Biochemical, genotoxic, histological and ultrastructural effects on liver and gills of fresh water fish Channa punctatus exposed to textile industry intermediate 2 ABS

Histopathological fingerprints and biochemical changes as multi-stress biomarkers in fish confronting concurrent pollution and parasitization

The current investigation examined histopathological and serum biochemical profiles to assess the interactive effects of river Saraswati's impaired physicochemical regime and parasite infection by ectoparasites (Trichodina sp., Gyrodactylus sp.) and endoparasites (Eustrongylides sp.) on health of fish (Channa punctatus). This study aimed at assessing the synergistic effects of the degraded water quality and parasitization on fish health looking through the lens of histopathology and serum biochemistry. Low dissolved O2, high free CO2, biochemical oxygen demand (BOD), and chemical oxygen demand (COD) indicate deteriorating water quality due to organic loading. The histopathological investigations revealed distinctive histopathological changes in gill, liver, and kidney of the fish as "signature" impairments inflicted by chronic (co)exposure to pollution and/or parasitization. Stress enzymes and altered serum biochemistry furnish excellent indicators of fish health because of their correlation with pollution and parasitization. Destined in a vicious cycle, fish health becomes adversely affected by degrading water qualities and parasitic infection in solo or combo.

Evaluation of Hepatotoxic Potential of an Azo Dye, Eriochrome Black T on Freshwater Catfish, Clarias batrachus

Nowadays, textile industries are one of the major contributors to water pollution, causing a devastating impact on aquatic ecosystems. Therefore, the current study aimed to investigate the impact of a textile azo dye, Eriochrome Black T (EBT), on the liver of a freshwater fish, Clarias batrachus. Fish were exposed to three concentrations of EBT, i.e., 1 mgL-1, 10 mgL-1 and 20 mgL-1, to evaluate oxidative stress markers such as level of lipid peroxidation (LPO) and activity of enzymatic antioxidants (SOD, CAT, GPx and GR), as well as histology and histochemitry following 96 h of exposure. The results revealed a significant increase (p < 0.05) in EBT bioaccumulation, resulting in elevated level of LPO and significant variation (p < 0.05) in the activities of antioxidant enzymes. The percent change calculation of oxidative stress markers of exposed fishes from control one showed that EBT had most significant impact on the fishes exposed to 20 mgL-1 of EBT. Histological and histochemical examinations also demonstrated the deteriorating impact of EBT on structural architecture of liver. Hence, the present study concludes that EBT causes detrimental impact on fish health by impairing its liver detoxification system and metabolism. Therefore, it is suggested to explore mechanism of EBT toxicity on aquatic organisms so that its hazardous risk can be monitored and preventive measures can be taken.

Bioremediation of azo dye: A review on strategies, toxicity assessment, mechanisms, bottlenecks and prospects

The synthetic azo dyes are widely used in the textile industries for their excellent dyeing properties. They may be classified into many classes based on their structure and application, including direct, reactive, dispersive, acidic, basic, and others. The continuous discharge of wastewater from a large number of textile industries without prior treatment poses detrimental effects on the environment and human health. Azo dyes and their degradation products are extremely poisonous for their carcinogenic, teratogenic and mutagenic nature. Moreover, exposure to synthetic azo dyes can cause genetic changes, skin inflammation, hypersensitivity responses, and skin irritations in persons, which may ultimately result in other profound issues including the deterioration of water quality. This review discusses these dyes in details along with their detrimental effects on aquatic and terrestrial flora and fauna including human beings. Azo dyes degrade the water bodies by increasing biochemical and chemical oxygen demand. Therefore, dye-containing wastewater should be effectively treated using eco-friendly and cost-effective technologies to avoid negative impact on the environment. This article extensively reviews on physical, chemical and biological treatment with their benefits and challenges. Biological-based treatment with higher hydraulic retention time (HRT) is economical, consumes less energy, produces less sludge and environmentally friendly. Whereas the physical and chemical methods with less hydraulic retention time is costly, produces large sludge, requires high dissolved oxygen and ecologically inefficient. Since, biological treatment is more advantageous over physical and chemical methods, researchers are concentrating on bioremediation for eliminating harmful azo dye pollutants from nature. This article provides a thorough analysis of the state-of-the-art biological treatment technologies with their developments and effectiveness in the removal of azo dyes. The mechanism by which genes encoding azoreductase enzymes (azoG, and azoK) enable the natural degradation of azo dyes by bacteria and convert them into less harmful compounds is also extensively examined. Therefore, this review also focuses on the use of genetically modified microorganisms and nano-technological approaches for bioremediation of azo dyes.

