Background: The leather industry and its products have a substantial impact on the economy of Bangladesh and have been recognized as a highly significant sector. Nevertheless, tannery poses potential risks to workers due to exposure to harmful chemicals and pollutants linked with tannery activities. The objective of this study was to evaluate the health hazards and healthcare-seeking behavior experienced by tannery workers residing in close proximity to the tannery area. Materials and methods: This cross-sectional study was carried out among tannery workers residing in the vicinity of the tannery industrial area in Hemayetpur, Savar, Dhaka. A total of 402 participants were conveniently interviewed in person using a pre-tested semi-structured questionnaire from January to December 2023. Results: The majority of participants were male (88%) predominantly young adults aged 20-30. In terms of employment, 34.6% worked in machinery-related tasks, with 66.4% having done so for 3-8 years. Self-reported health issues included joint pain (49.0%), frequent fever (33.3%), allergies (43.0%), chronic headaches (35.8%), itching (35.8%), rashes (19.9%), and coughing (35.8%). Statistically significant associations were found between these health problems and the duration of stay, department of work, and gender (p<0.005). The study also found that 70% of workers used personal protective equipment (PPE), mainly masks, and 61% received formal safety training. Regarding health-seeking behavior, 89.3% relied on allopathic medicine, with pharmacists being the main healthcare provider (89.3%). Furthermore, primary healthcare services (93.5%) were more commonly sought than specialized care. Conclusion: Policymakers and public health professionals can utilize these insights to develop strategies aimed at mitigating environmental hazards, enhancing healthcare facilities and promoting preventive measures. Chatt Maa Shi Hosp Med Coll J; Vol.24 (1); Jan 2025; Page 27-32

Assessing socio-environmental reporting practices in Bangladesh’s tannery industry

Exploration of functional genes in Brucella anthropi for hexavalent chromium bioremoval through gene mining: A whole genome sequencing based approach.

Environmental contamination from industrial activities remains a significant concern, with tanneries being major contributors of chromium (Cr) to aquatic systems. Cr, a heavy metal with multiple oxidation states, varies in toxicity and poses risks to both ecosystems and human health. In Portugal, the Alcanena region is particularly affected, hosting around 60 tanning industries. This study assessed total Cr levels in water from the Alviela River and Carvalho Stream, with particular focus on the impact of a local wastewater treatment plant (WWTP) that processes tannery effluents. Water samples were collected upstream and downstream of the WWTP discharge point. Analytical techniques included graphite furnace atomic absorption spectrometry and inductively coupled plasma optical emission spectroscopy, with a detection limit of 0.33 µg L−1. The highest Cr concentration (560 µg L−1) was found in the Carvalho Stream, downstream of the WWTP, confirming its contribution to local contamination. In the Alviela River, Cr concentrations ranged from 8 to 50 µg L−1 downstream of the WWTP, exceeding the predicted no-effect concentration for aquatic organisms and the safety limit for human consumption (25 µg L−1). These findings highlight, for the first time, the ongoing environmental impact of tannery effluents in this region and emphasize the urgent need for improved monitoring and pollution control measures.

Tannery workers in Bangladesh face persistent occupational health hazards due to exposure to toxic chemicals and limited safety protections. However, the factors of workers’ perceptions of these health risks remain insufficiently understood. This study investigates factors associated with health concern among tannery workers in the Savar Tannery Industrial Estate, drawing on a cross-sectional survey of 400 workers. Ordinal logistic regression analyses were conducted to examine the influence of sociodemographic characteristics, knowledge, attitude, and workplace practices. Overall, 87.5% of workers reported being concerned about health risks, including 42.5% who were very concerned. Male workers had significantly higher odds of expressing concern (aOR = 2.05, p = 0.01), as did workers with more than ten years of experience (aOR = 3.37, p = 0.033) and married workers (aOR = 1.61, p = 0.039). Knowledge-related variables were strong predictors; awareness of health hazards (aOR = 2.75, p = 0.022), recognition of harmful chemicals (aOR = 2.90, p = 0.006), and correct PPE knowledge (aOR = 3.17, p < 0.001) were each associated with greater concern. Conversely, rarely using PPE (aOR = 0.11, p = 0.005) and rarely washing exposed skin (aOR = 0.03, p < 0.001) were associated with substantially lower concern. These findings highlight critical gaps in safety training and protective practices, emphasizing the need for targeted interventions to strengthen occupational health literacy and promote safer behaviors in Bangladesh’s tannery sector.

