Contaminants In Environmental Matrices Research Articles

Heavy metal contamination in soils of industrial estates of Tamil Nadu, India and source identification by magnetic susceptibility.

An increase in erratic industrial activity has been a major contributing factor to the significant contamination in environmental matrices. This study aimed to ascertain the level of heavy metal contamination in soils in major industrial estates of Tamil Nadu as well as the threats to human health and the environment that concomitant with it. This led to the use of the total reflection X-ray fluorescence (TXRF) spectroscopy technique to analyse 31 soil samples. Thus, the mean heavy metal concentrations were found to be in the ascending order: As < Ni < Pb < V < Cu < Zn < Cl < Mn < Sr < Cr < Al < Fe. Pb, Cr, Cu, As, and Zn have been identified as predominantcontaminants in the study area using the conventional pollution indices such as geo-accumulation index (Igeo), contamination factor (CF), and enrichment factor (EF). The magnetic susceptibility measurements indicates that the percentage of frequency dependence of magnetic susceptibility of the studied soil samples varied from 0.88 to 11.15 and that represents the presence of admixture ofsuperparamagnetic (SP) particles in the soil samples. From the results of multivariate statistical analyses, the sources ofidentified heavy metals were classified as anthropogenic sources(Cr, Cu, Pb, As, and Zn),natural sources(V, Mn, Fe, Ni, and Sr ),and intermediate sources (Al and Cl).

Exploratory studies on the use of peanut shell biochar as a promising adsorbent for ivermectin removal from aqueous solutions: impact of biomass treatment, pyrolisis temperature and duration

The contamination of environmental matrices by chemical compounds poses a significant challenge for humanity, demanding focused attention from researchers and governments. Within aquatic environments, the emerging contaminants with potential ecotoxicological effects, even at low concentrations, have earned global interest among researchers. The persistence of these contaminants is exacerbated by specific physicochemical characteristics, hindering their natural degradation and removal through conventional water treatment methods. Biochar, a carbonaceous material produced through biomass pyrolysis at high temperatures, exhibits properties that effectively remove emerging contaminants from water. In this study, we investigated the impact of acidic biomass treatment on the removal efficiency of ivermectin from aqueous solutions. The materials were derived from untreated biomass, as well as basic and acidic-treated peanut shell (PS), subjected to pyrolysis at temperatures of 300, 400, 500, and 600 °C for 2, 3, and 4 hours. Characterization was conducted using TGA, ATR-FT-IR, SEM-EDS, and XRD. Quantification of ivermectin removal was performed using HPLC-DAD. The results showed that the removal was enhanced by temperature and time of pyrolysis, while the chemical treatments had different effects. The most effective removal tendency was observed with acidic biochar calcinated at 600 °C, demonstrating an average removal yield of 84.70%.

DETERMINAÇÃO POR ESPECTROMETRIA DE MASSAS DO POTENCIAL DE BIOACUMULAÇÃO DE CONTAMINANTES EMERGENTES EM BIOFILME

DETERMINATION BY MASS SPECTROMETRY OF THE BIOACCUMULATION POTENTIAL OF EMERGING CONTAMINANTS IN BIOFILM. Personal hygiene products, such as UV filters, are consumed daily and released at sewage treatment plants. The presence of these compounds in aquatic environments may cause concern, as their impacts are not yet fully known. Biofilms can be an innovative and simple tool for monitoring the bioaccumulation of contaminants such as UV filters in aquatic environments. The present work aimed to determine and evaluate the potential of bioaccumulation of these compounds in biofilm and in the surface waters of the Barigui River. The determination of contaminants in environmental matrices was performed by liquid chromatography coupled to triple-quadrupole mass spectrometry (LC-MS/MS). The validation of the methodology used was based on the acceptance criteria of the National Institute of Metrology, Quality and Technology (Inmetro). The results obtained in the samples ranged from the maximums of 5.85 μg L–1 of benzophenone-1 for water samples to 1907.40 μg kg–1 of benzophenone-3 for biofilm. The study showed that biofilm is a very useful new tool in environmental monitoring, mainly due to the bioaccumulation capacity of UV filters.

