Combined effects of cadmium and ultraviolet radiation on mortality and mineral content in common frog (Rana temporaria) larvae

Impact of Cadmium and Lead Exposure on Camel Testicular Function: Environmental Contamination and Reproductive Health

The free grazing habits of camels from various sources may cause heavy metals to bioaccumulate in their tissues and organs, possibly resulting in higher amounts of these toxic substances in their bodies over time. The aim of this study was to assess the exposure impact of lead (Pb) and cadmium (Cd) on bull camels of the Lassi breed, aged 7 to 8 years, at a site near the industrial area and another two non-industrial sites, to analyze the presence of heavy metals. Samples from three sites were collected from thirty camels (n = 10/each), soil and water (n = 30), and five different plants (n = 15/each) for analysis. Testes were collected for atomic absorption spectrometry (AAS), and hematoxylin-eosin (HE) staining. Serum samples were obtained to measure testosterone levels by radioimmunoassay (RIA). Samples were obtained from plants, soil, water, blood, serum and urine for AAS. According to the results, the testes' weight, length, width, and volume significantly decreased at the industrial site compared with the other two sites as a result of exposure to Cd and Pb. Additionally, blood testosterone concentrations were considerably lower at the industrial site, indicating a detrimental impact on testicular steroidogenesis. The histological investigation of the industrial site indicated structural disturbances, including seminiferous tubule degeneration and shedding, cellular debris in seminiferous tubules, lining epithelium depletion, and vacuolation. Elevated amounts of Cd and Pb were found at the industrial site when analyzed using water, soil, plants, testes, serum, and urine. These findings demonstrate the adverse effects of Pb and Cd exposure on camel testicular function, including decreased weight and altered steroidogenesis. These findings are essential for understanding the impact of exposure to Pb and Cd on camel reproductive function and for developing successful prevention and management plans for these exposures in this species.

Cadmium-induced toxicity to amphibian tadpoles might be exacerbated by alkaline not acidic pH level

Heavy metal pollution in natural water bodies generally interacting with other environmental stressors produces toxic effects on aquatic organisms. However, toxicological studies exploring interactive effects of these stressors are still limited. Here, tadpoles of the Zhenhai brown frog (Rana zhenhaiensis) were exposed to a 3 × 3 factorial combination, with three cadmium (Cd) concentrations (0, 10 and 100 μg/L) and three pH levels (5.0, 7.23 and 9.0) throughout the developmental period to assess combined toxic effects of Cd × pH on tadpole growth, development and physiology. Nearly all measured traits [including survival, metamorphosis and abnormality rate, metamorphosis time, post-metamorphic size, hepatic metal content, locomotor performance, antioxidant enzyme activity, and erythrocytic nuclear abnormality (ENA) frequency] were affected by Cd exposure, indicating notable Cd-induced toxicity to R. zhenhaiensis tadpoles. The pH level and its interaction with Cd also had significant impacts on most measured traits, such as survival rate, metamorphosis time, froglet jumping distance, hepatic Cd content, ENA frequency. Acidic (or alkaline) environment itself was toxic to tadpoles. However, high pH (but not low pH) level appeared to exacerbate Cd-induced toxicity to tadpoles. Excess free hydrogen ions under acidic environments might inhibit Cd2+ ions binding to cell surface, which reduced Cd accumulation in tissues. Under alkaline environments, other forms of Cd complexes in the aqueous phase probably contributed to promoting Cd accumulation. Our results indicated that Cd exposure could interact with different pH levels, producing diverse combined toxicities to amphibian larvae.

Detrimental effects of long-term exposure to heavy metals on histology, size and trace elements of testes and sperm parameters in Kermani Sheep

