ABSTRACT
Military activities in training areas can contaminate soil and groundwater through different persistent pollutants. This article reports the design of the operating procedure to assess and monitor the environmental impact of training activities carried out at the Capo Frasca military firing range (PCF) on the west coast of Sardinia. The procedure includes two steps: (i) a baseline investigation of soil to detect the impact of previous training activities at PCF, and (ii) the development of a post-training monitoring plan. Results of the baseline investigations revealed that the activities conducted at PCF over many decades have not significantly affected the soil quality. Energetic compounds (ECs) were found below the limit of detection (LOD), and some low exceedances of the screening values (SVs) for Cd, Cu, and Ni were recorded in small areas that coincided with parts of two operational areas. A human health risk assessment (HHRA) identified no relevant issues. Results of baseline investigation allowed the planning of a light, noninvasive post-training monitoring plan based on two levels, L1 and L2, where L1 involves only manual sampling of topsoil (0-0.2 m). If L1 reveals contamination, a more in-depth and extensive L2 follow-up monitoring will be implemented. Results of post-training monitoring are not yet available. This environmental investigation protocol is intended to be a practical tool for regulatory provisions and is expected to be useful and effective for firing range management. This investigation also emphasized that, compared with the international state-of-the-art, environmental surveys in Italian military ranges require the improvement of ECs set to be analyzed, lowering EC LOD, and establishing ECs SVs. In Sardinia, many military areas, including PCF, are considered areas of significant natural interest. Therefore, it is deemed beneficial to move beyond HHRA and undertake the ecological risk assessment. Integr Environ Assess Manag 2024;00:1-16. © 2024 SETAC.
ABSTRACT
In this paper we studied a resonate and fire relaxation oscillator subject to time dependent modulation to investigate phase-locking phenomena occurring in neurophysiological systems. The neural model (denoted LFHN) was obtained by linearization of the FitzHugh-Nagumo neural model near an hyperbolic fixed point and then by introducing an integrate-and-fire mechanism for spike generation. By employing specific tools to study circle maps, we showed that this system exhibits several phase-locking patterns in the presence of periodic perturbations. Moreover, both the amplitude and frequency of the modulation strongly impact its phase-locking properties. In addition, general conditions for the generation of firing activity were also obtained. In addition, it was shown that for moderate noise levels the phase-locking patterns of the LFHN persist. Moreover, in the presence of noise, the rotation number changes smoothly as the stimulation current increases. Then, the statistical properties of the firing map were investigated too. Lastly, the results obtained with the forced LFHN suggest that such neural model could be used to fit specific experimental data on the firing times of neurons.
