CONICET | Buscador de Institutos y Recursos Humanos

Effects of the June 2011 eruption of the Puyehue-Cordón Caulle volcanic complex (PCC-VC) on urban infrastructure, agriculture and public health in Argentina were investigated by a multidisciplinary team from New Zealand, the United Kingdom and Argentina. The team also studied the emergency management of the eruption crisis. Field work was carried out between 27 February and 16 March 2012. The team focused its efforts on the population centres that received the greatest ashfalls (Villa la Angostura, San Carlos de Bariloche and Ing. Jacobacci), and on agricultural regions affected by ashfall. A notable feature of this eruption (and other eruptions in Patagonia) has been the extensive remobilisation of unconsolidated ash deposits by the strong prevailing winds in the region. Towns on the steppe such as Jacobacci have been particularly severely affected, and at the time of our visit, severe air quality problems were continuing to occur on a regular basis. The public health response to the widespread ash fall was limited by a lack of information given to the population about: possible short and long term health effects of exposure to the ash; particle size and composition of the ash; and results of measurements of the ash concentrations in the air to assess the risk to respiratory health. The most important single finding is the absence of crystalline silica (which can cause silicosis) in the respirable ash fraction (PM4), but further tests on a wider geographical range of samples are needed to fully confirm this result. However, a large fraction of PM2.5 is present in the ash and the ash deposits are very persistent in the arid areas leading to continuing, abnormally high exposure to PM2.5 and PM10 in the settlements in the steppe region, which is of great concern as it could carry long term risks to respiratory health, such as chronic obstructive pulmonary disease (COPD), and reduction in lung growth in children, as well as aggravation of asthma in adults and children. A programme of background air pollution assessment and monitoring of ash levels inside houses and in individual groups of people at risk needs to be conducted in the steppe region as a matter of urgency, together with epidemiological research and respiratory disease surveillance. Special measures to reduce the infiltration of ash into homes and buildings such as schools during the frequent episodes of strong winds continue to be needed and should be more widely adopted. Methods to reduce the movement of ash by the winds and effective cleanup of ash from streets and around homes need to be actively pursued and strengthened. The eruption had severe effects on extensive livestock farming in the mallines in the Comallo to Jacobacci region, with stock losses of 40-60%. Causes of death included starvation, dehydration, rumen blockages and abrasion damage to teeth. The effects of the eruption were compounded by the pre-existing drought conditions in the region. Effects were comparatively less severe in farming areas closer to the volcano (with stock losses of around 25%). We have suggested some strategies for agricultural recovery based on our experiences of other eruptions in Patagonia. Generally, impacts on electricity networks, water supplies, wastewater treatment, communications networks and road transport were as expected from our studies of other eruptions. Probably the most severe and unexpected disruption was that Bariloche airport remained largely out of action well beyond its official closure period of one month for cleanup operations . This was due to caution 3 . The most important single finding is the absence of crystalline silica (which can cause silicosis) in the respirable ash fraction (PM4), but further tests on a wider geographical range of samples are needed to fully confirm this result. However, a large fraction of PM2.5 is present in the ash and the ash deposits are very persistent in the arid areas leading to continuing, abnormally high exposure to PM2.5 and PM10 in the settlements in the steppe region, which is of great concern as it could carry long term risks to respiratory health, such as chronic obstructive pulmonary disease (COPD), and reduction in lung growth in children, as well as aggravation of asthma in adults and children. A programme of background air pollution assessment and monitoring of ash levels inside houses and in individual groups of people at risk needs to be conducted in the steppe region as a matter of urgency, together with epidemiological research and respiratory disease surveillance. Special measures to reduce the infiltration of ash into homes and buildings such as schools during the frequent episodes of strong winds continue to be needed and should be more widely adopted. Methods to reduce the movement of ash by the winds and effective cleanup of ash from streets and around homes need to be actively pursued and strengthened. The eruption had severe effects on extensive livestock farming in the mallines in the Comallo to Jacobacci region, with stock losses of 40-60%. Causes of death included starvation, dehydration, rumen blockages and abrasion damage to teeth. The effects of the eruption were compounded by the pre-existing drought conditions in the region. Effects were comparatively less severe in farming areas closer to the volcano (with stock losses of around 25%). We have suggested some strategies for agricultural recovery based on our experiences of other eruptions in Patagonia. Generally, impacts on electricity networks, water supplies, wastewater treatment, communications networks and road transport were as expected from our studies of other eruptions. Probably the most severe and unexpected disruption was that Bariloche airport remained largely out of action well beyond its official closure period of one month for cleanup operations . This was due to caution 3 3 exercised by the major airlines in the face of continued activity at PCC-VC, and uncertainty about safe operating thresholds. Flight disruptions are likely to have had substantial effects on the tourism-focused economy of the region although this was beyond the scope of our study to evaluate. In terms of emergency management of the eruption crisis, it was evident to us that there is a dedicated and capable group of emergency and infrastructure managers who have worked hard to respond to and recover from the eruption crisis. However these individual efforts were hampered by poor overall coordination between local, regional and national levels of civil protection and poor liaison with scientific agencies and with volcano observatories in Chile. Given the frequency of eruptions from Andean volcanoes, it is vital that the lessons learned be embedded to reduce the vulnerability of this area to future eruptions. Finally, we would like to note that this report presents our observations of the eruption crisis in Argentina. It is not an official record of the event.