Revealing legacy effects of extreme droughts on tree growth of oaks across the Northern Hemisphere.

Forests are undergoing increasing risks of drought-induced tree mortality. Species replacement patterns following mortality may have a significant impact on the global carbon cycle. Among major hardwoods, deciduous oaks (Quercus spp.) are increasingly reported as replacing dying conifers across the Northern Hemisphere. Yet, our knowledge on the growth responses of these oaks to drought is incomplete, especially regarding post-drought legacy effects. The objectives of this study were to determine the occurrence, duration, and magnitude of legacy effects of extreme droughts and how that vary across species, sites, and drought characteristics. The legacy effects were quantified by the deviation of observed from expected radial growth indices in the period 1940-2016. We used stand-level chronologies from 458 sites and 21 oak species primarily from Europe, north-eastern America, and eastern Asia. We found that legacy effects of droughts could last from 1 to 5 years after the drought and were more prolonged in dry sites. Negative legacy effects (i.e., lower growth than expected) were more prevalent after repetitive droughts in dry sites. The effect of repetitive drought was stronger in Mediterranean oaks especially in Quercus faginea. Species-specific analyses revealed that Q. petraea and Q. macrocarpa from dry sites were more negatively affected by the droughts while growth of several oak species from mesic sites increased during post-drought years. Sites showing positive correlations to winter temperature showed little to no growth depression after drought, whereas sites with a positive correlation to previous summer water balance showed decreased growth. This may indicate that although winter warming favors tree growth during droughts, previous-year summer precipitation may predispose oak trees to current-year extreme droughts. Our results revealed a massive role of repetitive droughts in determining legacy effects and highlighted how growth sensitivity to climate, drought seasonality and species-specific traits drive the legacy effects in deciduous oak species.

Catheter-directed therapy for acute pulmonary embolism: results of a multicenter national registry.

INTRODUCTION AND OBJECTIVES: Catheter-directed therapy (CDT) for acute pulmonary embolism (PE) is an emerging therapy that combines heterogeneous techniques. The aim of the study was to provide a nationwide contemporary snapshot of clinical practice and CDT-related outcomes. METHODS: This Investigator-initiated multicenter registry aimed to include consecutive patients with intermediate-high risk (IHR) or high-risk (HR), acute PE eligible for CDT. The primary outcome of the study was in-hospital all-cause death. RESULTS: A total of 253 patients were included, of whom 93 (36.8%) had HR-PE, and 160 (63.2%) had IHR-PE with a mean age of 62.3±15.1 years. Local thrombolysis was performed in 70.8% and aspiration thrombectomy in 51.8%, with 23.3% of patients receiving both. However, aspiration thrombectomy was favored in the HR-PE cohort (80.6% vs 35%; P<.001). Only 51 patients (20.2%) underwent CDT with specific PE devices. The success rate for CDT was 90.9% (98.1% of IHR-PE patients vs 78.5% of HR-PE patients, P<.001). In-hospital mortality was 15.5%, and was highly concentrated in the HR-PE patients (37.6%) and significantly lower in IHR-PE patients (2.5%), P<.001. Long-term (24-month) mortality was 40.2% in HR-PE patients vs 8.2% in IHR-PE patients (P<.001). CONCLUSIONS: Despite the high success rate for CDT, in-hospital mortality in HR-PE is still high (37.6%) compared with very low IHR-PE mortality (2.5%).

Initial results of investigator initiated international database on catheter directed therapy of acute pulmonary embolism.

BACKGROUND: Catheter directed therapies (CDT) are widely used in the treatment of acute pulmonary embolism (PE). A multicenter registry was organized to evaluate their application in real life and to determine efficacy and safety of these procedures. Local experience of participating centers in percutaneous techniques for PE treatment was assessed. METHODS: An internet-based registry was designed to collect clinical, echocardiographic and laboratory data of consecutive PE patients treated with CDT in participating centers between 2017 and 2022. RESULTS: Under analysis were 145 consecutive patients with acute PE, aged 61 ± 15 years, treated with CDT in 7 centers: 50 (34.5%) patients with high-risk PE (HRPE), and 95 (65.5%) patients with intermediate-high risk PE (IHRPE). 100 (69%) patients were treated with dedicated devices, in 45 (31%) subjects a pigtail catheter was used. Total PE or CDT related in-hospital mortality in HRPE reached 14% (7 patients), while in IHRPE 3.2% (3 patients) (p = 0.032). 50% of PE or CDT related deaths occurred in patients treated with a pigtail catheter. All-cause mortality in 145 patients was 9.7%, and it was higher in HRPE than in IHRPE (18% vs. 5.3%, p = 0.019). The use of pigtail catheters compared to dedicated systems was associated with higher mortality (20% vs. 5%, p = 0.01). CONCLUSIONS: Catheter directed therapies is a real option of treating PE. It was used as primary therapy also in patients without contraindication for thrombolysis suggesting that clinical practice does not always follow current PE guidelines. Patients treated with dedicated CDT systems had a higher survival rate than subjects treated with pigtail catheters.