Study on the Effective Removal of Heavy Metals from the Tannery Industry Effluents using Natural Adsorbents

Evaluation of Surface Water Quality Affected by Industrial Effluents Near Tannery Industrial Area: Heavy Metal Concentrations and Ecological Toxicity Index Measurement

ABSTRACT The tannery industry faces a serious challenge in managing solid waste sustainably. The most hazardous form of solid waste is chromium-tanned solid waste, mainly consisting of leather shavings (LS) with elevated chromium levels. This study explored anaerobic co-digestion of LS with cow dung (CD), sawdust (SD), and food waste (FW) to enhance biogas production and waste stabilization. LS exhibited a low carbon-to-nitrogen ratio (3.01) and acidic pH (4.51 ± 0.42), necessitating co-substrate blending to optimize digestion conditions. Laboratory-scale batch reactors operated at 28 ± 3°C for 40 days revealed that the LS:CD:FW (1:1:1) mixture achieved the highest cumulative biogas yield (5895.2 mL kg−1 solid feed), methane content (53.63%), volatile solids reduction (51.99%), total organic carbon reduction (47.55%), and chemical oxygen demand removal (53.8%). In contrast, the LS:CD:SD (1:1:1) mixture yielded the lowest biogas output (3910.3 mL kg−1) due to high lignocellulosic content in SD. Notably, the digestate from LS:CD:FW contained 88.13 ppm of chromium, remaining below the 100 ppm soil safety threshold, indicating its potential for safe disposal. Results demonstrate that co-digestion with nutrient-rich substrates (CD, FW) significantly improves methane recovery and organic matter degradation from LS, while ensuring digestate safety. This approach offers a viable pathway for renewable energy generation and environmentally safer disposal of chromium-laden tannery waste.

ABSTRACTChromium‐bearing tannery sludge poses both environmental and resource challenges, but current methods often rely on high‐temperature calcination with inorganic Ca sources. To address this gap, this study investigates the synergistic effects of oyster shell (OS), a natural biomineralized calcium material, in chromium recovery from dewatered tannery sludge (TS) through co‐pyrolysis, with comparative analysis against inorganic calcium carbonate (CaCO3). Laboratory‐scale experiments were conducted at pyrolysis temperatures ranging up to 900°C, with varying OS concentrations. The results demonstrate that OS incorporation significantly influenced chromium phase transformation, effectively converting Cr2O3 (exclusive to TS) into chromate salts during the co‐pyrolysis process. The optimized co‐pyrolysis conditions achieved remarkable chromium recovery efficiency exceeding 95%, substantially outperforming the CaCO3‐assisted pyrolysis system. Mechanistic analysis revealed that the organic matrix proteins inherent in OS played a crucial role in facilitating chromium adsorption and subsequent phase transformation processes. This work provides a new way to recover chromium using OS powder, which performs better than CaCO3 and also utilizes marine waste material. The process improves chromium recovery and supports resource reuse in the tannery industry. This innovative co‐pyrolysis approach utilizing OS powder offers a sustainable and economically viable solution for chromium recovery, simultaneously addressing environmental concerns and resource utilization challenges in the tannery industry. Furthermore, the oxidation of Cr(III) to Cr(VI) in tannery wastewater not only enhances chromium recyclability but also promotes the conversion of waste streams into valuable resources, thereby advancing circular economy principles within the leather manufacturing sector.