Toxic and histopathological effects induced by exposure to the pesticide dicamba in carp Cyprinus carpio L

This study investigated the effects of dicamba (DIC), a widely used auxinic pesticide in agriculture, on carp fish as an experimental model, especially examining serum adrenocorticotropic hormone (ACTH), cortisol (CORT), growth hormone (GH), and insulin-like growth factor-1 (IGF-1) levels. Additionally, it analyzed serum tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and interleukin-6 (IL-6) levels, as well as histopathological changes in gill and liver tissues. Fish were exposed to varying doses (1.35 and 13.5 ppm) and durations (4 and 30 days). Sixty fish were randomly assigned to six groups (10 fish/group) and exposed to the specified DIC concentrations and durations. Following exposure, stress, growth, and immune parameters were assessed, along with pathological changes. Analyses revealed dose-dependent increases in ACTH, CORT, and TNF-α levels in both exposure periods compared to controls. Conversely, decreases in GH, IGF-1, IL-1β, and IL-6 levels were observed. A significant difference (p < 0.05) was noted in the changes of ACTH, CORT, TNF-α, GH, IGF-1, IL-1β, and IL-6 levels between the exposure periods in the subchronic phase for both dose groups. Histopathological examination identified significant alterations in gill and liver tissues across all dose groups. Gill pathology included epithelial separation (aneurysm), shortening and fusion of secondary lamellae, clubbing, reduced interlamellar space, and cartilage tissue damage. Liver histopathology showed hepatocellular degeneration, passive hyperemia, mononuclear cell infiltration, and hepatocyte vacuolization. In conclusion, dicamba exposure induced significant stress, growth, immune, and histopathological changes in carp, highlighting its potential harmful effects on aquatic organisms, especially at higher concentrations and prolonged exposure durations.

Protective Role of Sulforaphane against Physiological Toxicity of Triphenyltin in Common Carp (Cyprinus carpio haematopterus)

This experiment mainly explored the protective role of sulforaphane (SFN) against physiological toxicity of triphenyltin (TPT) in Cyprinus carpio haematopterus. In total, 320 Fish (56.90 ± 0.40 g) were randomly divided into four groups with four replicates each. The control group was fed the basal diet, the TPT group (TPT) was exposed to 10 ng L-1 TPT on the basis of the control group, the SFN + TPT group (TPT + SFN) was fed a diet supplemented with 10 mg kg-1 SFN on the TPT group, and the SFN group (SFN) was fed a diet supplemented with 10 mg kg-1 SFN. After 56 days of breeding trials, the results showed that TPT exposure resulted in a remarkable decrease (p < 0.05) in final weight, weight gain rate (WGR), specific growth rate (SGR), and condition factor (CF), but an increase (p < 0.05) in feed conversion ratio (FCR) and hepatosomatic index (HSI) of fish. TPT treatment decreased (p < 0.05) the amounts of hematocrit (Hct) and hemoglobin (Hb), plasma complement component 3 (C3) and C4 contents, alternative complement pathway (ACH50), acid phosphatase (ACP) and lysozyme (LZM) activities, liver glutathione (GSH) content, catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPX) activities, interleukin 10 (IL-10), and SOD mRNA expressions, but increased (p < 0.05) plasma alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities, liver malonaldehyde (MDA) content, tumor Cyclooxygenase 2 (COX2), and necrosis factor α (TNFα), IL-1β, and MDA mRNA expressions. A histological analysis of the liver showed that a higher occurrence rates of the hepatocyte hypertrophy, nuclear disappearance and hepatocyte vacuolization was observed in the hepatocytes of fish exposed to TPT, and it was accompanied by the dilation of hepatic sinusoids. In addition, the toxicity induced by TPT was significantly improved in the groups that were treated with SFN, and SFN was able to improve growth performance and immunity, alleviate TPT-induced changes in inflammatory factors, ameliorate oxidative stress, and increase the activity of antioxidant enzymes (p < 0.05). The addition of SFN also alleviated liver damage caused by TPT and protected the structural integrity of the liver. Overall, these findings suggest that TPT inhibited the growth, immunity, and antioxidant capacity of Cyprinus carpio haematopteru. Dietary SFN could be beneficial for growth promotion, immunity, antioxidant capacity, and protection of liver structural integrity. Therefore, SFN is a prospective feed supplement for ameliorating the damage caused to fish by TPT contamination.