Dental Age Estimation Using Multiphoton Microscopy: A Potential Tool for Forensic Science.

Normal aging affects the different structures of teeth, in particular, the dentine. These changes are useful in forensic disciplines as a tool for age estimation. Although multiphoton (MP) microscopy has been used to explore dental pieces, a relationship between age and MP response of the human dentine has not been proposed yet. The relationship between MP signals and natural dentine aging is investigated herein. An index of age (INAG) combining two-photon excitation fluorescence (TPEF) and second harmonic generation (SHG) images has been used to quantify these changes. The results show that the INAG significantly decreases with age. Moreover, peritubular dentine size and collagen internal properties are also modified with age. This information confirms the usefulness of this technique in forensic age estimation after disasters (natural or manmade) with a lack of comprehensive fingerprint database. Courts and other government authorities might also benefit from this tool when the official age of individuals under special circumstances is required for legal or medical reasons.

Recycling and persistence of iodine 127 and 129 in forested environments: A modelling approach.

Differences in the source and behaviour of 129I compared to 127I isotopes have been described for a variety of surface environments, but little is known about the cycling rates of each isotope in terrestrial ecosystems. We developed a compartment model of the iodine cycle in a forest ecosystem, with a labile and non-labile pool to simplify the complex fate of iodine in the forest floor and soil. Simulations were performed using atmospheric 127I and 129I inputs for sites differing in climate, vegetation, and soil. In general, considering dry deposition in addition to wet deposition improved model simulations. Model results support the view that soil is the sink for atmospheric iodine deposited in forest ecosystems, while tree vegetation has little influence on long-term iodine budgets. Modelling also showed that iodine cycling reaches equilibrium after a period of about 5000 years, mainly due to a gradual incorporation of iodine into the bulk stabilised soil organic matter. At steady state, this pool of non-labile iodine in soil can retain about 20% of total deposition with a mean residence time of 900 years, while the labile iodine pool is renewed after 90 years. The proportions of modern anthropogenic 129I in each modelled pool reflect those of stable 127I at least several decades after input to the forest; this result explains why isotopic disequilibrium is common in field data analysis. Volatilisation plays a central role in regulating iodine storage in soil and, therefore, its residence time, while drainage is a minor export pathway, except at some calcareous sites. Dynamic modelling has been particularly helpful for gaining insight into the long-term response of iodine partitioning to continuous, single or even varying deposition. Our modelling study suggested that better estimates of dry deposition of atmospheric iodine, weathering of parent rock, and volatilisation of the deposited iodine from soil and vegetation will be required for reliable predictions of iodine cycling in specific forests, because these processes remain insufficiently explored.

Iodine distribution and volatilization in contrasting forms of forest humus during a laboratory incubation experiment.

Radionuclides 129I (t1/2 = 15.7 × 106 years) and 131I (t1/2 = 8.02 days) are both introduced into the environment as a result of nuclear human activities. Environmental transfer pathways and fluxes between and within ecosystems are essential information for risk assessment. In forest ecosystems, humus degradation over time could result in re-mobilization and then downward migration and/or volatilization of intercepted 129I. In order to estimate the scale of these processes, humus (mull and moder forms) sampled under deciduous and coniferous forests were spiked with 125I- (t1/2 = 59.4 days), as a surrogate for 129I, in order to study the evolution of its water-soluble and organic fractions as well as the volatilization rate during humus degradation at laboratory scale. To our knowledge, this is the first time that interactions between iodine and contrasting forms of forest humus have been investigated. The evolution of native stable iodine (127I) pools in unspiked humus was also studied. The nature of the humus' organic matter appears to be a factor that impacts on the proportions of water-soluble and organic fractions of iodine and on their evolution. Iodine-125 was mainly organically bound (fraction for mulls and moders: ∼54-59 and 41-49%, respectively) and no clear evolution was observed within the 4-month incubation period. A large decrease in 125I water-solubility occurred, being more marked for mull (from ∼14-32 to 3-7%) than for moder (from ∼21-37 to 7-19%) humus. By contrast, a significant fraction was not extractible (∼38-43%) and varied in inverse proportion to the water-soluble fraction, suggesting a stabilization of iodine in humus after wet deposit. The nature of the humus organic matter also impacted on 125I volatilization. Although of the same order of magnitude, the total volatilization of 125I was higher for moders (∼0.039-0.323%) than for mulls (∼0.015-0.023%) within the 4-month incubation period. Volatilization rates for mulls were correlated with the water-soluble fraction, implying that volatilization of 125I could occur from the humus solution. Our results showed that humus is thus a zone of iodine accumulation by association with organic matter and that potential losses by lixiviation are significantly more important compared to volatilization.

