Leather Manufacturing Industry Research Articles

Study on the Influence of International Economic Law of Carbon Emission Trading on Environmental Sustainable Development

With the continuous development of global economic and trade activities, environmental problems have become an important factor restricting the sustainable development of all countries. How to realize the coordinated development of international trade and environmental protection has become a major issue facing the international community. Since China joined the WTO, its share of international trade has been increasing continuously. In order to deeply analyze the influence of international carbon emission trading policy on domestic carbon emissions, we use an input–output model and a GTAP analysis method to theoretically calculate the carbon emissions of the international trade of various departments in Shandong Province. At the same time, the implicit carbon emission index of various industries in 2022 is calculated through the direct energy consumption coefficient. The results show that there are significant differences in the impact of the carbon tariff system on different industries. In terms of the carbon emission index, the food processing industry showed a decrease of 18.99 Mt, while the implied carbon emission of the tobacco, textile and leather manufacturing industry reached 30.56 Mt due to the continuous expansion of trade scale. In contrast, the implied carbon emission level of the metal product processing industry reached 5.3 Mt, while the carbon emission of traditional trading industries such as coal mining was almost unaffected by international trade, and its carbon emission index reached the highest level of 5.89 in 2020. In terms of trade impact, high-trade industries such as the food processing industry are significantly affected by the carbon tariff policy, and their share has dropped from 5.89% to 3.95% in the past decade. The carbon emissions generated by GDP growth established by the GTAP model are more convincing. This model can directly reflect the energy efficiency of a region from the side. Based on the present situation of international trade, this paper analyzes the inequality of the current carbon tariff system, and puts forward some policies to optimize the energy structure to reduce carbon emissions and expand domestic demand to reduce the dependence on international trade. Through the GTAP model, we put forward policy suggestions to optimize the energy structure to reduce carbon emissions and the dependence on international trade by expanding domestic demand.

New materials-based on gelatin coordinated with zirconium or aluminum for ecological retanning

Ecological retanning agent is an effective way to solve the pollution source of leather manufacturing industry. In this study, the gelatin from chrome-containing leather shavings in the leather industry was used to realize sustainable leather post-tanning. The gelatin hydrolysate (GH) coordinated with Zr4+ or Al3+ to prepare eco-friendly retanning agents GH-Zr and GH-Al. The successful coordination between GH and metal ions was characterized by FTIR and XPS. The retanning agents were characterized by FTIR curve-fitting and circular dichroism spectroscopy. The results showed that the conformation of the secondary structure of the polypeptide became ordered and stable after coordinating with the metal ions. The particle size and weight average molecular weight of the retanning agents were ~1700 nm and ~2100, respectively, measured by nanoparticle size analyzer and gel permeation chromatography (GPC). The retanning agents were applied to retanning of chrome tanned leather and glutaraldehyde tanned leather. The abundant free amino from retanning agents can consume the free formaldehyde. Meanwhile, retanning agents can effectively improve the multiple binding sites, resulting in favorable thickening rate (>110 %) and excellent dye and fatliquor absorption rate with ~99.91 % and ~93.18 %. Thus, this strategy can provide a viable choice for solid leather waste and sustainable development of the leather industry.

Atomic-scale Ru anchored on chromium-shavings as a precursor for a pH-universal hydrogen evolution reaction electrocatalyst.

In the leather manufacturing industry, the management of substantial quantities of solid waste containing chrome shavings remains a formidable challenge. Concurrently, there is a pressing need for the development of pH-universal and economically viable electrocatalysts for the hydrogen evolution reaction (HER). In response to these intertwined challenges, this study proposes an innovative approach wherein the amino groups present on the surface of chrome shavings are utilized to immobilize single ruthenium atoms during pyrolysis, thereby facilitating the synthesis of hydrogen evolution electrocatalysts. The optimized sample, denoted as CN/Cr2O3/Ru-1, demonstrates exceptional electrocatalytic performance, exhibiting an ultra-low overpotential of -28 mV in 1.0 M KOH at a current density of 10 mA cm-2, and it also exhibits good performance in acidic and neutral electrolytes. Importantly, these overpotentials surpass those reported for many previous ruthenium-based catalysts. Density functional theory (DFT) calculations elucidate that both oxygen (O) and chromium (Cr) moieties within Cr2O3 can engage in favorable interactions with the coordination patterns of the ruthenium (Ru) atoms, thereby elucidating the synergistic enhancement conferred by the chromium element in CN/Cr2O3/Ru, which ultimately facilitates and promotes the catalytic activity of the ruthenium atoms serving as the catalytic center. This facile synthesis route not only presents a green solution for addressing waste chromium pollutants but also offers a promising avenue for the development of high-performance, cost-efficient electrocatalysts.

