Allergen Update

Halifax, Nova Scotia

Predominant pollen:

The tree pollen seasons can fluctuate from year to year by as much as three to four weeks at this site due to the effect of weather. Since fog plays such an important role at this site the counts do not necessarily always reflect how much pollen and gungal spores are being produced. The pollen seasons described here try to cover the time when each can occur.

Acer sp.- The maple season can start from early to late April and end the third week of May to mid-June. Mostly low and moderate counts are observed with the occational high obtained.

Alnus sp.- Alder season is highly affected by weather. The main pollen season can start from late March to mid-April and end mid to late June. Mostly low and moderate, with the occational high, counts are observed. They are important allergens and at these levels could cause allergic reactions.

Betula sp.- Birch can reach very high counts and the season can start from mid-April to early May and can end from the first week to the third week of June.

Tsuga sp.- The hemlocks usually only produce low counts but some years moderate counts can occur. The season varies a great deal from year to year due to the effect of weather and cyclical patterns. The season can start from mid-May to early June and end late May to mid-June.

Pinaceae family- The season for the pine, spruces and firs can start from the third week of April to the third week of May and end early lo late July. Very high counts are observed at this site. Significant allergens for individuals who are sensitized.

Cupressaceae family- The cedars, junipers, and yews produce low to moderate counts, with the occasional high count, throughout the pollen season. The season can vary a great deal and can start from late March to mid-April and end from early to mid-June.

Fraxinus sp.- The ash pollen season lasts well over a month. The seasons vary from year to year with most years only low and moderate counts observed. Some years high counts are possible. The season can start from early to late May and ends late May to mid-June. The season start and amount of pollen produced is very dependant on weather.

Populus sp.- The poplar and aspen can have a low early season in March. The main season can start from the first to the third week of April and end early to late May. Mostly low and moderate counts are observed.

Ulmus sp.- The elm season can vary in Halifax depending on where the sampling site is located. There is a season that can occur late May to early June with the Chinese elm but this is very site dependant. The main season for the elm can start from mid-April to early May and end early to mid-May. Low to high counts can be observed depending on sampling location and the weather.

Fagus sp.- The beech season can vary a great deal from year to year due to cyclical patterns and the effect of weather. Low counts are generally observed but moderate counts are possible in certain years. The season can start from the second to the third week of May and end from the third week of May to mid-June.

Quercus sp.- The oak season can start from the third week of April to the second week of May and end from the first to the third week of June. High counts are observed and some species are known to cause allergic reactions.

Gramineae family- The season with the highest counts occurs from early June to late July. Low and moderate counts are observed. The season can start from mid-May to early June and end late September to early October.

Ambrosia sp.- Ragweed counts are always low at this site but may be high enough to cause allergic reaction to individuals who are highly sensitized. The season can begin late July to early August and end late September. Ragweed population varies a great deal throughout this Province.

Plantago sp.- The plantains produce only low counts. The season can start from the third week of June to early July and end from the first to the third week of September. May cause allergic reactions in individuals who are highly sensitized.

Urticaceae sp.- The counts for the nettles are always low but they are important allergens due to their small size. The season can start from early to mid-July and end early to mid-September.

Predominant Spores:

Diatrypaceae sp.- Counts fluctuate throughout the whole counting season. The counts are particularly high in the spring and fall. Season continues well into October. They are not known to cause allergic reactions.

Erysiphe (Oospora) sp.- The powdery mildews occur from July and well into October.

Boletus sp.- Very high counts are observed. Season is from August to late October.

Coprinus sp.- The counts are significant but not as high as Ganoderma or Cladosporium. The season is from August and well into October. Considered an important allergen.

Ganoderma sp.- Very high counts are observed. The main season is mid-June to well into October. Considered an important allergen.

Uredinales sp.- Rusts are not found in very high numbers and the season is August to mid-October.

Ustilaginales sp.- The smuts occur mostly from June to mid-October.

Alternaria sp.- Moderate counts are observed in August and September. May play a significant role in allergies in highly sensitized individuals.

Botrytis sp.- Moderate and high counts are observed from late May to mid-October. Could play a significant role in causing allergic reactions.

Penicillium sp. & Aspergillus sp.- They occur throughout the counting season but the highest counts are from July to well into late fall.

Cladosporium sp.- This is the most prominant spore for the whole season. The highest counts occur from late March to late fall. Could cause allergic reactions in sensitized individuals.

Fusarium sp.- Very sporadic counts are observed throughout the whole counting season. The season is from the end of March to mid-October.

Epicoccum sp.- Does not reach really high numbers but may cause reactions in highly sensitized individuals. The main season is from approximately mid-June to late September.

Helicomyces sp.- Sporadic throughout the whole season but the highest counts are observed from the end of May to the end of September.

Last Updated : 4 March 2015

The information presented here is designed to inform, not replace, the relationship that exists between a patient and a medical professional.

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