Levels of rare earth elements on three abandoned mining sites of bauxite in southern Italy: A comparison between TXRF and ICP-MS.

The essential utilization of rare earth elements (REEs) for the production of several electronic devices is making the demand for them being increased all the time. This extensive use of these elements has also increased concern about human and environmental health. Previous studies have shown that REE levels are higher in environmental samples near mining sites, and they are highly possible to be transferred to biota. In this study, REE levels were determined in environmental samples collected from three abandoned mining sites of bauxite (Gargano, Otranto, and Spinazzola) in the region of Puglia, Southern Italy. The samples were digested and analyzed by two different techniques, Total X-Ray Fluorescence (TXRF) and Inductively Coupled Plasma - Mass Spectroscopy (ICP-MS) to investigate which technique is the most suitable for analysis of the REE content in samples from abandoned mining sites of bauxite. Only 6 REEs could be detected by TXRF, while all REEs were detected in all the samples by ICP-MS. Spinazzola is the richest site and Ce the most abundant REE in all three regions. REE levels are correlated between the soil and biota samples in many cases, although the calculation of the bioconcentration factor showed that REEs are not bioaccumulative. ICP-MS seems to be a more suitable technique for analysis of the whole REE content in environmental samples from abandoned mining sites of bauxite.

Aluminum exposure alters the pedal mucous secretions of the chocolate-band snail, Eobania vermiculata (Gastropoda: Helicidae).

Aluminum (Al) is used in everyday life and present in food drugs, packaging, industry, and agriculture. Although it is the most common metal in the Earth crust, a correlation has been demonstrated between its presence and various pathologies, even serious ones, especially of a neurological type. However, there is a histological gap regarding the role Al can have in contact with the covering and secreting epithelia. The alterations of the ventral and dorsal foot mucocytes and their secretions of the snail Eobania vermiculata caused by Al were investigated in situ by histochemical and lectin-histochemical techniques. Administration to different experimental groups took place for 3 and 9 days with 50 and 200 µM of AlCl3 . Several types of mucocytes were detected with a prevalent secretion of acid glycans in the foot of E. vermiculata. Sulfated glycans prevail in the dorsal region, with one type showing only fucosylated residues and another also having galactosaminylated and glycosaminylated residues. Carboxylated glycans prevail in the ventral region, with presence of galactosaminylated, glycosaminylated, and fucosylated residuals in both cells. Snails treated presented a general decrease of mucin amount in the secreting cells and affected the mucus composition. These changes could alter the rheological and functional properties of the mucus with possible implications for the health of the treated animals. RESEARCH HIGHLIGHTS: Snails were fed with Al-contaminated lettuce at different concentrations. In the foot mucocytes produced mucus with prevailing acidic glycans. In the treated resulted a reduction in the amount of mucus and an alteration of glycan composition.

Small noncoding RNAs and sperm nuclear basic proteins reflect the environmental impact on germ cells.

BACKGROUND: Molecular techniques can complement conventional spermiogram analyses to provide new information on the fertilizing potential of spermatozoa and to identify early alterations due to environmental pollution. METHODS: Here, we present a multilevel molecular profiling by small RNA sequencing and sperm nuclear basic protein analysis of male germ cells from 33 healthy young subjects residing in low and high-polluted areas. RESULTS: Although sperm motility and sperm concentration were comparable between samples from the two sites, those from the high-pollution area had a higher concentration of immature/immune cells, a lower protamine/histone ratio, a reduced ability of sperm nuclear basic proteins to protect DNA from oxidative damage, and an altered copper/zinc ratio in sperm. Sperm levels of 32 microRNAs involved in intraflagellar transport, oxidative stress response, and spermatogenesis were different between the two areas. In parallel, a decrease of Piwi-interacting RNA levels was observed in samples from the high-polluted area. CONCLUSIONS: This comprehensive analysis provides new insights into pollution-driven epigenetic alterations in sperm not detectable by spermiogram.