This study investigates the socioeconomic impact of the recently relocated tannery industries in Hemayetpur, Savar, Dhaka. The relocation has introduced significant changes in the local socioeconomic landscape. To achieve the research objective, this study employs a quantitative research approach, utilizing statistical tools such as tables, graphs, percentages, and ratios to systematically analyze the data. The findings indicate that the relocation has had a positive impact on key socioeconomic indicators, including housing development, transportation infrastructure, social security, and employment generation. The expansion of industrial activities has contributed to improved residential facilities, enhanced connectivity, increased community safety, and greater employment opportunities for the local workforce. These results highlight the broader implications of industrial relocation for regional development and economic growth.

Abstract Concrete is composed of many components such as cement, aggregates, and water. Concrete being a strong building material, it is widely utilized in the building sector for making various products with the addition of bound ingredients to enhance its strength and durability properties. Continued industrial development is critical to a country’s economic growth and progress. There is a huge demand for animal hides and skin which are processed to make leather products. The leather industry is one of the main sectors that generate good revenue for the Indian government. The amount of waste generated by this industry is significant and is classified as hazardous due to its complex content of toxic chemicals, heavy metals, and other contaminating substances. The Central Pollution Control Board (CPCB), established by the government, lists the leather industry as one of India’s major polluting industries. As the substantial quantities of solid waste generated by the tannery industry have a harmful effect on the environment and its inhabitants, it is essential to employ an effective waste management solution. The main aim is tannery sludge as a partial replacement for fine aggregate in the construction of a concrete block. The rising cost of watercourse sand, the use of sludge as a construction material. The concrete grades used for this investigation are M 20 , M 25 , and M 30 , and the fine aggregate is partially replaced with industrial sludge in varied percentages of 0% to 30%. The mechanical characteristics, properties and toughness of the prepared concrete block are examined through ANOVA and Life Cycle Assessment.

Due to their hazardous effects on human health and air quality, benzene and xylene constitute the primary pollutants. Coupling the physicochemical strategies with bacterial bioremediation is an emerging mode of decontamination. Considering the limited understanding of benzene and xylene degradation pathways in the genus Bacillus, failure of earlier documented bacteria to degrade these compounds due to poor optimization and complicated real-world contamination scenarios, we initiated the current project. It is an attempt to explore the gene repertoire and pathways associated with the bioremediation of benzene and xylene in new and efficient bacteria. Eleven bacteria were isolated from tannery industry soil in a previous study. Bacterial DNA was extracted by the organic method. To prepare a sample for whole genome sequencing (WGS) analysis, a mixture of genomic DNA was made by adding DNA from each isolate in equimolar concentration (100 ng). The sample was subjected to WGS. Results obtained as FASTq files were submitted to Sequence Read Archives (SRA), NCBI, to get the accession number assigned. Taxonomic profiling revealed that the sample was composed of phyla Proteobacteria (76%), Firmicutes (16%) and unclassified phyla (8%). Functional annotation unraveled the presence of benzoate, m-, p- and o-xylene isomers, benzene, aminobenzoate, 2-, 3- and 4-fluorobenzoate, toluene, chloroalkane and chloroalkene, naphthalene, polycyclic aromatic hydrocarbons (PAHs), dioxin, caprolactum, atrazine, styrene, and chlorobenzene and chlorocyclohexane degradation enzymes and pathways. It is the first ever study documenting the benzene degradation pathway similar to Gram-negative bacteria, in the genus Bacillus, inhabiting the tannery soil and coexistence of metabolic pathways for multiple organic pollutants.