A study on health issues of leather industry workers

Leather manufacturing company workers faced so many health issues. This study explores to investigate the health issues faced by workers in a leather manufacturing company located in Vaniyambadi District. Through a comprehensive assessment of the workers' health, including surveys, interviews, and analysis of medical records, the study identifies the prevalent health concerns and explores potential contributing factors. The findings reveal that workers in the leather manufacturing company experience a range of health issues, with body ache, joint pain, and headache being the most common problems reported. Other health issues identified include teeth problems, irritation in feet, urinary tract discomfort, giddiness, eye irritation, chest irritation, stomach discomfort, and various other symptoms. The study assesses the work environment and job tasks to identify potential occupational health risks that may contribute to the observed health issues. Factors such as long working hours, exposure to hazardous substances, ergonomic challenges, and inadequate safety measures are examined. Based on the study findings, recommendations are provided to address the identified health issues. These include implementing ergonomic improvements, enhancing health and safety training programs, providing personal protective equipment, and fostering a culture of health and well-being within the organization. The results of this study contribute to the understanding of health issues among workers in the leather manufacturing industry, providing valuable insights for the company and relevant stakeholders to enhance occupational health and improve worker well-being.

A “wrench-like” green amphoteric organic chrome-free tanning agent provides long-term and effective antibacterial protection for leather

Organic chrome-free tanning agents are an important part of the sustainable development in leather manufacturing industry. However, organic chrome-free tanning agents tanned leather have a low isoelectric point (pI < 5), which results in a low absorptivity of traditional anionic wet finishing materials; as a result, leather quality is poor, and tannery wastewater is difficult to treat. In addition, leather is easily eroded by bacteria and mold during its production, storage, and use, causing serious economic loss to enterprises and users. In this study, hexahydro-1,3,5-tris(hydroxyethyl)-s-triazine (HHTT), ethylene glycol glycidyl ether (EGDE), and collagen polypeptide (CP) were used as raw materials to prepare a wrench-like, antimicrobial, amphoteric, epoxy-terminated, organic chrome-free tanning agent (HHTT-EGDE-CP) with a pI of 5.21, and an epoxy value of 0.267 mol/100 g. HHTT-EHDE-CP can establish a stable covalent cross-linking with collagen fibers, thereby enhancing the physicochemical properties of leather, the absorptivity of anionic wet finishing materials, giving leather long-term and efficient antibacterial properties. Experimental results show, that the shrinkage temperature (78.8 °C) and the absorptivity of anionic fatliquors (93.1%) and dyes (97.5%) of HHTT-EGDE-CP-tanned leather surpassed those of leather tanned using commercial organic chrome-free tanning agents. Notably, the inhibition rates of HHTT-EGDE-CP-tanned leather against E. coli and S. aureus reached 99.93% and 99.99%, respectively. In addition, HHTT-EGDE-CP-tanned leather exhibited excellent inhibition against A. flavus and Asp. niger, with long-term and efficient antibacterial properties. This innovative technique offers new perspectives for designing and developing multifunctional green materials toward the sustainable development of industrial manufacturing.

