In this study, concentrations of radon in soil and the corresponding radiological health effects have been assessed in the Shaqlawa District, Erbil Governorate, Iraqi Kurdistan. Soil samples were taken across urban, suburban and agricultural areas at 25 locations. Radon concentrations were determined using CR-39 solid-state nuclear track detectors. Results showed Rn-222 concentrations from 39.5 to 95.4 Bq m(-3) and an average of 68.0 Bq m(-3). The average value of potential alpha energy concentration (PAEC) and annual effective dose (AED) was 11.03 mWL and 0.64 mSv y(-1), respectively. ELCR ranged from 1.3 & times; 10(-3) to 3.15 & times; 10(-3) and with a mean value of 2.25 & times; 10(-3). Dose estimates to organs showed a maximum mean exposure to the testes (0.41 mSv y(-1)) and bone marrow (0.35 mSv y(-1)), while the mean liver dose was minimal (0.24 mSv y(-1)). Most radon and radiological indices showed a near-normal distribution according to the statistical analyses, and radon concentration was significantly and positively correlated (r > 0.8) with hazard parameters. Kriging spatial mapping identified these high-radon areas related to fractured-calcerous lithologies, mainly the Shiransh-Aqrah-Bakhmah and Tayjru-Shiransh formations. Hierarchical cluster analysis revealed low, moderate and high radon clusters, which demonstrated that local variability exists and seems to be related to geology. These results provide an updated overview of soil radon levels and the expected health risks in the specific area of Shaqlawa, which is important baseline data to support better monitoring of environmental radiation, as well as planning for the health sector in this part of the region.
Southeast Alaska is one of the wettest places in the world, with some locations within the region receiving upwards of 6 metres of precipitation annually. Given the region's abundant precipitation, it is important to understand the mechanisms controlling the hydrologic cycle to better constrain past and future trends in climate. Accomplishing this requires the evaluation of isotopes in precipitation, as this is key to untangling the many drivers of the water cycle. However, there has never been a precipitation isotope study conducted in Southeast Alaska, vastly limiting our understanding of the water cycle in this region. To fill this gap, we report the first precipitation isotope results from Southeast Alaska, composed of monthly samples spanning 1 year between September 2023 and August 2024, thereby establishing an important regional baseline. We find that variations in temperature and precipitation amount during both a yearly and seasonal scale strongly influence the precipitation isotopic trends in the region, with the strength of the Aleutian Low a key factor in modulating precipitation isotopic trends.
Despite decades of protecting migrating animals by international treaties, conservation efforts are severely hampered by our limited understanding of large-scale seasonal movements, particularly in cryptic migratory animals like bats. Banding data from a field site on the Latvian coast of the Baltic Sea suggests that some European Nathusius' bats (Pipistrellus nathusii) move > 2000 km to their wintering range in Spain and France. As the banded bats were trapped en route, their summer origins remain unknown. Here, we used a stable hydrogen isotope approach to track the provenance of almost 700 P. nathusii moving southwards along the Latvian coast during three consecutive years. In general, P. nathusii originated from a large catchment area, with some geographic variation between years. About a quarter of all individuals came from areas south of Latvia, including northern Ukraine and neighbouring countries. This is consistent with the stable carbon isotope data, suggesting a summer origin south of the site for some of the captured bats. Our findings are in line with recent insights into the migratory orientation of temperate zone bats, with some individuals moving northwards before continuing to their southern wintering range. In conclusion, the migration of P. nathusii, and potentially also those of other temperate zone bats, may be more complex than previously anticipated.
Understanding fine-scale diet shifts in free-ranging wildlife remains challenging because high-resolution diet data are typically costly, invasive, or difficult to collect through time. Our objective was to determine whether delta & sup1;& sup3;C laser ablation-combustion-isotope ratio mass spectrometry (LA-IRMS) of hair could be used to detect the timing and direction of known diet switches among isotopically distinct foods fed to American black bears (Ursus americanus). We measured spatially resolved delta & sup1;& sup3;C values at similar to 200-& micro;m intervals along individual hairs from two captive bears fed controlled diets of corn, white-tailed deer, and trail mix. We converted tip-to-root positions along hairs to time using estimated hair growth rates of 0.72 +/- 0.34 mm/day for bear 1 and 0.55 +/- 0.17 mm/day for bear 2. We found that changes in hair delta & sup1;& sup3;C were as expected, corresponding closely with known diet switches. Across both trials and bears, delta & sup1;& sup3;C increased during corn feeding and declined during deer and trail-mix treatments. The isotopic profiles for bears in this study provide proof of concept that delta & sup1;& sup3;C LA-IRMS can detect multi-day diet switches from a single hair when the foods are isotopically distinct.
Studies on the effects of habitat fragmentation on animal trophic ecology have traditionally emphasised patch size or habitat loss, while the role of habitat quality has been comparatively overlooked. We investigated how habitat quality - assessed through as fine-scale variation of forest structure and food resource availability within patches - alongside patch attributes and landscape configuration, shapes the isotopic niche of the opossum Gracilinanus agilis in fragmented semideciduous dry forests of the central Brazilian Cerrado. Using a multiscale approach, we investigated the trophic responses of the species to environmental variation across 36 forest patches during two field campaigns conducted in 2018. Small mammals were live-trapped, habitat quality descriptors were quantified, and patch- and landscape-scale metrics (1-km buffer) were measured. Isotopic niche metrics were estimated from delta 13C and delta 15N values obtained from hair samples. Regression analyses showed that variation in delta & sup1;N-5 range (NR) increased with patch core area, indicating a broader range of trophic levels in larger and better-preserved patches. At the habitat-quality scale, the evenness of niche packing (SDNND) decreased with increasing vine abundance, suggesting that preferential understory use in more degraded forests may increase microhabitat overlap among individuals and leads to a more homogeneous trophic structure in isotopic space, with individuals more evenly packed within a narrower isotopic niche. SDNND also declined with higher termite abundance, indicating increased isotopic similarity among individuals as this resource became more intensively exploited. At the patch scale, SDNND increased with patch core area, suggesting greater trophic differentiation among individuals in larger patches with more pristine vegetation. Overall, trophic responses varied across spatial scales, with patch characteristics and habitat quality exerting stronger effects than landscape-level structure. Our findings highlight the importance of fine-scale environmental conditions in shaping the trophic niche structure and reinforce the need to incorporate habitat quality into fragmentation research.