Exposure to endocrine-disrupting chemicals (EDCs) has been hypothesized as a cause of declining sheep reproductive efficiency. Understanding the long-term effects of EDCs such as heavy metals on reproductive health requires investigation in 'real life' of sheep that are reared in industrial areas. The aim of this study was to evaluate the effect of long-term exposure of Kermani rams to high levels of environmental heavy metals probably emitted from a copper smelter at KhatoonAbad in ShahreBabak, Kerman province. Testicular characteristics were determined in randomly-selected rams (3-4 years old) at 4 directions (south, north, east, and west) and 4 distances (10, 20, 30, and 40 km) from the smelter. Testicular trace element contents, size, serum testosterone, histological attributes and seminal characteristics, except semen volume, were affected by both the direction and the distance from the smelter (P < 0.05). Testicular contents of Pb, Cd, Cr, and Ni, and sperm abnormalities were higher at 10 km south from the smelter and lower at 40 km west. Other parameters were higher at 40 km west and lower at 10 km south. Interestingly, the testicular contents of Cu at 10 km south were lower and associated with higher sperm abnormalities in the rams reared closer to the smelter. The highest weight, length and circumference of the testis were found at 40 km west. The lowest concentration of testosterone was observed at 10 km south, being 92.6% lower than the highest values obtained at 40 km west. The diameter of seminiferous tubules and epithelial height at 10 km south were 8.9% and 27.5% lower than the highest values obtained at 40 km west. A positive correlation between Pb, Cd, Cr and Ni contents in the testis with sperm abnormalities, and a negative correlation between these elements with the other parameters were found. It was concluded that long-term exposure to heavy metals might have been a cause of decreased fertility in rams and probably other living species in this region.

Seasonal variations in the blood concentration of selected heavy metals in sheep and their effects on the biochemical and hematological parameters

The main objective of this study was to assess the concentration of various heavy metals (Cd, Pb, Zn, Cu, Hg) in the blood of sheep, followed by biochemical and hematological analysis in order to reveal possible associations. Blood was collected in two different seasons: winter (fed by fodder) and spring (grazing animals). The higher concentrations of Pb (p < 0.01), Cu (p < 0.05) and Hg, but lower of Cd and Zn were found in spring. Evaluation of the biochemical and hematological parameters during different seasons showed a possible environmental effect on the health of animals. A statistically significant increase of Ca (p < 0.001), Mg (p < 0.05), urea (p < 0.001), TP (p < 0.05), glucose (p < 0.01), AST (p < 0.001), ALT (p < 0.001), ALP (p < 0.01), cholesterol (p < 0.001), bilirubin (p < 0.05), triglycerides (p < 0.001) and a decrease of P (p < 0.05), HGB (p < 0.05), MCHC (p < 0.05) and RDWc (p < 0.05) in spring was detected. The results of this study showed statistically significant correlations between Pb and ALP (r = 0.53) level in winter and between Pb and Ca (r = -0.73) in the spring. The hematological analysis revealed a significant correlation between Zn and RBC (r = 0.61), MCV (r = -0.74), MCH (r = -0.71) and between Pb and MCH (r = -0.55), PCT (r = -0.66), PDWC (r = -0.55) in the winter. A high positive significant correlations were found between Cd and RDWC (r = 0.77) and Cu and RDWC (r = 0.75). The significance of this work is the use the data in the preventive diagnosis of metabolic and production diseases. The collected data may serve as a control indicator to detect toxic hazards related to the heavy metal occurrence on animal health status.

Blood concentration of copper, cadmium, zinc and lead in horses and its relation to hematological and biochemical parameters

Environmental pollution results in serious health hazards to animals and blood analysis serves as a good alternative for health status assessment. The target of this study was to analyze the concentration of selected metals in equine blood, to analyze the blood parameters and to find possible correlations. Blood samples were collected from the vena jugularis of healthy adult horses. The highest concentration of all elements was found in whole blood (Cu 3.84 ± 0.90 mg L(-1); Cd = 0.81 ± 0.90 mg L(-1); Zn 26.67 ± 14.12 mg L(-1); Pb 9.33 ± 5.76 mg L(-1)). Higher concentrations of copper, cadmium, zinc and lead were detected in blood clots compared to blood sera (44.04%). A similar tendency was found for cadmium (50%), zinc (13.08%) and lead (46.02%), which showed generally higher concentrations in blood clots (cells). Correlation analysis proved some relations between analyzed elements. In blood clots there is a strong positive correlation between Cd - Pb (r = 0.93) and Zn - Pb (r = 0.71) was detected. For biochemical and hematological parameters mainly medium correlations were detected. Obtained results prove different correlations of analyzed elements in blood components as well as the effect on parameters of blood biochemical and hematological profiles.