Geospatial pattern of topsoil pollution and multi-endpoint toxicity in the petrochemical area of Augusta-Priolo (eastern Sicily, Italy).

The present study was aimed at identifying geospatial patterns of pollutants including concentrations and toxicity as complex environmental mixtures, in topsoil samples close to petrochemical facilities in the heavily industrialized area of Augusta and Priolo in south-eastern Sicily (Italy). Elemental analysis of soil was conducted by ICP-MS for 23 metals and 16 rare earth elements (REEs). Organic analyses were primarily focused on polycyclic aromatic hydrocarbons (PAHs) (16 parent homologs) and total aliphatic hydrocarbons (C10 - C40). Topsoil samples were tested for toxicity in multiple bioassay models including: 1) developmental defects and cytogenetic anomalies in sea urchin Sphaerechinus granularis early life stages; 2) growth inhibition of diatom Phaeodactylum tricornutum; 3) mortality in nematode Caenorhabditis elegans; and 4) induction of mitotic abnormalities in onion Allium cepa. Samples collected at sites closest to defined petrochemical facilities were highest in select pollutants and correlated with biological effects in different toxicity endpoints. A noteworthy finding was the increased level of total REEs in sites closest to petrochemical facilities, suggesting their contributions to identifying petrochemical sources of pollutants to the environment. The combined data obtained in the different bioassays allowed exploration of geospatial patterns of effect in biota as a function of contaminant levels. In conclusion, this study provides consistent data of soil toxicity, metal and REE contamination at Augusta-Priolo sampling sites, and may provide an appropriate baseline for epidemiological studies on high incidences of congenital birth defects in the area and identification of at-risk localities.

Aluminum induces a stress response in zebrafish gills by influencing metabolic parameters, morphology, and redox homeostasis.

Environmental air pollution and resulting acid rain have the effect of increasing aluminum levels in water bodies. We studied the effects of aluminum on fish gills, the tissue most exposed to aluminum, using zebrafish as an experimental model. Adult zebrafish were exposed to an aluminum concentration found in polluted environments (11 mg/L) for 10, 15 and 20 days and the effects on gill morphology, redox homeostasis (ROS content, NADPH oxidase, NOX, activity, oxidative damage, antioxidant enzymes, total antioxidant capacity, in vitro susceptibility to oxidants) and on behavioural and metabolic parameters (routine respiratory oxygen consumption rMO2, tail-beating frequency, cytochrome oxidase activity and muscle lactate content) were evaluated. Exposure to aluminum affects branchial histology, inducing alterations in primary and secondary lamellae and redox homeostasis, modifying ROS levels, NOX activity, lipid and protein oxidative damage, antioxidant enzymes, and total antioxidant capacities, and increases rMO2. The effects exhibited a time-dependent behaviour, suggesting the activation of an adaptive response. These changes are associated with a transition of muscle metabolism from aerobic to anaerobic, as suggested by the increase in muscle lactate content, which is probably functional to preserve locomotor performance. Overall, the results here reported provide new insights into the toxicity mechanisms of Al exposure on gill tissue and the subsequent adaptive response of aquatic species.

Impacts of Environmental Pollution on Brain Tumorigenesis.

Pollutants consist of several components, known as direct or indirect mutagens, that can be associated with the risk of tumorigenesis. The increased incidence of brain tumors, observed more frequently in industrialized countries, has generated a deeper interest in examining different pollutants that could be found in food, air, or water supply. These compounds, due to their chemical nature, alter the activity of biological molecules naturally found in the body. The bioaccumulation leads to harmful effects for humans, increasing the risk of the onset of several pathologies, including cancer. Environmental components often combine with other risk factors, such as the individual genetic component, which increases the chance of developing cancer. The objective of this review is to discuss the impact of environmental carcinogens on modulating the risk of brain tumorigenesis, focusing our attention on certain categories of pollutants and their sources.

Coffee Silverskin: Chemical and Biological Risk Assessment and Health Profile for Its Potential Use in Functional Foods.