Alteration in oxidative stress markers, digestive physiology and gut microbiota of Heteropneustes fossilis and Clarias batrachus exposed to eriochrome black T

Synthetic dyes are the primary cause of water pollution in industrial regions. Azo dyes account for 60-70% of such dyes used in the textile sector due to their numerous beneficial characteristics. Nevertheless, there is a dearth of knowledge regarding the toxicity of Eriochrome Black T (EBT), a widely used azo dye in the textile industry. Therefore, the current study was designed to investigate the effect of EBT exposure on two catfish species, Heteropneustes fossilis and Clarias batrachus. Following 96 h exposure to 1, 10 and 20 mgL-1 of EBT, the MDA content and activities of SOD, CAT and GR exhibited a rising trend. However, as the concentration of EBT increased in both species, GPx showed decreased activity. EBT exposure also altered gut morphometry as well as the three main digestive enzymes activity (increase in lipase and trypsin activity, while decrease in amylase activity). In addition, the exposure of EBT had a significant impact on the gut microbiota of both species. C. batrachus demonstrated the suppression or absence of beneficial gut commensals (Bacillus and Cetobacterium), whereas H. fossilis revealed the proliferation and appearance of beneficial commensal microbes (Bacillus, Bacteroides, Prevotella, and Megashaera). Furthermore, the expansion or absence of these microbial communities indicated that the gut microbiota of both species was involved in dye digestion, immunity and detoxification. Overall, the percent change calculation of all the selected biomarkers, together with gut microbiota analysis, indicates that C. batrachus was more vulnerable to EBT exposure than H. fossilis. The present investigation effectively demonstrated the toxic impact of EBT on fish health by employing oxidative stress markers, digestive enzymes, and the fish gut microbiota as a promising tool for screening the impact of dye exposure on digestive physiology in toxicological research.

Impact of continuous Triazophos exposure on Labeo rohita: Physiological, biochemical, and histological alterations and IBRv2 index assessment

