Physicochemical and toxicological profiling of ash from the 2010 and 2011 eruptions of Eyjafjallajökull and Grímsvötn volcanoes, Iceland using a rapid respiratory hazard assessment protocol.

The six week eruption of Eyjafjallajökull volcano in 2010 produced heavy ash fall in a sparsely populated area of southern and south eastern Iceland and disrupted European commercial flights for at least 6 days. We adopted a protocol for the rapid analysis of volcanic ash particles, for the purpose of informing respiratory health risk assessments. Ash collected from deposits underwent a multi-laboratory physicochemical and toxicological investigation of their mineralogical parameters associated with bio-reactivity, and selected in vitro toxicology assays related to pulmonary inflammatory responses. Ash from the eruption of Grímsvötn, Iceland, in 2011 was also studied. The results were benchmarked against ash from Soufrière Hills volcano, Montserrat, which has been extensively studied since the onset of eruptive activity in 1995. For Eyjafjallajökull, the grain size distributions were variable: 2-13 vol% of the bulk samples were <4 µm, with the most explosive phases of the eruption generating abundant respirable particulate matter. In contrast, the Grímsvötn ash was almost uniformly coarse (<3.5 vol%<4 µm material). Surface area ranged from 0.3 to 7.7 m2 g(-1) for Eyjafjallajökull but was very low for Grímsvötn (<0.6 m2 g(-1)). There were few fibre-like particles (which were unrelated to asbestos) and the crystalline silica content was negligible in both eruptions, whereas Soufrière Hills ash was cristobalite-rich with a known potential to cause silicosis. All samples displayed a low ability to deplete lung antioxidant defences, showed little haemolysis and low acute cytotoxicity in human alveolar type-1 like epithelial cells (TT1). However, cell-free tests showed substantial hydroxyl radical generation in the presence of hydrogen peroxide for Grímsvötn samples, as expected for basaltic, Fe-rich ash. Cellular mediators MCP-1, IL-6, and IL-8 showed chronic pro-inflammatory responses in Eyjafjallajökull, Grímsvötn and Soufrière Hills samples, despite substantial differences in the sample mineralogy and eruptive styles. The value of the pro-inflammatory profiles in differentiating the potential respiratory health hazard of volcanic ashes remains uncertain in a protocol designed to inform public health risk assessment, and further research on their role in volcanic crises is warranted.

Diverse mantle components with invariant oxygen isotopes in the 2021 Fagradalsfjall eruption, Iceland.

The basalts of the 2021 Fagradalsfjall eruption were the first erupted on the Reykjanes Peninsula in 781 years and offer a unique opportunity to determine the composition of the mantle underlying Iceland, in particular its oxygen isotope composition (δ18O values). The basalts show compositional variations in Zr/Y, Nb/Zr and Nb/Y values that span roughly half of the previously described range for Icelandic basaltic magmas and signal involvement of Icelandic plume (OIB) and Enriched Mid-Ocean Ridge Basalt (EMORB) in magma genesis. Here we show that Fagradalsfjall δ18O values are invariable (mean δ18O = 5.4 ± 0.3‰ 2 SD, N = 47) and indistinguishable from "normal" upper mantle, in contrast to significantly lower δ18O values reported for erupted materials elsewhere in Iceland (e.g., the 2014-2015 eruption at Holuhraun, Central Iceland). Thus, despite differing trace element characteristics, the melts that supplied the Fagradalsfjall eruption show no evidence for 18O-depleted mantle or interaction with low-δ18O crust and may therefore represent a useful mantle reference value in this part of the Icelandic plume system.

Pharmacokinetics of lignocaine in Icelandic horses after infiltration anaesthesia.

The pharmacokinetics of lignocaine was studied in four Icelandic horses after infiltration anaesthesia. A total of 240 mg of the drug was injected on either side of the left foreleg, over the medial and lateral branches of the palmar nerve. Blood samples were collected up to seven hours after injection and the concentrations of the drug in plasma were determined by gas chromatography/mass spectrometry. The results showed that lignocaine was rapidly absorbed. A mean maximum concentration of 232 ng/ml was observed after 20 minutes. In three of the horses the decline in the plasma concentration of the drug with time was best described by the sum of two exponential terms, but in one of the horses the decline was monoexponential. The mean half-life of the distribution phase (alpha) was 9.8 minutes and that of the elimination phase (beta) 48.4 minutes. In all the horses the plasma concentration was below the limit of detection (2 ng/ml) six hours after injection. Anaesthesia was tested in one horse and lasted for one hour.

[Immunization coverage in the Monkey Bay Head zone Malawi]. / Thornekjun bólusetningar barna vietha Monkey Bay, Malaví.

OBJECTIVE: To assess the immunization coverage of children in the Monkey Bay head zone, Malawi where the Icelandic International Development Agency (ICEIDA) has been working to improve health care services in the recent years. MATERIALS AND METHODS: A 30 by 7 cluster sample survey, as defined by WHO's Expanded Programme on Immunization (EPI) was conducted to estimate immunization coverage of children aged 12-23 months for tuberculosis (BCG), diphtheria, tetanus and pertussis (DTP), polio (OPV) and measles immunizations. The Head Zone consists of 97 villages with a population of around 105,000 inhabitants. Five health centres provide immunization services in the area. In total were 217 children in 30 clusters randomly selected and their immunization status by card or history registered. RESULTS: Immunization coverage by card or history was 97% for BCG, and 99%, 95% and 85% for DTP1, DTP2 and DTP3 respectively. Coverage of OPV1, OPV2 and OPV3 by card or history was 99%, 93% and 85% respectively. Coverage for measles by card or history was 78%. Fully immunized children by card or history were 152 or 70%. Two children had not received any immunizations. Drop-out rate from DTP1 to DTP3 vaccination by immunization card or history was 14.5%, and drop-out from DTP1 to Measles by card or history was 21%. CONCLUSION: These results indicate that access to childhood immunization in the Monkey Bay head zone is good while drop-out rate is high. This indicates that access to health services is adequate. However, the coverage of measles appears to be insufficient to prevent outbreaks, and must be improved. The efficacy in delivering immunization can be improved and enhanced utilization of the services offered should be sought.