The coffee supply chain is characterized by a complex network with many critical and unsustainable points producing a huge amount of waste products. Among these, coffee silverskin (CS), the only by-product of the coffee roasting phase, has an interesting chemical profile that suggests potential use as a food ingredient. However, few data on its safety are available. For this reason, the purpose of the study was to assess the occurrence of chemical and biological contaminants in CS, and the resulting risk due to its potential consumption. Essential, toxic, and rare earth elements, polycyclic aromatic hydrocarbons (PAHs), process contaminants, ochratoxin A (OTA), and pesticides residues were analyzed in three classes of samples (Coffea arabica CS, Coffea robusta CS, and their blend). Furthermore, total mesophilic bacteria count (TMBC) at 30 °C, Enterobacteriaceae, yeasts, and molds was evaluated. The risk assessment was based upon the hazard index (HI) and lifetime cancer risk (LTCR). In all varieties and blends, rare earth elements, pesticides, process contaminants, OTA, and PAHs were not detected except for chrysene, phenanthrene, and fluoranthene, which were reported at low concentrations only in the arabica CS sample. Among essential and toxic elements, As was usually the most representative in all samples. Microorganisms reported a low load, although arabica and robusta CS showed lower contamination than mixed CS. Instead, the risk assessment based on the potential consumption of CS as a food ingredient did not show either non-carcinogenic or carcinogenic risk. Overall, this study provides adequate evidence to support the safety of this by-product for its potential use in functional foods.

Comparison between Macro and Trace Element Concentrations in Human Semen and Blood Serum in Highly Polluted Areas in Italy.

Macro and trace elements are important regulators of biological processes, including those ones linked to reproduction. Among them, Ca, Cu, Fe, K, Mg, Mn, Na, Se, and Zn ensure normal spermatic functions. Hence, the aim of this study was to evaluate the concentrations of 26 macro and trace elements (Al, As, Ba, Be, Ca, Cd, Co, Cr, Cu, Fe, Hg, K, Li, Mg, Mn, Na, Ni, Pb, Rb, Sb, Se, Sn, Sr, U, V, and Zn) in blood serum and also in semen of healthy young men, homogeneous for age, anthropometric characteristics, and lifestyle, living in three highly polluted areas in Italy. Furthermore, a comparison among three geographical areas was performed to highlight any difference in the investigated parameters and, overall, to speculate any correlations between chemical elements and semen quality. Statistically significant differences (p < 0.05) among the three areas were found for each investigated element, in both semen and serum samples, where inter-area differences were more evident in semen than in blood serum, suggesting human semen as an early environmental marker. Considering the homogeneity of three cohorts, these differences could be due more to environmental conditions in the recruiting areas, suggesting that variations in those involved in reproductive-associated pathways can have an impact on male fertility. Nevertheless, more research is needed to evaluate threshold values for sperm dysfunction and male infertility. Actually, the role of different dietary intake and environmental exposure underlying the observed differences in the recruiting areas is under further investigation for the same cohort.

Aluminium exposure leads to neurodegeneration and alters the expression of marker genes involved to parkinsonism in zebrafish brain.