Pesticides are commonly used in agriculture and aquaculture. Triazophos, an organophosphate-based pesticide, is widely used in agriculture to control many insect pests. Due to its high photochemical stability and mode of action, Triazophos could persist in the aquatic ecosystem and cause toxic effects on non-target organisms. We have studied the potential toxic effects of Triazophos on L. rohita. Primarily, we determined the median lethal concentration (LC50) of Triazophos for 24 and 96 h. Next, we studied acute (96 h, LC50-96 h) toxicity. Then, we studied chronic (35 days, 1/10th LC50-24 h Treatment I: 0.609 mg/L, 1/5th LC50-96 h Treatment II: 1.044 mg/L) toxicity. We analyzed blood biomarkers such as hematology (Hb, Hct, RBC, WBC, MCV, MCH and MCHC), prolactin, cortisol, glucose and protein levels. Concurrently, we analyzed tissue biomarkers such as glycogen, GOT, GPT, LDH and histopathology. IBRv2 index assessment method was also to evaluate the Triazophos toxicity. Studied hematological, hormonal, biochemical and enzymological biomarkers were affected in Triazophos treated groups when compare to the control group. The changes in these biomarkers were statistically significant at the 0.05 alpha level. Triazophos exposed fish shown a severe degenerated primary and secondary lamellae, lamellar fusion, hypertrophy and telangiectasia in the gills. In the hepatic tissue, it caused moderate necrosis, blood congestion, distended sinusoids with minor vacuolation, prominent pyknotic nuclei, hypertrophy, cloudy swelling of cells, lipid accumulation and fibrotic lesions. In the renal tissue, Triazophos caused thickening of Bowman's capsule, hyaline droplets degeneration, irregular renal corpuscle, congestion, cellular swelling, degeneration of tubular epithelium, necrosis, shrunken glomerulus, vacuolated glomerulus, hypertrophy, exudate and edema. IBRv2 analysis suggested that tissue biomarkers are highly sensitive to Triazophos toxicity and prolonged exposure could cause serious health effects like acute toxicity in fish. Triazophos could cause multiorgan toxicity at studied concentrations.

Toxic effects of aniline in liver, gills and kidney of freshwater fish Channa punctatus after acute exposure

Aniline (C6H5NH2) is one of the hazardous aromatic amine where an amino group -NH2) is connected to phenyl ring (C6H5). Based on the evaluation of the 96-hour LC50 of aniline, two sublethal concentrations (4.19 mg/l and 8.39 mg/l) were selected for acute exposure tests in freshwater fish Channa punctatus. The liver, gills and kidney of fish being the principal sites of xenobiotic material accumulation, respiration, biotransformation, and excretion are the focus of the present study. Throughout the exposure time, the comet assay revealed increased tail length and tail DNA percentage indicating maximum damage to liver, gills and kidney of treated group after 96 h. After acute exposure, there was a significant (p ≤ 0.05) increase in the enzymatic activity of glutathione-S-transferase (GST) and acetylcholinesterase (AChE), whereas decline in superoxide dismutase (SOD) and catalase (CAT) activity was observed. Meanwhile, levels of malondialdehyde (MDA) increased over the exposure period for both concentrations. After 96 h of exposure, degree of tissue change (DTC) was evaluated in liver, gill and kidney of aniline exposed fish. Additionally, light microscopy revealed multiple abnormalities in liver, gills and kidney of all the treated groups. Significant changes were observed in the levels of biochemical markers viz., glucose, triglyceride, cholesterol, aspartate transaminase, alanine transaminase and urea following a 96-hour exposure to aniline. Studies using ATR-FTIR and transmission electron microscopy (TEM) revealed changes in biomolecules and structural abnormalities in several tissues of the aniline-exposed groups in comparison to the control group respectively.

Microplastics have additive effects on cadmium accumulation and toxicity in Rice flower carp (Procypris merus)

Procypris merus, a local fish species found in Guangxi, China is often exposed to both microplastics (MPs) and Cd. However, it remains unclear how these two pollutants affect P. merus. Therefore, we investigated the effects of MPs on Cd accumulation in P. merus. To this end, P. merus was separately exposed to Cd and MPs (500 μg/L) or their combination for 14 days. We found that MPs enhanced Cd accumulation in liver and gills of P. merus. Further, both the single-contaminant (MP and Cd) and combined treatments resulted in lesions in these two tissues, with more severe damage associated with the combined treatment. Even though the effect of MP on the antioxidant defense system of P. merus was limited, the Cd-only and combined treatments considerably affected the antioxidant parameters of P. merus, with the combined treatment showing a stronger effect. GO and KEGG analyses revealed that the differentially expressed genes (DEGs; TNF-related apoptosis-inducing ligand receptor, trail-r) in the Cd-only treatment group were enriched for immune-related GO terms and cell growth and death related pathways, indicating that Cd toxicity affected immune defense in P. merus. The MP-only treatment downregulated DEGs (acyl-CoA synthetase long chain family member 1a, acsl1a) related to lipid metabolism, possibly leading to lipid accumulation in the liver. The combined treatment also upregulated DEGs (aspartate aminotransferase 1, ast 1) associated with immune-related GO terms and amino acid metabolism pathways, suggesting that it affected immune function in P. merus, thereby negatively impacting its health. Results indicated that MPs have additive effects on Cd accumulation and toxicity in rice flower carp. Consequently, MPs ingested by P. merus can promote Cd accumulation, more adverse effects on the health may occur after combined exposure, which can eventually reach humans through the food chain and pose potential risks to human health.