The effluent from the tannery industry contains high concentrations of organic pollutants, particularly chromium (Cr), which is a priority pollutant that harms human health, plants, animals, and affects compliance with environmental standards. This study significantly reduced tannery wastewater pollution and its toxic effects through the innovative use of an integrated treatment system with a coagulation/flocculation/settling process followed by a membrane bioreactor (MBR). Experiments were conducted to maximize the removal of pollutants by evaluating the effects of pH values, coagulant doses in the chemical treatment, and the biological treatment coupled with membrane separation within the MBR. The results indicated that optimizing the parameters achieved the highest reductions during the chemical treatment step: 97% for Cr, 63% for chemical oxygen demand (COD), and 90% for turbidity. The wastewater was then treated using the MBR system, which further improved removal efficiency to 99% for Cr, 96% for COD, and 99.8% for turbidity. These outcomes demonstrate the effectiveness of the hybrid treatment process in significantly lowering pollutant concentrations in tannery wastewater, ensuring compliance with Environmental Protection Agency (EPA) standards and the regulatory obligations under European Regulation (EU) 2020/741. This hybrid approach offers promising potential for broader industrial applications.

Optimization of electro-Fenton process applied to the treatment of codfish brines in a context of industrial symbiosis.

ABSTRACT The current work elucidates the role of ultrasound (US) and advanced oxidation process (AOP) in intensifying the treatment of tannery industry effluent using electron beams. A ultrasound treatment under conditions of a power of 120 W, a duty cycle of 70% and 20 kHz resulted in a COD reduction of 41.7% after 60 min while US + H2O2 + O3 combination gave 83.33% COD reduction at H2O2 loading of 300 ppm, O3 loading of 2 l/min and a 30 min treatment. The pre-treated samples were subjected to electron beam irradiations at different dosages. Only electron beam-treated samples showed a lesser COD reduction of 0.21%, 0.67% and 44.4%, whereas the US + H2O2 + O3 pre-treatment followed by electron beam irradiation gave a COD reduction of 83.33%, 84.38% and 87.48% for 3, 5 and 30 kGy as the dosage, respectively. The effect of electron beam irradiation as a pre-treatment for AOP was also studied wherein the electron beam irradiation had little effect on the COD reduction of the sample and hence this strategy was not considered feasible. Overall, the hybrid oxidative process of US + O3 + H2O2 followed by electron beam irradiation is the best approach for the desired reduction in COD and obtaining colourless effluent.

BackgroundWith the rapid increase in industrialization, irrigation through waste or sewage water is a common practice due to low and scarce freshwater supply. Plants are exposed to hazardous metals that accumulate in plant tissues and negatively affect them. Therefore, current study aimed to investigate the phytodiversity and morpho-anatomical modification of wild plants irrigated by tannery effluents. Six wild plant species were collected from different sites of Multan near tannery industries through the quadrate method.ResultsResults indicated that Cynodon dactylon L. had the highest relative cover, relative frequency, relative density, and important index value, i.e., 35, 10, 30, and 75% followed by other species. The morpho-anatomical modifications showed a reduction in leaf characteristics in C. dactylon, Eragrostis barrelieri Daveau, Polypogon monpeliensis L., Solanum nigrum L., Triticum aestivum L., except in Asparagus adscendens Roxb. A decrease in leaf length was observed in all species with maximum reduction of 55% in T. aestivum followed by P. monpeliensis. Similarly, reduction in metaxylem area was observed in T. aestivum, whereas sclerenchymatous thickness found to increase in P. monpeliensis by 15%. Asparagus adscendens showed decrease by 70% in comparison to other species.ConclusionVariation in the trend of the morpho-anatomical parameters as well as phytodiversity helps to understand the tolerance potential of the wild plants under wastewater irrigation released by tannery industries and that adverse developmental features in wild plants could be used as bioindicators of toxic heavy metal pollution.

