Toxic Load Research Articles

Pollution Level and Assessment of a Tropical River in Pahang Malaysia

Rivers are often contaminated with metals. This study was conducted on the Jempul River in Jengka, Pahang, Malaysia, due to the agricultural activities carried out along this river. The aims are to investigate the levels of certain metals (namely Al, Fe, Mn, and Pb), identify their likely sources, assess their toxicity loads, and estimate the associated health risks. Inductively coupled plasma optical emission spectrometry (ICP-OES) was used to determine metal concentrations. The concentrations were discovered in the following order: Fe > Al > Mn > Pb, for both dry and wet conditions. The highest concentration in water sample was observed for Fe (1.28 mg/l) in the dry condition and the lowest was detected for Pb (0.04 mg/l) in the wet condition. Principal component analysis (PCA) indicated that the metals originate from natural and anthropogenic sources. Based on metal toxicity load (MTL) calculations, it is recommended that approximately 73% of Pb, 60% of Mn, and 58% of Al be eliminated from the river water to ensure its safety. Children are more susceptible to non-cancer and cancer hazards than adults. This study suggests that extensive exposure assessment and detailed monitoring of water quality indicators should be carried out.

Oxygen-limited niches enhance activated sludge resilience to shock loads and mitigate antibiotic resistance

Conventional activated sludge (CAS) used in wastewater treatment plants that receive industrial wastewater are frequently challenged by toxic pollutants, which may impede the stable and efficient removal of pollutants. Additionally, these toxic pollutants may also contribute to the spread of antibiotic resistance genes (ARGs). This study introduces a novel approach by incorporating oxygen-limited niches (i.e., anaerobic/anoxic zones) into CAS systems, demonstrating a significant improvement in resilience against toxic shock loads and ARG mitigation. Pilot-scale experiments revealed that oxygen-limited niches can positively impact the removal of conventional pollutants under toxic shock conditions and enhance the degradation of pharmaceuticals. 16S rRNA gene and metagenomic sequencing highlighted significant differences in microbial communities between the anaerobic/anoxic and aerobic zones. Furthermore, metagenomic analysis revealed that the oxygen-limited niches lead to lower abundance of ARGs, and the proportion of high-risk ARGs in anaerobic/anoxic zone was significantly lower than that in CAS. 14 genera potentially involved in ARG propagation were identified, and their abundance was obviously lower in anaerobic/anoxic zone. Our findings highlight the introduction of oxygen-limited niches as a modification to CAS systems, offering a new and promising strategy for managing toxic shocks, enhancing pollutant degradation, and reducing the health risks associated with ARGs in wastewater treatment processes.

Bifidumbacterin forte in the treatment of acute viral hepatitis

Relevance. In patients with acute viral hepatitis A and B, favorable conditions are created for the development of dysbacteriosis. As a result, the toxic load on the liver increases. For effective treatment of acute viral hepatitis A and B, it is necessary to examine for intestinal dysbiosis before and after treatment and subsequent correction of identified disorders. Aim. To study the clinical course, functional state of the liver, intestinal microflora in patients with acute viral hepatitis A and B and the effectiveness of using bifidumbacterin forte for the correction of intestinal microflora. Materials and methods. The work used clinical and laboratory data from 54 patients with acute viral hepatitis A and B. The main group of patients received bifidumbacterin forte against the background of basic therapy. Patients in the comparison group were on traditional therapy. Clinical, biochemical, bacteriological parameters were observed before the start of therapy and 15 days after its start, serological markers - upon admission. Results. During the therapy, in patients of the main group, the disappearance of intoxication, lethargy, weakness, pain, and normalization of liver size were observed earlier in comparison with the control group. Symptoms of pigment metabolism disorders disappeared significantly earlier: yellowness of the skin, itching of the skin, changes in the color of urine and feces. A dynamic study of liver tests demonstrated a more rapid reverse development of biochemical disorders of the functional state of the liver in patients who received bifidumbacterin forte as part of complex treatment. Conclusion. The use of bifidumbacterin forte in patients with acute viral hepatitis A and B against the background of basic treatment has a positive effect on some clinical manifestations, biochemical parameters, and individual components of the intestinal microflora.

