Cardiorespiratory health effects associated with sulphurous volcanic air pollution.

OBJECTIVE: To investigate cardiorespiratory health effects associated with chronic exposure to volcanogenic sulphur dioxide (SO2) and fine sulphate particle (< or = 0.3 microm) air pollution emitted from Kilauea Volcano, Hawaii. STUDY
DESIGN: Environmental-epidemiological cross-sectional study.
METHODS: An air study was conducted to measure exposure levels in the downwind area, and to confirm non-exposure in a reference area. Cross-sectional health data were collected from 335 adults, > or = 20 years of age, who had resided for > or = 7 years in the study areas. Prevalence was estimated for cardiorespiratory signs, and self-reported symptoms and diseases. Logistic regression analysis estimated effect measures between exposed and unexposed groups considering potential confounding including age, gender, race, smoking, dust and body mass index (BMI). Student's t-tests compared mean differences in blood pressure (BP), pulse and respiratory rates.
RESULTS: There were statistically significant positive associations between chronic exposure and increased prevalence of cough, phlegm, rhinorrhoea, sore/dry throat, sinus congestion, wheezing, eye irritation and bronchitis. The magnitude of the associations differed according to SO2 and fine sulphate particulate exposure. Group analyses found no differences in pulse rate or BP; however, significantly faster mean pulse rates were detected in exposed non-medicated, non-smoking participants with BMI <25, and in participants aged > or = 65 years. Higher mean systolic BP was found in exposed participants with BMI <25.
CONCLUSIONS: Long-term residency in active degassing volcanic areas may have an adverse effect on cardiorespiratory health in adults. Further study at Kilauea is recommended, and the authors encourage investigations in communities near active volcanoes worldwide. Public health interventions of community education, and smoking prevention and cessation are suggested.