Galvanic current dosage and bacterial concentration are determinants of the bactericidal effect of percutaneous needle electrolysis: an in vitro study.

Percutaneous needle electrolysis (PNE) is a physiotherapy technique that has been shown to be effective in different pathologies such as tendinopathies or mammary fistula. For many years, theoretical bactericidal and germicidal effects have been attributed to this type of galvanic currents, partly explained by the changes in pH that it generates. However, these effects have not yet been demonstrated. The aim of this study was to evaluate the bactericidal effect and the changes in pH caused by PNE. S. aureus were prepared in two different solutions (TSB and saline solution) and in different concentrations (from 9 to 6 Log10 CFU/mL). Bacteria were treated with three experimental PNE doses to assess bacterial death levels and the changes caused to the pH of the medium. The viable cell count showed that all experimental PNE doses had a bactericidal effect against a high concentration (9 Log10 CFU/mL) of S. aureus in saline solution (p < 0.001). Furthermore, we found that when the concentration of bacteria decreased, a lower dose of galvanic current generated the same effect as a higher dose. Changes in pH were registered only in experiments performed with saline solution. PNE had a bactericidal effect against S. aureus and the level of this effect was mainly modulated by the solution, the bacterial concentration and the dose. Changes affecting pH were modulated by the type of solution and there was no relationship between this and bacterial death.

Climate sensitivity and drought seasonality determine post-drought growth recovery of Quercus petraea and Quercus robur in Europe.

Recent studies have identified strong relationships between delayed recovery of tree growth after drought and tree mortality caused by subsequent droughts. These observations raise concerns about forest ecosystem services and post-drought growth recovery given the projected increase in drought frequency and extremes. For quantifying the impact of extreme droughts on tree radial growth, we used a network of tree-ring width data of 1689 trees from 100 sites representing most of the distribution of two drought tolerant, deciduous oak species (Quercus petraea and Quercus robur). We first examined which climatic factors and seasons control growth of the two species and if there is any latitudinal, longitudinal or elevational trend. We then quantified the relative departure from pre-drought growth during droughts, and how fast trees were able to recover the pre-drought growth level. Our results showed that growth was more related to precipitation and climatic water balance (precipitation minus potential evapotranspiration) than to temperature. However, we did not detect any clear latitudinal, longitudinal or elevational trends except a decreasing influence of summer water balance on growth of Q. petraea with latitude. Neither species was able to maintain the pre-drought growth level during droughts. However, both species showed rapid recovery or even growth compensation after summer droughts but displayed slow recovery in response to spring droughts where none of the two species was able to fully recover the pre-drought growth-level over the three post-drought years. Collectively, our results indicate that oaks which are considered resilient to extreme droughts have also shown vulnerability when droughts occurred in spring especially at sites where long-term growth is not significantly correlated with climatic factors. This improved understanding of the role of drought seasonality and climate sensitivity of sites is key to better predict trajectories of post-drought growth recovery in response to the drier climate projected for Europe.

Selenium distribution in French forests: Influence of environmental conditions.

Selenium is a trace element and an essential nutrient. Its long-lived radioisotope, selenium 79 is of potential radio-ecological concern in surface environment of deep geological repository for high-level radioactive waste. In this study, the influence of environmental, climatic and geochemical conditions on stable Se (as a surrogate of 79Se) accumulation was statistically assessed (PCA analysis, Kruskall-Wallis and Spearman tests) based on the analysis of its concentration in litterfall, humus, and soil samples collected at 51 forest sites located in France. Selenium concentrations were in the ranges: 22-369, 57-1608 and 25-1222 µg kg-1 respectively in litterfall, humus, and soil. The proximity of the ocean and oceanic climate promoted Se enrichment of litterfall, likely due to a significant reaction of wet deposits with forest canopy. Se content was enhanced by humification (up to 6 times) suggesting that Se concentrations in humus were affected by atmospheric inputs. Selenium stock in humus decreased in the order of decreasing humus biomass and increasing turnover of organic matter: mor > moder > mull. Positive correlations between Se content and geochemical parameters such as organic carbon content, total Al and total Fe confirmed the important role of organic matter (OM) and mineral Fe/Al oxides in Se retention in soils.