Myco‐remediation of selenium contaminated environment and future prospects: An overview

AbstractSelenium is a trace element which is an essential micronutrient for all organisms. Though it is essential, if taken in excess leads to toxicity. Hence have a detrimental effect on the health. Selenium exists in various oxidation states out of which selenite and selenate are toxic and forms the major part of the pollutant in the ecosystem. Therefore, there is an urgent need to address this issue in an eco‐friendly, efficient, and substantial way to protect the environment from further deterioration. In this regard, fungi have developed unique metabolic pathways to nullify the toxic effects of these pollutants and the process is known as mycoremediation. Mycoremediation is a cost‐effective, environmentally friendly, and efficient approach of environmental remediation that addresses organic, inorganic, and developing toxins (such as antibiotics and pharmaceuticals) by using fungus or their components. An alternative, environmentally friendly method for cleaning up contaminants in environmental matrices is provided by mycoremediation. This is due to the fact that most organic toxins are broken down rather than removed, which lowers the possibility of pollutants entering the food chain through bioaccumulation. Fungi possess robust morphology and various catabolic enzymes capable of using pollutant as a growth substrate. They transform the toxic selenium species via a series of biochemical reaction such as oxidation, reduction, methylation, and demethylation into nontoxic elemental selenium and selenium nanoparticles. Mycoremediation is a process subset that employs to fungi to degrade and restore contaminated Eco‐System. For this reason, a potential framework of “mycoremediation” was proposed to make it easier for this promising to report global environmental issues.

Bibliometric research analysis of molecularly imprinted polymers (MIPs): evidence and research activity dynamics

The escalating issue of water pollution has become a worldwide issue that has captured the attention of numerous scientists. Molecularly imprinted polymers (MIPs) have emerged as adaptable materials with exceptional attributes, including easy synthesis, low cost, remarkable durability, long life, and accessibility. These attributes have motivated researchers to develop novel materials based on MIPs to tackle hazardous contaminants in environmental matrices. The purpose of this paper was to conduct a bibliometric analysis on MIPs’ publications, in order to shed light on the developments and focus points of the field. The selected publications were obtained from Scopus database and subjected to a filtering process, resulting in 11,131 relevant publications. The analysis revealed that the leading publication source (journal) is Biosensors and Bioelectronics; the mostly employed keywords are solid-phase extraction, electrochemical sensor, and molecular recognition; and the top contributing countries are China, Iran, and the USA. The Latent Dirichlet Allocation (LDA) algorithm was used for extracting thematic axes from the textual content of the publications. The results of the LDA model showcase that the topic of synthesis and performance of MIPs for environmental applications can be considered as the most dominant topic with a share value of 72.71%. From the analysis, it can be concluded that MIPs are a cross-disciplinary research field.

Spectroscopic performance evaluation and modeling of a low background HPGe detector using GEANT4

Low background gamma spectrometry employing HPGe detectors is a sensitive technique for measuring low-level radioactivity in environmental applications, material screening, and for rare decay searches. This work presents spectroscopic performance evaluation and modeling of a low background measurement setup developed at IIT Ropar in Punjab, India, to measure trace natural radioactive elements, with a particular interest in studying low-level radioactivity in soil and/or rock samples to generate specific inputs for low background experiments. The performance test and characterization of a low background cryocooled HPGe detector with relative efficiency of ∼33% have been carried out. An effective detector model has been developed using GEANT4 Monte Carlo simulation to determine the response of the detector over an energy range of 80.9–1408 keV and compared with the experimental performance of the detector. The response of the detector obtained using Monte Carlo simulations agrees reasonably well within 93% level of confidence, indicating only 7% deviation in the comparison. The present setup offers improved detection limits of primordial radionuclides (U/Th and K) to measure radioactive contamination in environmental matrices, which has been used elsewhere (Thakur, 2023).

