Tetsuya Endo, Osamu Kimura, Masaru Terasaki, Shotaro Nakagun, Yoshihisa Kato, Yukiko Fujii, Koichi Haraguchi, C Scott Baker
{"title":"Carbon, nitrogen, and oxygen stable isotope ratios of striped dolphins and short-finned pilot whales stranded in Hokkaido, northern Japan, compared with those of other cetaceans stranded and hunted in Japan.","authors":"Tetsuya Endo, Osamu Kimura, Masaru Terasaki, Shotaro Nakagun, Yoshihisa Kato, Yukiko Fujii, Koichi Haraguchi, C Scott Baker","doi":"10.1080/10256016.2023.2234590","DOIUrl":"https://doi.org/10.1080/10256016.2023.2234590","url":null,"abstract":"<p><p>Strandings of striped dolphins (SD) and short-finned pilot whales (PW) in Hokkaido, northern Japan, are rare but have recently increased, probably due to global warming. We quantified <i>δ</i><sup>13</sup>C, <i>δ</i><sup>15</sup>N, and <i>δ</i><sup>18</sup>O in muscles of SD (<i>n</i> = 7) and PW (<i>n</i> = 3) stranded in Hokkaido and compared these values with those in muscles (red meat products) of hunted SD and PW in three areas of central and southern Japan. <i>δ</i><sup>18</sup>O in stranded SD, except for the calf, decreased with increasing body length (BL), whereas <i>δ</i><sup>13</sup>C increased, with no BL-related changes in <i>δ</i><sup>15</sup>N. The variability of <i>δ</i><sup>18</sup>O (range of maximum and minimum) was larger in the stranded SD (7.5 ‰) than of the hunted SD in three areas (0.9, 1.9, and 1.4 ‰), whereas that of <i>δ</i><sup>15</sup>N was smaller in the stranded SD than in the hunted SD. Similarly, the variability of <i>δ</i><sup>18</sup>O was larger in the stranded PW in Hokkaido (3.3 ‰) than in the hunted PW in central Japan (1.4 ‰). The larger variability of <i>δ</i><sup>18</sup>O and smaller variability of <i>δ</i><sup>15</sup>N in stranded SD imply long-term sojourning in coastal waters and feeding on small amounts of limited prey species at low trophic levels before death.</p>","PeriodicalId":14597,"journal":{"name":"Isotopes in Environmental and Health Studies","volume":"59 3","pages":"230-247"},"PeriodicalIF":1.3,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10199429","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Leonard I Wassenaar, Cedric Douence, Susan Fortson, Douglas S Baer
{"title":"Automated rapid triple-isotope (<i>δ</i><sup>15</sup>N, <i>δ</i><sup>18</sup>O, <i>δ</i><sup>17</sup>O) analyses of nitrate by Ti(III) reduction and N<sub>2</sub>O laser spectrometry.","authors":"Leonard I Wassenaar, Cedric Douence, Susan Fortson, Douglas S Baer","doi":"10.1080/10256016.2023.2222222","DOIUrl":"https://doi.org/10.1080/10256016.2023.2222222","url":null,"abstract":"<p><p>The nitrogen and oxygen (<i>δ</i><sup>15</sup>N, <i>δ</i><sup>18</sup>O, <i>δ</i><sup>17</sup>O) stable isotopic compositions of nitrate (<math><mrow><mi>N</mi></mrow><msubsup><mrow><mi>O</mi></mrow><mn>3</mn><mtext>-</mtext></msubsup></math>) are crucial tracers of nutrient N sources and dynamics in aquatic and atmospheric systems. Methods to reduce aqueous <math><mrow><mi>N</mi></mrow><msubsup><mrow><mi>O</mi></mrow><mn>3</mn><mtext>-</mtext></msubsup></math> to N<sub>2</sub>O gas (microbial or Cd method) before <sup>15</sup>N and <sup>18</sup>O isotope analyses require multi-step conversion or toxic chemicals, and <sup>17</sup>O in N<sub>2</sub>O cannot be disentangled by IRMS due to isobaric interferences. This technical note describes the automation of the stable-isotope analyses of nitrate by coupling the new Ti method with a headspace autosampler and an N<sub>2</sub>O triple-isotope laser analyzer based on off-axis integrated cavity output spectroscopy. The automation yielded accurate and precise results for routine determinations of <i>δ</i><sup>15</sup>N, <i>δ</i><sup>18</sup>O, and <i>δ</i><sup>17</sup>O values for aqueous nitrate in environmental waters. Systematic corrections were required for cavity pressure, N<sub>2</sub>O concentration and water vapour content to obtain the highest precision for all three isotopic ratios. For the first time, an automated laser-based system facilitates routine low-cost triple isotope analyses in studies where high-temporal resolution isotope analyses of NO<sub>3</sub><sup>-</sup> are required but have been, until now, cost-prohibitive and time-consuming (e.g. atmospheric N pollution).</p>","PeriodicalId":14597,"journal":{"name":"Isotopes in Environmental and Health Studies","volume":"59 3","pages":"297-308"},"PeriodicalIF":1.3,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10143568","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Karina Pfrimer, Roberto Botelho Ferraz Branco, Tom Preston, Márcia Sv Salles, Luiz C Roma-Junior, Eduardo Ferriolli
