TY - JOUR
T1 - Mineralogical analyses and in vitro screening tests for the rapid evaluation of the health hazard of volcanic ash at Rabaul volcano, Papua New Guinea
AU - Le Blond, Jennifer S.
AU - Horwell, Claire J.
AU - Baxter, Peter J.
AU - Michnowicz, Sabina A. K.
AU - Tomatis, Maura
AU - Fubini, Bice
AU - Delmelle, Pierre
AU - Dunster, Christina
AU - Patia, Herman
PY - 2010/11
Y1 - 2010/11
N2 - The continuous ash and gas emissions from the Tavurvur cone in Rabaul caldera, Papua New Guinea, during 2007-08, raised concerns regarding how exposure would affect the respiratory health of nearby populations and impact on the environment. As part of a formal evaluation of the effects of volcanic emissions on public health, we investigated the potential health hazard of the ash using a suite of selected mineralogical analyses and in vitro toxicity screening tests. The trachy-andesitic ash comprised 2.1-6.7 vol.% respirable (sub-4 mu m diameter) particles. The crystalline silica content was 1.9-5.0 wt.% cristobalite (in the bulk sample) with trace amounts of quartz and/or tridymite. Scanning electron microscopy showed that the ash particles were angular with sparse, fibre-like particles (similar to 3-60 mu m max. diameter) observed in some samples, which we confirmed to be CaSO4 (gypsum, at <6 wt.% in the bulk samples) and not asbestiform fibres. The ash specific surface area was low (0.1-2.7 m(2) g(-1)). The leached solution from one of the ash samples was slightly acidic (pH 5.6), but did not contain high levels of toxic metals (such as F, Cu, Zn, Mn, As, Ni and Cd) when compared to previously tested volcanic ash leachates. Ash samples generated potentially-harmful hydroxyl radicals through an iron-mediated catalytic reaction, in the range of 0.15-2.47 mu mol m(-2) (after 30 min of reaction). However, measurement of particle oxidative capacity (potential oxidative stress reaction using ascorbic acid) and silica-like injury to red blood cells (erythrolysis assay, i.e. measurement of cell death) nevertheless revealed low biological reactivity. The findings suggest that acute exposure to the ash would have a limited potential to exacerbate pre-existing conditions such as asthma or chronic bronchitis, and the potential for chronic exposure leading to silicosis was low.
AB - The continuous ash and gas emissions from the Tavurvur cone in Rabaul caldera, Papua New Guinea, during 2007-08, raised concerns regarding how exposure would affect the respiratory health of nearby populations and impact on the environment. As part of a formal evaluation of the effects of volcanic emissions on public health, we investigated the potential health hazard of the ash using a suite of selected mineralogical analyses and in vitro toxicity screening tests. The trachy-andesitic ash comprised 2.1-6.7 vol.% respirable (sub-4 mu m diameter) particles. The crystalline silica content was 1.9-5.0 wt.% cristobalite (in the bulk sample) with trace amounts of quartz and/or tridymite. Scanning electron microscopy showed that the ash particles were angular with sparse, fibre-like particles (similar to 3-60 mu m max. diameter) observed in some samples, which we confirmed to be CaSO4 (gypsum, at <6 wt.% in the bulk samples) and not asbestiform fibres. The ash specific surface area was low (0.1-2.7 m(2) g(-1)). The leached solution from one of the ash samples was slightly acidic (pH 5.6), but did not contain high levels of toxic metals (such as F, Cu, Zn, Mn, As, Ni and Cd) when compared to previously tested volcanic ash leachates. Ash samples generated potentially-harmful hydroxyl radicals through an iron-mediated catalytic reaction, in the range of 0.15-2.47 mu mol m(-2) (after 30 min of reaction). However, measurement of particle oxidative capacity (potential oxidative stress reaction using ascorbic acid) and silica-like injury to red blood cells (erythrolysis assay, i.e. measurement of cell death) nevertheless revealed low biological reactivity. The findings suggest that acute exposure to the ash would have a limited potential to exacerbate pre-existing conditions such as asthma or chronic bronchitis, and the potential for chronic exposure leading to silicosis was low.
KW - Public health
KW - Hazard assessment
KW - Rabaul
KW - Volcanic ash
KW - Multidisciplinary
KW - MOUNT-ST-HELENS
KW - AIRBORNE PARTICULATE MATTER
KW - SOUFRIERE HILLS VOLCANO
KW - AFRICAN GOLD MINERS
KW - OXIDATIVE STRESS
KW - RADICAL GENERATION
KW - ACTIVE CALDERA
KW - AIR-POLLUTION
KW - ASCORBIC-ACID
KW - EL-CHICHON
UR - http://www.scopus.com/inward/record.url?scp=78149495773&partnerID=8YFLogxK
U2 - 10.1007/s00445-010-0382-7
DO - 10.1007/s00445-010-0382-7
M3 - Article
SN - 0377-0273
VL - 72
SP - 1077
EP - 1092
JO - Bulletin of Volcanology
JF - Bulletin of Volcanology
IS - 9
ER -