Speciation of 127I and 129I in atmospheric aerosols at Risø, Denmark: insight into sources of iodine isotopes and their species transformations

Luyuan Zhang, Xiaolin Hou, Sheng Xu

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    Abstract

    Speciation analysis of iodine in aerosols is a very useful approach for understanding geochemical cycling of iodine in the atmosphere. In this study, overall iodine species, including water-soluble iodine species (iodide, iodate and water-soluble organic iodine), NaOH-soluble iodine and insoluble iodine have been determined for 129I and 127I in the aerosols collected at Risø, Denmark, between March and May 2011 (shortly after the Fukushima nuclear accident) and in December 2014. The measured concentrations of total iodine are in the range of 1.04–2.48 ng m−3 for 127I and (11.3–97.0) × 105 atoms m−3 for 129I, and 129I / 127I atomic ratios of (17.8–86.8) × 10−8. The contribution of Fukushima-derived 129I (peak value of 6.3 × 104 atoms m−3) is estimated to be negligible (less than 6 %) compared to the total 129I concentration in northern Europe. The concentrations and species of 129I and 127I in the aerosols are found to be strongly related to their sources and atmospheric pathways. Aerosols that were transported over the contaminated ocean, contained higher amounts of 129I than aerosols transported over the European continent. The high 129I concentrations of the marine aerosols are attributed to secondary emission from heavily 129I-contaminated seawater rather than primary gaseous release from nuclear reprocessing plants. Water-soluble iodine was found to be a minor fraction to total iodine for both 127I (7.8–13.7 %) and 129I (6.5–14.1 %) in ocean-derived aerosols, but accounted for 20.2–30.3 % for 127I and 25.6–29.5 % for 129I in land-derived aerosols. Iodide was the predominant form of water-soluble iodine, accounting for more than 97 % of the water-soluble iodine. NaOH-soluble iodine seems to be independent of the sources of aerosols. The significant proportion of 129I and 127I found in NaOH-soluble fractions is likely bound with organic substances. In contrast to water-soluble iodine however, the sources of air masses exerted distinct influences on insoluble iodine for both 129I and 127I, with higher values for marine air masses and lower values for terrestrial air masses.
    Original languageEnglish
    JournalAtmospheric Chemistry and Physics
    Volume16
    Pages (from-to)1971-1985
    ISSN1680-7316
    DOIs
    Publication statusPublished - 2016

    Bibliographical note

    © Author(s) 2016. CC Attribution 3.0 License.

    Cite this

    @article{2ca2567669014a1b9b8a7e83dd63ff85,
    title = "Speciation of 127I and 129I in atmospheric aerosols at Ris{\o}, Denmark: insight into sources of iodine isotopes and their species transformations",
    abstract = "Speciation analysis of iodine in aerosols is a very useful approach for understanding geochemical cycling of iodine in the atmosphere. In this study, overall iodine species, including water-soluble iodine species (iodide, iodate and water-soluble organic iodine), NaOH-soluble iodine and insoluble iodine have been determined for 129I and 127I in the aerosols collected at Ris{\o}, Denmark, between March and May 2011 (shortly after the Fukushima nuclear accident) and in December 2014. The measured concentrations of total iodine are in the range of 1.04–2.48 ng m−3 for 127I and (11.3–97.0) × 105 atoms m−3 for 129I, and 129I / 127I atomic ratios of (17.8–86.8) × 10−8. The contribution of Fukushima-derived 129I (peak value of 6.3 × 104 atoms m−3) is estimated to be negligible (less than 6 {\%}) compared to the total 129I concentration in northern Europe. The concentrations and species of 129I and 127I in the aerosols are found to be strongly related to their sources and atmospheric pathways. Aerosols that were transported over the contaminated ocean, contained higher amounts of 129I than aerosols transported over the European continent. The high 129I concentrations of the marine aerosols are attributed to secondary emission from heavily 129I-contaminated seawater rather than primary gaseous release from nuclear reprocessing plants. Water-soluble iodine was found to be a minor fraction to total iodine for both 127I (7.8–13.7 {\%}) and 129I (6.5–14.1 {\%}) in ocean-derived aerosols, but accounted for 20.2–30.3 {\%} for 127I and 25.6–29.5 {\%} for 129I in land-derived aerosols. Iodide was the predominant form of water-soluble iodine, accounting for more than 97 {\%} of the water-soluble iodine. NaOH-soluble iodine seems to be independent of the sources of aerosols. The significant proportion of 129I and 127I found in NaOH-soluble fractions is likely bound with organic substances. In contrast to water-soluble iodine however, the sources of air masses exerted distinct influences on insoluble iodine for both 129I and 127I, with higher values for marine air masses and lower values for terrestrial air masses.",
    author = "Luyuan Zhang and Xiaolin Hou and Sheng Xu",
    note = "{\circledC} Author(s) 2016. CC Attribution 3.0 License.",
    year = "2016",
    doi = "10.5194/acp-16-1971-2016",
    language = "English",
    volume = "16",
    pages = "1971--1985",
    journal = "Atmospheric Chemistry and Physics",
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    Speciation of 127I and 129I in atmospheric aerosols at Risø, Denmark: insight into sources of iodine isotopes and their species transformations. / Zhang, Luyuan; Hou, Xiaolin; Xu, Sheng.