Sustainable leather making — An amphoteric organic chrome-free tanning agents based on recycling waste leather

Currently, globally, 90 % of the tannery is still tanned by using chrome, resulting in chromium-containing wastewater and chromium-containing solid waste that will cause serious harm to the environment. Under the pressure of environmental protection, on the one hand, the leather manufacturing industry should to dispose the current problem of chromium pollution, especially chromium-containing solid waste (chromium-containing waste leather (CCWL)), on the other hand, to popularize chrome-free tanning agent. Organic chrome-free tanning agents are the way forward for chrome-free tanning agents. However, organic chrome-free tanning agents exhibit several limitations with respect to their preparation and applications: The preparation process is not eco-friendly, and physicochemical properties of tanned crust leather are poor. More importantly, the leather tanned by an organic chrome-free tanning agent has low absorptivity of traditional anionic wet finishing materials, resulting in high total dissolved solids in tannery wastewater, which increased the difficulty of tannery wastewater treatment, and posed a potential threat to the environment. In this study, collagen polypeptide (CP) was extracted by using in situ dechromization and industrial trypsin from CCWL, followed by modification with ethylene glycol diglycidyl ether (EGDE) to obtain an epoxy-terminated, biomass-based, amphoteric organic, chrome-free tanning agent (CP-EGDE) with a high isoelectric point of 5.16, and an epoxy value of 0.316 mol/100 g. CP-EGDE can be applied in the pickling-free and salt-free tanning processes to prepare wet white leather and the tannery wastewater with good degradability. The shrinkage temperature (Ts = 84.9 °C), grain flatness, fullness, softness, yellowing resistance, mechanical properties, absorptivity of traditional anionic fatliquor (88.4 %) and dyes (95.3 %) of CP-EGDE tanned leather exceeded those of commercial organic chrome-free tanning agents. This research considered both environmental protection and leather quality, especially greatly improving the absorptivity of traditional anionic wet finishing materials. CP-EGDE is expected to replace chrome tanning agents and has good application prospects.

Superhydrophobic Modification of Collagen Fiber

Tanning is considered to be the crosslinking reaction between collagen fibers and tanning agents, and a majority of tanning reactions result in suppressed water absorption and enhanced hydrophobicity of leather. However, extensive use of tanning agents may bring a burden to the environment. Herein, to facilitate a sustainable leather manufacturing industry, we propose a revolutionary strategy of “tanning” without tanning agents. Based on this strategy, superhydrophobic collagen fibers (FAS-CFs) were fabricated through dehydration, followed by superhydrophobic modification. Dehydration aimed to eliminate the “sticky” effect of water on collagen fiber to obtain a dispersed hierarchical structure. Superhydrophobic modification not only dispersed and stabilized the fiber structures, but also protected the fiber dispersity from water immersion. Compared with chrome-tanned collagen fibers (Cr-CFs) and glutaraldehyde-tanned collagen fibers (G-CFs), FAS-CFs showed higher hydrophobicity, lower water absorption, and superior mechanical properties. Meanwhile, FAS-CFs exhibited a high thermal denaturation temperature of 92.5°C and retained their original shape after being heated to 100°C. Therefore, our proposed strategy is expected to be a potential substitute for conventional tanning and might contribute to cleaner and sustainable leather manufacturing.

Characteristics, Sources, and Risk Assessment of Perlyfluoroalkyl Substances in Surface Water and Sediment of Luoma Lake

Through the investigation and detection of the surface water and sediments of Luoma Lake, the structure and occurrence characteristics of PFASs (perlyfluoroalkyl substances) in the two types of media were analyzed, and the principal component analysis method was used to analyze the characteristics of such substances in the surface water. The source was analyzed, and the potential health risks of such substances were evaluated using the risk quotient method. The results showed that a total of 13 PFASs were detected in the surface sediments of Luoma Lake, and one more species was detected in the surface water (PFTeA); ρ(ΣPFASs) in the surface water ranged from 46.09 to 120.34 ng·L-1, and ω(ΣPFASs) in sediments ranged from 2.22 to 9.55 ng·g-1. PFPeA was the major component in surface water, and the mass fraction of PFPeA was 38%. PFBA was the major component in sediment, and the mass fraction of PFPeA was 61%. The multi-media PFASs in Luoma Lake were mainly short-chain substances; the high concentration area of PFASs in the surface water of Luoma Lake was concentrated and distributed at the mouth of the northern rivers. Its concentration showed a decreasing trend from north to south, and the content of PFASs in the sediments showed a decreasing trend from southwest to northeast. The distribution of ΣPFASs, PFBA, and PFOS in the sediments of Luoma Lake and the TOC content in the sediment were related; the principal component analysis showed that the PFASs in the surface water of Luoma Lake were mainly from textile flame retardant, rubber product emulsification, food packaging processes and paper surface treatment industries, the metal electroplating industry, and leather and textile manufacturing industries. PFASs in the surface water of Luoma Lake were at a relatively low health risk level.

