Effects of volcanic gas (vog) on the lung function and self-reported symptoms of Hawai'i Volcanoes National Park workers

Thesis (Ph.D.)--University of Hawaii at Manoa, 2008.Conclusion. Visual vog observers can provide reliable data which are correlated with data from SO2 and PM1.0 monitors. Visually observed vog is as useful tool of predicting self-reported symptoms as SO2 and PM1.0 monitors. Network of visual observes can provide useful assessment of the park.Introduction. Kilauea, the largest stationary source of sulfur dioxide (SO2) in the nation, has been erupting continuously since 1986. The visible cloud (vog) formed by emitted gases in combination with moisture and sunlight may be directed by the wind and can be visible throughout the Hawaii Islands. Kilauea is located in the Hawaii Volcanoes National Park (HVNP) which has 5,000 visitors daily and is the workplace of 750 employees who have the highest exposure to vog.Methods. This cohort study was designed to examine the association between volcanic emissions (vog) as indicated by the degree of particulate matter (PM1.0), sulfur dioxide SO2, and visual assessment (VVI) and its impact on self-reported symptoms and lung function measurements in HVNP workers. Self-reported symptoms and PEF and FEV1 measurements were recorded daily by park workers and volunteers.Results. Visually observed vog, PM1.0 and SO2 were statistically significantly associated with self-reported symptoms: cough, wheeze, headache, shortness of breath, sore, itchy, watery eyes, and irritation of nose/sinus/throat but not with PEF and FEV1. Increases in SO2 seemed to have an immediate (0 days lag) effect on symptoms; during maximum SO2 days of the period of study (SO2 max = 173 ppb) the odds of having symptoms increased by two fold for the same day compared to days with the lowest SO2 measurement (SO2 min = 0 ppb). The greatest relationship between PM1.0 and symptoms is delayed by one day; one day after the maximum PM1.0 (PM1.0 max = 7.85 um/m3), the odds of having symptoms increase by 1.5 times compared to days with the lowest PM1.0 measurement (PM1.0 min = 0 ppb). In contrast, the relationship between visual vog index (VVI) and symptoms seem to be greatest two days after exposure; two days after "heavy haze" (VVI = 3) the odds of having symptoms increase by 1.53 compared to "clear" days (VVI = 0).Includes bibliographical references (leaves xxx-xxx).Also available by subscription via World Wide Web181 leaves, bound 29 c