Перспективные направления в области разработки и использования препаратов бактериофагов

The article discusses the use of bacteriophages as a promising research area of creating effective and environmentally friendly tools and methods for combating antimicrobial resistance and natural pollution. Breakthrough technologies for developing customized polyvalent (complex) and genetically engineered phages as well as their structural elements will improve the quality of patient care, increase the epidemiological well-being of the population, reduce the risks of infectious and non-infectious morbidity and the toxic load on the environment. The above should be integrated into the up-to-date concept of the biological security of the state. Keywords: bacteriophages, infections, environment, biological safety, antibiotic resistance.

Honey bees and mason bees as biological indicators of landscape pesticide loads: Different results but similar conclusions

Agricultural environments, including crop and non-crop areas, often provide important pollen and nectar resources for managed and wild bees. However, these resources may be contaminated with pesticides detrimental to bees and other non-target organisms, including humans. Differences in life-history traits among bee species influence food resource exploitation and pesticide exposure. This study assesses the potential of honey bees (Apis mellifera) and mason bees (Osmia), two bee species with highly contrasting functional traits, as biological indicators of pesticide exposure in 34 Italian agricultural farms. Pollen loads of both species were used to identify pollen species collected and to analyse multi-residue levels of pesticides. Pesticide risk indexes were calculated for honey bees, mason bees and humans. In mason bees, pesticide risk was not influenced by plant diversity. In agreement with their pollen preferences and short foraging ranges, mason bees collected a high proportion of pollen from flowers of the target crop. Conversely, pesticide risk decreased with increasing pollen diversity in honey bees. In agreement with their generalist foraging habits and long foraging ranges honey bees collected a greater diversity of pollen species and a lower proportion of target crop pollen. Although honey bees and mason bees showed similar toxic loads and pesticide composition, at a field scale pesticide risk of one species is not a good indicator of the risk to the other species. Our study confirms that bees in agricultural environments are pervasively exposed to multi-residue pesticide loads. Exposure is conditioned by specific bee traits but is also highly context-dependent.

Complex means for the prevention of combined mycotoxicosis of birds

Poultry meat is in great demand in the food market. The main method of producing poultry meat is raising broilers. The growth of broiler chickens is largely determined by balanced feeding. In recent years, poultry diets have increasingly included biologically active additives with a pronounced positive effect on the viability and productivity of poultry. In this regard, the purpose of our study was to study the effectiveness of the use of complex preventive measures for experimental combined T-2 and aflatoxicosis in broiler chickens, taking into account the clinical, hematological status and organ weight. Broiler chickens were divided into 4 groups: birds of the first group (biological control) received only complete feed that did not contain mycotoxins; the second group served as a toxic control (feed was contaminated with a mixture of mycotoxins); the third group received a basic diet contaminated with a mixture of mycotoxins with the addition of complex agent No. 1 (plant glucans, hepatoprotector, vitamins E and C, immunostimulant); the fourth group is the main diet, contaminated with a mixture of mycotoxins with the addition of complex agent No. 2 (natural mineral bentonite, succinic acid, immunostimulant, vitamin A, probiotic based on bifidobacteria and lactobacilli). The duration of administration of toxins and prophylactic agents is 21 days. Complex agents were administered at a dose of 0.25% of the diet. As a result of the use of these agents, a decrease in the toxic load on the body was noted, which was manifested by an improvement in the clinical condition of chickens and normalization of morphological blood parameters. These results suggest that the complexes can be an effective means for reducing the toxic effects of mycotoxins on the body of broiler chickens with combined mycotoxicoses.

Ornamental plants as vectors of pesticide exposure and potential threat to biodiversity and human health

The production of conventional ornamental plants is pesticide-intensive. We investigated whether pesticide active ingredients (AIs) are still present in ornamentals at the time of purchase and assessed their potential ecotoxicity to non-target organisms. We purchased 1000 pot plants and 237 cut flowers of different species from garden centers in Austria and Germany between 2011 and 2021 and analyzed them for up to 646 AIs. Ecotoxicological risks of AIs were assessed by calculating toxic loads for honeybees (Apis mellifera), earthworms (Eisenia fetida), birds (Passer domesticus), and mammals (Rattus norvegicus) based on the LD50 values of the detected AIs. Human health risks of AIs were assessed on the basis of the hazard statements of the Globally Harmonized System. Over the years, a total of 202 AIs were detected in pot plants and 128 AIs in cut flowers. Pesticide residues were found in 94% of pot plants and 97% of cut flowers, with cut flowers containing about twice as many AIs (11.0 ± 6.2 AIs) as pot plants (5.8 ± 4.0 AIs). Fungicides and insecticides were found most frequently. The ecotoxicity assessment showed that 47% of the AIs in pot plants and 63% of the AIs in cut flowers were moderately toxic to the considered non-target organisms. AIs found were mainly toxic to honeybees; their toxicity to earthworms, birds, and mammals was about 105 times lower. Remarkably, 39% of the plants labeled as “bee-friendly” contained AIs that were toxic to bees. More than 40% of pot plants and 72% of cut flowers contained AIs classified as harmful to human health. These results suggest that ornamental plants are vectors for potential pesticide exposure of consumers and non-target organisms in home gardens.