Aluminium, despite being extremely widespread in the world, is a non-essential metal to human metabolism. This metal is known to have toxic effects on a variety of organs including the brain and is considered an etiological factor in neurodegenerative diseases. However, the molecular mechanisms by which aluminium exerts neurotoxic effects are not yet completely understood. Zebrafish is an animal model also used to study neurodegenerative diseases since the overall anatomical organization of the central nervous system is relatively conserved and similar to mammals. Adult zebrafish were exposed to 11 mg/L of Al for 10, 15, and 20 days and the neurotoxic effects of aluminium were analysed by histological, biochemical, and molecular evaluations. Histological stainings allowed to evaluation of the morphology of the brain parenchyma, the alteration of myelin and the activation of neurodegenerative processes. The expression of the Glial Fibrillary Acidic Protein, a marker of glial cells, was evaluated to observe the quantitative alteration of this important protein for the nervous system. In addition, the poly(ADP-ribose) polymerase activity was measured to verify a possible oxidative DNA damage caused by exposure to this metal. Finally, the evaluation of the markers involved in Parkinsonism was assessed by Real-Time PCR to better understand the role of aluminium in the regulation of genes related to Parkinson's neurodegenerative disease. Data showed that aluminium significantly affected the histology of cerebral tissue especially in the first periods of exposure, 10 and 15 days. This trend was also followed by the expression of GFAP. At longer exposure times, there was an improvement/stabilization of the overall neurological conditions and decrease in PARP activity. In addition, aluminium is involved in the deregulation of the expression of genes closely related to Parkinsonism. Overall, the data confirm the neurotoxicity induced by aluminium and shed a light on its involvement in neurodegenerative processes.

Hydrochemical, isotopic and microbiota characterization of telese mineral waters (Southern Italy).

The study deals with the analyses of springs and wells at the base of Montepugliano Hill that represents the SE edge of the wide carbonate Matese massif (Campania, southern Italy). At the base of the hill, from west to east and for almost one kilometre, cold springs HCO3-Ca type (Grassano springs, ~ 4.5 m3/s; TDS: about 0.45 g/L) pass to hypothermal, HCO3-Ca type, sulphurous and CO2-rich springs (~ 1 m3/s with TDS > 1 g/L). Some of the latter are widely used in Telese Spa and Centro Relax Spa. Chemical and isotopic analyses carried out for this study support the hypothesis that all these waters (mineral and non-mineral) have the same catchment area, which is located in the Matese massif. As regards the sulphurous springs, they receive both meteoric waters infiltration and uprising of deeper waters rich in endogenous CO2 and H2S gases through important faults systems. Far from these faults, the chemistry of groundwater is scarcely (or not at all) affected by these deep fluid enrichment processes. This scheme is very significant; in fact, when very important groundwater resources are present, it is possible to use both mineral waters in Spa and, in areas far from the faults, those not yet mineralized. Finally, at Montepugliano Hill, in the final stage of the flow path, groundwater is also affected by change in the microbiome: this could provide a basis for comparison between various mineral waters.

Comparative Fatty Acid Profiling of Edible Fishes in Kuala Terengganu, Malaysia.

The aim of this study was to compare the relative nutritional benefit of edible Malaysian fishes from the coast of Terengganu in Malaysia, as well as to perform a taxonomical characterization and metal assessment. Discrimination between species was carried out by a morphological and molecular approach by evaluating the total concentrations of metals by ICP-MS analyses and the fatty acids (FA) composition using the GC-MS approach on the fish fillet tissues. The taxonomical studies detected fishes of 11 families and 13 species. The heavy metal assessment showed that all detected elements did not exceed the regulatory limit stated by Malaysian Food Regulations. The proportion of saturated fatty acids (SFA) ranged from 33 to 58.34%, followed by the polyunsaturated fatty acids (PUFA) values from 24 to 51.8%, and the lowest proportion was of monounsaturated fatty acids (MUFA), ranging from 12.7 to 35.9%. The ω-3/ω-6 PUFA and PUFA/SFA ratios were determined in the range 1.1 to 7.4 and 0.35 to 1.6, respectively. The C20:5 ω-3 and C22:6 ω-3 acids were detected at levels comparable to those found in the corresponding species from similar tropical marine ecosystems. The high FA values can be useful biochemical tools for comparing the relative nutritional benefits of these biodiverse and non-toxic edible Malaysian fishes.

New Insights into Alterations in PL Proteins Affecting Their Binding to DNA after Exposure of Mytilus galloprovincialis to Mercury-A Possible Risk to Sperm Chromatin Structure?

