ISLAMABAD: Regular rainfall in the region this year has been a blessing for the residents of Islamabad as they have been prevented from the spread of pollen allergy amid the coronavirus threat.

After dropping to a very low level of 485 particles per cubic metre (PCM) on Friday, the pollen count in Islamabad surged to 8,642pcm on Sunday due to a bright sunshine.

Rains starting on Thursday night and followed by around 55mm rainfall on Friday dropped the pollen count by Saturday noon.

The pollen particles flying in the air get wet in rainfall and flow down with the water whereas their presence increases in dry, sunny and windy conditions.

On March 23, the pollen count crossed over 45,000pcm for a brief period but sharply declined due to rains and cool weather on March 25 to around 2,000 level and again surged to 30,000pcm on March 26.

With another wet spell expected from Thursday, pollen count will drop again

The pollen concentration increases gradually with the onset of spring season and attains its peak around full blossom. However, this year the pollen spread did not start in the first week of March in the twin cities but surged to a high level for three days only due the continuous rainfall after regular intervals.

The most abundant pollen types in Islamabad are from eight plant species. Paper mulberry, eucalyptus, pines, besides abundant grass, dandelions, other shrubs such as acacia and cannabis are the key sources of pollen in the federal capital.

Out of all these plants, paper mulberry shares about 97pc of the total pollen and its concentration touches the extreme limits of about 40,000 per cubic metre of air at the peak of the blossom season.

Due to the vegetation and moisture in the city, many varieties of fungi too release pollen and moulds in the air.

People suffering from asthma and respiratory diseases experience serious consequences due to the sharp increase in pollen concentrations.

Traditionally, there are around nine rainy days in the month of March. However, this year Islamabad has already witnessed 15 days of precipitation and as a result little time was available for the plants and trees to release their spores in the air.

As a shallow westerly waves is affecting upper parts of the country and another round of downpour is expected from early Tuesday, the pollen count will drop again.

The pollen season continues up to mid-April and spores start to die down. As the daytime temperature increases beyond their survival capacity, allergy sensitive individuals are expected to pass the spring without any serious complaint.

Published in Dawn, March 30th, 2020