Fínar agnir í andrúmslofti og hjartaáföll

Í nýlegri rannsókn við Rice háskólann í Houston kom í ljós að fyrir hver 10 µg/m³ sem styrkur PM_2.5 eykst (sólarhringsmeðaltal), daginn sem hjartaáfall verður eða daginn áður, eykst hættan á hjartaáfalli um 2% – 9%.

Þarna voru rannsökuð tilfelli hjartaáfalla utan spítala (Out of Hospital Cardiac Arrests) í Houston, yfir 8 ára tímabil, meira en 11 þúsund tilfelli. Fundu að fyrir 6 µg/m³ sem styrkur PM_2.5 eykst (sólarhringsmeðaltal) daginn sem hjartaáfall verður og daginn áður, aukast líkurnar á hjartaáfalli um 4.6%.
Heimild:
L. Raun and K. B. Ensor. 2012. Association of Out-of-Hospital Cardiac Arrest with Exposure to Fine Particulate and Ozone Ambient Air Pollution from Case Crossover Analysis Results: Are the Standards Protective? James Baker III Institute for Public Policy, Rice University.

Svifryksmengun yfir mörkum 13. febrúar 2013

Svifyrkmengun var yfir sólarhrings heilsuverndarmörkum, sem eru 50 µg/m³, þann 13. febrúar síðastliðinn við Grensásveg. Stöðin mælir á 30 mín fresti og var meðaltal þeirra 42 mælinga (af 48) sem tókust þann daginn 55 µg/m³.

Umferð var, án efa, aðalástæða þess að styrkur svifryks var þetta hár. Bæði útblástur og síðan einnig uppþyrlun af götum, eins og mátti glöggt sjá í umferðinni á miðvikudag, olli háum styrk svifryks. Mjög hægur vindur var og jafnvel mögulega hitahvarf, sem tryggir að NO_x úr útblæstri bíla og svifryk fóru ekki langt !

Loft(ekki)gæði í Peking og suður af Himalaya fjöllum

Mökkur suður af Himalaya-fjöllum

Suður af Himalaya-fjöllum er einskonar “á” af mekki (e. haze), sem verður til vegna gróðurelda sem kveiktir eru vegna landbúnaðar, iðnaðar- og umferðar- mengunar. Til að gera þetta verra eru síðan hitahvörf á þessu svæði, sem loka mengunina við yfirborð jarðar. Takið sérstaklega hvernig fjallgarðurinn afmarkar “ánna” til norðurs.

Indland og Bangladesh svæðið suður af Himalaya-fjöllum þann 11. janúar 2013. Image courtesy of NASA/Rapidfire.

Þessi mynd, frá 10. janúar 2013, sýnir þetta jafnvel enn betur – víðara sjónarhorn.

10. janúar 2013. Image courtesy of NASA/Rapidfire.

Ótrúleg svifryksmengun í Peking (Beijing).

Samkvæmt fréttum og mælingum, hefur styrkur PM2.5 í Peking (Beijing) náð 886 µg/m3 (held að þetta séu klukkustundar-gildi) á nokkrum stöðum og víða yfir 700 µg/m3. Svona hefur þetta verið í nokkra daga. Heilsuverndarmörk samkvæmt WHO eru 25 µg/m3 (mögulega 20 µg/m3) – þannig að þarna er mengunin að fara amk 30-falt yfir sett mörk !

Í Kína er víða nóg af uppsprettum fyrir svifryk, orkuver keyrð á kolum, mikil aukning í einkabílaeign og svo hafa veðurskilyrðin verið þess háttar að styrkurinn eykst – lítill vindur sér í lagi. Það þarf því ekki mikið til að styrkur svifryksmengunar fari yfir heilsuverndarmörk og veldur þetta miklum áhyggjum.

Yfirvöld hafa reynt að sporna við menguninni síðastliðna daga með því að takmarka framkvæmdir og iðnað, banna notkun obinberra bíla og beint því til skóla að draga úr útiveru.

Ekki einstakt

Á sama tíma, samkvæmt mælingum (reyndar í frétt) í Dehli, Indlandi, á nokkuð venjulegum, jafnvel vindasömum, degi er styrkur PM2.5 engu að síður á bilinu 130 til 565 µg/m3 !

