5 research outputs found
The chemical composition of rivers and snow affected by the 2014/2015 Bárðarbunga eruption, Iceland
Post-print (lokagerð höfundar)The 2014/15 Bárðarbunga volcanic eruption was the largest in Iceland for more than 200 years. This eruption released into the atmosphere on average 60,000 tonnes/day of SO2, 30,000 tonnes/day of CO2, and 500 tonnes/day of HCl affecting the chemical composition of rain, snow, and surface water. The interaction of these volcanic gases with natural waters, decreases fluid pH and accelerates rock dissolution. This leads to the enhanced release of elements, including toxic metals such as aluminium, to these waters. River monitoring, including spot and continuous osmotic sampling, shows that although the water conductivity was relatively stable during the volcanic unrest, the dissolution of volcanic gases increased the SO4, F, and Cl concentrations of local surface waters by up to two orders of magnitude decreasing the carbon alkalinity. In addition the concentration of SiO2, Ca, Mg, Na and trace metals rose considerably due to the water–molten lava and hot solid lava interaction. The presence of pristine lava and acidic gases increased the average chemical denudation rate, calculated based on Na flux, within Jökulsá á Fjöllum catchment by a factor of two compared to the background flux.
Melted snow samples collected at the eruption site were characterised by a strong dependence of the pH on SO4, F and Cl and metal concentrations, indicating that volcanic gases and aerosols acidified the snow. Protons balanced about half of the negatively charged anions; the rest was balanced by water–soluble salts and aerosols containing a variety of metals including Al, Fe, Na, Ca, and Mg. The concentrations of F, Al, Fe, Mn, Cd, Cu, and Pb in the snowmelt water surpassed drinking- and surface water standards. Snowmelt–river water mixing calculations indicate that low alkalinity surface waters, such as numerous salmon rivers in East Iceland, will be more affected by polluted snowmelt waters than high alkalinity spring and glacier fed rivers.The authors would like to thank associate editor Alessandro Aiuppa for handling this manuscript. Two anonymous reviewers are greatly thanked for their constructive comments which improved the manuscript. This study was funded by Ríkislögreglustjórinn Almannavarnadeild – The National Commissioner of the Icelandic Police, Jarðvísindastofnun Háskólans – Institute of Earth Sciences University of Iceland, Veðurstofa Íslands - IMO and Rannsóknamiðstöð Íslands - The Icelandic Centre for Research RANNÍS (Grant # 163531-051). The authors would like to thank all of those who helped in collecting the water and snow samples: Morgan Thomas Jones, Sverre Planke, Dougal Jerram, John Millett, Helgi Alfredsson, Þorsteinn Jónsson, Nicole Keller, Sveinbjörn Steinþórsson, Ingibjörg Jónsdóttir, Catherine Gallagher, Thor Thordarson, Ármann Höskuldsson, Jón Ottó Gunnarsson, Morten Riishuus, Ólafur Freyr Gíslason, Hermann Arngrímsson, Njáll Fannar Reynisson, Svava Björk Þorláksdóttir, Daði Þorbjörnsson, Lukasz Kowolik. Rósa Ólafsóttir is gratefully thanked for helping in maps preparation. We also thank all colleagues and co-workers from the Institute of Earth Sciences and IMO for the fruitful discussions during this time of the Bárðarbunga unrest.Peer reviewe
External otitis in school children after an intensive swimming course
Neðst á síðunni er hægt að nálgast greinina í heild sinni með því að smella á hlekkinn View/OpenObjective: This study reports an outbrake of external otitis in boarding school children after they had participated in an intensive swimming course. The infective agent isolated was P. aeruginosa. The question is raised whether the outbrake was caused by water contaminated by bacteria or intensive bathing. Material and methods: Twenty-seven children from a rural boarding school, aged 10 to 14 years participated in an obligatory swimming course for two weeks. As the outbrake became evident all the children were examined by two doctors with an otomicroscope. Bacterial culture was taken from the external acoustic meatus (EAM) on both sides and a tympanogram was performed on all. Subjective evaluation of symptoms was achieved by using a questionnaire. Eight weeks after the swimming course ended all participants were investigated again with an ear microscope and control bacterial culture was taken from the EAM for appreciation of the outcome. Results: Seventeen (63%) of the 27 children had symptoms of external otitis on the first visit. Microscopic investigation of those infected revealed seven (41.2%) children with mild, four (23.5%) with mode¬rate and six (35.3%) with severe inflammation of the EAM. Of those children affected 12 (70.6%) had infection in both ears. P. aeruginosa was isolated from 11(64,7%) of those affected and from two of those who had no symptoms. The mean onset of symptoms was 2.1 days (standard error 0.5) after the swimming course had ended. The mean time for symptom relief was 11.4 days (standard error 2.2). Conclusions: Intensive swimming courses in pools where the quality of the water is checked sporadically is not advised. If intensive swimming courses are necessary the concentration of chlorine should be carefully monitored as well as checked for growth of both Cloriform bacteria and P. aeruginosa.Tilgangur: Tilgangur rannsóknarinnar var að lýsa faraldri hlustarbólgutilfella sem stafaði af P. aeruginosa í kjölfar sundnámskeiðs í heimavistarskóla. Efniviður og aðferðir: Tuttugu og sjö börn á aldrinum 10-14 ára, nemendur í heimavistarskóla á Austurlandi tóku þátt í sundnámskeiði sem stóð í tvær vikur. Börnin fóru í sund fjórum sinnum á dag (mánudag-föstudag) á tveggja vikna tímabili. Þegar ljóst varð að tilfellum hlustarbólgu fór fjölgandi meðal þeirra voru öll börnin skoðuð af tveimur læknum með eyrnarsmásjá, einnig var gerð hljóðhols- (þrýstings) mæling á miðeyrum. Bakteríuræktanir voru teknar úr hlust báðum megin. Niðurstöður: Alls fengu 17 (63%) af börnunum einkenni hlustarbólgu meðan á sundnámskeiðinu stóð eða strax á eftir. Skoðun með eyrnasmásjá sýndi að sjö þeirra höfðu væg bólgueinkenni, fjögur millistigs en sex höfðu miklar bólgubreytingar í hlustargangi. Tólf (70,6%) þessara bama höfðu bólgubreytingar báðum megin. P. aeruginosa ræktaðist frá 11 (64,7%) þeirra sem höfðu einkenni en tveimur sem höfðu engin einkenni. Einkenni byrjuðu að meðaltali 2,1 degi (staðalskekkja 0,5) eftir að námskeiðinu lauk og stóðu í 11,4 daga (staðalskekkja 2,2). Alyktanir: Ekki er hægt að ráðleggja endurteknar sundlaugarferðir á stuttum tíma nema gæði vatnsins séu tryggð með reglulegu eftirliti og ræktunum á bæði kólíbakteríum og P. aeruginosa
Thrombolytic therapy in Egilsstaðir district. Five cases in a two year period
Neðst á síðunni er hægt að nálgast greinina í heild sinni með því að smella á hlekkinn View/OpenEgilsstadir is a rural district in Iceland with a population of 3100 people. In 1993 prehospital thrombolytic therapy started in Egilsstaðir district. A protocol was made and used as a therapeutic guide. In a period of two years five patients have been treated. Four of them got thrombolytic therapy started within four hours since beginning of symptoms. Two of the patients had successful reperfusion of the coronary arteries and two more had positive results. All of the cases were treated successfully without complications and then transferred to a special cardiology unit. Our experience is that prehospital thrombolytic therapy can easily be done in a rural setting. We consider the time gain in starting thrombolytic therapy before transferal to hospital critical to prevent morbidity and save lives. Our experience is positive to encourage continuation of prehospital thrombolytic therapy in rural settings.Egilsstaðalæknishérað er eitt víðfeðmasta læknishérað landsins, sem nær yfir Fljótsdalshérað, Eiða- og Hjaltastaðaþinghár, Borgarfjörð eystri, Tungu-, Hlíðar- og Jökuldalshrepp og norður yfir Möðrudalsöræfi að Víðidal. Að jafnaði starfa þrír til fjórir læknar í héraðinu með heildaríbúafjölda um 3.100 manns, sem getur aukist talsvert á sumrin vegna ferðamanna. Árið 1993 var farið að beita segaleysandi meðferð í Egilsstaðalæknishéraði. Samin var meðferðaráætlun í byrjun, sem var fylgt í