Cr (III) genotoxicity and oxidative stress: An occupational health risk for leather tannery workers of South Asian developing countries.

In the leather industry, Cr (III) is used as a basic tanning agent. The wastewater discharged from the tannery industry contains a high concentration of chromium. Recent studies indicate the genotoxic effects especially DNA damage and oxidative stress of Cr (III) in tannery workers. Cr (III) interacts with DNA to form DNA cross-links and DNA strand breaks. It also modifies the oxidative DNA base through the Haber-Weiss reaction. The present study is based on an overview of scientific literature and previous observations regarding the effects of tannery chromium effluents on exposed workers and the population in the vicinity. This study strongly suggests for use of a non-toxic substitute of chromium to be used for the tanning process and placement of tannery industries on the outskirts of the city. In South Asian developing countries like India, Pakistan and Bangladesh where the economy is strongly dependent on leather manufacturing industries, there is a need to spread proper information regarding the harmful effects of chromium toxicity to the workforce employed in the tannery and also to the people living in the surrounding area. Workers should be provided with the required safety protections like gloves, aprons, foot/shoe covers, masks, etc. Last but most important on an immediate basis is the installation of the proper efficient waste treatment plant, so that, waste should be treated before moving out of the industry.

Application of value stream mapping (VSM) in low-level technology organizations: a case study

PurposeThis research aims to improve the performance and productivity of low-level technology organizations using lean tools – value stream mapping (VSM). In order to investigate the application of VSM in low-level technology organizations, this study takes footwear manufacturing organizations as a case study.Design/methodology/approachIdentifying a suitable organization was the first step for conducting the case study, followed by product family identification. Time and motion studies are used to determine the cycle time and identify the value-adding and non-value-adding activities, respectively. After making necessary observations and calculations, the current state map was developed. Different improvement proposals were identified, and the future state map was constructed.FindingsAs a result, 56.3% cycle time reduction and 69.7% reduction in lead time were obtained, confirming its application in low-level technology organizations to improve their performance and productivity. This promising result indicates that a significant improvement can be achieved if VSM is applied in low-level organizations other than footwear industries, such as the clothing and furniture industries. Speed is investigated to be one of the parameters in motion study.Research limitations/implicationsThis study focuses on low-level technology organizations, specifically leather shoe manufacturing industries. But experiences gained from implementing this study are realistic and applicable in similar organizations.Practical implicationsPerformance and productivity improvement are critical issues to be addressed in low-level technology organizations, especially in the leather footwear manufacturing sector. This can be achieved through VSM by identifying and removing the wastes. VSM can be applied to low-level organizations as well. VSM is a powerful tool that helps managers and practitioners in identifying wastes and opportunities for improvement.Originality/valueThe paper addresses applicability of VSM in the production process of low-level technology organizations with an original industrial case study in Ethiopia.

