Crested porcupines (Hystrix cristata) as sentinels of environmental metal contamination in Central Italy

Background and Purpose: Contamination by potentially toxic metals represents one of the main environmental issues threatening biodiversity and the proper functioning of ecosystems, with direct repercussions on human health. In this context, toxicological biomonitoring plays a fundamental role in assessing the presence and spread of such substances. The selection of representative “sentinel” species is crucial to ensure effective monitoring. In Italy, one such species is the crested porcupine (Hystrix cristata), a large semi-fossorial rodent of African origin. Its broad ecological tolerance, generalist diet, sedentary and territorial habits, and close contact with soil and vegetation make H. cristata an excellent indicator of local contamination. Furthermore, its long lifespan allows for the progressive accumulation of contaminants over time, making it a suitable species for evaluating chronic exposure to pollutants in mixed agricultural and forested environments. This study aimed, for the first time on a global scale, to assess the concentrations of barium (Ba), cadmium (Cd) and lead (Pb) in liver and kidney of crested porcupine. The investigation sought to determine the presence and quantitative levels of these elements within a selected area, the Abruzzo region, to evaluate potential differences in concentrations between the two tissues, sex and age and to explore possible correlations between contamination levels and land use. Methods: Between 2022 and 2025, liver and kidney were collected from 30 carcasses of Hystrix cristata. Local authorities granted permission for the necropsy of the carcasses. Anamnestic information includimg age and sex were desumed from the necropsy and sampled animals were categorized based on the latitude and longitude coordinates in the WGS84 (EPSG: 4326) reference system of their deaths for inclusion in the CORINE Land Cover (CLC) classes. The instrumental analysis of Ba, Cd, and Pb was performed using an inductively coupled plasma mass spectrometer (Q-ICP-MS iCAP RQ) in standard mode using matrix-matching calibration to minimize the effect of the matrix. Shapiro-Wilk normality tests showed that the distribution of elements’s concentrations was not normal. Non-parametric Mann-Whitney and Kruskal-Wallis tests were applied to compare concentrations of inorganic elements among matrixes, animal sex, age and CLC distribution. Data were shown as median with 1st (Q1) and 3rd (Q3) quartiles and as mean and standard deviation (SD). Results: In liver and kidney metal concentrations were distributed as follows: Cd>Ba>Pb. The mean and median value of metals in liver were: Ba (138.7±118.7 μg/kg; 112 μg/kg Q1=46.8, Q3=171.8); Cd (140.3±199.6 μg/kg; 40 μg/kg Q1 22, Q3 220); Pb (61.5±87.4; 33 μg/kg Q1=24.5, Q3=54.5). In kidney mean and median concentrations were as follows: Ba (140.2±302; 60.5 Q1=42.3, Q3=114.5); Cd (950.4±1453.3, 326.5 Q1 121, Q3 1191.8); Pb (75.8±71.7, 53.5 Q1=35.5, Q3=88). The differences between matrixes showed as Cd were statistically significant higher in kidney compared to liver (p<0.05). Differences in centatrations of metals were not significant according to sex, age and CLC distribution. However, according to CLC datased animals were distributed as follows: 17% urban fabric, 27% arable land, 13% permanent crops, 27% heterogeneous agricitural areas, and 17% forests. Conclusions: The ecological traits of Hystrix cristata support its use as an effective sentinel species for terrestrial ecosystem monitoring. The results presented in this study provide the first global baseline values for potentially toxic metal concentrations in this species, contributing to a better understanding of contaminant bioaccumulation processes in Mediterranean terrestrial mammals. Cadmium concentrations in the kidney matrix were found to be significantly higher than those of other metals. According to the CLC dataset, the species’ distribution is consistent with its ethological characteristics. Considering its ongoing northward expansion and increasing interaction with anthropogenic environments, H. cristata may represent a highly valuable biological model for integrated studies on wildlife toxicology, environmental change, conservation management, and human health protection