Við getum verið þakklát fyrir rok og rigningu hér á Íslandi ! Vissulega höfum við ekki jafnsterkar uppsprettur fyrir svifryksmengun, en engu að síður getur styrkurinn risið nokkuð hratt ef hitahvörf og stillur eru. Þessar tölur sem nefndar eru hér að ofan eru þó á við áramót í stillu.

Svifryk um áramót

Það var nú heldur minna af flugeldum þessi áramótin en oft áður – fannst manni að minnsta kosti.

Mælingar á PM10 frá Grensásvegi (GRE), Fjölskyldu- og húsdýragarðinum (FHG) og færanlegri mælistöð (FAR, Ártúnsholti, rétt suðaustan við gatnamót Birtingakvíslar og Straums), sýna að mengunin var tiltölulega skammvinn þessi áramót, en náði þó ansi háu gildi á FAR (þó hefur mælst yfir 2300 µg/m3 um áramót).

Tilraun var gerð til að mæla fínar- og örfínar agnir yfir áramótin og get ég vonandi sagt frá niðurstöðum þeirra mælinga fljótlega.

Að lokum, til gamans, þá sáust brennur á gervitunglamyndum frá því um kl. 22:20 í gærkvöldi (31. des, 2012). Þetta eru hitamyndir, þannig að brennurnar sjást sem svartir dílar – ef vel er að gáð.

NOAA via VÍ

Gleðilegt nýtt ár !

Ný grein um dreifingu H2S frá jarðvarmavirkjunum

Ný grein um dreifingu H₂S frá jarðvarmavirkjunum í nágrenni Reykjavíkur og veðuraðstæður sem valda því að styrkurinn nær yfir 50 µg/m^3.

Throstur Thorsteinsson, Julia Hackenbruch, Einar Sveinbjörnsson, Thorsteinn Jóhannsson. 2013. Statistical assessment and modeling of the effects of weather conditions on H₂S plume dispersal from Icelandic geothermal power plants. Geothermics 45: 31 - 40.

Greinin á síðu útgefandans Geothermics

Abstract
Episodes of high atmospheric load of hydrogen sulfide (H₂S), where the concentration is over 50 μg m⁻³ hourly average value, occur about 80 times a year in Reykjavik (data from 2007 to 2009). H₂S originates mainly from two geothermal power plants 25–30 km (south-)east of Reykjavik, at Hellisheidi and Nesjavellir. Certain weather-dependent dispersion conditions, such as wind, cloud cover and air temperature, allow the transport of emissions towards Reykjavik and the neighboring cities, causing local air pollution. High concentrations of H₂S occur within a narrow range of weather conditions, namely slow (mean value 2 ± 1 m s⁻¹) easterly (114° ± 23°) winds, together with cold air temperatures (median value −3 °C) and preferably no, or little, cloud cover. A classification of weather types shows the preferred occurrence of high H₂S concentrations in connection with low atmospheric exchange and autochthonous weather. Stable atmospheric stratification and inversions enable the transport of H₂S emissions to Reykjavik. The measured concentrations, the short lived peaks in concentration and different values at nearby measurement stations, indicate a very narrow plume, which fits well with a Gaussian plume distribution model.

Heilsufarsáhrif eldgosssins í Eyjafjallajökli 2010

Ný grein í BMJ Open - frír aðgangur að pdf.

BMJ Open 2012;2:e001851 doi:10.1136/bmjopen-2012-001851

• Public health

Health effects following the Eyjafjallajökull volcanic eruption: a cohort study

1. Hanne Krage Carlsen1,2, 
2. Arna Hauksdottir1, 
3. Unnur Anna Valdimarsdottir1,
4. Thorarinn Gíslason3, 
5. Gunnlaug Einarsdottir4, 
6. Halldor Runolfsson5, 
7. Haraldur Briem6,
8. Ragnhildur Gudrun Finnbjornsdottir1, 
9. Sigurdur Gudmundsson7, 
10. Thorir Björn Kolbeinsson8,
11. Throstur Thorsteinsson9, 
12. Gudrun Pétursdóttir10

Abstract

Objectives The study aimed to determine whether exposure to a volcanic eruption was associated with increased prevalence of physical and/or mental symptoms.

Design Cohort, with non-exposed control group.

Setting Natural disasters like volcanic eruptions constitute a major public-health threat. The Icelandic volcano Eyjafjallajökull exposed residents in southern Iceland to continuous ash fall for more than 5 weeks in spring 2010. This study was conducted during November 2010–March 2011, 6–9 months after the Eyjafjallajökull eruption.