{"title":"Intrinsic labelling of common beans with <sup>2</sup>H<sub>2</sub>O to enable estimates of protein digestibility.","authors":"Karina Pfrimer, Roberto Botelho Ferraz Branco, Tom Preston, Márcia Sv Salles, Luiz C Roma-Junior, Eduardo Ferriolli","doi":"10.1080/10256016.2023.2234592","DOIUrl":"https://doi.org/10.1080/10256016.2023.2234592","url":null,"abstract":"<p><strong>Background: </strong>The use of plant protein intrinsically labelled with stable isotopes provides an innovative solution to assess the efficiency of protein intake by humans. Here, the incorporation of <sup>2</sup>H has been applied to intrinsically labelled plant protein in the common bean. This study aimed to evaluate which is the best phenological phase of seed maturation to incorporate the heavy hydrogen isotope <sup>2</sup>H into seed amino acids. Common beans (<i>Phaseolus vulgaris</i> L.) were grown in pots, then, after 50 days sowing, <sup>2</sup>H<sub>2</sub>O dissolved in irrigation water was applied, then again at an interval of either 3, 6, 9, and 12 days.</p><p><strong>Results: </strong>Applications of <sup>2</sup>H<sub>2</sub>O at 6, 9, and 12 days after the first application, in the full-flowering stage, were the best treatments for enriching protein-bound amino acids in the bean seed with <sup>2</sup>H.</p><p><strong>Conclusion: </strong>All treatments resulted in enrichment above 500 ppm, so the treatments (quantity and timing of <sup>2</sup>H<sub>2</sub>O addition) were deemed successful for enriching bean seeds. This makes the intrinsically labelled seeds suitable for preparing test meals to assess the digestion and essential amino acid absorption of common bean amino acids in human subjects.</p>","PeriodicalId":14597,"journal":{"name":"Isotopes in Environmental and Health Studies","volume":"59 3","pages":"290-296"},"PeriodicalIF":1.3,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10146234","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Isotopic niches of the Northern shoveler <i>Spatula clypeata</i> in spring migratory stopover sites in the Marais breton, France.","authors":"Axelle Moreau, Pierrick Bocher, Pascal Bonnin, Sébastien Farau, Christine Dupuy","doi":"10.1080/10256016.2023.2208865","DOIUrl":"https://doi.org/10.1080/10256016.2023.2208865","url":null,"abstract":"<p><p>The Northern shoveler, <i>Spatula clypeata</i>, makes several migratory stopovers to reach its breeding site in the best conditions. These stopovers allow the species to replenish their reserves. Therefore, feeding efficiency at such sites is essential. Despite its importance, few studies have been conducted on the spring ecology of the shoveler, particularly on its diet at stopover sites. Therefore, this study focused on the Northern shoveler's feeding habit during its spring migratory stopover in the Marais breton (MB), a wetland situated in Vendée (France, Atlantic coast). The shoveler's plasma and potential food resources were studied using a stable carbon and nitrogen isotope analysis. The study showed that the shoveler feeds primarily on microcrustaceans, especially Cladocera and Copepoda; Chironomidae larvae, Corixidae, Hydrophilidae larvae, and particulate organic matter. This last food source, the POM, had never been highlighted before.</p>","PeriodicalId":14597,"journal":{"name":"Isotopes in Environmental and Health Studies","volume":"59 3","pages":"217-229"},"PeriodicalIF":1.3,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10496653","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nimisha Singh, Rohit Pradhan, Raghavendra P Singh, Praveen K Gupta
