Phytoremediation Potential of Native Plant Species in Mine Soils Polluted by Metal(loid)s and Rare Earth Elements.

Mining activity has an adverse impact on the surrounding ecosystem, especially via the release of potentially toxic elements (PTEs); therefore, there is an urgent need to develop efficient technologies to remediate these ecosystems, especially soils. Phytoremediation can be potentially used to remediate contaminated areas by potentially toxic elements. However, in soils affected by polymetallic contamination, including metals, metalloids, and rare earth elements (REEs), it is necessary to evaluate the behavior of these toxic elements in the soil-plant system, which will allow the selection of the most appropriate native plants with phytoremediation potential to be used in phytoremediation programs. This study was conducted to evaluate the level of contamination of 29 metal(loid)s and REEs in two natural soils and four native plant species (Salsola oppositifolia, Stipa tenacissima, Piptatherum miliaceum, and Artemisia herba-alba) growing in the vicinity of a Pb-(Ag)-Zn mine and asses their phytoextraction and phytostabilization potential. The results indicated that very high soil contamination was found for Zn, Fe, Al, Pb, Cd, As, Se, and Th, considerable to moderate contamination for Cu, Sb, Cs, Ge Ni, Cr, and Co, and low contamination for Rb, V, Sr, Zr, Sn, Y, Bi and U in the study area, dependent of sampling place. Available fraction of PTEs and REEs in comparison to total concentration showed a wide range from 0% for Sn to more than 10% for Pb, Cd, and Mn. Soil properties such as pH, electrical conductivity, and clay content affect the total, available, and water-soluble concentrations of different PTEs and REEs. The results obtained from plant analysis showed that the concentration of PTEs in shoots could be at a toxicity level (Zn, Pb, and Cr), lower than toxic but more than sufficient or natural concentration accepted in plants (Cd, Ni, and Cu) or at an acceptable level (e.g., V, As, Co, and Mn). Accumulation of PTEs and REEs in plants and the translocation from root to shoot varied between plant species and sampling soils. A. herba-alba is the least efficient plant in the phytoremediation process; P. miliaceum was a good candidate for phytostabilization of Pb, Cd, Cu, V, and As, and S. oppositifolia for phytoextraction of Zn, Cd, Mn, and Mo. All plant species except A. herba-alba could be potential candidates for phytostabilization of REEs, while none of the plant species has the potential to be used in the phytoextraction of REEs.

Effects of microplastics on physiological performance of marine bivalves, potential impacts, and enlightening the future based on a comparative study.

This review aims to explore the effects of microplastics and their corresponding additives on the physiological performances of marine bivalves together with their related genes. We identified gaps based on studies that were conducted on other organisms, and we conducted a comparative study on similar and relevant aspects for exploring future potential areas of study and interest. Microplastics are widely dispersed in all forms of media (solid, liquid, and gas). Exposure to an organism (including humans) is inevitable. However, impacts depend on the concentration of exposure, location of a biomarker being observed, and treatment involved. Different shapes, colors, and polymer types are reported and the transfer of microplastics along the food chain are recorded. The impacts of microplastics intensify when coupled with other chemicals or additives (referred to as xenobiotics) in a treated group. Thus, the degree of inhibition or enhancement of a physiological response magnifies when a coexposure of microplastic and a xenobiotic occurs. Microplastics have been observed to reduce immune system functionality by reducing hemocytes count, distorting oxidative system, respiration, and increasing energy consumption in bivalves due to physiological modulations that result from ingestion of microplastics or their additives. We found knowledge gaps and suggested future research directions to fully understand the impact of microplastics and their additives on marine bivalves.

Mapping the distribution of mercury (II) chloride in zebrafish organs by benchtop micro-energy dispersive X-ray fluorescence: A proof of concept.

BACKGROUND: Mercury (Hg) is a globally ubiquitous pollutant and one of the most dangerous metal contaminants, which presents a high risk of bioaccumulation in living organisms. In this study, we mapped the distribution of Hg and other trace elements in zebrafish (Danio rerio), which were exposed to mercury (II) chloride in order to assess its toxicity, bioaccumulation and distribution in fish organs. METHODS: Adult zebrafish were exposed for 7 days to different concentrations of mercury (II) chloride and the elemental distribution was obtained through the micro-energy dispersive X-ray fluorescence technique (µ-EDXRF). RESULTS: The results showed that Hg levels, measured in fish tissues, were indicative of bioaccumulation within some of its organs (e.g. visceral mass, gills), and that the physiological processes of accumulation were highly dose-dependent. In addition, the results showed higher concentrations of Hg in the gills. Moreover, other trace elements (e.g. Fe, Cu and Zn) levels were not altered after fish exposure to mercury(II) chloride. CONCLUSION: The µ-EDXRF results were assessed along with the determination of some oxidative stress biomarkers (e.g. antioxidant enzymes) to understand the effects behind the Hg bioaccumulation and toxicity. These results suggest that the metabolic changes in zebrafish due to the exposure to Hg are consistent with oxidative stress.

