately four weeks and can occur from mid-April to early June.
Populus sp.- The poplar and aspen season is from late March to the end of April. Some of the counts are high and may cause allergic reactions.
Carya- The hickories pollinate for two to three weeks and the season can occur from early May to late June with some moderate counts.
Castenea- The chestnuts are important allergens and the season lasts approximately two weeks and it can occur from mid-May to late June. The Horse Chestnut, which is the most allergenic, is found in significant numbers.
Cupressaceae group- The cedars, junipers and yews produce moderate and high counts from late March to late May.
Fraxinus sp.- The ash pollination season occurs between April and late May. High counts are observed and they are considered to be allergenic in highly sensitized individuals.
Pinaceae group- This group includes the spruce, fir and pine trees. High counts are observed from May to late June. The time of the season can vary from year to year by as much as two weeks.
Quercus sp.- The oaks have two distinct seasons. The first pollination is short and occurs from mid to late April. The main season, which produces the most pollen, occurs mostly in May. The oaks are considered to be highly allergenic.
Ulmus sp.- The elm are important allergens. The season lasts almost one month and can occur from late March to late April. Moderate counts are observed.
Salix- The willow season is from mid-April to late May with low to high counts. They may cause allergic reactions.
Morus- Mulberry season lasts at least a month and can occur from early May to mid-June. Low to high counts are observed.
Gramineae- The grasses produce moderate to high pollen counts from the end of May to the end of July. The season starts early May and lasts until mid-October.
Ambrosia sp.- Ragweed pollen is observed from mid-July until mid to late October with the highest counts occurring the second week of August to late September.
Urtica sp.- Nettles occur in significant numbers that may cause allergic reactions and the season is mid-June to mid-September.
Predominant spores:
Diatrypaceae sp.- The counts are sporadic throughout the whole counting season. High counts can be observed from late March to mid-October.
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 mid-May to mid-September with great fluctuations in counts from day to day. This is probably due to the effect of weather. Moderate and high counts are observed from April to mid-October.
Erysephe (Oospora)- Powdery mildew - The season is from mid-April to mid-October. Low to high counts are observed.
Boletus sp.- The season for this spore is very sporadic with some very high counts observed. It may be of significance in causing allergic reactions. The season is from June to mid-October.
Coprinus sp.- This mushroom can produce some moderate and high counts from mid-April to mid-October. It is considered an important allergen.
Ganoderma sp.- This bracket fungus can produce very high counts from June to mid-October. It is considered an important allergen.
Uredinales- The rusts do occur in really high numbers in the late summer but not enough is known about their significance in causing allergic reactions at these levels. The season is from early May to late October.
Ustilaginales- The smuts can reach high counts, allergenicity is unknown. The season is mid-April to mid-October with some high counts.
Alternaria sp.- The counts do get high and some species are known to cause allergic reactions. The season is from April to mid-October. The highest counts occur from 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. High counts are observed from mid-March to late fall.
Botrytis sp.- This may be a significant allergen although the counts do not get very high. The season is from May to the end of September.
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.
Epicoccum sp.- Some species are known to cause allergic reactions and the season, with moderate and high counts, is from June to mid-October.
Fusarium sp.- Counts are very sporadic throughout the whole counting season. The majority of the season occurs from May to mid-October with some high counts. Can cause allergic reactions.
Helicomyces sp.- Season is from May to the end of September producing moderate and high counts. The season is very sporadic.
Pithomyces sp.- Season is mostly in the low to moderate range from June to mid-October.
Polythrincium sp.- Allergenicity is unknown but significant counts are observed from July to the end of September.
Torula sp.- Some species are known to cause allergic reactions. Moderate counts are observed from June to mid-October. The season is sporadic.
Myxomycetes- Moderate counts are observed from June to late September.
Last Updated: 28-March-2006
Copyright (c) 2000 Aerobiology Research Laboratories, All Rights Reserved
Contact info@aerobiology.ca for more information