Mercury (Hg) is a highly toxic and widespread pollutant. We previously reported that the exposure of Mytilus galloprovincialis for 24 h to doses of HgCl2 similar to those found in seawater (range 1-100 pM) produced alterations in the properties of protamine-like (PL) proteins that rendered them unable to bind and protect DNA from oxidative damage. In the present work, to deepen our studies, we analyzed PL proteins by turbidimetry and fluorescence spectroscopy and performed salt-induced release analyses of these proteins from sperm nuclei after the exposure of mussels to HgCl2 at the same doses. Turbidity assays indicated that mercury, at these doses, induced PL protein aggregates, whereas fluorescence spectroscopy measurements showed mercury-induced conformational changes. Indeed, the mobility of the PLII band changed in sodium dodecyl sulphate-polyacrylamide gel electrophoresis, particularly after exposure to 10-pM HgCl2, confirming the mercury-induced structural rearrangement. Finally, exposure to HgCl2 at all doses produced alterations in PL-DNA binding, detectable by DNA absorption spectra after the PL protein addition and by a decreased release of PLII and PLIII from the sperm nuclei. In conclusion, in this paper, we reported Hg-induced PL protein alterations that could adversely affect mussel reproductive activity, providing an insight into the molecular mechanism of Hg-related infertility.

Combined Effects of Wildfire and Vegetation Cover Type on Volcanic Soil (Functions and Properties) in A Mediterranean Region: Comparison of Two Soil Quality Indices.

Mediterranean regions are the most impacted by fire in Europe. The effects of fire on soil greatly vary according to several factors such as vegetation cover type, but they are scarcely studied. Therefore, this research aimed at evaluating the combined impacts of fire and vegetation on single soil characteristics and on the overall soil quality and functionality through two soil quality indices, simple additive (SQI) and a weighted function (SQIFUNCT). In order to reach the aims, burnt and unburnt soils were collected under different vegetation cover types (herbs and shrubs, black locust, pine and holm oak) within the Vesuvius National Park. The soils were analyzed for the main abiotic (water and organic matter content, total C, N, Ca, K, Cu and Pb concentrations, C/N ratio) and biotic (microbial and fungal biomasses, basal respiration, ß-glucosidase activity) characteristics. On the basis of the investigated soil characteristics, several soil functions (water retention, nutrient supply, contamination content, microorganism habitat and activities), and the soil quality indices were calculated. The results showed that the impact of fire on soil quality and functionality was mediated by the vegetation cover type. In fact, fire occurrence led to a decrease in water and C/N ratio under herbs, a decrease in C concentration under holm oak and a decrease in Cu and Pb concentrations under pine. Although the soil characteristics showed significant changes according to vegetation cover types and fire occurrence, both the additive and weighted function soil quality indices did not significantly vary according to both fire occurrence and the vegetation cover type. Among the different vegetation cover types, pine was the most impacted one.

Spermatozoa Transcriptional Response and Alterations in PL Proteins Properties after Exposure of Mytilus galloprovincialis to Mercury.

Mercury (Hg) is an environmental pollutant that impacts human and ecosystem health. In our previous works, we reported alterations in the properties of Mytilus galloprovincialis protamine-like (PL) proteins after 24 h of exposure to subtoxic doses of toxic metals such as copper and cadmium. The present work aims to assess the effects of 24 h of exposure to 1, 10, and 100 pM HgCl2 on spermatozoa and PL proteins of Mytilus galloprovincialis. Inductively coupled plasma-mass spectrometry indicated accumulation of this metal in the gonads of exposed mussels. Further, RT-qPCR analyses showed altered expression levels of spermatozoa mt10 and hsp70 genes. In Mytilus galloprovincialis, PL proteins represent the major basic component of sperm chromatin. These proteins, following exposure of mussels to HgCl2, appeared, by SDS-PAGE, partly as aggregates and showed a decreased DNA-binding capacity that rendered them unable to prevent DNA damage, in the presence of CuCl2 and H2O2. These results demonstrate that even these doses of HgCl2 exposure could affect the properties of PL proteins and result in adverse effects on the reproductive system of this organism. These analyses could be useful in developing rapid and efficient chromatin-based genotoxicity assays for pollution biomonitoring programs.