{"title":"The role of continental evapotranspiration on water vapour isotopic variability in the troposphere.","authors":"Nimisha Singh, Rohit Pradhan, Raghavendra P Singh, Praveen K Gupta","doi":"10.1080/10256016.2023.2212834","DOIUrl":"https://doi.org/10.1080/10256016.2023.2212834","url":null,"abstract":"<p><p>Rainforests play an important role in hydrological and carbon cycles, both at regional and global scales. They pump large quantities of moisture from the soil to the atmosphere and are major rainfall hotspots of the world. Satellite-observed stable water isotope ratios have played an essential role in determining sources of moisture in the atmosphere. Satellites provide information about the processes involving vapour transport in different zones of the world, identifying sources of rainfall and distinguishing moisture transport in monsoonal systems. This paper focuses on major rainforests of the world (Southern Amazon, Congo and Northeast India) to understand the role of continental evapotranspiration in influencing tropospheric water vapour. We have used satellite measurements of <sup>1</sup>H<sup>2</sup>H<sup>16</sup>O/<sup>1</sup>H<sub>2</sub><sup>16</sup>O from Atmospheric InfraRed Sounder (AIRS), evapotranspiration (ET), solar-induced fluorescence (SIF), precipitation (P), atmospheric reanalysis-derived moisture flux convergence (MFC) and wind to discern the role of ET in influencing water vapour isotopes. A global map of the correlation between <i>δ</i><sup>2</sup>H<sub>v</sub> and ET-P flux indicates that densely vegetated regions in the tropics show the highest positive correlation (r > 0.5). Using mixing models and observations of specific humidity and isotopic ratio over these forested regions, we discern the source of moisture in pre-wet and wet seasons.</p>","PeriodicalId":14597,"journal":{"name":"Isotopes in Environmental and Health Studies","volume":"59 3","pages":"248-268"},"PeriodicalIF":1.3,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10143039","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Adil M Hussein, Kamal O Abdullah, Aziz H Fattah, Ranjdar R Mohammed-Ali
{"title":"Estimating atmospheric radon deviation using statistical coefficients: Sulaymaniyah city, Iraq, as a case of study.","authors":"Adil M Hussein, Kamal O Abdullah, Aziz H Fattah, Ranjdar R Mohammed-Ali","doi":"10.1080/10256016.2023.2195175","DOIUrl":"https://doi.org/10.1080/10256016.2023.2195175","url":null,"abstract":"<p><p>The authors studied the atmospheric radon concentration with associated meteorological parameters variation during the dust events from July to November 2017. We obtained the meteorological parameters data in weather station of Sulaymaniyah city, Iraq. In the environmental monitoring plan, the atmospheric radon fluctuated from 15 to 48 Bq m<sup>-3</sup> around the mean value of 31.5 ± 7 Bq m<sup>-3</sup> within the summer. In autumn, varied from 22 to 46 Bq m<sup>-3</sup> with a mean value of 34 ± 12 Bq m<sup>-3</sup>. We employed this to determine the radon level anomalously. Using the modified statistical coefficients, such as the residual deviation (RD), residual fluctuation ratio (RFR), <i>F-</i>test, and <i>p-</i>value coefficients. Among the atmospheric radon fluctuation values, particularly one anomalous (42 Bq m<sup>-3</sup>) on 25 July was determined because the excessive value of the RD was 1.9 σ, and the RFR value was 66 %. Corresponding to our coefficients criteria, the minimum level of atmospheric radon (22 Bq m<sup>-3</sup>) does not consider anomalous because of increasing wind speed. Based on this, our method for determining the atmospheric radon anomalies that are influenced by the missed factors beyond the mentioned meteorological parameters is accurate.</p>","PeriodicalId":14597,"journal":{"name":"Isotopes in Environmental and Health Studies","volume":"59 2","pages":"202-215"},"PeriodicalIF":1.3,"publicationDate":"2023-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9811144","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Tatyana N Karmanova, Natalia Y Feoktistova, Alexei V Tiunov