Continuous removal of caffeine in a horizontal-flow anaerobic immobilized biomass bioreactor: identification of transformation products.

Anaerobic bioreactors are an efficient technology for the biodegradation of emerging contaminants in environmental matrices. In this work, a horizontal-flow anaerobic immobilized biomass (HAIB) bioreactor was used to remove caffeine (CAF), which is frequently found in various aqueous matrices. The acrylic bench top bioreactor, with dimensions of 100 × 5.00cm, was operated with a hydraulic retention time (HRT) of 12h, during 45weeks, under mesophilic conditions. The operation was performed in 4 phases: without CAF addition (phase I); CAF spiked at 300μg L-1 (phase II); CAF at 600μg L-1 (phase III); and CAF at 900μg L-1 (phase IV). Samples of bioreactor influent and effluent were analyzed by liquid chromatography/tandem mass spectrometry (LC-MS/MS). The bioreactor removed organic matter (OM) and CAF with efficiencies of 88 and 93%, respectively. The first-order apparent removal constant (Kapp) values for OM and CAF were 0.419 and 0.304h-1, respectively. Five transformation products (TPs) were identified, with m/z 243, 227, 211, and 181 (two products). The HAIB bioreactor is a suitable system for the removal of CAF present in wastewater, even at a concentration level of µg L-1.

Emergence of microplastics in the aquatic ecosystem and their potential effects on health risks: The insights into Vietnam

The increase of microplastic contamination in Vietnam is a growing concern due to various domestic, agricultural, and industrial activities. The use of plastic mulch and sludge application in agricultural farmland, textile production, daily consumer items, cleaning agents, and health/personal care products contribute significantly to the increasing microplastic pollution in the aquatic ecosystem. The concentration of microplastics reported in surface water ranged from 0.35 to 519,000 items m−3, with fibers and fragments being the most prevalent shapes. Notably, the high concentration of microplastics was observed in lakes, canals, and megacities such as Ha Noi and Ho Chi Minh City, which poses potential health risks to the local community via drinking-water supply and food chains. As an emerging pollutant, MPs are the transport vectors for contaminants in environmental matrices that act as a carrier of hazardous pollutants, release toxic compounds, and evenly aggregate/accumulate in biota. Recent studies have reported the presence of microplastics in various marine organisms, including fish and shellfish, highlighting the risk of ingestion of these particles by humans and wildlife. Thus, it is imperative to monitor microplastic contamination in the ecosystem to provide helpful information for the government and local communities. Efforts should be taken to reduce microplastic pollution at the source to minimize potential effects on ecological and health safety. This review paper emphasizes the urgent need for further research on microplastic pollution in Vietnam and highlights potential solutions to mitigate this emerging environmental threat. Keyworkssingle-use plastics; microplastics; ecosystems; plastic waste; health risk; ecological and health safety; pollution mitigation.

Identification, characterization, and implications of microplastics in soil – A case study of Bhopal, central India

Microplastic contamination in environmental matrices is posing new challenges for scientific community and general public across the globe. Wide-spectrum application of plastics in various commercial products has increased the production of plastics and various polymeric materials. Owing to poor recycling and waste management practices, it is expected that a large number of microplastics will be generated which may be transported into the soil, water, and air. Present study reports the occurrence of microplastics in soil of Bhopal, Madhya Pradesh which is the first study in Central region of India. Study found that a total of 752.5±6.36 microplastic particles were present in all the 10 soil samples collected. The highest amount at any one site is reported to be 180±13.44 particles/kg. The microplastic particles varied in size, shape, and colour as well. Chemical composition analysis revealed that particles belonged to five different polymer classes viz. polyethylene, polypropylene, polyvinyl chloride, polyethylene terephthalate, and polyvinyl acetate. Implications of microplastics’ presence in studied area might lead to contamination in the nearby wetland (lake), national park, and groundwater. Detailed studies are, therefore, required to explore the presence of microplastics in various other environmental matrices and their correlation with anthropogenic activities in the Central Indian region.