Molecular Alterations in Spermatozoa of a Family Case Living in the Land of Fires. A First Look at Possible Transgenerational Effects of Pollutants.

In our previous work, we reported alterations in protamines/histones ratio, in DNA binding of these proteins and their involvement in DNA oxidative damage in 84% of the young men living in the Land of Fires. In the present work, we extended our findings, evaluating any alterations in spermatozoa of a family case, a father and son, living in this area, to also give a first look at the possibility of transgenerational inherited effects of environmental contaminants on the molecular alterations of sperm nuclear basic proteins (SNBP), DNA and semen parameters. In the father and son, we found a diverse excess of copper and chromium in the semen, different alterations in SNBP content and low DNA binding affinity of these proteins. In addition, DNA damage, in the presence of CuCl2 and H2O2, increased by adding both the father and son SNBP. Interestingly, son SNBP, unlike his father, showed an unstable DNA binding and were able to produce DNA damage even without external addition of CuCl2, in line with a lower seminal antioxidant activity than the father. The peculiarity of some characteristics of son semen could be a basis for possible future studies on transgenerational effects of pollutants on fertility.

Discovery of the Involvement in DNA Oxidative Damage of Human Sperm Nuclear Basic Proteins of Healthy Young Men Living in Polluted Areas.

DNA oxidative damage is one of the main concerns being implicated in severe cell alterations, promoting different types of human disorders and diseases. For their characteristics, male gametes are the most sensitive cells to the accumulation of damaged DNA. We have recently reported the relevance of arginine residues in the Cu(II)-induced DNA breakage of sperm H1 histones. In this work, we have extended our previous findings investigating the involvement of human sperm nuclear basic proteins on DNA oxidative damage in healthy males presenting copper and chromium excess in their semen. We found in 84% of those males an altered protamines/histones ratio and a different DNA binding mode even for those presenting a canonical protamines/histones ratio. Furthermore, all the sperm nuclear basic proteins from these samples that resulted were involved in DNA oxidative damage, supporting the idea that these proteins could promote the Fenton reaction in DNA proximity by increasing the availability of these metals near the binding surface of DNA. In conclusion, our study reveals a new and unexpected behavior of human sperm nuclear basic proteins in oxidative DNA damage, providing new insights for understanding the mechanisms related to processes in which oxidative DNA damage is implicated.

Sediment contamination by heavy metals and ecological risk assessment: The case of Gulf of Pozzuoli, Naples, Italy.

Heavy metal concentrations in sediments of the Gulf of Pozzuoli, GoP, and northwest of the Gulf beyond Monte di Procida, MdP, were determined. The enrichment factor, EF, revealed in GoP strong pollution with peaks for Cr and Cu of 61.1 and 96.9. High EF Cr, Cu, and Ni values were observed for MDP. Geoaccumulation index, Igeo, rates GoP extremely polluted by Cr and Cu, Igeo > 5, and MdP heavily polluted by Cr, moderately to heavily polluted by Cu, and heavily to extremely polluted by Ni. Contamination factor, Cf, was high in GoP and varied: Cu > Cr > Ni > Cd > Hg > Zn > Pb > As, and those of Cr, Cu and Ni largely surpassed the thresholds in MdP. The ecological and comprehensive ecological risk placed Cr, Cu, Hg and Ni at high or serious risk level in the Gulf, with a peak of 465 for Cu and at a moderate level in MdP except for a very high risk for Ni.

Protamine-like proteins' analysis as an emerging biotechnique for cadmium impact assessment on male mollusk Mytilus galloprovincialis (Lamarck 1819).