Treatment of Real Tannery Industrial Wastewater via Sequential Biological and US/UV/activated Persulfate-Hydrogen Peroxide Processes

Tannery wastewater (TWW) is highly complex and is characterised by high contents of organic, inorganic, and nitrogenous compounds, sulphides, chromium, dissolved solids, and suspended solids. Therefore, our novelty lies in identifying the microbes which are used to degrade harmful azo dyes present in tannery effluent. Based upon the rising problems in tannery industries, the untreated effluent is discharged; to achieve zero effluent, the organisms are isolated from tannery effluent identified as Aeromonas hydrophila (OQ690635) and screened against the degradation potential against the azo dyes and further processed the azo dye-degrading organism for 16S rRNA sequencing. The optimisation was done in various parameters, which resulted in the highest 94% degradation at 37°C of 7 pH at the 60th hour in 10% of inoculum concentration, which influenced azo dye degradation and confirmed the degradation profile by FT-IR secondary alcohol, alkyne group, alcohol and nitro compounds, isothiocyanate, amine salt, alkyne had been removed and confirmed, also the treated Real-time effluent by novel bacteria which has shown 93% of degradation and also degradation profile by FT-IR and proven toxic free confirmed by GC-MS analysis. Thus, the bacteria isolated in this study can be used as eco-friendly biological expedients for the remediation and detoxification of azo dyes. This could be considered an efficient treatment method for various industrial effluents, as it provides zero sludge disposal during the treatment of industrial effluents.

The tannery industry generates substantial amounts of solid leather residues, posing environmental challenges due to their protein-rich composition and, in the case of tanned leather, heavy metal content like chromium, lead and cadmium. This study is part of a broader project aiming to valorise leather residues through the development of adapted formulations for different additive manufacturing (AM) techniques. Specifically, it focuses on investigating the cold crystallization behaviour of leather polymer composites (LPC) with a polylactic acid (PLA) matrix, intending to develop LPC filaments for fused filament fabrication, an AM technique. Two LPC formulations, LPC10PLA and LPC15PLA with 10% and 15% (in volume) of leather powder, respectively, were prepared. Differential scanning calorimetry assessed the cold crystallization behaviour at four different heating rates (2.5, 5, 7.5 and 10 °C min−1). The addition of leather particles accelerated the crystallization rate, resulting in well-defined exothermal peaks compared to neat PLA. Avrami, Ozawa and Liu’s kinetic models were employed, with Avrami and Liu’s models successfully describing the crystallization behaviour, while Ozawa’s method failed. Both models indicated a faster crystallization rate and the formation of three-dimensional crystalline structures in the presence of leather particles, suggesting their role as nucleating agents. Activation energy values determined by Friedman’s model, and polarized optical microscopy images also corroborate such behaviour. This research aims to demonstrate the potential for valorising leather residues through AM applications while revealing their crystallization behaviour.Graphical abstract

Benzene is a pervasive contaminant and human carcinogen. Its remediation from environmental resources using conventional procedures has always been challenging due to high cost and incomplete benzene degradation. The present study was designed to explore highly efficient bacteria with benzene degrading potential from tannery industry soil, which might be used as an alternative to these conventional benzene removal remedies. Bacterial isolation was performed using benzene (80 μl/1,000 ml) supplemented with minimal salt media (MSM). Characterization of isolates was carried out by performing growth curve analysis, Gram staining, biochemical characterization via Remel RapID™ NF PLUS System (Thermo Scientific™, Thermo Fisher Scientific, Inc., USA), antibiotic sensitivity profiling, 16S rRNA gene sequencing, benzene removal efficiency estimation assay, FTIR, and GC-MS profiling. Five bacteria isolated in the present study were identified as Paracoccus aestuarii PUB1, Bacillus tropicus PUB2, Bacillus albus PUB3, Bacillus subtilis PUB4, and Bacillus cereus PUB6. All of these fast-growing bacteria were Gram-positive except P. aestuarii PUB1. Maximum benzene removal efficiency (30 mg/l per 25 h) was found in B. tropicus PUB2. Comparing the FTIR spectra of bacterial culture supernatant versus control revealed the peaks shifting corresponding to benzene ring bonds breaking. GC-MS analysis identified the metabolic intermediates from benzoate methylation and benzaldehyde pathways. These bacteria can be employed for benzene degradation via enzyme-based nanoparticle synthesis or cloning of relevant genes in eco-friendly expression systems.