Cadmium-induced toxicity on larvae of the common Asian toad Duttaphrynus melanostictus (Schneider 1799): evidence from empirical trials

This paper investigates the toxicity of cadmium (Cd) on young stages of the common Asian toad Duttaphrynus melanostictus (Schneider 1799). Signs of acute toxicity were evident in tadpoles repeatedly exposed to five concentrations ranging from 0.002 to 2 mg L(-1)of Cd which included environmentally relevant levels. Mortality at concentrations of 0.02 mg L(-1) and above was enhanced from 2 % at 0.02 mg L(-1) to 100 % at 1 mg L(-1), in a dose-dependent manner. Significant growth impairment was evident at 0.20 mg L(-1) with the larvae being markedly smaller. Delayed metamorphosis and retarded swimming were also observed. Therefore levels of Cd recorded in some freshwater bodies in Sri Lanka (e.g. 0.2 mg L(-1)) may be detrimental to the young stages of D. melanostictus.

In vitro effect of nickel on bovine spermatozoa motility and annexin V-labeled membrane changes

In this study the effect of in vitro culture of bovine spermatozoa with nickel (NiCl(2)) on spermatozoa motility and membrane changes was analyzed. The spermatozoa motility significantly decreased after 120 min of culture at the concentration of 1000 μM Ni ml(-1) (P < 0.05) and after 240 min of culture at the concentration of 500 and 1000 μM Ni ml(-1) (P < 0.001) as compared with control. The progressive motility was the highest in the control group and in the groups with the lowest nickel concentrations (7.8 and 125 μM Ni ml(-1)). The progressive spermatozoa motility was significantly altered even after 30 min of culture in the group with the highest nickel concentration (1000 μM Ni ml(-1)). A significant decrease in progressive motility from the concentration of 250 μM Ni ml(-1) was detected after 240 min of culture. Concentrations from 125 μM Ni ml(-1) in various time periods of culture stimulated spermatozoa motility after 30 min (P < 0.001), but later an inhibitory effect was noted. After 240 min of in vitro spermatozoa culture with 125 μM Ni ml(-1) a typical Annexin V fluorescence reaction was detected. Fluorescence was detected in mitochondrial segment of bovine spermatozoa. In spermatozoa exposed to higher nickel concentrations the Annexin V-positive reaction was detected also on the spermatozoa head membrane. In the group with the highest concentration and the longest time of exposure (1000 μM Ni ml(-1); 240 min) the apoptotic Annexin-positive regions were detected not only in the mitochondrial part, but also in the spermatozoa head (acrosomal and postacrosomal part), showing significant alteration of spermatozoa membrane integrity.

Effects of environmental change on wildlife health

Environmental change has negatively affected most biological systems on our planet and is becoming of increasing concern for the well-being and survival of many species. At an organism level, effects encompass not only endocrine disruptions, sex-ratio changes and decreased reproductive parameters, but also include teratogenic and genotoxic effects, immunosuppression and other immune-system impairments that can lead directly to disease or increase the risk of acquiring disease. Living organisms will strive to maintain health by recognizing and resolving abnormal situations, such as the presence of invading microorganisms or harmful peptides, abnormal cell replication and deleterious mutations. However, fast-paced environmental changes may pose additional pressure on immunocompetence and health maintenance, which may seriously impact population viability and persistence. Here, we outline the importance of a functional immune system for survival and examine the effects that exposure to a rapidly changing environment might exert on immunocompetence. We then address the various levels at which anthropogenic environmental change might affect wildlife health and identify potential deficits in reproductive parameters that might arise owing to new immune challenges in the context of a rapidly changing environment. Throughout the paper, a series of examples and case studies are used to illustrate the impact of environmental change on wildlife health.