Here we report the industrial pollution effects due to cadmium on the reproductive health of Mytilus galloprovincialis. Mussels were removed from the biofouling of a Conatex panel after one year exposition at a polluted site near a disposal metallurgical factory. A high cadmium bioaccumulation was observed in the testis of mussels housed at the polluted site, with respect to a control site, as determined by inductively coupled plasma-mass spectrometry, along with a 10 fold increase in metallothionein 20 kDa gene (mt20) expression levels determined by qPCR. Furthermore, mussels transferred into laboratory tanks from the reference site, and exposed to 1.5, 5 and 10 µM CdCl2, revealed a 1.7, 3.2 and 4.5 fold expression increase in the testis mt20, respectively, and a positive correlation with cadmium bioaccumulation was found. To evaluate a potential detrimental risk of such alterations on spermatozoa, we carried out electrophoretic analyses on their protamine-like proteins. As determined by AU-PAGE, after 1.5 µM CdCl2 exposure, protamine-like proteins also display major alterations with respect to those obtained after 5 and 10 µM CdCl2 exposure. All protamine-like proteins isolated from the polluted biofouling were in an aggregated form and displayed the same reduced DNA binding affinity of the protamine-like proteins obtained after 1.5 µM CdCl2 as demonstrated EMSA with sperm genomic DNA. Our results contribute to the studies concerning cadmium induced testis alterations and highlight protamine-like proteins' analysis as an emerging biotechnique for cadmium impact assessment on Mytilus galloprovincialis, for the sensitivity of the in vivo and in vitro changes of protamine-like proteins' state and their DNA binding affinity.

Relevance of arginine residues in Cu(II)-induced DNA breakage and Proteinase K resistance of H1 histones.

This work analyzes the involvement of arginines in copper/H2O2-induced DNA breakage. Copper is a highly redox active metal which has been demonstrated to form compounds with arginines. For this aim we used mixtures of pGEM3 DNA plasmid and two types of H1 histones which differ only in their arginine content. The sperm H1 histone from the annelid worm Chaetopterus variopedatus (arginine content 12.6 mol% K/R ratio 2) and the somatic H1 histone from calf thymus (arginine content 1.8 mol% and K/R ratio 15). Copper/H2O2-induced DNA breakage was observed only in presence of sperm H1 histones, but it was more relevant for the native molecule than for the deguanidinated derivative (K/R ratio 14), in which 80% of arginine residues were converted to ornithine. Further, copper induced proteinase K resistance and increase of DNA binding affinity on native sperm H1 histones. These observations are consistent with a copper induced reorganization of the side-chains of arginine residues. Copper, instead, did not affect DNA binding affinity of somatic and deguanidinated H1 histones, which show similar K/R ratio and DNA binding mode. These results indicate that arginine residues could affect these H1 histones properties and provide new insights into copper toxicity mechanisms.

Comparative toxicity of seven rare earth elements in sea urchin early life stages.

The widespread use of rare earth elements (REEs) in a number of technological applications raises unanswered questions related to REE-associated adverse effects. We have previously reported on the multiple impact of some REEs on the early life stages of the sea urchin Paracentrotus lividus. The present investigation was to evaluate REE toxicity to early life stages in two unrelated sea urchin species, Sphaerechinus granularis and Arbacia lixula. The comparative toxicities were tested of seven REEs, namely yttrium, lanthanum, cerium, neodymium, samarium, europium and gadolinium as chloride salts at concentrations ranging from 10-7 to 10-4 M. The evaluated endpoints included developmental defects and cytogenetic anomalies in REE-exposed embryos/larvae, and decreased fertilization success and offspring damage following sperm exposure. The results showed different toxicity patterns for individual REEs that varied according to test species and to treatment protocol, thus showing toxicity scaling for the different REEs. Further, the observed effects were compared with those reported for P. lividus either following embryo or sperm exposures. S. granularis showed a significantly higher sensitivity both compared to A. lixula and to P. lividus. This study provides clear-cut evidence for distinct toxicity patterns among a series of REEs. The differences in species sensitivity at micromolar REE levels may warrant investigations on species susceptibility to impacts along polluted coasts.