We studied the usefulness of a real-time pollen counter (KH-3000, Yamato Manufacturing Co. Ltd.).
Airborne pollen was measured with a Durham pollen counter and a KH-3000 from February 1, 2002 to April 30, 2002 in Wakayama city, and the results were analyzed and compared with each other statistically. We took account of the influence of weather conditions on the results. In addition, a characteristic of circadian rhythm of airborne pollen was examined.
The features of the pollen scatter pattern in 2002 were as follows: The counts for Japanese cedar pollen and Japanese cypress pollen were smaller than the average year. The Japanese beech pollen count was larger than the average year. Correlations between the outcomes of the 2 pollen counters were r=0.65 for Japanese cedar pollen and r=0.61 for the total pollen, except pine pollen.
The circadian rhythm of the airborne pollen observed with the KH-3000 did not correlated significantly to temperature, humidity, atmospheric pressure or wind velocity. However, a tendency did emerge: on a clear day, a large amount of pollen was observed in the evening and at night. On a cloudy day, no obvious peak of pollen dispersion was observed in a day. On a rainy day, a large number of pollen was observed before the start of rainfall, but no pollen grains were observed during the rain. No pollen was observed on snowy days, however unexpected peaks were recorded that were not related to the pollen count. The peaks were thought to be caused by snow.
We concluded that the KH-3000 is a useful device for measuring pollen, however, the Durham pollen counter presently used is still needed to measure pollen, because the operation of the KH-3000 was influenced by weather: it could not distinguish pollen from snow. Our findings suggest the circadian rhythm of airborne pollen depends on the weather.
