Mineral and potentially toxic element profiles in the soil-feed-animal continuum: Implications for public, environmental, and livestock health in three pasture-based sheep farming systems.

Grazing livestock derive most of their mineral requirements from foraging. The presence of toxic elements in soils has become a significant concern for food safety and ecosystem services. Understanding the mineral content profiles in soil and forage is crucial for assessing animal health, predicting potential transfers of minerals or heavy metals into the food-chain, and assessing threats to the environment and human health. In this study, Na, Mg, P, K, Ca, Mn, Fe, Co, Cu, Zn, Se, As, Cd, Hg, and Pb were measured to determine the mineral status of three different pasture-based farming systems (with grazing sheep livestock) in a Spanish region of significant economic importance. A risk assessment evaluation of animal, environmental, and human health was performed on soil, forage, feed, serum, milk, and wool. Notably, traces of Pb, and As were identified in pastures in all farms. Our calculation of pollution indices revealed moderate levels of contamination by various elements, including Co, Cu, Zn, Se, As, Cd, Hg, and Pb. The two farms with more intense agrosystem practices showed a significant potential ecological risk, characterized by high soil levels of Hg and Cd. Animals from these farms also had high concentrations of these metals in wool. Although the target Hazard Quotient derived from milk consumption suggests that dairy products from this area are safe for consumption for adults, only milk from a dehesa farm (mix of woodland and pastureland) was free of potential health concerns related to Pb exposure. Our assessment of mineral profiles reveals a cohesive relationship between soil quality and derived animal products, particularly of the Merino sheep breeding and farming system. The results reveal the importance of adopting and reinforcing strategies to preserve dehesas as a sustainable and environmentally friendly agrosystem in the western Mediterranean region.

Biomarker responses and lethal dietary doses of tau-fluvalinate and coumaphos in honey bees: Implications for chronic acaricide toxicity.

Evidence suggests that acaricide residues, such as tau-fluvalinate and coumaphos, are very prevalent in honey bee colonies worldwide. However, the endpoints and effects of chronic oral exposure to these compounds remain poorly understood. In this study, we calculated LC50 and LDD50 endpoints for coumaphos and tau-fluvalinate, and then evaluated in vivo and in vitro effects on honey bees using different biomarkers. The LDD50 values for coumaphos were 0.539, and for tau-fluvalinate, they were 12.742 in the spring trial and 8.844 in the autumn trial. Chronic exposure to tau-fluvalinate and coumaphos resulted in significant changes in key biomarkers, indicating potential neurotoxicity, xenobiotic biotransformation, and oxidative stress. The Integrated Biomarker Response was stronger for coumaphos than for tau-fluvalinate, supporting their relative lethality. This study highlights the chronic toxicity of these acaricides and presents the first LDD50 values for tau-fluvalinate and coumaphos in honey bees, providing insights into the risks faced by colonies.

Biochemical Effects of Heavy Metals and Organochlorine Compounds Accumulated in Different Tissues of Yellow-Legged Gulls (Larus Michahellis).

In the present study, livers, kidneys and adipose tissue of Yellow-legged Gull (Larus michahellis) were collected. Samples were used to determine relationships between heavy metals/metalloids in liver and kidneys (Hg, Cd, Pb, Se and As) or persistent organic pollutants in adipose tissue (7 PCBs and 11 organochlorine pesticides) with biomarkers of oxidative stress (CAT, GPx, GR, GSH, GST, MDA) analysed in both internal organs. Three possible influencing variables have been studied: age, sex and sampling area. As a result, statistically significant differences (P < 0.05, P < 0.01) were only found according to the sampling area, with differences among the three studied areas found in both organs. Significant positive correlations (P < 0.01) were found in liver (Hg vs. GST; Se vs. MDA) and in kidney (As vs. GR; As vs. GPx; PCB52 vs. CAT; PCB138 vs. CAT). The scarcity in correlations suggests that the levels of pollutants found in animals were not high enough to trigger an effect at the oxidative level.

