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Can You Count on Daily Pollen Counts?
Media-reported daily pollen counts can be helpful for pollen-sensitive individuals in determining medication according to reports published in the August 2004 Annals of Allergy, Asthma and Immunology, the scientific journal of the American College of Allergy, Asthma and Immunology (ACAAI).
Pollen counts are usually reported in community broadcasts as low, medium and high, rather than absolute values. Results from a single sample are often applied to a large region, although there may be very significant differences in vegetation and meteorological factors within that area.
Investigator Constance H. Katelaris, M.D., Ph.D., from the Institute for Immunology and Allergy Research, Westmead Hospital in Sydney, Australia, and colleagues studied the pollen counts found among three trap sites within a 30 km (18.6 mile) area.
The comparison between low- and high-count days among the three sites revealed a variance rate of 8 percent to 17 percent.
The authors conclude that the count from one trap is a reasonable estimation for the purposes of informing the public of the prevailing pollen levels. However, clinical researchers that depend on pollen counts should ensure that data collection is local and applicable to the subject group being studied.
Jay M. Portnoy, Children's Mercy Hospital in Kansas City, Mo., noted in an editorial that even though pollen collection is affected by many factors including geography, location, elevation, time of day, type of collection device, duration of collection and weather conditions, the current approach of monitoring pollen and spore exposure from a central station is the only practical one at this time.
Both reports emphasize that it is not known how much pollen exposure is required to elicit a certain degree of symptoms, which depends on the duration and route of exposure, the sensitivity of the individual and how their symptoms are measured.
According to Dr. Portnoy, despite the complexities involved in using community-wide pollen counts to estimate personal exposure, informed allergic individuals can act to reduce their allergy symptoms. Daily pollen reports also increase awareness of allergy triggers and may encourage community efforts to reduce exposure to certain types of pollen. |
