Leather Tannery Research Articles

Clean technological change in developing-country industrial clusters: Mexican leather tanning

In many cities in developing countries, clusters of small and medium-sized enterprises create severe pollution problems. Because conventional regulatory approaches are typically ineffective in such situations, policy responses have increasingly focused on promoting voluntary clean technological change. Yet the data and analysis needed to guide such efforts are scarce. This article uses original firm-level survey data on a cluster of small and medium-scale leather tanneries in Leon, Guanajuato—Mexico’s leather goods capital—to identify the factors that drive the adoption of two clean tanning technologies. Using a multivariate probit model to estimate a system of seemingly unrelated regressions, we find—in contrast to conventional wisdom—that neither firm size nor regulatory pressure is positively correlated with adoption. Rather, the key driver of adoption is the firm’s human capital, the same factor that often explains conventional productivity-enhancing technological change. We also find that a private-sector trade association is an important source of technical information about clean technologies.

Effect of phenolic compounds on the rapid direct enzymatic detection of β-D-galactosidase and β-D-glucuronidase

For the detection of indicator bacteria such as total coliforms or Escherichia coli (E. coli), microbial enzyme profiles are a preferred option compared to classical methods, because the reactions are more sensitive and rapid to perform and bacteria can be detected and enumerated through specific enzyme activities (Romprẻ et al., 2002). Chromogenic or fluorogenic enzyme substrates are used to detect the enzymes b-D-galactosidase (β-GAL) and b-D-glucuronidase (β-GUD). The chromogenic enzyme substrates are phenol-based, for example the enzyme substrates for β-GUD are p-nitrophenyl-b-D-glucuronide (PNPG) and 5-bromo-4-chloro-3-indolyl-b-D-glucuronide (XGLU), where PNPG produces ρ-nitrophenol (a yellow colour) and XGLU produces a blue indoxyl product. The fluorogenic substrate used to detect β-GUD is 4-methylumbelliferyl-b- D-glucuronide (MUG) (Manafi, 1996; 2000). β-GAL is detected by using the chromogenic substrates chlorophenol red- β-galactopyranoside (CPRG) and o-nitrophenyl-b-D-galactopyranoside (ONPG) (Edberg et al., 1988; Cheng et al., 2002). As phenolic compounds have extensive industrial applications, they are often found to be present in the aquatic environment (Llompart et al., 2002; Asan and Isildak, 2003). Several major sources are responsible for the presence of these phenolic compounds in the environment, e.g. pesticides, bactericides, wood preservatives and dyes. Phenolic compounds are also present in pulp processing, petroleum refining, leather tannery, textiles and plastics (Lee et al., 1996; Angelino and Gennaro, 1997; Pẽnalver et al., 2002; Asan and Isildak, 2003; Lupetti et al., 2004). Furthermore, phenols may also be found in fertilizers and explosives (Aktas et al., 2006). Keywords : coliforms, E. coli, faecal, b-D-galactosidase, b-D-glucuronidase, inhibition, wastewater

Associations of Fertility and Pregnancy Outcomes with Leather Tannery Work in Mongolia

To our knowledge, reproductive health effects among male leather tannery workers have not been previously investigated. Tannery work involves exposure to chromium, solvents, and other chemicals, which has been associated with adverse pregnancy and fertility outcomes in animals or humans in some studies. This study retrospectively investigates the association of male leather tannery work with preterm delivery, spontaneous abortion, time to pregnancy, and infertility by comparing tannery employees to other workers in Ulaanbaatar, Mongolia. Participants were randomly selected from current employee rosters at eight tanneries and two bread-making companies. The results of this research suggest that tannery work may be associated with reduced fertility in males. The study had limited statistical power, and some factors are likely to have biased findings toward the null hypothesis; other limitations and possible sources of undetermined bias give reason for cautious interpretation. Additional studies should be conducted to further examine fertility among tannery workers.

Associations of Fertility and Pregnancy Outcomes with Leather Tannery Work in Mongolia

Associations of Fertility and Pregnancy Outcomes with Leather Tannery Work in Mongolia

LEATHER FROM ANOTHER ERA

LIFE IS ABOUT TO CHANGE in Hazaribagh, the old tannery district of Dhaka, Bangladesh’s capital. Within two years—if the scenario currently envisaged pans out—the district’s 206 leather tanneries will either shut their doors or move to a different part of the city. Once relocated, their effluent will be treated and their workers will operate in far safer conditions. Some 30,000 workers and much equipment will move. A way of life will disappear in Hazaribagh, but no one is complaining. The district’s tanneries belong to a long-gone era. They dump their untreated waste into drains and ditches that lead to the Buriganga River, the main river flowing through Dhaka. Workers handle corrosive chemicals without protective gear and walk around the tanneries barefoot. The homes of tannery workers in Hazaribagh are built next to contaminated streams, ponds, and canals. The air is polluted by informal leather recyclers who burn scraps of leather to produce cooking oil, soap ...