Microbial fingerprinting techniques and their role in the remediation of environmental pollution

Environmental pollution has increased in recent decades as a result of enhanced anthropogenic activities, poor farming techniques, and industrial growth. In the elimination of resistant environmental toxins (metals), bioremediation has been found as a desirable and efficient approach to environmental safety. Genomics, proteomics, metagenomics, metabolomics, transcriptomics, along with multidisciplinary approaches are used to characterize the function, metabolism, and composition of microbes, as well as to elucidate the environment based on changes in microbes, which has significant and directing relevance in environmental management, monitoring, and repair. Molecular microbiology approaches, among other microbial biodegradation techniques, have transformed microbial biotechnology, resulting in high-throughput and quick methods for culture-independent evaluation and utilization of bacteria existing in contaminated sites. Pollutants existing in contaminated locations, whether inorganic or organic, can disrupt the ecosystem by harming the fauna and flora. Because of its comparably high efficacy and safety, the microbial molecular biology technique might greatly increase the efficiency of naturally existing microbes for field bioremediation. Recent approaches with numerous techniques, including polymerase chain reaction (PCR), denaturating gradient gel electrophoresis (DGGE), fluorescence in situ hybridization (FISH), amplified ribosomal DNA (rDNA) restriction analysis (ARDRA), terminal restriction fragment length polymorphism (TRFLP), rRNA intergenic spacer analysis (RISA), and single-strand conformational polymorphism (SSCP) can be used selectively in studies of microbial ecology and flora have supplied exceptional information about microbial communities and their function in bio-remediating environmental pollution. This review provides an overview of the uses of microbial fingerprinting approaches in the bioremediation of various contaminants in environmental matrices, as well as an explanation of current breakthroughs in such techniques' applications.

Insights on the Dynamics and Toxicity of Nanoparticles in Environmental Matrices.

The manufacturing rate of nanoparticles (10–100 nm) is steadily increasing due to their extensive applications in the fabrication of nanoproducts related to pharmaceuticals, cosmetics, medical devices, paints and pigments, energy storage etc. An increase in research related to nanotechnology is also a cause for the production and disposal of nanomaterials at the lab scale. As a result, contamination of environmental matrices with nanoparticles becomes inevitable, and the understanding of the risk of nanoecotoxicology is getting larger attention. In this context, focusing on the environmental hazards is essential. Hence, this manuscript aims to review the toxic effects of nanoparticles on soil, water, aquatic, and terrestrial organisms. The effects of toxicity on vertebrates, invertebrates, and plants and the source of exposure, environmental and biological dynamics, and the adverse effects of some nanoparticles are discussed.

Validation of bacterial markers to discriminate against the source of nitrate contamination: a promising application within the EU Nitrates Directive

