radhydРадиационная гигиенаRadiatsionnaya Gygiena = Radiation Hygiene1998-426X2409-9082NIIRG10.21514/1998-426X-2016-9-3-14-27radhyd-376Research ArticleНаучные статьиScientific articlesДинамика содержания 7Ве, 40K, 134Cs и 137Cs в эпифитных лишайниках (род Usnea) на островах Кунашир и Сахалин после аварии на АЭС «Фукусима-1»Temporal variations of 7Be, 40K, 134Cs and 137Cs in epiphytic lichens (genus Usnea) at the Sakhalin and Kunashir islands after the Fukushima accidentРамзаевВ. П.RamzaevV. P.

197101, Россия, Санкт-Петербург, ул. Мира, д. 8

PhD, leading researcher, Saint-Petersburg Research Institute of Radiation Hygiene after Professor P.V. Ramzaev, Federal Service for Surveillance on Consumer Rights Protection and Human Well-Being (Mira St., 8, Saint-Petersburg, 197101, Russia

V.Ramzaev@mail.ruБарковскийА. Н.BarkovskyA. N.

the Head of the Laboratory of External Exposure, Saint-Petersburg Research Institute of Radiation Hygiene after Professor P.V. Ramzaev, Federal Service for Surveillance on Consumer Rights Protection and Human Well-Being

ГромовА. В.GromovA. V.

Candidate of Biological Sciences, the Head of the Radiochemical Laboratory, Saint-Petersburg Research Institute of Radiation Hygiene after Professor P.V. Ramzaev, Federal Service for Surveillance on Consumer Rights Protection and Human Well-Being

ИвановС. И.IvanovS. A.

the Head of the Laboratory on Emergency Preparedness, Saint-Petersburg Research Institute of Radiation Hygiene after Professor P.V. Ramzaev, Federal Service for Surveillance on Consumer Rights Protection and Human Well-Being

КадукаМ. В.KadukaM. V.

junior researcher of the Radiochemical Laboratory, Saint-Petersburg Research Institute of Radiation Hygiene after Professor P.V. Ramzaev, Federal Service for Surveillance on Consumer Rights Protection and Human Well-Being

Санкт-Петербургский научно-исследовательский институт радиационной гигиены имени профессора П.В. Рамзаева, Федеральная служба по надзору в сфере защиты прав потребителей и благополучия человека, Санкт-Петербург, РоссияРоссияSaint-Petersburg Research Institute of Radiation Hygiene after Professor P.V. Ramzaev, Federal Service for Surveillance on Consumer Rights Protection and Human Well-Being, Saint-Petersburg, RussiaRussian Federation201609102016931427Copyright © Рамзаев В.П., Барковский А.Н., Громов А.В., Иванов С.И., Кадука М.В., 20162016Рамзаев В.П., Барковский А.Н., Громов А.В., Иванов С.И., Кадука М.В.Ramzaev V.P., Barkovsky A.N., Gromov A.V., Ivanov S.A., Kaduka M.V.Данная работа распространяется под лицензией Creative Commons Attribution 4.0.This work is licensed under a Creative Commons Attribution 4.0 License.https://www.radhyg.ru/jour/article/view/376