Evaluating efficacy of Pseudomonas sp. EN-4 to lower the toxic potential of 4-bromophenol and assessing its competency in simulated microcosm

An indigenous bacterium Pseudomonas sp. EN-4 had been reported earlier for its ability to co-metabolise 4-bromophenol (4-BP), in presence of phenol (100 mg/L) as co-substrate. The present study was undertaken to validate the efficacy of biotransformation by comparing the toxicity profiles of untreated and EN-4 transformed samples of 4-BP, using both plant and animal model. The toxicity studies in Allium cepa (A. cepa) indicated to lowering of mitotic index (MI) from 12.77% (water) to 3.33% in A. cepa bulbs exposed to 4-BP + phenol, which reflects the cytotoxic nature of these compounds. However, the MI value significantly improves to 11.36% in its biologically treated counterpart, indicating normal cell growth. This was further supported by significant reduction in chromosomal aberrations in A. cepa root cells exposed to biologically treated samples of 4-BP as compared to untreated controls. The oxidative stress assessed by comparing the activity profiles of different marker enzymes showed that the activities of superoxide dismutase (SOD), ascorbate peroxidase (APX) and guaiacol peroxidase (GPX) were reduced by 56%, 72%, and 37% respectively, in EN-4 transformed samples of 4-BP + phenol compared to its untreated counterpart. Similar trends were evident in the comet assay of fish (Channa punctatus) blood cells exposed to untreated and biologically treated samples of 4-BP. The comparative studies showed significant reduction in tail length (72.70%) and % tail intensity (56.15%) in fish blood cells exposed to EN-4 treated 4-BP + phenol, compared to its untreated counterpart. The soil microcosm studies validated the competency of the EN-4 cells to establish and transform 4-BP in soil polluted with 4-BP (20 mg/kg) and 4-BP + phenol (20 + 100 mg/kg). The isolate EN-4 achieved 98.08% transformation of 4-BP in non-sterile microcosm supplemented with phenol, indicating to potential of EN-4 cells to establish along with indigenous microflora.

Enrichment and distribution of 3,6-dichlorocarbazole in red crucian carp (Carassius auratus) and its hepatotoxicity

Polyhalogenated carbazoles (PHCZs) are a class of organohalogen compounds where the hydrogen atom on the carbazole ring is replaced by a halogen atom. In recent years, PHCZs have drawn increasing concern due to their persistence, dioxin-like toxicity, bioaccumulation, potential ecological hazards and widespread occurrence in the environment. Current research on the enrichment and depuration of PHCZs in biological tissues and organs is insufficient, and the liver toxicity is unclear. Herein, to understand the enrichment and elimination of 3,6-DCCZ in fish tissues and organs as well as the hepatotoxicity, we exposed the red crucian carp to 20 and 100 μg/L of 3,6-DCCZ for 20 days followed by a depuration period of 10 days. The 3,6-DCCZ enrichment in each organ tissue was classified from high to low: brain > liver, intestine, gill > muscle. For depuration, 3,6-DCCZ was quickly excreted in the various organs of the red crucian carp; however, the liver depuration was slow, with the concentration of 3,6-DCCZ was maintained at 0.25-0.35 μg/g. 3,6-DCCZ exposure at both tested concentrations induced oxidative stress in red crucian carp, causing lipid peroxidation and DNA damage, as well as some histopathological changes in the liver, such as cell vacuolization, nucleus pyknosis, nucleus pleomorphism, no nucleus areas. Additionally, the 3,6-DCCZ exposure at higher concentration (100 μg/L) caused more serious damage and abnormal lipid metabolism in the red crucian carp liver.