Toxic Metal Element Concentration in 31 Food Fishes from River Ganga: Risk Assessment on Human Consumption.

Consumption of toxic metal contaminated fish is a significant risk to human health. The Ganga river is one of the vital river systems in India, and it nurtures a rich biodiversity of flora and fauna. In the present study, screening of potential toxic metal elements (Cd, Cr, Mn, Cu, Pb, Ni, Zn, and As) was undertaken in 31 food fishes, especially the small indigenous fishes (SIFs) from the lower stretch of river Ganga by inductively coupled plasma mass spectrometry (ICP-MS). The concentration of toxic metal elements varied among different fish species. Among the toxic metal elements studied, Cr, Zn, and As were found to be dominant in Eleotris fusca; Cd, Ni, and Pb were highest in Securicula gora; Cu was highest in Cabdio morar; and Mn was highest in Coilia dussumieri. The average pollution load index values (APLI) for all the fishes analyzed were less than one except for Eleotris fusca, which indicated no serious toxic metal element pollution load. The estimated daily intake values (EDI) for the toxic metal elements were found to be within the permissible maximum tolerable daily intake (MTDI). Among the fishes studied, only a few species showed hazard index (HI) greater than one, indicating non-carcinogenic health risks. Similarly, the target carcinogenic values (TCR) for most of the toxic metal elements were below the permissible limit (10-4) in the fishes that assures minimal cancer risk. This study provides a comprehensive data on the composition of potential toxic metal elements of 31 food fishes from the lower stretch of the river Ganga, the first of its kind, and suggests the necessity of periodic monitoring of these in the aquatic ecosystem.

A comprehensive evaluation of the contamination scenario and water quality in the gas fields of north-east region, Bangladesh

Gas fields generate a significant volume of produced water, disposed in the vicinity of gas fields in Bangladesh after processing. It may have a variety of effects on ecology and the environment. This study was conducted to assess the contamination scenario and quality of produced and discharged water from gas fields in northeastern Bangladesh. The physicochemical analyses for this study were performed using standard procedures. Based on the outcomes of the analyzed samples, the current research employs a variety of indexing and statistical approaches to investigate the overall status of the studied water. The physiochemical analysis revealed high electrical conductivity (EC), total dissolved solid (TDS), salinity, and Na contents in both produced and discharged water. No severe cases have been identified, certain metals, such as Fe, Ni, and Cd, have been detected at levels high enough to impact specific index values in some cases. The results of the weighted contamination index (WCI) indicated mild to considerable pollution in the gas field region. The average score of potential ecological risk (PER) reflects minimal ecological risk. The heavy metal toxicity load (HTML) reveals negligible metal pollution in the studied water. The agricultural risk indices displayed increased sodium concentrations and EC, resulting in salinity and sodium risks. The magnesium absorption ratio is within the allowable range. In addition, the average heavy metal pollution index (HMPI) value demonstrates that the produced and discharged water is unsuitable for drinking. The entropy-based water quality index (EWQI) is below the threshold limit (<100) for all samples, indicating satisfactory water quality. This study is an early effort to evaluate the quality of wastewater produced and discharged from gas fields in Bangladesh. The findings of this research will provide valuable insights for future researchers and regulators in effectively managing and mitigating pollution from wastewater.