Целью исследования являлось изучение динамики содержания техногенных и природных радионуклидов в эпифитных лишайниках рода Usnea, собранных на островах Сахалин и Кунашир (Сахалинская область, Россия) после аварии на АЭС «Фукусима-1». В работе были использованы как уже опубликованные результаты (2011–2013 гг.), так и новые экспериментальные данные (2015 г.). Всего в период 2011–2015 гг. были отобраны 62 пробы лишайников, в которых с использованием полупроводниковых гамма-спектрометров было определено содержание гамма-излучающих радионуклидов. Удельная активность техногенных радионуклидов 134Cs и 137Cs и естественных радионуклидов 7Ве и 40K находилась в диапазоне (<0,53) – 41,3, 0,55 – 50,6, 99 – 603 и 35 – 95 Бк/кг (на сухой вес) соответственно. Удельная активность 134Cs и 137Cs в лишайниках с о. Кунашир была статистически значимо выше, чем в лишайниках с о. Сахалин. На данный момент удельная активность радиоцезия в лишайниках является низкой: <6 Бк/кг для 137Cs и <1 Бк/кг для 134Cs. Снижение удельной активности 137Cs в лишайниках с 2011 по 2015 г. соответствует биологическому периоду полуочищения 1,2 года для о. Кунашир и 1,1 года для о. Сахалин. Удельные активности 137Cs и 134Cs в лишайниках Usnea сильно и статистически значимо коррелированы (r = 0,978; P < 0,01). В промежутке 2011–2013 гг. биологический период полуочищения лишайников от 134Cs составлял 1,2 года, что совпадало с соответствующим периодом полуочищения от 137Cs. Совокупный коэффициент перехода радионуклидов в лишайники, Tag, в момент времени t = 0 после аварии на АЭС «Фукусима-1» оценивается для 134Cs величиной 0,56 м2/кг на о. Сахалин и 0,31 м2/кг на о. Кунашир. Использование значений биологического периода полуочищения и Tag 134Cs, полученных для лишайников с о. Кунашир, показало, что род Usnea является надежным инструментом для прогнозирования общего поверхностного загрязнения цезием-134 о. Шикотан, который расположен рядом с о. Кунашир. В отличие от радиоцезия, естественные радионуклиды 7Be и 40K, содержащиеся в лишайниках Usnea, не показали каких-либо четких временных изменений. Никакой корреляции не было найдено между 7Be и 40К, а также между 40К и радиоизотопами цезия. Однако наблюдалась положительная и статистически значимая (P <0,05) корреляция между 7Be и радиоизотопами цезия. Широкое распространение и обилие лишайников рода Usnea на юге Сахалинской области, а также высокие значения Tag для радиоцезия, содержащегося в лишайниках, делают их подходящими природными мониторами очень низких уровней атмосферных выпадений радионуклидов цезия.

Temporal variations of radionuclide levels in the epiphytic Usnea sp. lichens from the two islands Sakhalin and Kunashir, the Sakhalin region, Russia have been evaluated using the already published (2011–2013) and new experimental data (2015). A total of 62 lichen samples were measured using high purity germanium γ-ray detectors and multichannel analyzers. In the period 2011–2015, activity concentrations of the anthropogenic radionuclides 134Cs and 137Cs and the natural radionuclides 7Be and 40K were found to be in the range of (<0.53)–41.3, 0.55–50.6, 99–603 and 35–95 Bq kg–1 on dry weight, respectively. The activity concentrations of 134Cs and 137Cs in lichens were statistically significantly higher at Kunashir than at Sakhalin. The present-day levels of radiocesium activity concentrations in lichens are low: < 6 Bq kg–1 for 137Cs and <1 Bq kg–1 for 134Cs. A decline in the annual median 137Cs activity concentrations in lichens from 2011 to 2015 corresponds to a biological half-life of 1.2 y for Kunashir and 1.1 y for Sakhalin. The activity concentrations of 137Cs and 134Cs in lichens were strongly correlated (r=0.978, P<0.01) and the 134Cs biological half-life value of 1.2 y in the period 2011–2013 was similar to the corresponding 137Cs biological half-life value. The soil-tolichens aggregated transfer factor, Tag, for 134Cs at time t=0 after the Fukushima accident is calculated as 0.56 m2 kg–1 at Sakhalin and 0.31 m2 kg–1 at Kunashir. In contrast to radiocesium, the natural radionuclides 7Be and 40K did not show clear time-dependent variations in the Usnea lichens. No correlation was found between 7Be and 40K as well as between 40K and cesium radioisotopes. However, positive and statistically significant (P<0.05) correlations were obtained between 7Be and cesium radioisotopes. High abundance of the Usnea sp. lichens in the study area and large values of Tag for radiocesium in the lichens make these organisms suitable candidates for detection of low levels of airborne radioactive contamination of the environment.

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The authors declare that there are no conflicts of interest present.