Cortisol, cortisone and DHEAS in epidermis and scales of fish Aphanius fasciatus: HPLC-MS/MS measurement of stress indicators as proxies for natural and human-induced factors.

Fish health can be affected by a multitude of stressors. Acute and chronic stress assessment via specific hormones monitoring has become a trending research topic. Common investigated matrices are blood and plasma, but recently less invasive substrates have been identified. As chemical composition of skin mucus/epidermis has been demonstrated to link with acute stress, and of scales with chronic stress in fish, the aim of the study was firstly to improve the determination of three stress hormones, namely cortisol (COL), cortisone (CON), and dehydroepiandrosterone-3-sulfate (DHEAS), in skin mucus/epidermis and scales of Aphanius fasciatus. Secondly, an evaluation of the impact of different environments on hormones concentrations was carried out. A liquid chromatography coupled to tandem mass spectrometry method (HPLC-MS/MS) and a preanalytical procedure were validated to determine COL, CON and DHEAS. This methodology was applied to compare a pull of field-collected fish with a pull of fish housed in the laboratory for one year. Our results highlighted a significant presence of cortisol and cortisone in epidermis of the latter pull (averagely 0.10 and 0.14 ng mg-1, respectively), while in the first pull both hormones were much less concentrated (averagely 0.006 and 0.008 ng mg-1, respectively). Scales of both pulls showed presence of hormones, with a higher concentration for fish housed in the laboratory, although a relevant difference in concentration was found only for cortisone. DHEAS was always below the limit of detection.

Airborne polar pesticides in rural and mountain sites of North-Eastern Italy: An emerging air quality issue.

North-Eastern Italy and in particular Veneto Region, stands out as a major centre of agriculture and viticulture which has rapidly expanded in the last decade with high productivity indexes. In this context, assessing atmospheric pollution caused by crop spraying with pesticides in rural areas and their transport to high-altitude remote sites is crucial to provide a basis for understanding possible impacts on the environment and population health. We aim to improve existing methods with a highly sensitive technique by using high pressure anion exchange chromatography coupled to a triple quadrupole mass spectrometer. Thus, a total of fourteen polar pesticides were determined in aerosol samples collected from August to December 2021 at Roncade (Venetian plain) and Col Margherita Observatory (Dolomites). The observatory was chosen as the background site as it is representative of the surrounding alpine region. Some samples revealed a substantial amount of cyanuric acid mainly at Roncade (mean concentration of 10 ± 10 ng m-3), glyphosate and fosetyl-aluminium (0.1 ± 0.2 and 0.1 ± 0.1 ng m-3, respectively). Surprisingly, some pesticides have been also found at Col Margherita, a high mountain background site, with concentrations an order of magnitude lower than at Roncade. This is the first time that fourteen polar pesticides have been assessed in the aerosol phase of the Po' Valley and detected at a high-altitude remote site, and consequently this study provides the first data on their occurrences in Italian aerosols. It represents a basis for the assessment of risks for humans.