The European Community (EC) Nitrates Directive (ND) (Council Directive 1991/676/EEC) aims to avoid water pollution by nitrates from poor farming practices. Under the ND, Nitrate Vulnerable Zones (NVZs) have been defined as areas where the concentration of agricultural nitrates in surface or groundwater exceeds 50 mg/L. Groundwater is one of the main sources of drinking water in Europe, so ensuring its quality is of significant importance. Monitoring of water parameters, the identification of pollution, the development of good agricultural practice codes is included in ND as measures and action programs. ND provides for the attribution of areas affected by nitrate pollution to the NVZ in which farmers must comply with measures necessary to reduce nitrogen in excess and protect the quality of environmental matrices. However, in some cases the quality of water bodies remains poor, suggesting that some action measures are ineffective or need improvements. Nevertheless, nitrates in excess in groundwater might be related to industrial inputs, untreated waste discharge, and sewage spilling. Due to this, identifying non-agricultural contributions to nitrate groundwater pollution can be of great interest. With this aim, the employment of biomarkers such as microbes associated with the intestinal tract of a specific host is under study for identifying fecal pollution. This strategy is known, in scientific literature, as Microbial Source Tracking (MST)(Furtula et al. 2011)The amplification of 16S rRNA genes of host-specific Bacteroidales allows discriminating against human and livestock fecal sources in samples from nitrate polluted environment. The aim of this work is to evaluate the sensitivity and specificity of these intestinal biomarkers in groundwater samples collected along with the Apulian Region (Southern Italy) in order to assess the applicability of the MST in the employ of ND. A preliminary study was carried out to validate the performance of seven markers for MST using two different approaches: Polimerase Chain Reaction (PCR) and quantitative Real-time PCR (qPCR) assays. For both PCR and qPCR experiments selected primer sets were checked using fecal samples of known origin as positive controls. PCR assay was used for human (HF74 and Enterococcus faecalis) (Bernhard and Field 2000, Jackson et al. 2004), cattle (CF123) (Bernhard and Field 2000), equine (HoF597) (Dick et al. 2005), and pig (Pig163) (Dick et al. 2005) markers screening. Two additional markers were tested through Real-time PCR: human (Human- Bacteroides) (Seurinck et al. 2005) and zootechnical (BacPre I) (Kobayashi et al. 2012). The results indicate that biomarkers can be considered reliable in distinguishing human from animal pollution. Nevertheless, our studies show that the tests conducted with the human Enterococcus faecalis biomarker do not discriminate the zootechnical source from the human one. In some cases, PCR-tested biomarkers cannot determine the source of contamination in environmental matrices due to the detection limit. Animal and human fecal markers were widely detected on eleven groundwater samples through Real Time PCR, highlighting the prevalent source of contamination in the environmental matrix. This research provides evidence that MST technology is a valid tool for local authorities to identify the source of nitrate contamination and review uncertainties during the NVZs definition and the action program development required by the European Nitrate Directive.

Minimizing transient microenvironment-associated variability for analysis of environmental anthropogenic contaminants via ambient ionization

The rapid and quantitative analysis of anthropogenic contaminants in environmental matrices is crucial for regulatory testing and to elucidate the environmental fate of these pollutants. Direct ambient mass spectrometry (AMS) methodologies greatly increase sample throughput, can be adapted for onsite analysis and are often regarded as semi-quantitative by most developed protocols. One of the limitations of AMS, especially for on site analysis applications, is the irreproducibility of the measurements related to the occurrence of transient microenvironments (TME) and variable background interferences. In this work we report an effective strategy to minimize these effects by hyphenating, for the first time, solid phase microextraction (SPME) arrow to mass spectrometry via a thermal desorption unit (TDU) and direct analysis in real time (DART) source. The developed method was optimized for the extraction and analysis of pesticides and pharmaceuticals from surface water. It was demonstrated that the hyphenation of the SPME and TDU-DART resulted in reduced background contamination, indicating the suitability of the method for onsite analysis even in variable and non-ideal environments. Model analytes were quantitated in the low μg/L range with a total analysis time of less than 5 min, linear dynamic ranges (LDR) and interday reproducibility for most compounds being 2.5–500 μg/L and lower than 10%, respectively. The developed approach provides an excellent analytical tool that can be applied for the onsite high-throughput analysis of water samples as well as air and aereosols. Considering the tunability of our extraction process, time-resolved environmental monitoring can be achieved onsite within minutes.

Metal Contamination of an Underground Gold Picking Zone in the Department of Djekanou, Cote D’Ivoire