Heavy metal toxicity and its human health assessment: A preliminary study from the Perumal Lake sediments, Tamil Nadu, India

The current investigation manifests the heavy metal toxicity and its human health assessment to appraise the environmental deterioration of the sediments within the Perumal Lake, Tamil Nadu, India. Five surface samples were collected from the Perumal Lake in 2023, which undergoes the selective perception of the granulometric analysis, implying supremacy of the clay content and limited sand and silt contents. The organic matter indicates the higher input of waste disposal, and the CaCO3 illustrates the existence of shell fragments in the lake environments. Noteworthy results of the heavy metal concentration as arranged in the devaluation order as Zn &gt; Cu &gt; Fe &gt; Cr &gt; Ni &gt; Mn &gt; Pb &gt; Co &gt; Cd. Followed by the heavy metal concentration, the environmental contamination indices such as Igeo denote that except for Cd metal, other heavy metals indicate moderate to extreme pollution status. The Enrichment Factor (Ef) illustrates Fe, Co, Cd, Zn, Cu, Ni, and Pb, highlighting no metal enrichment. In contrast, Mn and Cr reveal low metal enrichments, and the Cf reveals all the heavy metals, which argues for low to high contamination ranges. The Cd and the mCd are categorized as very high, and PERI underscores the low-risk category. The Hazard Index (HI) of the non-carcinogenic category and carcinogenic demonstrates that children and adults are primarily at risk of ingestion. At the same time, the dermal pathway indicates low jeopardy to children and adults and no risk to humans. The Heavy Metal Toxicity Load (HMTL) poses the sample location three registers a significant accumulation of toxic contagion proposed to remove from the sediments. Realm of heavy metal toxicity and its human health assessment underscores for researchers in environmental quality determination, and the strategies discussed such as phytoremediation, in-situ capping, and biotechnological techniques, may be helpful in evaluation and implement remediation methods of pollution in aquatic environments.

Oczyszczanie i waloryzacja ścieków z wytłoczyn z oliwek

Wastewater generated during the production of pomace olive oil is complex and highly variable due to different cultivation and processing characteristics. It has a high toxic organic load, low pH, and high chemical and biological demands. To reduce the concentration of chemical oxygen demand (COD) and total phenolic compounds (TPh) in pomace olive oil wastewater, several treatment processes have been studied. These include: (i) coagulation/flocculation, (ii) electrocoagulation, (iii) peroxy-electrocoagulation, (iv) electrochemical peroxidation, (v) Fenton, (vi) electro-Fenton, (vii) photo-Fenton, and (viii) adsorption. Coagulation/flocculation and electrocoagulation resulted in a maximum COD removal of 16%, while techniques involving the addition of hydrogen peroxide (iii-vii) had an average of 78% TPh removal but only 20% COD removal. Adsorption resulted in a maximum of 29% COD and 75% TPh removal. None of the tested techniques were able to remove more than 50% of COD, indicating the difficulty of removing organic matter in this effluent. However, advanced oxidation techniques were effective in degrading phenolic compounds, although they required relatively high dosages of oxidant.

Oscillations in Neuronal Activity: A Neuron-Centered Spatiotemporal Model of the Unfolded Protein Response in Prion Diseases.

Many neurodegenerative diseases (NDs) are characterized by the slow spatial spread of toxic protein species in the brain. The toxic proteins can induce neuronal stress, triggering the Unfolded Protein Response (UPR), which slows or stops protein translation and can indirectly reduce the toxic load. However, the UPR may also trigger processes leading to apoptotic cell death and the UPR is implicated in the progression of several NDs. In this paper, we develop a novel mathematical model to describe the spatiotemporal dynamics of the UPR mechanism for prion diseases. Our model is centered around a single neuron, with representative proteins P (healthy) and S (toxic) interacting with heterodimer dynamics (S interacts with P to form two S's). The model takes the form of a coupled system of nonlinear reaction-diffusion equations with a delayed, nonlinear flux for P (delay from the UPR). Through the delay, we find parameter regimes that exhibit oscillations in the P- and S-protein levels. We find that oscillations are more pronounced when the S-clearance rate and S-diffusivity are small in comparison to the P-clearance rate and P-diffusivity, respectively. The oscillations become more pronounced as delays in initiating the UPR increase. We also consider quasi-realistic clinical parameters to understand how possible drug therapies can alter the course of a prion disease. We find that decreasing the production of P, decreasing the recruitment rate, increasing the diffusivity of S, increasing the UPR S-threshold, and increasing the S clearance rate appear to be the most powerful modifications to reduce the mean UPR intensity and potentially moderate the disease progression.