Atmospheric iodine, selenium and caesium depositions in France: I. Spatial and seasonal variations.

The spatial distribution and seasonal variations of atmospheric iodine (I), selenium (Se) and caesium (Cs) depositions remain unclear and this precludes adequate inputs for biogeochemical models. We quantified total concentrations and fluxes of these elements in rainfalls from 27 monitoring sites in France with contrasted climatic conditions; monthly measurements were taken over one year (starting in 2016/09). Since speciation of I and Se can impact their behaviour in the environment, analysis of their inorganic compounds was also conducted. Our results showed that annual I concentrations in rainfall were much higher than those of Se and Cs (annual means = 1.56, 0.044 and 0.005 µg L-1, respectively). The annual iodine concentrations were highly positively correlated with those of marine elements (i.e. Na, Cl and Mg), involving higher I concentrations under oceanic climate than for transition, continental and mountainous ones. Furthermore, common patterns were found between Se concentrations and both marine and terrestrial components consistent with the various sources of Se in atmosphere. The association of Cs with two anthropogenic components (i.e. NH4+ and NO3-) used in agriculture supports the hypothesis of its terrestrial origin (i.e. from atmospheric dusts) in rainfall. We found higher rainfall concentrations of I during the warmest months for all climates. However, no specific seasonal trend occurred for Se and Cs. On annual average, rainfall contained mostly unidentified selenium compounds (inorganic Se proportions = 25-54%) and equal proportions of inorganic and unidentified I compounds. Concentrations of iodate were higher under oceanic climate consistent with an iodine marine-origin.

Atmospheric iodine, selenium and caesium depositions in France: II. Influence of forest canopies.

Estimation of the canopy influence on atmospheric inputs of iodine (I), selenium (Se) and caesium (Cs) in terrestrial ecosystems is an essential condition for appropriate biogeochemical models. However, the processes involved in rain composition modifications after its passage through forest canopy have been barely studied for these elements. We monitored I, Se and Cs concentrations in both rainfall and throughfall of fourteen French forested sites throughout one year, and estimated dry deposition and canopy exchange fluxes for these elements, as well as speciation of I and Se. Comparison of rainfall and throughfall elemental composition highlighted an important impact of forest canopy on both (i) concentrations and fluxes of I, Se and Cs, and (ii) I and Se species. For the three elements, most of their throughfall concentrations were higher than corresponding rainfall. The increase of throughfall elemental fluxes was mostly due to dry deposition for I and Se although the canopy exchange model revealed some sorption within the canopy in most cases; for Cs, foliage leaching was most influencing. Regarding speciation, iodine species in rainfall were highly modified by forest canopy with an important increase of unidentified I proportion in throughfall (on average 49 and 82% in rainfall and throughfall, respectively), possibly due to washoff of dry deposition and/or to transformation into organic forms. Similarly, while rainfall was composed of 26-54% of inorganic Se, inorganic species were undetectable in throughfall. This dataset represents key information to improve modelling of I, Se and Cs cycling within forest ecosystems.

[Risk factors for in-hospital mortality in patients with acute myocardial infarction during the COVID-19 outbreak]. / Factores de riesgo de muerte hospitalaria en pacientes con infarto agudo de miocardio durante la pandemia de la COVID-19.