{"title":"High <i>δ</i><sup>13</sup>C values in red squirrels <i>Sciurus vulgaris</i> explained by a reliance on conifer seeds.","authors":"Tatyana N Karmanova, Natalia Y Feoktistova, Alexei V Tiunov","doi":"10.1080/10256016.2023.2179045","DOIUrl":"https://doi.org/10.1080/10256016.2023.2179045","url":null,"abstract":"<p><p>Eurasian red squirrels <i>Sciurus vulgaris</i> have unusually high <i>δ</i><sup>13</sup>C values compared to other forest rodents, which is seemingly related to the consumption of <sup>13</sup>C-enriched conifer seeds. To test this hypothesis, we analyzed the hair of wild and zoo-kept red squirrels, seeds of pine and spruce, and feathers of specialized and opportunistic consumers of conifer seeds, crossbills <i>Loxia</i> spp., and woodpeckers <i>Dendrocopos major</i>. Data on the isotopic composition (<i>δ</i><sup>13</sup>C and <i>δ</i><sup>15</sup>N values) of hair or feathers of other species of forest rodents and birds were obtained from published studies. The range of mean <i>δ</i><sup>13</sup>C values of hair of wild forest rodents (19 species) exceeded 10 ‰. All squirrel species had high <sup>13</sup>C content, <i>S. vulgaris</i> having maximum <i>δ</i><sup>13</sup>C values. In contrast, <i>S. vulgaris</i> kept in captivity had an isotopic composition similar to other captive rodents. The feathers of crossbills were enriched in <sup>13</sup>C compared to other forest birds (15 species), while seeds of coniferous trees often had higher <i>δ</i><sup>13</sup>C values compared to seeds of other woody plants. Distinctiveness of the isotopic composition of mammals and birds feeding on the seeds of coniferous trees suggests that this resource can be traced through the entire forest food web.</p>","PeriodicalId":14597,"journal":{"name":"Isotopes in Environmental and Health Studies","volume":"59 2","pages":"180-191"},"PeriodicalIF":1.3,"publicationDate":"2023-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9433839","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Fabrizio Ambrosino, Giuseppe La Verde, Carlo Sabbarese, Vincenzo Roca, Antonio D'Onofrio, Mariagabriella Pugliese
{"title":"The first indoor radon mapping in the Campania region, Italy.","authors":"Fabrizio Ambrosino, Giuseppe La Verde, Carlo Sabbarese, Vincenzo Roca, Antonio D'Onofrio, Mariagabriella Pugliese","doi":"10.1080/10256016.2023.2189249","DOIUrl":"https://doi.org/10.1080/10256016.2023.2189249","url":null,"abstract":"<p><p>For the first time, a map of the <sup>222</sup>Rn gas has been produced in the Campania region, the southern part of Italy, based on the activity concentration measured in indoor environments. This work is part of the radon mitigation policy and complies with the recent Italian Legislative Decree 101/2020, which implements the European Basic Safety Standards, Euratom Directive 59/2013, where Member States must declare areas with elevated levels of indoor radon concentration. The obtained map, divided by Campania municipalities, identifies priority areas with activity concentration values exceeding the reference level of 300 Bq m<sup>-3</sup>. In addition, an effective statistical analysis of the dataset has been carried out.</p>","PeriodicalId":14597,"journal":{"name":"Isotopes in Environmental and Health Studies","volume":"59 2","pages":"192-201"},"PeriodicalIF":1.3,"publicationDate":"2023-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9440916","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Germain Esquivel-Hernández, Ioannis Matiatos, Ricardo Sánchez-Murillo, Yuliya Vystavna, Raffaella Balestrini, Naomi S Wells, Lucilena R Monteiro, Somporn Chantara, Wendell Walters, Leonard I Wassenaar