hverju tilfelli. Í vissum tilfellum var haft samband við hjartasérfræðing til að staðfesta greiningu. Á tveggja ára tímabili hafa fimm sjúklingar verið meðhöndlaðir. Fjórir þeirra fengu meðferð innan fjögurra klukkustunda frá byrjun einkenna. Tveir sjúklingar fengu öruggt endurflæði kransæða og tveir aðrir sýndu merki um jákvæðan árangur. Gangur í öllum tilfellum var án alvarlegra fylgikvilla og voru sjúklingar fluttir á sérhæfða hjartadeild eftir meðferð. Okkar reynsla er að segaleysandi meðferð megi koma við í héraði á einfaldan hátt án mikils tilkostnaðar. Við áætlum einnig að sá tími sem sparast sé mikilvægur til að draga úr sjúkleika og dauðsföllum af völdum kransæðastíflu. Þótt um fá tilfelli og stuttan tíma sé að ræða er reynsla okkar hvetjandi fyrir áframhald á segaleysandi meðferð í héraði
Thrombolytic therapy in Egilsstaðir district. Five cases in a two year period
Neðst á síðunni er hægt að nálgast greinina í heild sinni með því að smella á hlekkinn View/OpenEgilsstadir is a rural district in Iceland with a population of 3100 people. In 1993 prehospital thrombolytic therapy started in Egilsstaðir district. A protocol was made and used as a therapeutic guide. In a period of two years five patients have been treated. Four of them got thrombolytic therapy started within four hours since beginning of symptoms. Two of the patients had successful reperfusion of the coronary arteries and two more had positive results. All of the cases were treated successfully without complications and then transferred to a special cardiology unit. Our experience is that prehospital thrombolytic therapy can easily be done in a rural setting. We consider the time gain in starting thrombolytic therapy before transferal to hospital critical to prevent morbidity and save lives. Our experience is positive to encourage continuation of prehospital thrombolytic therapy in rural settings.Egilsstaðalæknishérað er eitt víðfeðmasta læknishérað landsins, sem nær yfir Fljótsdalshérað, Eiða- og Hjaltastaðaþinghár, Borgarfjörð eystri, Tungu-, Hlíðar- og Jökuldalshrepp og norður yfir Möðrudalsöræfi að Víðidal. Að jafnaði starfa þrír til fjórir læknar í héraðinu með heildaríbúafjölda um 3.100 manns, sem getur aukist talsvert á sumrin vegna ferðamanna. Árið 1993 var farið að beita segaleysandi meðferð í Egilsstaðalæknishéraði. Samin var meðferðaráætlun í byrjun, sem var fylgt í hverju tilfelli. Í vissum tilfellum var haft samband við hjartasérfræðing til að staðfesta greiningu. Á tveggja ára tímabili hafa fimm sjúklingar verið meðhöndlaðir. Fjórir þeirra fengu meðferð innan fjögurra klukkustunda frá byrjun einkenna. Tveir sjúklingar fengu öruggt endurflæði kransæða og tveir aðrir sýndu merki um jákvæðan árangur. Gangur í öllum tilfellum var án alvarlegra fylgikvilla og voru sjúklingar fluttir á sérhæfða hjartadeild eftir meðferð. Okkar reynsla er að segaleysandi meðferð megi koma við í héraði á einfaldan hátt án mikils tilkostnaðar. Við áætlum einnig að sá tími sem sparast sé mikilvægur til að draga úr sjúkleika og dauðsföllum af völdum kransæðastíflu. Þótt um fá tilfelli og stuttan tíma sé að ræða er reynsla okkar hvetjandi fyrir áframhald á segaleysandi meðferð í héraði
The effects of different settings on outcome when screening for high blood pressure
Neðst á síðunni er hægt að nálgast greinina í heild sinni með því að smella á hlekkinn View/OpenIntroduction: It has become increasingly popular to offer blood pressure measurements under circumstances that differ from the usual setting, for example measurements in supermarkets, pharmacies, at exhibitions etc. It is well known that environmental factors as well as doctor and patient relationship can affect blood pressure measurement. This must be considered in the diagnosis and treatment of hypertension. The aim of this study was to evaluate some of these phenomena. Material and methods: Subjects attending local supermarket in a rural community were offered blood pressure measurement two Friday afternoons. All measurements were done in a sitting position with a fully automatic blood pressure recorder, AND UA-767. Hypertension was diagnosed if blood pres¬sure exceeded 