Ecohydrological responses to diversion of groundwater: case study of a deep-rock repository for spent nuclear fuel in Sweden.

Planning and license applications concerning groundwater diversion in areas containing water-dependent or water-favored habitats must take into account both hydrological effects and associated ecological consequences. There is at present no established methodology to assess such ecohydrological responses. Thus, this paper describes a new stepwise methodology to assess ecohydrological responses to groundwater diversion from, e.g., water-drained pits, shafts, tunnels, and caverns in rock below the groundwater table. The methodology is illustrated using the planned deep-rock repository for spent nuclear fuel at Forsmark in central Sweden as a case study, offering access to a unique hydrological and ecological dataset. The case study demonstrates that results of ecohydrological assessments can provide useful inputs to planning of monitoring programs and mitigation measures in infrastructure projects. As a result of the assessment, artificial water supply to wetlands is planned in order to preserve biological diversity, nature values, and vulnerable species.

Obstructive sleep apnea among survivors of combat-related traumatic injury: a retrospective cohort study.

STUDY OBJECTIVES: Obstructive sleep apnea is prevalent among military members despite fewer traditional risk factors. We sought to determine the incidence and longitudinal predictors of obstructive sleep apnea in a large population of survivors of combat-related traumatic injury and a matched control group. METHODS: Retrospective cohort study of military service members deployed to conflict zones from 2002-2016 with longitudinal follow-up in the Veterans Affairs and Military Health Systems. Two cohorts of service members were developed: (1) those who sustained combat injuries and (2) matched, uninjured participants. RESULTS: 17,570 service members were retrospectively analyzed for a median of 8.4 years. After adjustment, traumatic brain injury (hazard ratio [HR] 1.39, 95% confidence interval [CI] 1.20-1.60), posttraumatic stress disorder (HR 1.24, 95% CI 1.05-1.46), depression (HR 1.52, 95% CI 1.30-1.79), anxiety (HR 1.40, 95% CI 1.21-1.62), insomnia (HR 1.71, 95% CI 1.44-2.02), and obesity (HR 2.40, 95% CI 2.09-2.74) were associated with development of obstructive sleep apnea. While combat injury was associated with obstructive sleep apnea in the univariate analysis (HR 1.25, 95% CI 1.17-1.33), the direction of this association was reversed in the multivariable model (HR 0.74, 95% CI 0.65-0.84). In a nested analysis, this was determined to be due to the effect of mental health diagnoses. CONCLUSIONS: The incidence of obstructive sleep apnea is higher among injured service members (29.1 per 1,000 person-years) compared to uninjured service members (23.9 per 1,000 person-years). This association appears to be driven by traumatic brain injury and the long-term mental health sequelae of injury. CITATION: Haynes ZA, Stewart IJ, Poltavskiy EA, et al. Obstructive sleep apnea among survivors of combat-related traumatic injury: a retrospective cohort study. J Clin Sleep Med. 2022;18(1):171-179.

Analysis of water flow paths: methodology and example calculations for a potential geological repository in Sweden.

Safety assessment related to the siting of a geological repository for spent nuclear fuel deep in the bedrock requires identification of potential flow paths and the associated travel times for radionuclides originating at repository depth. Using the Laxemar candidate site in Sweden as a case study, this paper describes modeling methodology, data integration, and the resulting water flow models, focusing on the Quaternary deposits and the upper 150 m of the bedrock. Example simulations identify flow paths to groundwater discharge areas and flow paths in the surface system. The majority of the simulated groundwater flow paths end up in the main surface waters and along the coastline, even though the particles used to trace the flow paths are introduced with a uniform spatial distribution at a relatively shallow depth. The calculated groundwater travel time, determining the time available for decay and retention of radionuclides, is on average longer to the coastal bays than to other biosphere objects at the site. Further, it is demonstrated how GIS-based modeling can be used to limit the number of surface flow paths that need to be characterized for safety assessment. Based on the results, the paper discusses an approach for coupling the present models to a model for groundwater flow in the deep bedrock.