Prevalence of burnout syndrome among veterinarians in Spain.

OBJECTIVE: Burnout is a syndrome of emotional distress common in health-care professions. The aim of this study was to assess the potential levels of burnout syndrome among veterinarians in Spain as well as different factors involved in its prevalence. SAMPLE: 282 Spanish veterinarians (57.4% women and 42.6% men). PROCEDURES: All data were obtained through an online survey. The instrument utilized for this purpose was the Maslach Burnout Inventory Human Services Survey (adapted to a Spanish-speaking population), with analyses performed using statistical software. Moreover, a sociodemographic questionnaire was utilized. RESULTS: Within the considered population, 23% suffered from burnout syndrome and the average scores were 29 points for emotional exhaustion, 14 points for depersonalization, and 35 points for personal accomplishment. A higher prevalence of burnout was associated with small animal clinicians (75.3%) and women (66.1%), in comparison to large animal clinicians (24.6%) and men (33.8%). CLINICAL RELEVANCE: This study showed for the first time that burnout syndrome is a current and highly relevant risk for Spanish veterinarians. The results obtained could help to raise awareness of this reality and the factors involved in the development or exacerbation of this syndrome.

Evaluating the chronic effect of two varroacides using multiple biomarkers and an integrated biological response index.

There is mounting evidence that acaricides are among the most prevalent medicinal compounds in honey bee hive matrices worldwide. According to OCDE guideline No. 245 chronic lethal concentration of tau-fluvalinate (at concentrations ranging from 77.5 to 523.18 ppm), coumaphos (59.8 ppm) and dimethoate (0.7 ppm) were determined. The activity of the biomarkers acetylcholinesterase (AChE), carboxylesterase (CbE), glutathione S-transferase (GST), catalase (CAT) and malondialdehyde (MDA) was analysed and as they are implicated in neurotoxicity, biotransformation and antioxidant defences, these values were combined into an integrated biomarker response (IBR). There was enhanced AChE, CAT and GST activity in honey bees exposed to tau-fluvalinate, while dimethoate inhibited AChE activity. Both dimethoate and coumaphos inhibited CbE activity but they enhanced CAT activity and MDA formation. Our results highlight how these biomarkers may serve to reveal honey bee exposure to commonly used acaricides.

Heavy metals and metalloid levels in the tissues of yellow-legged gulls (Larus michahellis) from Spain: sex, age, and geographical location differences.

In the present study, mercury (Hg), cadmium (Cd), lead (Pb), selenium (Se), and arsenic (As) were measured in liver, kidney, and feathers of adult, juvenile, and chick seagulls (Larus michahellis) collected from the northwest of Spain. Age, sex, and the geographical location of samples were considered variables that can influence metal bioaccumulation, for which concentrations were determined by means of ICP-MS. The mean concentrations (dry weight) found in seagulls were 7.01 ± 0.37 mg Hg/kg, 22.82 ± 2.83 mg Cd/kg, 7.36 ± 1.36 mg Pb/kg, 18.64 ± 0.63 mg Se/kg, and 10.64 ± 0.59 mg As/kg. Regarding the different factors analyzed, Hg was the only metal showing sex-related differences, being significantly higher (p < 0.05) the concentrations found in feathers of males (1.26 ± 0.12 mg/kg) than those in females (0.99 ± 0.11 mg/kg). A highly significant (p < 0.01) increase in levels of some metals was found in liver related to the increase of age: Hg (adults (A) 3.33 ± 0.22 mg/kg vs chicks (C) 1.76 ± 0.28 mg/kg), Cd (A 4.74 ± 0.62 mg/kg vs C 1.79 ± 0.2), Pb (A 0.65 ± 0.12 mg/kg vs juveniles 0.4 ± 0.11 mg/kg), and Se (A 7.56 ± 0.43 mg/kg vs C 5.24 ± 0.53 mg/kg). Positive correlations between Cd-Hg and Se-Hg were found in liver (p < 0.001), kidney (p < 0.001), and feathers (p < 0.05 and p < 0.001, respectively). The associations found may reflect antagonistic interactions between Se and Cd on Hg toxicity. The results suggest that L. michahellis can reveal local contamination around the foraging and breeding sites and can be a very useful monitoring instrument for assessing heavy metal contamination and sentinel species of environmental health.