Concentration of lead, cadmium, mercury and arsenic in leg skeletal muscles of three species of wild birds

The aim of this study was to monitor accumulation of lead, cadmium, mercury and arsenic in leg skeletal muscle of some wild birds from selected areas of Slovakia and the correlations among the heavy metals. A total of 160 wild birds representing 3 species-Eurasian coot (Fulica atra) (n = 24), mallard (Anas platyrhynchos) (n = 68) and pheasant (Phasianus colchicus) (n = 68) were involved for analyses. Concentrations of heavy metals from samples were measured using atomic absorption spectrophotometry (AAS). Metal concentrations are expressed as mg/kg wet weight. The order of lead and arsenic concentrations in muscles of wild birds were as follows: mallard > pheasant > Eurasian coot; in the case of arsenic the differences were significant (P < 0.05). Muscle of Eurasian coot accumulated the highest concentration of cadmium and mercury followed by pheasant and the lowest in mallard, but differences were not significant (P > 0.05). Moderately negative correlations were noted in pheasant between cadmium and mercury (r = -0.39), and between mercury and arsenic (r = -0.45). Moderately negative correlation between cadmium and arsenic (r = -0.31) was found for Eurasian coot.

Antioxidant status and selected biochemical parameters of porcine ovarian granulosa cells exposed to lead in vitro

The objective of this study was to determine the activity of superoxide dismutase (SOD), total antioxidant status (TAS) and release of calcium, phosphorus, magnesium, sodium, potassium, total lipids, totals proteins, glucose, cholesterol and triglycerides by porcine ovarian granulosa cells cultured in vitro after lead acetate administration. The parameters were analyzed using semi-automated clinical chemistry analyzer Microlab 300, microprocessor-controlled analyzer EasyLite and spectrophotometer Genesys 10. Cells were cultured with lead acetate trihydrate [Pb(CH(3)COO)(2).3H(2)O] as follows: group Max (5 mg Pb(CH(3)COO)(2).3H(2)O/10 mL), group A (2.5 mg/10 mL), group B (0.83 mg/10 mL), group C (0.625 mg/10 mL), group D (0.455 mg/10 mL) and the control group without lead exposure for 18 hrs. The highest TAS was estimated in the control group without lead treatment in comparison with other groups (MAX, A, B, C, D). Statistical analyses showed significantly lower value (P < 0.05) in group B. The activity of SOD was the lowest in the control group in comparison to those exposed to in vitro lead culture. A significant decrease (P < 0.05) of calcium content in group MAX in comparison with control group was determined. Release of phosphorus by ovarian granulosa cells was significantly lower (P < 0.05; 0.01; 0.001) in all the treated groups in comparison with control group. Lead was found to stimulate the release of magnesium and potassium by granulosa cells, but the increase remained statistically insignificant. The highest concentration of glucose was noted in control group, but the differences were not significant either. No significant differences (P > 0.05) were detected in concentration of other studied parameters among observed groups, too.

Cadmium availability to freshwater mussel (Unio tumidus) in the presence of organic matter and UV radiation

The influence of ultraviolet radiation (UV) on cadmium availability to freshwater mussel (Unio tumidus) in the presence of organic matter was investigated. Water solutions containing 1000, 500, and 250 microg x L(-1) of cadmium and 28.8 mg x L(-1) of total organic carbon (TOC) were exposed to ecologically relevant biologically effective UV-A and UV-B irradiances of 1.73 x 10(-6) W x cm(-2) and 1.50 x 10(-5) W x cm(-2) respectively for 12 h. The availability of cadmium was measured directly as Cd concentration in gills, mantle, digestive gland and foot, and indirectly as its impact on the content of essential cations. The concentration of cadmium ions, soluble forms of cadmium, pH and conductivity in UV irradiated solutions were also measured. UV exposures resulted in a decrease of the TOC to 25.9 mg x L(-1), followed by a decrease in the total concentration of Cd soluble forms, increase in the concentration of cadmium bound to particulate matter, and increase in the concentration of free cadmium ions in comparison to non-irradiated mixtures. Mussels from mixtures exposed to UV accumulated more cadmium than specimens from non-irradiated mixtures. This was confirmed by the fluctuations of essential cations, i.e. decreases in the contents of Zn, Ca, Fe and increase of the Cu content. Na/K molar ratios in gills were negatively correlated with cadmium content, while a positive trend occurred in other organs. We suggest that in UV-exposed water more ionic forms of cadmium occur. On the other hand more cadmium is also bound to particulate matter. Our research indicate that the increase of cadmium accumulation in mussels grown in humic acid solutions exposed to UV were most probably related to the increase in the concentration of cadmium bound to particulate matter.