Multimetal exposure: Challenges in diagnostics, prevention, and treatment.

Extensive use of heavy metals has posed a serious concern for ecosystem and human too. Heavy metals are toxic in nature and their accumulation in human body causes serious disorders such as neurological disease, cardiac disease, gastrointestinal problems, skin disorders, reproductive disease, lungs diseases, and so on. Furthermore, heavy metals not only affect the human health but also have a negative impact on the economy. In the current review, we have elaborated the impact of heavy metal exposure on human health and socioeconomics. We have discussed the molecular mechanism involved in the heavy metal-induced human disorders such as oxidative stress, neuroinflammation, and protein misfolding. Finally, we discussed the preventive measure and treatment strategy that could counter the negative effects of heavy metal intoxications. In conclusion, there is a substantial correlation between heavy metals and the onset and advancement of several health issues. Chelation treatment could be a useful tactic to lessen the toxic metal load and the difficulties that come with it.

Distribution, toxicity load and risk assessment of heavy metals in the groundwater of Dhemaji, Assam, India

Metal contamination in drinking water has drawn attention since it gravely jeopardizes human health. This study was conducted in pre- and post-monsoon season in 2021 at Dhemaji, Assam, India. It characterized metal pollutants in groundwater, their distribution, possible sources, and evaluated the potential toxicity and associated health risk assessment. The seasonal mean concentration of Fe in both seasons is observed highest followed by Mn, Zn, Cu, As, and Ni. Furthermore, the metal concentrations during pre-monsoon are comparatively higher. The geogenic processes and agricultural practices are the major sources of groundwater metal contamination as evident from the statistical analysis. The different pollution indices viz. Heavy-metal Pollution Index (HPI), Heavy-metal Evaluation Index (HEI) and Degree of Contamination (Cd) suggested that groundwater is not suitable for drinking uses. The Heavy Metal Toxicity Load (HMTL) suggesting As, Co, Mn and Hg should be removed from the groundwater to ensure safety. Water pollution indices (WPI) suggest that Fe, Mn, As and Ni are the main pollution-causing metals in the study area which may be restored under the BIS and WHO limit by diluting the water. The human health risk has been calculated by carcinogenic and non-carcinogenic risk assessment. The non-carcinogenic risk for adults and children is within the threshold limit. The carcinogenic risk shows that continuous exposure of As and Ni may give rise to cancer among adults and children in the region. Therefore, comprehensive groundwater quality monitoring with well-planned treatment should be needed to provide safe and clean drinking water in the studied area.

Seasonal bee communities vary in their responses to resources at local and landscape scales: implication for land managers

ContextThere is great interest in land management practices for pollinators; however, a quantitative comparison of landscape and local effects on bee communities is necessary to determine if adding small habitat patches can increase bee abundance or species richness. The value of increasing floral abundance at a site is undoubtedly influenced by the phenology and magnitude of floral resources in the landscape, but due to the complexity of measuring landscape-scale resources, these factors have been understudied.ObjectivesTo address this knowledge gap, we quantified the relative importance of local versus landscape scale resources for bee communities, identified the most important metrics of local and landscape quality, and evaluated how these relationships vary with season.MethodsWe studied season-specific relationships between local and landscape quality and wild-bee communities at 33 sites in the Finger Lakes region of New York, USA. We paired site surveys of wild bees, plants, and soil characteristics with a multi-dimensional assessment of landscape composition, configuration, insecticide toxic load, and a spatio-temporal evaluation of floral resources at local and landscape scales.ResultsWe found that the most relevant spatial scale and landscape factor varied by season. Early-season bee communities responded primarily to landscape resources, including the presence of flowering trees and wetland habitats. In contrast, mid to late-season bee communities were more influenced by local conditions, though bee diversity was negatively impacted when sites were embedded in highly agricultural landscapes. Soil composition had complex impacts on bee communities, and likely reflects effects on plant community flowering.ConclusionsEarly-season bees can be supported by adding flowering trees and wetlands, while mid to late-season bees can be supported by local addition of summer and fall flowering plants. Sites embedded in landscapes with a greater proportion of natural areas will host a greater bee species diversity.