Recent Strategies for the Remediation of Textile Dyes from Wastewater: A Systematic Review

The presence of dye in wastewater causes substantial threats to the environment, and has negative impacts not only on human health but also on the health of other organisms that are part of the ecosystem. Because of the increase in textile manufacturing, the inhabitants of the area, along with other species, are subjected to the potentially hazardous consequences of wastewater discharge from textile and industrial manufacturing. Different types of dyes emanating from textile wastewater have adverse effects on the aquatic environment. Various methods including physical, chemical, and biological strategies are applied in order to reduce the amount of dye pollution in the environment. The development of economical, ecologically acceptable, and efficient strategies for treating dye-containing wastewater is necessary. It has been shown that microbial communities have significant potential for the remediation of hazardous dyes in an environmentally friendly manner. In order to improve the efficacy of dye remediation, numerous cutting-edge strategies, including those based on nanotechnology, microbial biosorbents, bioreactor technology, microbial fuel cells, and genetic engineering, have been utilized. This article addresses the latest developments in physical, chemical, eco-friendly biological and advanced strategies for the efficient mitigation of dye pollution in the environment, along with the related challenges.

Triphenylmethane dye (C52H54N4O12) is potentially a hazardous substance in edible freshwater fish at trace level: toxicity, hematology, biochemistry, antioxidants, and molecular docking evaluation study

Malachite green (C₅₂H₅₄N₄O₁₂) is a synthetic dye that is used in textile industries as a colorant and in aquaculture sectors to contain microbial damage. Aquatic contamination of malachite green (MG) has been reported globally. Fish is the highest trophic organism among aquatic inhabitants, highly sensitive to waterborne contaminants (metals, coloring agents, etc.). Toxicity of waterborne chemicals on nontarget organisms can be determined by assessing biomarkers. Assessing blood parameters and tissue antioxidants (enzymatic and nonenzymatic) is useful to evaluate MG toxicity. To initiate the MG toxicity data for freshwater fish (Cyprinus carpio), the median lethal toxicity was primarily evaluated. Then, hematological, blood biochemical (glucose, protein, and cholesterol) and tissue biochemical (amino acids, lipids), and vital tissue (gills, liver, and kidney) antioxidant capacity (CAT, LPO, GST, GR, POxy, vitamin C, and GSH) of C. carpio were analyzed under acute (LC_50-96 h) and sublethal (Treatment I-1/10^th and Treatment II-1/5^th LC_50-96 h) exposure periods (28 days). Molecular docking for MG with hemoglobin was also obtained. Biomarkers examined were affected in the MG-treated groups with respect to the control group. Significant changes (p < 0.05) were observed in hematology (Hb, RBCs, and WBCs), glucose, proteins, lipids and tissue CAT, LPO, and GST activities under acute MG exposure. In sublethal treatment groups, biomarkers studied were significant (p < 0.05) throughout the study period. The potential for MG binding to hemoglobin was tested in this study. MG is potentially a multiorgan toxicant. Literally a chemical that is harmful to the aquatic environment if safety is concerned.