Illegal gold mining has developed in recent years in the department of Djekanou with the rising cost of gold on the world market, due to the slump in local agricultural products and the unemployment of young people of working age. It has become an essential activity along with agriculture and farming in rural areas. It is an effective way to fight poverty. However, this practice is likely to cause significant environmental damage. Thus, to assess the environmental quality of this region prone to gold mining activity, the determination of the level of metallic contamination of environmental matrices (soils and sediments) was carried out. Four (4) soil and sediment sampling campaigns took place in dry and rainy seasons on the illegal gold mining site and near the dam, all located at about 685 m from Yobouekro, on the gold washing site of Taffissou at 3,425 m from Djekanou and at Groudji in the department of Djekanou. The sediment sampling was carried out by Strahler's method, while that of the soils was taken at random over the extent of the gold washing sites. The total concentrations of metals in the different matrices were determined by atomic absorption spectrophotometry (AAS). The analytical results show that the metal contents are lower than the natural content of each element in the earth's crust (UCC). Gold mining activities are not currently a source of metallic contamination of the environment. Also, the contamination factors recorded from the concentrations of metals are all less than 1, indicating low contamination of sediments and soils by trace metal elements despite intense gold mining activity. Notwithstanding, the evaluation of the environmental quality from the concentrations of the metals Cd, Co, Cr, Hg and Pb compared to the American guide values SQGs (TEC and PEC), it is noted that the receiving environment is contaminated only by mercury, cadmium and cyanide; the values of the other parameters studied being lower than the guide values. The two matrices mentioned above were also assayed with cyanide and the results revealed that the sites of Groudji and Taffissou are contaminated.

Potential application in amoxicillin removal of Alcaligenes sp. MMA and enzymatic studies through molecular docking.

Antibiotic contamination in environmental matrices is a serious global problem which leads to an increase in the proliferation of antibiotic resistance genes. Amoxicillin is ubiquitous in the environment, but there is hardly any information on the dissipation of amoxicillin by the microbial community. In view of this, the present study focusses on the removal of amoxicillin using amoxicillin-resistant bacteria, Alcaligenes sp. MMA. Bacteria were characterized using antibiotic tests, biochemical and molecular analysis. Alcaligenes sp. MMA was able to remove up to 84% of amoxicillin in 14days in M9 minimal media, and the degradation products were confirmed using LC-MS/MS, including the benzothiazole, 2-Amino-3-methoxyl benzoic acid, 4-Hydroxy-2-methyl benzoic acid, 5-Amino-2-methylphenol and 3,5-Bis(tert-butyl)-2-hydroxybenzaldehyde, at the end of 14th day which further shows the removal of amoxicillin by the bacterial strain. Differential expression of porins was found in the presence of amoxicillin as a sole source of carbon and energy for the bacterial strain. Molecular interaction using in silico studies were performed which showed the formation of a hydrogen bond between amoxicillin and porins.

A Review on the Status of Mercury Pollution in Pakistan: Sources and Impacts.

Mercury (Hg) contamination in environmental matrices and associated human exposure has been recognized as a critical long-lasting issue worldwide. However, studies are still elusive that summarized the overall status of Hg pollution and its impacts on public health in Pakistan. Hence, this review encompasses the environmental prevalence, potential sources, and human exposure tendencies to Hg contamination in Pakistan. Reviewed literature revealed jolting levels of Hg in various environmental samples, such as dust, soil, water, and air collected from the residential and industrial areas. Inhalation of Hg via dust particle was identified as the primary pathway for human exposure, while atmospheric deposition and gold mining are identified as the two primary sources of Hg contamination in the environment. Considering human exposure, the highest bioaccumulation of Hg was ranged from 5885 to 8698µg/kg in hair samples collected from the residents of the Kashmir Valley, Pakistan. However, in the lower Himalayan regions, including Islamabad and Swabi, the concentration of Hg in hair samples was reported at 1085µg/kg, slightly beyond WHO devised reference dose (RfD) of Hg (1000µg/kg). This review revealed the worst scenario of Hg contamination in human biomatrices and environmental compartments in Pakistan, which needed immediate rehabilitation measures.

Passive sampling of polar emerging contaminants in Irish catchments.

Passive sampling (PS) is a very useful approach for the monitoring of emerging contaminants in environmental matrices, showing greater sensitivity than can be achieved by current best practice - grab sampling - and is applicable to a wide variety of compounds. An EU Directive (2013/39/EC) has added substances to the existing Water Framework Directive (WFD) Priority Substance list. Investigation into PS in the monitoring of these compounds is necessary to show the potential of this technique in supporting monitoring requirements under the WFD. A catchment-based approach evaluated the occurrence of these compounds in Irish surface waters. This work deals with the challenges associated with the use of PS in a legislative context, and for routine monitoring of emerging contaminants. Looking at a number of sites across Ireland, upstream and downstream of wastewater treatment plants, the focus was on polar analytes and polar PS (POCIS). With method limits of detection (LODs) of 0.001 mg L-1 pharmaceuticals and endocrine disrupting chemicals (EDCs) were found in water and passive samples alike, whereas the polar pesticides were not often detected or were below the annual average environmental quality standard levels. The results of this study show the potential for PS as a monitoring technique for emerging and watch-list chemicals.