INTRODUCTION AND OBJECTIVES: Despite advances in treatment, patients with acute myocardial infarction (AMI) still exhibit unfavorable short- and long-term prognoses. In addition, there is scant evidence about the clinical outcomes of patients with AMI and coronavirus disease 2019 (COVID-19). The objective of this study was to describe the clinical presentation, complications, and risk factors for mortality in patients admitted for AMI during the COVID-19 pandemic. METHODS: This prospective, multicenter, cohort study included all consecutive patients with AMI who underwent coronary angiography in a 30-day period corresponding chronologically with the COVID-19 outbreak (March 15 to April 15, 2020). Clinical presentations and outcomes were compared between COVID-19 and non-COVID-19 patients. The effect of COVID-19 on mortality was assessed by propensity score matching and with a multivariate logistic regression model. RESULTS: In total, 187 patients were admitted for AMI, 111 with ST-segment elevation AMI and 76 with non-ST-segment elevation AMI. Of these, 32 (17%) were diagnosed with COVID-19. GRACE score, Killip-Kimball classification, and several inflammatory markers were significantly higher in COVID-19-positive patients. Total and cardiovascular mortality were also significantly higher in COVID-19-positive patients (25% vs 3.8% [P < .001] and 15.2% vs 1.8% [P = .001], respectively). GRACE score > 140 (OR, 23.45; 95%CI, 2.52-62.51; P = .005) and COVID-19 (OR, 6.61; 95%CI, 1.82-24.43; P = .02) were independent predictors of in-hospital death. CONCLUSIONS: During this pandemic, a high GRACE score and COVID-19 were independent risk factors associated with higher in-hospital mortality.Full English text available from:www.revespcardiol.org/en.

Risk factors for in-hospital mortality in patients with acute myocardial infarction during the COVID-19 outbreak.

INTRODUCTION AND OBJECTIVES: Despite advances in treatment, patients with acute myocardial infarction (AMI) still exhibit unfavorable short- and long-term prognoses. In addition, there is scant evidence about the clinical outcomes of patients with AMI and coronavirus disease 2019 (COVID-19). The objective of this study was to describe the clinical presentation, complications, and risk factors for mortality in patients admitted for AMI during the COVID-19 pandemic. METHODS: This prospective, multicenter, cohort study included all consecutive patients with AMI who underwent coronary angiography in a 30-day period corresponding chronologically with the COVID-19 outbreak (March 15 to April 15, 2020). Clinical presentations and outcomes were compared between COVID-19 and non-COVID-19 patients. The effect of COVID-19 on mortality was assessed by propensity score matching and with a multivariate logistic regression model. RESULTS: In total, 187 patients were admitted for AMI, 111 with ST-segment elevation AMI and 76 with non-ST-segment elevation AMI. Of these, 32 (17%) were diagnosed with COVID-19. GRACE score, Killip-Kimball classification, and several inflammatory markers were significantly higher in COVID-19-positive patients. Total and cardiovascular mortality were also significantly higher in COVID-19-positive patients (25% vs 3.8% [P <.001] and 15.2% vs 1.8% [P=.001], respectively). GRACE score> 140 (OR, 23.45; 95%CI, 2.52-62.51; P=.005) and COVID-19 (OR, 6.61; 95%CI, 1.82-24.43; P=.02) were independent predictors of in-hospital death. CONCLUSIONS: During this pandemic, a high GRACE score and COVID-19 were independent risk factors associated with higher in-hospital mortality.

Aging and trace elements in human coronal tooth dentine.

Teeth are a fundamental tool in forensic odontology for identification in a legal context of those individuals who cannot be identified visually or by other means. Dentine presents physiological exchanges of in trace elements after a period of mineralization and several factors can affect its concentration. The aim of this study was to investigate the concentration of 25 trace elements in the coronal dentine according to sex and type of tooth to determine their relationship with age. A total of 25 trace elements were analyzed in 150 human coronal dentine. Teeth were classified into three age groups, sex and tooth type. The trace elements were grouped as potentially toxic or essential. Inductively Coupled Plasma-Mass Spectrometry and Atomic Emission Spectroscopy were used. The toxic and essential elements were detected in the following order of concentration: Al > Pb > Sn > Li > As > Cd and Ca > P > Mg > Na > S > K > Sr > Zn > Ba > Fe > B > Ti > Mn > Cr > Ni > Cu > Co > Se > V. Our findings show an increase in the concentration of toxic (Pb, Li and Sn) and essential (B, Ba, K, Sr, S and Mg) elements in coronal dentin related to the age of the teeth, regardless of sex. The concentrations of Pb and K in dentin of molars and premolars are the elements that best relate their variations with age. In view of our results, the analysis of these trace elements in dentin in combination with other types of techniques could be established as an element to consider in age dating studies in different forensic situations.

Validity and Reliability of a New Optoelectronic System for Measuring Active Range of Motion of Upper Limb Joints in Asymptomatic and Symptomatic Subjects.

