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Health Tips / Hayfever - Information on pollen

What is a pollen count?

The pollen count is the number of pollen grains per cubic metre (m3) of air, recorded over 24 hours. The results are sometimes stated as low, moderate, high or very high.

These can be explained a follows : hen are the pollen counts highest?

The pollen count will be at its highest on a perfect summer day; clear sky, no rain and gentle breezes. The factors which influence the pollen counts can be explained as follows:

· Amount of sunlight
Higher counts are found on sunny days as pollen spreads and transfers from one flower to another, while the lower counts are associated with overcast and cloudy days.

· Wind Effects
Higher counts are produced when winds are light, below Force 4.

· Time of the day
Counts are usually lower early in the day. The peak level is reached in the late afternoon and evening, while there are morning peaks also. Lowest levels are usually around midday.

· Location
Pollen counts in rural grassy areas are much higher than urban areas. However, research has shown that a higher percentage of children in urban areas suffer from hayfever than in rural areas. This is thought to be due to increased traffic pollution.

· Time of the year
Flowers produce most pollen in the summer months. Pollen counts reach the highest in the months of June and July. In March to May, the temperatures are usually quite low resulting in low counts.

· Rainfall
Rain will wash the pollen out of the air, especially rain in the early morning.

When do different pollens cause Hayfever?

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Last update: 16/05/2013 12:38 • Previous update: 30/11/-0001 00:00