Use of fiberglass support in the application of dried-spot technique with dispersion liquid-liquid microextraction for the determination of Co, Cr, Cu, Ni and Pb by Energy Dispersive X-Ray Fluorescence Spectrometry

Contamination of environmental matrices with toxic metals is a serious problem. It is important to determine the concentration of such metals, particularly in agricultural soils, due to their negative impact on human life. This work aimed to determine a more adequate solid support and better operating conditions in the application of dried-spot technique on dispersion liquid-liquid microextraction (DLLME) for determine of cobalt, lead, chromium, copper, and nickel by applying Energy Dispersive X-ray Fluorescence Spectrometry (EDXRF). The solid supports studied were qualitative and quantitative filter paper, cellulose ester membrane and glass fiber. The parameters for DLLME, such as pH and volumes of solvent dispersive and extractor, were evaluated and optimized to reduce the limit of detection for the analytical method. A fiberglass backing had a superior result compared to another substrate to add the preconcentrated rich phase. Preconcentration factors were 58, 158; 90; 69 and 78 for Co, Cr, Cu, Ni and Pb respectively and the limits of detection were 0.2, 0.2, 0.1, 0.5 and 0.1 mg kg−1 respectively. The method was validated according to IUPAC recommendations. The combination of these techniques (DLLME-EDXRF) improves significantly the signal-to-noise ratio by concentrating the X-ray beam in a small diameter by applying a thin sample holder and removing the matrix effect. The developed methodology makes it possible to extend the application of EDXRF to quantify trace concentration of metal in soils.

Estrogenic Compounds: Chemical Characteristics, Detection Methods, Biological and Environmental Effects

Several chemical compounds are being studied for their capacities to cause imbalances in several biological systems. Some of those are able to affect the endocrine system and are known as endocrine disruptors. Many negative effects can be induced in the organisms by the action of these chemicals, highlighting the capacity to cause a decrease in the fertility rate, sex inversion, and problems in embryonic development and even cancer in humans. Those contaminants can be found in different environmental conditions, in groundwater, sediments, residual waters, sludges, and even in drinking water. The purpose of this review is to provide a general overview of the main estrogenic endocrine disruptors and their effects on living organisms, showing the most frequently used tools to detect these contaminants in environmental matrices. According to the data found, there is a need to develop more studies and improve the techniques, in order to effectively determine the mechanism of action of these contaminants and, thus, establish appropriate strategies for their removal from the environment and reduce their actions on living beings.

Microbes in Heavy Metal Remediation: A Review on Current Trends and Patents.

Heavy metal pollution in the environmental samples like soil, water and runoff water is a worldwide problem. Such contamination of environmental matrices by the heavy metals accumulates due to various activities involving human driven sources and industries, although agriculture and sewage disposal are the largest source for the heavy metal contamination. Disposal of heavy metals or waste products containing heavy metals in the environment postures a trivial threat to public safety and health. Heavy metals are persistence and they can also cause biomagnifications and accumulate in food chain. Microbial bioremediation of heavy metal is emerging as an effective technique. Microbial bioremediation is a highly efficient environmental friendly procedure which also reduces the cost of cleanup process associated with heavy metal contamination. New methods for removal of heavy metals from the environmental samples are under development and most recent advancements have been made in exploring the knowledge of metal-microbes interactions and its use for heavy metal remediation. This review paper will focus on the microbial bioremediation process and highlight some of the newly developed patented methods for microbial bioremediation of the heavy metals from the environmental samples using microbial populations.