The aim of this study was to evaluate the validity of the Veloflex infrared dynamic angle-meter (Veloflex-IDA) and the intra- and inter-rater reliability when measuring the ranges of motion (ROMs) of the upper limb joints. Thirty-five healthy and 20 symptomatic participants were evaluated. Twelve upper limb movements were measured in two sessions with the Veloflex-IDA, which is a device composed of a camera that tracks the trajectory of retro-reflective markers. In addition, a goniometer was used in the first session to evaluate concurrent validity. Validity and agreement were evaluated by Pearson correlation coefficient (r) and Bland-Altmann plots. Intra- and inter-rater reliability were evaluated using intra-class correlation (ICC), standard error of measurement (SEM), and minimal detectable change (MDC). Both instruments showed excellent correlation for all movements (r range from 0.992 to 0.999). The intra- and inter-rater reliability were excellent (ICC range from 0.95 to 0.99 and 0.90 to 0.98, respectively). Intra-rater reliability showed SEMs <1.38% and <5.19% and inter-rater reliability SEMs <2.26% and <5.22% for asymptomatic and symptomatic, respectively. Veloflex-IDA is a valid and reliable alternative to measure the upper limb joints' ROM and it can be used in clinical practice and research after basic training.

Effect of different ergonomic supports on muscle activity of dentists during posterior composite restoration.

BACKGROUND: The aim of this study was to evaluate the effect of different ergonomic supports on the muscle activity of two trunk muscles while a group of dentists performed a common dental procedure on a phantom head, divided into three tasks. METHODS: A one-way repeated measures study (ANOVA) was conducted on a group of 36 dentists. The middle trapezius and lumbar erector spinae muscles were measured with and without the use of different ergonomic supports (ergonomic stool, magnification lenses and both) using a portable surface electromyography (sEMG) device. Intraclass correlation coefficients (ICCs) and the absolute standard error of measurement (SEM) were used to establish the reliability of the baseline measures without ergonomic supports. RESULTS: The sEMG showed excellent ICCs (ranging from 0.92 to 0.99) and SEM. Bonferroni post hoc tests showed differences between the three ergonomic supports (p < 0.001) in both muscles studied. The lowest muscle activity measurement occurred with the isolated used of magnification lenses. The use of the ergonomic stool increased the muscle activity of the middle trapezius and lumbar erector spinae muscles to a greater extent than the magnification lenses. The combination of the ergonomic stool and the magnification lenses produced a different effect on each muscle.

The Combination of Different Ergonomic Supports during Dental Procedures Reduces the Muscle Activity of the Neck and Shoulder.

Ergonomic supports have become popular for the prevention of musculoskeletal disorders. This study sought to evaluate the efficacy of different ergonomic supports and their combination to reduce muscle activity of the neck and shoulder muscles. A one-way repeated measures design was used to evaluate 36 practicing dentists while they performed three posterior composite restoration procedures on a phantom head. Portable surface electromyography (sEMG) recordings were used to measure the muscle activity of three muscles (Upper Trapezius, Lateral Deltoid and Anterior Deltoid) in the dominant upper extremity, with and without the use of different ergonomic supports (ergonomic stool, magnification lenses and both) during the performance of these tasks. A repeated measures analysis of variance was used. The muscle activity of all muscles differed significantly across the four ergonomic conditions during the three tasks. The use of ergonomic supports such as magnification lenses, the ergonomic stool, or the combination of both, is effective for decreasing the muscle activity of the three muscles during the three tasks, when compared to standard practice. In addition, the decrease of muscle activity was higher using magnification lenses when compared to the ergonomic stool. Furthermore, the greatest decrease was found with the combination of both supports.

Iodine budget in forest soils: Influence of environmental conditions and soil physicochemical properties.

Due to its longevity, radioisotope 129I is a health concern following potential releases in the environment which raises questions about residence and exposure times relevant for risk assessments. We determined 127I concentrations (as a surrogate for 129I) in a series of French forest soils (i.e. litters, humus and mineral soils) under different vegetation and climate conditions in order to identify the major processes affecting its accumulation and persistence in the soil column. The input fluxes linked to rainfall, throughfall and litterfall were also characterized. Main results obtained showed that: (i) rainfall iodine concentrations probably influenced those of litterfall through absorption by leaves/needles returning to the ground; (ii) throughfall was the major iodine input to soils (mean = 83%), compared to litterfall (mean = 17%); (iii) humus represented a temporary storage of iodine from atmospheric and biomass deposits; (iv) iodine concentrations in soils depended on both the iodine inputs and the soil's ability to retain iodine due to its organic matter, total iron and aluminium concentrations; (v) these soil properties were the main factors influencing the accumulation of iodine in the soil column, resulting in residence times of 419-1756 years; and (vi) the leaching of iodine-containing organic matter dissolved in soil solution may be an important source of labile organic iodine for groundwater and streams.