PURPOSE: Corollary to a study of respiratory health effects of volcanic air pollution in Hawai'i Island schoolchildren, we studied airborne pollens in Pahala, a community downwind of Kilauea volcano's major vent.
METHODS: Airborne pollen was collected between 28 May and 30 Oct 2010 using a Burkard recording sampler on a 1-story roof-top. Meteorological data was obtained from a meteorological station at neighboring Ka'u High School. Pollen and wind direction were analyzed at 2-hr intervals each day.
RESULTS: A total of 18 pollen morphological types were identified. Total pollen geometric mean (GM) 24-hr concentration was 25 grains/m3 (range 1-136/m3) for the 3-month period. Predominant types (GM concentration, grains/m3) included Cecropia (10.3), Trema (7.3), Broussonetia-like (3.2), Poaceae (1.9), Myrica faya (1.3), and Myrtaceae (including Eucalyptus) (1.3). Pollen was recovered during 79% of the 2-hour periods . Trema was most frequently recovered (44%) followed by Cecropia, Broussonetia-like, Poaceae, Myrica faya, and Myrtaceae (42%, 19%, 14%, 5%, and 4%, respectively). Rank order by percent cumulative pollen closely paralleled frequency with Cecropia having the largest recovery (47% of all grains), followed by Trema, Broussonetia, Poaceae, Myrica faya, and Myrtaceae (23%, 17%, 4%, 1.4%, 1.3%, respectively). Maximum concentrations for total pollen, Cecropia, and Trema were 390, 332, and 109/m3, respectively. All of the predominant pollen types recovered were from naturalized taxa, not native to Hawaii. Land breezes from the northwest and sea breezes from the east and southeast were noted. Fifty- six percent of pollen was recovered during the mid-day hours, when winds from the east and southeast prevailed. A total of 1.13 inches fell on 17 of the 94 days. GM total pollen concentrations were 26 and 17/m3 on dry and rainy days, respectively
CONCLUSIONS: In this desert community during summer months, the 24-hr GM pollen concentration was 25 grains/m3, predominantly of non-native species.
CLINICAL IMPLICATIONS: Pollen characterization can aid our understanding of respiratory risks attributable to volcanic vs other sources of air pollution.
DISCLOSURE: The following authors have nothing to disclose: Elizabeth Tam, Michael Muilenberg
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