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Medical AI Inquiry: You was designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.  Labels: AIMS, METHOD, RESULTS. Meshes: Acute Disease, Adult, Anti-Asthmatic Agents, Asthma, Female, Humans, Male, New Zealand, Surveys and Questionnaires, Volcanic Eruptions.
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Under the volcano: fire, ash and asthma? Context: To investigate the prevalence of respiratory symptoms in known asthmatics, following exposure to airborne volcanic ash particles caused by the eruptions of Mount Ruapehu, New Zealand, commencing September 1995. A one page postal questionnaire was sent to 1392 previously identified asthmatics 2 months after the first major eruption. Two hundred and thirty seven subjects had moved from the area, died or gone overseas since the original contact 4 years previously; therefore the target population was 1155 subjects of whom 361 lived in the exposed area and 794 in the nonexposed areas. The response rates were 246 (68.1%) in the exposed group and 477 (60.1%) in the nonexposed group making a total of 723 individuals. The prevalence of nocturnal shortness of breath in the last two months was 29.3% in the exposed group and 24.7% in the nonexposed (OR = 1.26, 95% CI; 0.83-1.78). Similarly 30.9% of the exposed group had an asthma attack in the last 2 months compared to 31.9% of the nonexposed group (OR = 0.96, 95% CI; 0.69-1.33). Finally, 48.4% of the exposed group used asthma medication in the 2 months following the eruption in comparison to 53% of the nonexposed group (OR = 0.83, 95%, CI; 0.61-1.12).
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The study showed no association between living in an area exposed to volcanic ash particles and either asthma symptoms or the use of asthma medication. There was a small but nonsignificant increase in nocturnal shortness of breath in the exposed group.