A “Taiji-Bagua” inspired multi-functional amphoteric polymer for ecological chromium-free organic tanned leather production: Integration of retanning and fatliquoring

Comprehensive promotion of chrome-free organic tanning system has become an inevitable trend for cleaner production in leather manufacturing industry. However, the imbalance of interface charge between conventional anionic wet finishing material and organic tanned leather leads to poor quality of finished leather. Herein, a novel amphoteric polymer P (AA-AM-C12DM) as retanning and fatliquoring dual-functional wet finishing material was prepared by free radical polymerization using acrylic acid (AA), acrylamide (AM), and (2-methacryloyloxyethyl) dodecyl ammonium bromide (C12DM) as raw materials in an aqueous system and further applied in TWS organic tanned leather. Comprehensive structural and performance characterization of P (AA-AM-C12DM) confirmed the presence of amphoteric groups and hydrophobic long chains in its structure. Number average molecular weight and isoelectric point were determined to be 6396 g mol−1 and 5.16, respectively. The physical and mechanical properties, morphology of the P (AA-AM-C12DM)-treated leather, and their reactivities to anionic dye were investigated. The effect of hydrogen bond and ionic bond, which resulted from reactions between the carboxyl groups, amide groups, cation N+ in P (AA-AM-C12DM), and the pendant amino groups, hydroxyl groups, carboxyl groups from collagen fibers, benefitted in enhancing the physical and mechanical properties of crust leather and their reactivity to anionic dye. Moreover, P (AA-AM-C12DM) showed remarkable environmental benefits compared to the commercial fatliquor, by significantly promoting dye absorption as high as 96.57%. These findings provide a potential application of P (AA-AM-C12DM) to coordinate well with an ecological chrome-free organic tanning system, significantly promoting the cleaner production in the leather industry.

Production of tannins from Acacia nilotica pods for the leather manufacturing industry – extractions, characterization, and optimization using design of experiment

The pods of Acacia nilotica were successfully utilized for the extraction of tannins using a methanol/water extraction medium. The experimental design employed for the extraction was a central composite design that enabled the evaluation of the effects of time, temperature, and methanol concentration on the dependent variables of extraction yield, total phenolic contents (TPC, as gallic acid equivalents (GAE)), and antioxidant activity (AA, as millimoles of ascorbic acid equivalents (AAE)). Response surface models were developed for the three responses, and statistical analysis of variance was performed to determine the optimum values of the independent variables and the coefficients of determination. The maximum extraction yield of 46.2 wt% (pod extract) was achieved at 200 min, 85 °C, and 40% methanol concentration. Similar conditions also led to the attainment of 50.7 wt% TPC and 51.3 mmol AAE/100 g pod. The coefficients of determinations were 0.9750 for extraction yield, 0.9626 for TPC, and 0.9774 for AA, which indicated that the model equations obtained fitted the experimental data. The result of the retanning of the leather using the extracted A. nilotica tannins also showed that the tear and tensile strength, as well as the elongation at break, of the leather samples were within the range obtained when chestnut extract and chrome tannin were used.

Respiratory Health Upshots due to Contaminated Living Environment: A Cross-Sectional Study of the Industrial Belt of Kanpur City, India

In recent decades, air pollution has become a real threat to the lives and health of populations around the world. Today, about 92% of the world’s population lives in areas with low air quality standards. In India, in particular, air pollution is one of the main causes of respiratory and allergic diseases, asthma, chronic obstructive pulmonary disease, pneumonia, and even tuberculosis. The purpose of this study is to analyze the extent of the spread of respiratory diseases in people living near the leather manufacturing industry in Jammu, Kanpur, India. The source of information is a cross-sectoral survey of male workers from the Jammu area, for which a three-stage sampling model is used. The study area selected areas of Bujiat, Motinagar, and Asharfabad because of the high concentration of the population employed in leather processing plants. During the study, the authors used one- and two-dimensional statistics. The study showed that there are no major benefits of civilization in the study areas: housing, water, hygiene and sanitation, waste treatment, etc. In the last 12 months, it was found that 11% of the population in the aforementioned territory experienced symptoms such as wheezing or wheezing at any time of the day, ie permanently, and another 9% of the population were waking up from chest tightness in the previous 12 months. During the survey period, 10% of the respondents had coughing sputum at least three months before the day or night. The rapid spread of various respiratory diseases may be associated with higher levels of air pollution. The article presents the recommendations of the authors on adherence to the principles of fair industrial activity within the framework of corporate social responsibility and the promotion of sustainable development of territories. Keywords: living environment, morbidity, respiratory health, workers.