    In: Atmospheric Chemistry and Physics, Vol. 16, 2016, p. 1971-1985.

    Research output: Contribution to journalJournal articleResearchpeer-review

    TY - JOUR

    T1 - Speciation of 127I and 129I in atmospheric aerosols at Risø, Denmark: insight into sources of iodine isotopes and their species transformations

    AU - Zhang, Luyuan

    AU - Hou, Xiaolin

    AU - Xu, Sheng

    N1 - © Author(s) 2016. CC Attribution 3.0 License.

    PY - 2016

    Y1 - 2016

    N2 - Speciation analysis of iodine in aerosols is a very useful approach for understanding geochemical cycling of iodine in the atmosphere. In this study, overall iodine species, including water-soluble iodine species (iodide, iodate and water-soluble organic iodine), NaOH-soluble iodine and insoluble iodine have been determined for 129I and 127I in the aerosols collected at Risø, Denmark, between March and May 2011 (shortly after the Fukushima nuclear accident) and in December 2014. The measured concentrations of total iodine are in the range of 1.04–2.48 ng m−3 for 127I and (11.3–97.0) × 105 atoms m−3 for 129I, and 129I / 127I atomic ratios of (17.8–86.8) × 10−8. The contribution of Fukushima-derived 129I (peak value of 6.3 × 104 atoms m−3) is estimated to be negligible (less than 6 %) compared to the total 129I concentration in northern Europe. The concentrations and species of 129I and 127I in the aerosols are found to be strongly related to their sources and atmospheric pathways. Aerosols that were transported over the contaminated ocean, contained higher amounts of 129I than aerosols transported over the European continent. The high 129I concentrations of the marine aerosols are attributed to secondary emission from heavily 129I-contaminated seawater rather than primary gaseous release from nuclear reprocessing plants. Water-soluble iodine was found to be a minor fraction to total iodine for both 127I (7.8–13.7 %) and 129I (6.5–14.1 %) in ocean-derived aerosols, but accounted for 20.2–30.3 % for 127I and 25.6–29.5 % for 129I in land-derived aerosols. Iodide was the predominant form of water-soluble iodine, accounting for more than 97 % of the water-soluble iodine. NaOH-soluble iodine seems to be independent of the sources of aerosols. The significant proportion of 129I and 127I found in NaOH-soluble fractions is likely bound with organic substances. In contrast to water-soluble iodine however, the sources of air masses exerted distinct influences on insoluble iodine for both 129I and 127I, with higher values for marine air masses and lower values for terrestrial air masses.

    AB - Speciation analysis of iodine in aerosols is a very useful approach for understanding geochemical cycling of iodine in the atmosphere. In this study, overall iodine species, including water-soluble iodine species (iodide, iodate and water-soluble organic iodine), NaOH-soluble iodine and insoluble iodine have been determined for 129I and 127I in the aerosols collected at Risø, Denmark, between March and May 2011 (shortly after the Fukushima nuclear accident) and in December 2014. The measured concentrations of total iodine are in the range of 1.04–2.48 ng m−3 for 127I and (11.3–97.0) × 105 atoms m−3 for 129I, and 129I / 127I atomic ratios of (17.8–86.8) × 10−8. The contribution of Fukushima-derived 129I (peak value of 6.3 × 104 atoms m−3) is estimated to be negligible (less than 6 %) compared to the total 129I concentration in northern Europe. The concentrations and species of 129I and 127I in the aerosols are found to be strongly related to their sources and atmospheric pathways. Aerosols that were transported over the contaminated ocean, contained higher amounts of 129I than aerosols transported over the European continent. The high 129I concentrations of the marine aerosols are attributed to secondary emission from heavily 129I-contaminated seawater rather than primary gaseous release from nuclear reprocessing plants. Water-soluble iodine was found to be a minor fraction to total iodine for both 127I (7.8–13.7 %) and 129I (6.5–14.1 %) in ocean-derived aerosols, but accounted for 20.2–30.3 % for 127I and 25.6–29.5 % for 129I in land-derived aerosols. Iodide was the predominant form of water-soluble iodine, accounting for more than 97 % of the water-soluble iodine. NaOH-soluble iodine seems to be independent of the sources of aerosols. The significant proportion of 129I and 127I found in NaOH-soluble fractions is likely bound with organic substances. In contrast to water-soluble iodine however, the sources of air masses exerted distinct influences on insoluble iodine for both 129I and 127I, with higher values for marine air masses and lower values for terrestrial air masses.

    U2 - 10.5194/acp-16-1971-2016

    DO - 10.5194/acp-16-1971-2016

    M3 - Journal article

    VL - 16

    SP - 1971

    EP - 1985

    JO - Atmospheric Chemistry and Physics

    JF - Atmospheric Chemistry and Physics

    SN - 1680-7316

    ER -