{"title":"Nitrate isotopes (<i>δ</i><sup>15</sup>N, <i>δ</i><sup>18</sup>O) in precipitation: best practices from an international coordinated research project.","authors":"Germain Esquivel-Hernández, Ioannis Matiatos, Ricardo Sánchez-Murillo, Yuliya Vystavna, Raffaella Balestrini, Naomi S Wells, Lucilena R Monteiro, Somporn Chantara, Wendell Walters, Leonard I Wassenaar","doi":"10.1080/10256016.2023.2177649","DOIUrl":"https://doi.org/10.1080/10256016.2023.2177649","url":null,"abstract":"<p><p>Stable isotope ratios of nitrogen and oxygen (<sup>15</sup>N/<sup>14</sup>N and <sup>18</sup>O/<sup>16</sup>O) of nitrate (NO<sub>3</sub><sup>-</sup>) are excellent tracers for developing systematic understanding of sources, conversions, and deposition of reactive atmospheric nitrogen (N<sub>r</sub>) in the environment. Despite recent analytical advances, standardized sampling of NO<sub>3</sub><sup>-</sup>) isotopes in precipitation is still lacking. To advance atmospheric studies on N<sub>r</sub> species, we propose best-practice guidelines for accurate and precise sampling and analysis of NO<sub>3</sub><sup>-</sup> isotopes in precipitation based on the experience obtained from an international research project coordinated by the International Atomic Energy Agency (IAEA). The precipitation sampling and preservation strategies yielded a good agreement between the NO<sub>3</sub><sup>-</sup> concentrations measured at the laboratories of 16 countries and at the IAEA. Compared to conventional methods (e.g., bacterial denitrification), we confirmed the accurate performance of the lower cost Ti(III) reduction method for isotope analyses (<sup>15</sup>N and <sup>18</sup>O) of NO<sub>3</sub><sup>-</sup> in precipitation samples. These isotopic data depict different origins and oxidation pathways of inorganic nitrogen. This work emphasized the capability of NO<sub>3</sub><sup>-</sup> isotopes to assess the origin and atmospheric oxidation of N<sub>r</sub> and outlined a pathway to improve laboratory capability and expertise at a global scale. The incorporation of other isotopes like <sup>17</sup>O in N<sub>r</sub> is recommended in future studies.</p>","PeriodicalId":14597,"journal":{"name":"Isotopes in Environmental and Health Studies","volume":"59 2","pages":"127-141"},"PeriodicalIF":1.3,"publicationDate":"2023-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9440527","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Determination of nitrate sources in a karst plateau reservoir based on nitrogen and oxygen isotopes.","authors":"Jie Kong, Zhongfa Zhou, Yongliu Li, Xianmei Liu, Chaocheng Wen, Jiangting Xie","doi":"10.1080/10256016.2023.2176850","DOIUrl":"https://doi.org/10.1080/10256016.2023.2176850","url":null,"abstract":"<p><p>Investigating the sources, migration and proportional contribution of nitrate is essential to effectively protect water quality. <i>δ</i><sup>15</sup>N-NO<sub>3</sub><sup>-</sup>, <i>δ</i><sup>18</sup>O-NO<sub>3</sub><sup>-</sup> and Stable Isotope Analysis in R (SIAR) were used to qualitatively and quantitatively analyse nitrate sources in the Pingzhai Reservoir water body. The values of <i>δ</i><sup>15</sup>N-NO<sub>3</sub><sup>-</sup> and <i>δ</i><sup>18</sup>O-NO<sub>3</sub><sup>-</sup> in water vary with season. Soil organic nitrogen and chemical fertilisers are the main sources of nitrate in autumn, while domestic sewage and livestock manure are the primary sources of nitrate in winter and spring. The SIAR results showed that chemical fertilisers, livestock manure, sewage, and soil organic nitrogen had the highest proportional contribution. In autumn, the proportional contribution of chemical fertilisers to river and reservoir were 47 and 51 %. During winter, the proportional contributions of livestock manure and sewage to river and reservoir were 53 and 68 %, respectively, and in spring 49 and 68 %, respectively. Considering the fragility of karst ecosystems, strict measures should be formulated for the use of chemical fertilisers and standards for sewage discharge should be raised. Control nitrogen input from agricultural activities and prevent water quality deterioration.</p>","PeriodicalId":14597,"journal":{"name":"Isotopes in Environmental and Health Studies","volume":"59 2","pages":"142-160"},"PeriodicalIF":1.3,"publicationDate":"2023-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9495087","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}