140 mm Hg systolic and/or 90 mmHg diastolic (according to WHO standards). Those who had hypertension were followed by two office and six home measurements. For the statistical analysis, a t-test for paired data was used. Results are reported as means. Results: Total of 125 subjects had their blood pressure measured. By the WHO criteria 64 (51.2%) of the subjects had hypertension. Mean blood pressure was significantly higher in the supermarket compared to office both for systolic, 17.1 (C.I:12.8-21.4)mmHg, and diastolic, 5.2 (0.1:2.7-7.7) mmHg, blood pressure. Eighty per cent of the subjects had normal blood pressure at home. Compared to supermarket the mean blood pressure reduction was 29.3 (0.1:24.7-33.9) mmHg for systolic and 10.1 (0.1:7.2-13.0) mmHg for diastolic. A "white coat effect" (office vs. home BP) was present. Mean blood pressure reduction 12.9 mmHg (0.1:10.1-15.7) mmHg for systolic and 5.0 mmHg (0.1:3.4-6.6) for diastolic. Conclusions: This unconventional approach to blood pressure screening seems to be both cheap and acceptable for the public. Blood pressure measurements under these circumstances on the other hand are not directly comparable to the standard values given by WHO and should be looked on as reflecting the blood pressure each given time. Environmental factors therefore influence the blood pressure measurement greatly. The interaction between the physician and the patient seems to be a major factor in the office vs. home blood pressure difference, the so called white coat effect. On the other hand there must be another explanation for the difference between blood pressure measurement in supermarket "and at home. Different circumstances and their effect on reference values when offering blood pressure measurements must be taken into consideration. This should be kept in mind when diagnosing hypertension.Inngangur: Að undanförnu hefur færst í vöxt að bjóða upp á blóðþrýstingsmælingar við aðrar aðstæður en venjulega hefur tíðkast, svo sem á sýningum, í apótekum og stórverslunum. Tilgangur þessarar rannsóknar var að kanna mun á blóðþrýstingsmælingum við mismunandi aðstæður. Efniviður og aðferðir: Farið var í kjörbúð tvö föstudagssíðdegi milli kl. 17 og 19 þar sem þeim sem vildu var boðið upp á blóðþrýstingsmælingu. Notaður var sjálfvirkur blóðþrýstingsmælir, AND UA-767. Háþrýstingur var greindur ef slagbilsþrýstingur var yfir 140mmHg og/eða hlébilsþrýstingur var yfir 90 mmHg (miðað við staðla WHO). Þeim sem voru yfir viðmiðunarmörkum var síðan fylgt eftir með mælingum á stofu í tvö skipti og sex heimamælingum. Við tölfræðiútreikning var notað parað t-próf og niðurstöður birtast sem meðaltal. Niðurstöður: Alls létu 125 manns mæla blóðþrýstinginn. Af þeim greindust 64 (51,2%) með háþrýsting við hópmælinguna. Niðurstöður sýna að einungis fimmtungur þeirra reyndist hafa háþrýsting og fjórir fimmtu voru með eðlilegan blóðþrýsting samkvæmt heimamælingum. Meðallækkun frá hópmælingu miðað við heimamælingu var 29,3 mmHg (C.I: 24,7¬33,9) í slagbilsþrýstingi en 10,1 mmHg (C. 1:7,2-13,0) í hlébilsþrýstingi. Þegar bornar voru saman stofumælingar og heimamælingar var meðallækkun á slagbilsþrýstingi 12,9 mmHg (C.I:10,1-15,7) og hlébilsþrýstingi 5,0 mmHg (C.I: 3,4-6,6). Meðallækkun frá hópmælingu miðað við stofumælingu var 17,1 mmHg (C.I:12,8-21,4) í slagbilsþrýstingi og 5,2 mmHg (C.I: 2,7-7,7) í hlébilsþrýstingi. Ályktun: Óhefðbundnar blóðþrýstingsmælingar eru hvort tveggja ódýrar og aðgengilegar fyrir almenning. Slíkar mælingar er hins vegar vafasamt að bera saman við þau viðmiðunargildi sem gefin eru upp af WHO og líta ber á að þær endurspegli það ástand sem ríkir á hverjum tíma fyrir sig. Umhverfi virðist því hafa mikil áhrif á blóðþrýstinginn. Samband sjúklings og læknis er einnig stór þáttur í mismuni milli blóðþrýstings sem mældur er á stofu og heima, svokölluð hvítsloppaáhrif (white coat effect). Hins vegar verður að leita eftir öðrum skýringum á samanburði blóðþrýstingsmælinga á verslunarstöðum og heima fyrir. Taka verður tillit til ólíkra aðstæðna og áhrifa þeirra á viðmiðunargildi þegar boðið er upp á slíkar mælingar og hafa þetta í huga þegar háþrýstingur er greindur