Wastewater from leather tanning and processing in Palestine: Characterization and management aspects

Leather manufacturing industry has major environmental impacts. Characterization of tannery's wastewater (WW) is a key step in the management of wastewater released from various processes. This study presents some physicochemical characteristics measured in wastewater. It compares the pollution loads released from both goat and cow hides processing. The main pollution characteristics of wastewater released from two local tanneries were determined experimentally, through analyzing real samples of industrial discharges. These include chemical oxygen demand (COD), total solids (TS), total dissolved solids (TDS), total suspended solids (TSS), pH, and the concentrations of chloride, ammonia (NH3) and chromium in both states, Cr (III) and Cr (VI). Characterization of such processes effluents assists in identifying waste generation rates and discharges, and then in recommending cleaner production options. The results shows that the amount of WW produced in the local Palestinian tanneries is much lower than tanneries worldwide, whereas it is more concentrated with pollutants. Liming process has the highest COD and the highest pH value, where tanning process releases WW highly concentrated with chromium. Real process measurements and mass balance calculations indicated that the chromium uptake efficiency is only 46.6%. Such a low efficiency indicates that cleaner production measures are essential in local tanneries.

Health Issues among Women Employees in Leather and Leather Related Manufacturing Industries in Chennai

Overview: Nowadays women are playing multi-task generally neglecting their health but focus much on work and family. Does women working in leather and leather related industries affected with any health issues? What are the different types of health issues they face? In this article we are mainly focusing on health issues faced by the women employees in leather and leather related industries. Design/Methodology/Approach: The study followed a descriptive research design; quantitative research has been used; convince sampling is used among 149 women employees in leather and leather related manufacturing industry in Chennai in India. Structured questionnaire was developed using a five-point Likert scale. The SPSS 22.0 statistical tool was used to examine, one way anova, paired correlation, factor analysis used to interpret and analyze the data. Findings: The study enlightens different type of health issues faced by women employees working in leather and leather related products and violence faced by women employees in their workplace and their home. Women are suffering physically, psychologically and even their inner health has been affected because of the conflict, violence against them, working condition in the organization and also because of sexual harassment. Keywords: Health Issues, Role Conflict, Violence, Women Employees

Design Key Performance Indicator for Sustainable Warehouse: A Case Study in a Leather Manufacturer

This research discussed the design of Key Performance Indicators (KPIs) for sustainable warehouse for leather manufacturing industry. A thirty four indicators are found from literature study and validated by experts using likert scale. A number of 30 KPIs are declared valid then suggested to be KPIs for sustainable warehouse for leather manufacturing industry. The KPIs consisted of 12 economical indicators,10 social indicators and 8 environmental indicators. To find out the priority of each KPIs, then their importance weight are identified using analytical hierarchy process (AHP) by sending AHP questionnaire to experts. The result shows that Economical factor is the most dominant factor (0,4796) followed by social factor (0,4055) and environmental factor (0,1150).The KPIs and its weight can be used as guidance for leather manufactures to increase their sustainable performance.

Análisis de los tiempos de preparación para la reducción de desperdicios en el proceso de troquelado. Caso aplicado industria de calzado.

En la presente investigación se analiza la reducción de desperdicios en los tiempos de preparación del proceso de troquelado en tres líneas de producción de industrias manufactureras de calzado de cuero. Se estudia los productos con mayor demanda a través de un análisis de segmentación de productos ABC, una vez establecidos los mismos, se inicia con el levantamiento de información de todas las actividades que conforman el proceso de troquelado, realizando un estudio de tiempos, y luego un análisis acerca de las actividades en las que existen tiempos de preparación, para determinar los desperdicios dentro del proceso. En la investigación se utilizó la metodología SMED que busca reducir los tiempos de preparación transformando actividades internas del proceso en actividades externas. En el proceso de troquelado al poseer maquinas manuales se procede con la reducción de tiempos en las actividades de preparación de materiales y la estandarización de los procesos. Como resultados se obtuvieron reducción de desperdicios de tiempo en un 3% en la línea de calzado casual, 6% en la línea de calzado deportivo de mujer y 10 % en la línea de calzado de seguridad industrial en la producción diaria de cada uno de los procedimientos que comprenden el proceso de troquelado los mismos.