Concentração de elementos traços em serpentes do litoral e da região serrana do Espírito Santo / Trace element concentration in snakes of coastal and serrana region of the State of Espírito Santo, Brazil

Os elementos químicos, em sua maioria, encontram-se em ciclos bioquímicos e geoquímicos fechados e em concentrações que não causam efeitos nocivos aos organismos. Contudo, ações antrópicas aceleradas promovem alterações ambientais, como o aumento no aporte de contaminantes. Com essas informações, o presente trabalho buscou caracterizar a presença aos elementos traços em duas espécies de serpentes comuns na região sudeste, Boa constrictor e Bothrops jararaca. Os exemplares de B. constrictor (n=18) foram provenientes de atropelamentos ocorridos no trecho da Rodovia ES-060 do Km 0 ao Km 67,5. Os exemplares de B. jararaca (n=18) foram capturados por fazendeiros na zona rural da região serrana do Espírito Santo. Foram analisados 1 grama de fragmento de rim, de espécimes necropsiados. Os rins coletados foram digeridos com mistura ácida (HNO3;HCl; 1:1) a 300oC, 40min e a quantificação de microelementos (Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb e Zn) foi realizada por espectrometria de emissão óptica com plasma indutivamente acoplado (ICP OES). Não foram observadas diferenças significativas entre machos e fêmeas, exceto para Cromo nas B. constrictor (p=0,03), com média de 1,6595 nas concentrações de Cr nas fêmeas e 0,2896 em machos. Contudo, quando foram comparadas as diferentes espécies de serpentes, diferentes concentrações foram encontradas, para todos os elementos determinados, com destaque para o Ferro com uma concentração de 106,2mg/g em B. constrictor e 120,3mg/g em B. jararaca, provavelmente por esses animais virem de áreas próximas à portos de minério de ferro. A concentração de Zinco em B. constrictor foi de 1261,8mg/g e em B. jararaca foi de 28,4mg/g. O presente estudo indica que as serpentes analisadas, que habitam as regiões da Grande Vitória e serrana do Espírito Santo apresentam elevadas concentrações dos microelementos Zn e Fe.(AU)

Chemical elements are mostly involved in biochemical and geochemical cycles in concentrations which are harmless for organisms. However, accelerated human actions promote environmental changes such as the increase in contaminant intake. With this information, this study aimed to characterize the presence of trace elements in two snake species common in Southeastern Brazil, Boa constrictor and Bothrops jararaca. Copies of B. constrictor (n=18) were from pedestrian accidents which occurred on Highway stretch ES-060 from Km 0 to Km 67.5. Copies of B. jararaca (n=18) were captured by farmers in a rural mountainous area of Espíirito Santo State, Brazilo. They were analyzed 1 kidney fragment grass, autopsied specimens. Harvested kidneys were digested with acid mixture (HNO3 e HCl 1:1) at 300°C, 40 min and quantification of microelementos (Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb and Zn) were determined by spectrometric optical emission with inductively coupled plasma (ICP OES). significant differences between males and females were observed, except for Chrome in B. constrictor (p=0.03), with an average of 1.6595 in Cr concentration of females and 0.2896 in males. However, when different species of snakes were compared, different concentrations were found for all elements, especially iron with a concentration of 106.2mg/g in B. constrictor and 120.3mg/g in B. jararaca; probably these animals came from areas near iron ore ports. The concentration of zinc in B. constrictor was 1261.8mg/g and in B. jararaca 28,4mg/g. This study indicates that the analyzed snakes, which inhabit the regions of Greater Victoria and the mountainous region of the State of Espírito Santo have high concentrations of the microelements Zn and Fe.(AU)

Cadmium and high temperature effects on brain and behaviour of Lymantria dispar L. caterpillars originating from polluted and less-polluted forests.

Insects brain as a part of nervous system is the first-line of fast stress response that integrate stress signals to regulate all aspects of insect physiology and behaviour. The cadmium (Cd) bioaccumulation factor (BF), activity of the neurotoxicity biomarker acetylcholinesterase (AChE), dopamine content, expression and amount of Hsp70 in the brain and locomotor activity were evaluated in the 4th instar of Lymantria dispar L. caterpillars fed a Cd supplemented diet and reared in an optimal temperature regime (23 °C) and/or exposed to high temperature (28 °C). The insects originated from two forests, one close to "Nikola Tesla" thermoelectric power plant, Obrenovac (polluted population), and the other Kosmaj mountain (less-polluted population, far from any industrial region). The Cd BF was higher in the less-polluted than in the polluted population especially at the high ambient temperature. AChE activity and dopamine content were changed in the brains of L. dispar from both populations in the same manner. Hsp70 concentration in caterpillar brains showed opposite trends, a decrease in the less-polluted and an increase in the polluted population. Locomotor activity was modified in both Lymantria dispar populations, but the pattern of changes depended on the stressors and their combined effect. ACh activity and dopamine content are sensitive parameters to Cd exposure, regardless of pollutant experience, and might be promising biomarkers in monitoring forest ecosystems.