The Kilauea Volcano adult health study, Hawai'i, United States

After 22 years of eruption at Kilauea Volcano, Hawai'i, an environmental, epidemiological, and ethnographic study was conducted to assess for adverse health effects from chronic exposure to volcanogenic air pollution. Environmental data from 2003 indicated that Kau District, from 37 to 74 km downwind from the eruption, was being exposed to concentrations of volcanic sulfur dioxide gas (SO2) and fine aerosol particles (≤0.3mum) that warranted public health concern. Ambient SO2 average concentrations, measured with diffusion tubes, ranged from 6 to 34 ppbv over three-weeks. SO2 penetrated indoors up to 71% of the ambient concentration. Fine aerosol concentrations, measured with a cascade impactor, ranged from 0.61 to 11.82 mug/m3. Volcanogenic air pollution is strongly correlated with altitude, displaying a pattern of increasing fine aerosol particles and decreasing SO2 with rise in elevation, attributed to rapid oxidation as diurnal wind patterns blow the eruption plume from oceanic terrain landward to more abundant oxidation sources. In 2004, health effects were assessed by a cohort prevalence survey of 335 randomly sampled adult residents. Exposed cohorts of SO2 and sulfate aerosol were from Kau District, and an unexposed control cohort from the extreme north end of the island. Prevalence ratios between the exposed cohorts and control revealed substantially increased prevalence of cough (310%), phlegm (270%), throat irritation (600%), rhinorrhea (740%), sinus congestion (160%), eye irritation (430%) and bronchitis (210%). Blood pressure and respirations were also significantly elevated. Elderly non-smokers had an 8 beat per minute faster average pulse rate than control counterparts. Qualitative descriptions of health responses to the eruption were obtained by open-ended questions and unstructured interviews in the natural setting. Thirty-five percent of exposed participants perceived that their health had been affected by the eruption. Current and former smokers described being most affected. The human-health response to chronic exposure of volcanogenic air pollution may result in a sulfur illness syndrome with identified primary and secondary characteristics. Adult populations with long-term residency in active and degassing volcanic areas may experience an excess burden of cardio-pulmonary illness. Further work is warranted in all communities along Kilauea's plume path and at other degassing volcanoes worldwide.