Prioritizing Type of Industry through Health Risk Assessment of Occupational Exposure to Dimethylformamide in the Workplace.

The purpose of this study was to classify hazards at an industrial level and evaluate the exposure risks of workers exposed to dimethylformamide (DMF) used as a solvent in the workplace and to determine industries that need priority measures in managing DMF exposure. We calculated hazard quotients at an industrial level. The exposure data of DMF in the workplace were obtained from the work environment monitoring program provided by the Korea Occupational Safety and Health Agency. The evaluation was conducted on textile manufacturing, leather manufacturing, chemical manufacturing, pharmaceutical manufacturing, and rubber manufacturing industries, which have many unit work sites handling DMF. The highest central tendency exposure and reasonable maximum exposure were 2.13 and 18.66 mg/m3 for the rubber product manufacturing industry, respectively. A total of 63.8% of workplaces in the textile manufacturing sector had a hazard quotient higher than 1. The highest risk for exposure to DMF is in the rubber and plastic manufacturing industry, and the lowest risk was in the medical materials and pharmaceutical manufacturing sector. Based on this study, effective management of DMF exposure could be achieved by establishing priority management measures for the textile and rubber and plastic product industries.

Potential health risk of heavy metals in the leather manufacturing industries in Sialkot, Pakistan

This is a systematical report on the potential health risk of heavy metals from the leather industries in Pakistan based on multiple biological matrices of the exposed workers and indoor dust samples. The adverse impacts of heavy metals on the oxidative enzyme and their risks to workers’ health were also explored. Our results indicated that the level of Cr in indoor industrial dust was more than twice, compared to the background household dust. Blood, urine and hair samples of exposed workers showed significantly high concentrations of heavy metals, compared to those in the control group. Superoxide dismutase (SOD) level in the blood samples expressed significant positive correlation with Cr and Ni. Total hazard quotients (HQs)/hazard index (HI) were >1, and Cr (VI) exhibited higher cancer risks than that of Cd in the exposed workers. In addition, the PCA-MLR analysis confirmed that the industrial sections; cutting, shivering/crusting, and stitching were the principal contributors of heavy metals in the biological entities of the workers. Taken together, our results highlighted the occupationally exposed groups would likely to experience the potential health risks due to excessive exposure to the heavy metals from the leather industries.

Reduction of Excessive Trimming and Reject Leather by Integration of 7 QC Tools and QC Story Formula: The Case Report of Sheba Leather PLC

At the present time most of Ethiopian leather manufacturing industries are facing tough competition globally due to deteri-orated quality of leather. Clearly known that poor quality results in increasing manufacturing cost. Lastly, the industry becomes unprofitable. In addition, the industries are forced to lose their customers. Sheba leather Industry PLC is one of Ethiopian leather manufacturing industry facing this problem. So, the purpose of the project is to decrease extreme trimmed and rejected leather, to introduce a system that is capable of solving the problem, to expand findings to other sections of the industry. There was a problem of trimmed and rejected skin leather at re-tanning and crust preparation section. 14,879.92 kg of trimmed skin leather and 8,164 pieces of rejected leather. The problem solving methodology approach was used during the project work to reduce both trimmed and rejected leather. Quality control 7 tools were also applied as per the nature of the steps of problem solving. The findings after completion of the implementation period the excessive trimmed leather is reduced to 8,524 kg by 42.71% improvement. The rejected leather of minimized to 5,241 pieces of leather by 35.80% improvement. In addition, systems like standard operation procedure, standardization of four basic autonomous maintenance activities, quality control process chart and operator skill analysis are introduced on potential areas. Besides, the area of the finished leather also improves by 2.2% relative to the input size of the leather. Finally, the department managers took responsibility to sustain the substantial improvements and expand these systems to hide production section of the company.