Participants Adult (18–80 years of age) eruption-exposed South Icelanders (N=1148) and a control population of residents of Skagafjörður, North Iceland (N=510). The participation rate was 72%.

Main outcome measures Physical symptoms in the previous year (chronic), in the previous month (recent), General Health Questionnaire (GHQ-12) measured psychological morbidity.

Results The likelihood of having symptoms during the last month was higher in the exposed population, such as; tightness in the chest (OR 2.5; 95% CI 1.1 to 5.8), cough (OR 2.6; 95% CI 1.7 to 3.9), phlegm (OR 2.1; 95% CI 1.3 to 3.2), eye irritation (OR 2.9; 95% CI 2.0 to 4.1) and psychological morbidity symptoms (OR 1.3; 95% CI 1.0 to 1.7). Respiratory symptoms during the last 12 months were also more common in the exposed population; cough (OR 2.2; 95% CI 1.6 to 2.9), dyspnoea (OR 1.6; 95% CI 1.1 to 2.3), although the prevalence of underlying asthma and heart disease was similar. Twice as many in the exposed population had two or more symptoms from nose, eyes or upper-respiratory tract (24% vs 13%, p<0.001); these individuals were also more likely to experience psychological morbidity (OR 4.7; 95% CI 3.4 to 6.5) compared with individuals with no symptoms. Most symptoms exhibited a dose–response pattern within the exposed population, corresponding to low, medium and high exposure to the eruption.

Conclusions 6–9 months after the Eyjafjallajökull eruption, residents living in the exposed area, particularly those closest to the volcano, had markedly increased prevalence of various physical symptoms. A portion of the exposed population reported multiple symptoms and may be at risk for long-term physical and psychological morbidity. Studies of long-term consequences are therefore warranted.

Figure 2. Venn diagram of exposed and non-exposed participants reporting one or more key symptom 6–9 months after the Eyjafjallajökull eruption. Eye symptoms: irritation, itch or other discomfort; nasal symptoms: sneeze or runny nose without having a cough; cough and/or phlegm: often cough without having a cold and/or phlegm during winter. The numbers do not add up due to rounding.

Fyrstu heilsufarseinkenni vegna eldgossins í Eyjafjallajökli 2010

Ný grein í BMJ Open - opinn aðgangur að pdf.

BMJ Open 2012;2:e000343 doi:10.1136/bmjopen-2011-000343

• Public health

A survey of early health effects of the Eyjafjallajökull 2010 eruption in Iceland: a population-based study

1. Hanne Krage Carlsen1, 
2. Thorarinn Gislason2,3, 
3. Bryndis Benediktsdottir2,3,
4. Thorir Bjorn Kolbeinsson4, 
5. Arna Hauksdottir1, 
6. Throstur Thorsteinsson5, 
7. Haraldur Briem6

Abstract

Objective To estimate physical and mental health effects of the Eyjafjallajökull volcanic eruption on nearby residents.

Design Cross-sectional study.

Setting The Icelandic volcano Eyjafjallajökull erupted on 14 April 2010. The eruption lasted for about 6 weeks and was explosive, ejecting some 8 million tons of fine particles into the atmosphere. Due to prevailing winds, the ash spread mostly to the south and south-east, first over the rural region to the south, later over the Atlantic Ocean and Europe, closing European air space for several days.

Participants Residents (n=207) of the most ash-exposed rural area south and east of the volcano.

Methods The study period was from 31 May to 11 June 2010. Participants were examined by a physician. To ascertain respiratory health, standardised spirometry was performed before and after the use of a bronchodilator. All adult participants answered questionnaires about mental and physical health, their children's health and the use of protective equipment.

Results Every other adult participant reported irritation in eyes and upper airway when exposed to volcanic ash. Adults (n=26) and children (n=5) with pre-existing asthma frequently reported worsening of their symptoms. No serious health problems requiring hospitalisation could be attributed to the eruption. The majority of the participants reported no abnormal physical or mental symptoms to the examining physician. Compared to an age- and gender-matched reference group, the ash-exposed participants reported lower smoking rates and were less likely to have ventilation impairment. Less than 10% of the participants reported symptoms of stress, anxiety or depression.

Conclusions Short-term ash exposure was associated with upper airway irritation symptoms and exacerbation of pre-existing asthma but did not contribute to serious health problems. The exposure did not impair respiratory function compared to controls. Outdoor use of protective glasses and face masks was considered protective against irritation in eyes and upper airway.