Presence of pharmaceutical compounds, levels of biochemical biomarkers in seafood tissues and risk assessment for human health: Results from a case study in North-Western Spain.

This study assessed the presence of 27 pharmaceutically active compounds belonging to common therapeutic groups (cardiovascular, antiashmatic, psychoactive, diuretic, analgesic/anti-inflammatory, and antibiotic drugs) in the tissues of representative seafood species of bivalves, cephalopods, arthropods, and fish of high economic importance and consumption rates in North-Western Spain. Four pharmaceutical compounds, out of the 27 analyzed, were detected in the collected samples. The benzodiazepine citalopram was detected in the tissues of common octopus (14.1 ng g-1 dry weight) and pod razor (9.4 ng g-1 dw). The anxiolytic venlafaxine was detected in the tissues of common cockle (2.9 ng g-1 dw). The veterinary antiparasitic ronidazole was found in pod razor (2.3 ng g-1 dw) and, finally, the psychoactive compound alprazolam was also measured in common octopus (0.3 ng g-1 dw). Hazard quotients were calculated to assess the hazard posed by the consumption of the sampled seafoods. Octopus and pod razor tissues containing citalopram and alprazolam exceeded our chosen hazard limits (HQ > 0.1) for toddlers who are high consumers of seafood (HQ values between 0.18 and 0.27). A battery of biochemical biomarkers of effects (acetylcholinesterase, glutathione S-transferase; catalase, glutathione peroxidase and glutathione reductase enzymes activities and reduced/oxidized glutathione and malondialdehyde levels) was applied to samples of the study species with the aim of characterizing their basal levels and evaluating their suitability as a tool in the monitoring chronic exposure to environmental contaminants such as those analyzed in this study. According to the measured biomarkers, pod razor and cockles have the potential to be good bioindicator species, based on the observed among-site differences detected on acetylcholinesterase, glutathione S-transferase, catalase, glutathione peroxidase activities; reduced/oxidized glutathione and malondialdehyde levels.

Mercury (Hg), Lead (Pb), Cadmium (Cd), Selenium (Se), and Arsenic (As) in Liver, Kidney, and Feathers of Gulls: A Review.

Mercury (Hg), lead (Pb), cadmium (Cd), selenium (Se), and arsenic (As) are metals or metalloids of high concern because of their effects on the environment and, specially, their potential toxicity on the animals inhabiting there. Due to their relevance, these elements have been object of several biomonitoring studies in different animal species around the world. Birds are widespread and, as species, are able to supply specific and relevant information about the regions where they live, being useful as bioindicators, as long as they are not birds with a strong migratory character. The main goal of this review is to summarize data collected from different studies using seabirds, paying special attention to gulls, in order to be helpful for coming studies and regulatory affairs.Several tissues have been used to evaluate Hg, Cd, Pb, Se, and As concentrations in seabirds, being focused the present review in those analyzing the liver, kidneys, and feathers. The most frequently analyzed tissue for Hg was the liver, followed by feathers, and finally kidney. For Cd levels, most of the studies were carried out in the liver, followed by feathers and kidneys. Pb, Se, and As levels were determined to a lesser extent. Feathers should be taken carefully as indicator of accumulation of pollutants, since procedure during analysis may lead to controversial results.Some authors reported that interspecific differences in the exposure of elements are determined by multiple factors, including properties of the contaminant, species, feeding habits, migratory status, sex, and age.The present review provides a comprehensive overview of the analyzed elements' occurrence in different species of seabirds, including gulls. Therefore, it can be a useful database providing for Hg, Pb, Cd, Se, and As levels in different tissues of seabirds.