Toxicity of tributyltin chloride on haarder (Liza haematocheila) after its acute exposure: Bioaccumulation, antioxidant defense, histological, and transcriptional analyses

Liza haematocheila is exposed to various chemical contaminants from anthropogenic sources, including tributyltin chloride (TBTC). Yet the toxicity mechanism of TBTC on haarder remains unclear. The haarder was exposed to different doses (0, 10%, 20%, and 50% of LC₅₀-96 h) of TBTC. In this study, the results revealed its high bioaccumulation in the livers and significant alteration for development. The activities of antioxidant enzymes superoxide dismutase, catalase, and glutathione peroxidase decreased after 96-h exposure to TBTC, this accompanied by an increased malondialdehyde level. TBTC exposure caused the intense production of reactive oxygen species, a reduction in total blood cell count in serum, and apoptosis-related alterations in livers, indicating that enhanced oxidative stress occurred in the process of TBTC exposure. Histological results revealed angiorrhexis and infiltration of inflammatory cells, vacuolar degeneration of hepatocytes in the livers, and swelling, fusion, and disintegration of gill organs. Interestingly, the obtained transcriptional profiles indicated that high doses of TBTC caused energy disorder, apoptosis, and adipogenesis restriction mediated by cytokines and adipokines in Jak-STAT and adipocytokine signaling pathways. In summary, acute exposure to high doses of TBTC could impair the antioxidant system and pathways related to energy, apoptosis and adipogenesis, eventually posing a serious challenge to the fitness of haarder individuals and its fish populations as marine resources.

Impact of sublethal phenol in freshwater fish Labeo rohita on biochemical and haematological parameters

Phenol, an aromatic chemical commonly found in domestic and industrial effluents, upon its introduction into aquatic ecosystems adversely affects the indigenous biota, the invertebrates and the vertebrates. With the increased demand for agrochemicals, a large amount of phenol is released directly into the environment as a byproduct. Phenol and its derivatives tend to persist in the environment for longer periods which in turn poses a threat to both humans and the aquatic ecosystem. In our current study, the response of Labeo rohita to sublethal concentrations of phenol was observed and the results did show a regular decrease in biochemical constituents of the targeted organs. Exposure of Labeo rohita to sublethal concentration of phenol (22.32 mg/L) for an epoch of 7, 21 and 28 days shows a decline in lipid, protein, carbohydrate content and phosphatase activity in target organs such as the gills, muscle, intestine, liver and kidney of the fish. The present study also aims to investigate the toxic effects of phenol with special reference to the haematological parameters of Labeo rohita. At the end of the exposure period, the blood of the fish was collected by cutting the caudal peduncle with a surgical scalpel. And it was observed that the red blood corpuscle count (RBC), white blood corpuscle (WBC), haemoglobin count (Hb), packed cell volume (PCV), mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH) and mean corpuscular haemoglobin concentration (MCHC) values showed a decline after exposure to phenol for 7 days, while white blood corpuscle (WBC) shows an increased count. At 21 days and 28 days, all the haematological parameters showed a significant decrease.

A critical review on the treatment of dye-containing wastewater: Ecotoxicological and health concerns of textile dyes and possible remediation approaches for environmental safety

The synthetic dyes used in the textile industry pollute a large amount of water. Textile dyes do not bind tightly to the fabric and are discharged as effluent into the aquatic environment. As a result, the continuous discharge of wastewater from a large number of textile industries without prior treatment has significant negative consequences on the environment and human health. Textile dyes contaminate aquatic habitats and have the potential to be toxic to aquatic organisms, which may enter the food chain. This review will discuss the effects of textile dyes on water bodies, aquatic flora, and human health. Textile dyes degrade the esthetic quality of bodies of water by increasing biochemical and chemical oxygen demand, impairing photosynthesis, inhibiting plant growth, entering the food chain, providing recalcitrance and bioaccumulation, and potentially promoting toxicity, mutagenicity, and carcinogenicity. Therefore, dye-containing wastewater should be effectively treated using eco-friendly technologies to avoid negative effects on the environment, human health, and natural water resources. This review compares the most recent technologies which are commonly used to remove dye from textile wastewater, with a focus on the advantages and drawbacks of these various approaches. This review is expected to spark great interest among the research community who wish to combat the widespread risk of toxic organic pollutants generated by the textile industries.