Prospects for pharmacological screening of oral detoxification drugs with differentiation of targeted pathologies in animal husbandry

In the modern livestock sector, the domestic industry of the North-West region, cases of poisoning of animals on farms and large complexes are increasingly occurring. This is primarily due to the intensive use of various synthetic modulators, growth stimulants, fertilizers in the agronomic industry and the excessive use of antibiotics, hormones and other veterinary drugs in animal husbandry.Pharmacological screening of oral detoxification agents with differentiation of target pathologies is a promising direction in the development of domestic animal husbandry. A reasonable choice of sorbents in each individual case of poisoning allows you to quickly achieve a therapeutic effect, reduce the toxic load on the animal’s body, which further ensures sustainable productivity and high quality products. This work highlights the results of some studies on the functional activity of the most common enterosorbents in relation to toxins of various natures.Based on the results of the study, it was noted that with an increase in pH from 2.0 (rennet model) to 7.5 (analogue of the distal small intestine), a release of part of the indicator substance from the pores of the sorbent (desorption) is observed, which reduces its absolute sorption effect [5] . The lowest desorption value was shown by atoxyl (8.5%) and phytopos (9.0%). That is why these drugs are the most effective oral detoxification agents for toxins with a molecular weight close to methylene blue.The maximum adsorption effect for various poisonings in animals can be achieved by using sorbing agents that are highly selective for a particular toxin. Research on the choice of oral detoxification agents with differentiation of target pathologies significantly expands the database on existing sorbents, makes it possible to prevent and treat poisonings of various types more effectively, and provides opportunities for the combined use of various adsorbent substances.

Health risk and pollution associated with trace metals in the waters of the Ebolowa municipal lake basin (Central Africa): evidence from hydrochemistry, quality indices, and statistical analyses.

The aim of this study was to investigate the status of trace metals (As, Cr, Cu, Ni, Pb, Fe, and Zn) and health and carcinogenic risk associated then in the Ebolowa Municipal Lake (EML) basin. To this end, 21 water samples were collected from the EML and its two tributaries, Mfoumou and Bengo'o, and analyzed by Quantofix method (nanocolors and visiocolor ECO) by using the MACHEREY-NAGEL photometer. The data were processed using multivariate statistics. The results showed that all the physicochemical parameters (pH, EC, and TDS), with the exception of TDS, comply with were within WHO limits. The distribution of trace metals at the three sites investigated was as follows: Zn (80-400 ± 1.58µg/L) > Cu (50-150 ± 9.38µg/L) > Fe (10-40 ± 0.71µg/L) > Pb (1-20 ± 3.02µg/L) > As (1-9 ± 0.44µg/L) > Ni (1-9 ± 1.48µg/L). However, the highest values were observed in the EML and the Mfoumou River, where Pb pollution was noted. Statistical analysis showed that anthropogenic inputs increase the presence of Cr, Cu, Pb, and Zn. Trace Metal Pollution Index values were below 15 at all sites, illustrating low levels of pollution. The trace metal evaluation index values for the Bengo'o stream are pure (mean = 0.6), slightly affected in the Mfoumou stream (mean = 2.0), and moderately affected in the EML (mean = 2.2). The toxicity load index values illustrate that the waters studied are toxic. The non-carcinogenic (HI) and carcinogenic (CR) health risk index values suggest a risk linked to oral ingestion in the LME and Mfoumou watercourses. The latter appears to be the main source of allochthonous pollutant input to the EML.

Emerging pollutants in textile wastewater: an ecotoxicological assessment focusing on surfactants.

Water and several chemicals, including dyestuffs, surfactants, acids, and salts, are required during textile dyeing processes. Surfactants are harmful to the aquatic environment and induce several negative biological effects in exposed biota. In this context, the present study aimed to assess acute effects of five surfactants, comprising anionic and nonionic classes, and other auxiliary products used in fiber dyeing processes to aquatic organisms Vibrio fischeri (bacteria) and Daphnia similis (cladocerans). The toxicities of binary surfactant mixtures containing the anionic surfactant dodecylbenzene sulfonate + nonionic fatty alcohol ethoxylate and dodecylbenzene sulfonate + nonionic alkylene oxide were also evaluated. Nonionic surfactants were more toxic than anionic compounds for both organisms. Acute nonionic toxicity ranged from 1.3mg/L (fatty alcohol ethoxylate surfactant) to 2.6mg/L (ethoxylate surfactant) for V. fischeri and from 1.9mg/L (alkylene oxide surfactant) to 12.5mg/L (alkyl aryl ethoxylated and aromatic sulfonate surfactant) for D. similis, while the anionic dodecylbenzene sulfonate EC50s were determined as 66.2mg/L and 19.7mg/L, respectively. Both mixtures were very toxic for the exposed organisms: the EC50 average in the anionic + fatty alcohol ethoxylate mixture was of 1.0mg/L ± 0.11 for V. fischeri and 4.09mg/L ± 0.69 for D. similis. While the anionic + alkylene oxide mixture, EC50 of 3.34mg/L for D. similis and 3.60mg/L for V. fischeri. These toxicity data suggested that the concentration addition was the best model to explain the action that is more likely to occur for mixture for the dodecylbenzene sulfonate and alkylene oxide mixtures in both organisms. Our findings also suggest that textile wastewater surfactants may interact and produce different responses in aquatic organisms, such as synergism and antagonism. Ecotoxicological assays provide relevant information concerning hazardous pollutants, which may then be adequately treated and suitably managed to reduce toxic loads, associated to suitable management plans.

