Health Impacts of Volcanic Activity in Oceania.

Volcanoes cause a wide range of hazardous phenomena. Close to volcanic vents, hazards can be highly dangerous and destructive and include pyroclastic flows and surges, ballistic projectiles, lava flows, lahars, thick ashfalls, and gas and aerosol emissions. Direct health impacts include trauma, burns, and exacerbation of respiratory diseases. Far-reaching volcanic hazards include volcanic ashfalls, gas and aerosol dispersion, and lahars. Within Oceania, the island arc countries of Papua New Guinea (PNG), the Solomon Islands, Vanuatu, Tonga, and New Zealand are the most at-risk from volcanic activity. Since 1500ad, approximately 10,000 lives have been lost due to volcanic activity across Oceania, with 39 lives lost since 2000. While volcano monitoring and surveillance save lives, residual risks remain from small, sudden, unheralded eruptions, such as the December 9, 2019 eruption of Whakaari/White Island volcano, New Zealand which has a death toll of 21 at the time of writing. Widespread volcanic ashfalls can affect the habitability of downwind communities by contaminating water supplies, damaging crops and buildings, and degrading indoor and outdoor air quality, as well as disrupting transport and communication networks and access to health services. While the fatality rate due to volcanic eruptions may be low, far greater numbers of people may be affected by volcanic activity with approximately 100,000 people in PNG and Vanuatu displaced since 2000. It is challenging to manage health impacts for displaced people, particularly in low-income countries where events such as eruptions occur against a background of low, variable vaccination rates, high prevalence of infectious diseases, poor sanitation infrastructure, and poor nutritional status. As a case study, the 2017-2018 eruption of Ambae volcano, Vanuatu caused no casualties but triggered two separate mandatory off-island evacuations of the entire population of approximately 11,700 people. On the neighboring island of Santo, a health disaster response was coordinated by local government and provided acute care when evacuees arrived. Involving primary care clinicians in this setting enhanced local capacity for health care provision and allowed for an improved understanding of the impact of displacement on evacuee communities.