Effects of Volcanic Fog (Vog) on the Health of Hawaii Volcano National Park Workers

Kilauea is the longest actively erupting volcano in the world. Sulfur dioxide (SO2), Hg, ash, CO2, H2S, and other gases are expelled in abundance from Kilauea volcano during the eruptive phases. Since 1986, Kilauea volcano has typically effused 1,000-2,000 tons per day of SO2 into the air over the Big Isle. Hawaii residents are acutely aware of the volcanic fog (vog) exposures and rose concern of the possible health effects. Hawaii Island has the state highest prevalence of asthma, and emergency department and hospital inpatient admission rates for both children and adults. This study followed 110 Hawaii Volcano National Park workers for eight months and measured daily lung function (FEV1 and PEF) and daily symptoms (wheezing, coughing, eye irritation, etc) and compares them to the presence of the visual vog (index ranged from 0 to 3) and instrument measured particular matter <1 µm (PM1) and SO2. The mean intra-correlation between the visual vog observers was 0.9. The moderate correlation (0.36 - 0.45) between SO2 and PM1 was observed for the same day and the following day. Visual vog index was the good predictor for instrument measured SO2 and PM1. SO2, PM1, and vog index were not good predictors for FEV1 and PEF after adjusting for variation between individuals and medication use. However symptoms such as cough, wheeziness and headache were significantly higher during voggy days (measured by SO2, PM1 and the visual vog) and the following day after adjusting. Visual vog index was the predictor for elevated symptoms overall.