Participatory assessment of pollution and health risk in artisanal and small-scale gold mining communities in Colombia

The predominantly Afro-descendant communities of Yolombó and La Toma depend on the region's rich natural resources through livelihoods such as farming, fishing, and artisanal and small-scale gold mining (ASGM). Previous studies of the region have identified elevated levels of mercury in several surface and groundwater sites. Furthermore, recent regional studies have identified human health risks associated with mercury exposure through hazard quotient (HQ) modeling and global sensitivity and uncertainty analysis (GSUA). However, there has yet to be a comprehensive analysis of water pollution involving different metals and metalloids potentially present in ASGM-influenced areas to estimate the associated environmental and human health impacts. In this study, we employed a participatory methodology to identify sources of exposure in Colombian ASGM communities through surveys, consumption diaries, and interviews. We then screened for relevant metals and metalloids through groundwater analysis using inductively coupled plasma optical emission spectroscopy (ICP-OES) and cold vapor atomic absorption spectrometry (CV-AAS). Furthermore, we calculated water pollution indices, including heavy metal pollution index (HPI), degree of contamination (Cd), heavy metal toxicity load (HMTL) and heavy metal evaluation index (HEI). Finally, we quantified human health risks related to groundwater consumption through the HQ and hazard index (HI). Although the groundwater assessed in this study generally meets United States and Colombian regulatory standards, heightened Fe, Mn, and Al levels were observed. The pollution indices generally agreed that three of the sites tested showed medium to high pollution levels. The HI showed that the combined effect of all metals tested did not substantiate risk for most participants. However, the HI of one participant, a child, exceeded the 1.00 threshold. Furthermore, the presence of Pb, despite meeting regulatory limits, necessitates further scrutiny due to its substantial impact on pollution and human health hazard indices.

Purification, kinetic characterization of thermostable multicopper oxidase from the oyster mushroom and its versatility for greener agro-pulp bio bleaching in the paper industry.

Production of a thermostable laccase from Pleurotus florida was reported for the first time, both in submerged and solid-state fermentation using agro-industrial residues. This enzyme was purified using ammonium sulphate precipitation (60-90%), Sephadex G-100 and DEAE column ion exchange chromatography, respectively. The laccase was purified to 21.49 fold with an apparent molecular weight of 66 kDa and had an optimal pH of 5 with temperature stability at 60°C. Metal ions such as Cu2+ (91.26 µmole/mL/min), Mg2+ (68.15 µmole/mL/min), and Fe2+ (1.73 µmole/mL/min) enhanced the laccase activity, but Fe2+ (1.73µmole/mL/min) inhibited the enzyme activity. The purified laccase had Km and Vmax of 16.68 mM and 26.73 µmole/mL/min for guaiacol as a substrate. The isolated enzyme was characterized by FT-IR which revealed bands at 3655.0 cm-1, 2894.7 cm-1, and 1151.7 cm-1 corresponding to primary amines, C-H stretch, and amide -III, respectively. The enzymatic bio bleaching of paddy straw pulp was found to be most effective which resulted in a lowering of kappa number and yellowness by 19.47% & 17.84% whereas an increase in brightness and whiteness by 41.92%. & -19.61%. Thus, this might be stated that the crude laccase from P. florida can be exploited to reduce the toxic waste load for managing environmental pollution and helps in enhancing the yield and quality of the paper.