The use of microemulsions to remove chromium from industrial sludge

In this work microemulsion systems were used to remove chromium from leather tannery sediments. The sludge was treated by a solid–liquid extraction process (acid digestion). The effects of particle size, digestion temperature and digestion time with regards to the efficiency of chromium removal were considered. The raw sludge (3 Mesh) was dried, grounded and sieved. Particles with 3, 14, 65, 100, 200, and 325 Mesh were evaluated. Sludge digestion solutions were prepared using each studied granule size at 25 °C, 70 °C, and 95 °C. Microemulsion extraction experiments to remove chromium III from the acid digestion solution were made according to a Scheffé Net experimental design methodology, using microemulsion systems inside the Winsor II region (System I) and inside the microemulsion region (Winsor IV – System II). A statistical treatment was used to obtain the isoresponse plots. Chromium extraction percentages were up to 73.3% for System I and up to 93.4% for System II.

Biological waste management of leather tannery effluents in India: current options and future research needs

This paper reviews the major biological treatment methods applied for tannery effluents in India. Anaerobic methods and activated sludge process have been the preferred treatment options. Sequencing batch reactor process holds promise for tannery effluents but the technology is yet to see the light of the day in India. Design of aerobic systems needs major overhaul through modelling approaches of the International Water Association (IWA). The failure of aerobic systems to deal with persistent substances in tannery wastewater has prompted the use of advanced treatment methods; their application however to large-scale treatment plants remains a major challenge.

Effect of the Detoxification on the Shrinkage Temperature and pH of Chromium Leather Waste, Another Promising Way for the Tannery Pollution

The leather tannery industry produces a significant amount of solid chromium waste. Environmental concerns and escalating landfill costs are becoming increasingly serious problems to the leather industry and alternative disposal methods are needed. This research describes the possibility of decrease of the shrinkage temperature and to increase the pH value of leather waste by detoxification treatment with use of tartrate potassium. Through this investigation, we have established that is more possible to reduce the shrinkage temperature and neutralizing the acidity of this waste without his degradation or digestion and with decreasing of his chromium content about 95%. The use of reaction time of 72 h generates the optimal decreasing of the shrinkage temperature of waste leather about 42°C close to the one of hide at native state (before tanning process) which reveal another ecological and simple way for the treatment of the chromium containing leather waste.

Genotoxicity of water from the Paraguay River near Cáceres–MT, Brazil in the Drosophila wing‐spot test

The genotoxic activity of surface water samples from four sites along the Paraguay River, near Cáceres, Mato Grosso State, Brazil, was investigated using the Drosophila melanogaster Somatic Mutation and Recombination test (SMART). Effluents from sanitary sewers and agroindustrial effluents (residual effluents from slaughterhouses, leather tanneries, and dairies) flow into the Paraguay River, and directly or indirectly contaminate water from sampling sites 1-3. Site 4 was an upriver reference site that received no domestic or agroindustrial discharges. Water was collected at 4 time periods: September 2003 and August 2004 (periods of low water or drought); and April 2004 and March 2005 (periods of high water or flood). Chromium concentrations above statutory limits were detected at sites 1-3 (August 2004), and sites 1, 2 and 4 (March 2005). Sulfur compounds were also detected at sites 1-3. The SMART performed using standard (ST) cross flies detected genotoxic responses in only two samples, the August 2004 site 1 sample and the March 2005 site 2 sample. Many more samples were positive using high bioactivation (HB) cross flies: site 1 (all collection periods), site 2 (September 2003 and April 2004), and site 3 (September 2003 and August 2004). Mutant frequency comparisons between marker-heterozygous and balancer-heterozygous flies from the HB cross indicated that the positive genotoxic responses for the site 2 (April 2004) and site 3 (September 2003) samples were due mainly to mitotic recombination. Our findings indicate that the section of the Paraguay River within the urban perimeter of Cáceres is contaminated with genotoxic agents.

Occupational health risks among the workers employed in leather tanneries at Kanpur.

In a cross-sectional study, a random sample of 197 male workers drawn from different sections of 10 leather tanneries in Kanpur were selected for the assessment of health risks. A control group comprising of 117 male subjects belonging to a similar age group and socioeconomic strata, who never had any occupational exposure in the leather tanneries, were also examined for the comparison purpose. The findings revealed a significantly higher prevalence of morbidity among the exposed workers in contrast to that observed in the controls (40.1% vs. 19.6%). The respiratory diseases (16.7%) were mainly responsible for a higher morbidity among the exposed workers whereas the gastrointestinal tract problems were predominant in the control group. The urinary and blood samples collected from the exposed group showed significantly higher levels of chromium, thereby reflecting the body burden of Cr in the exposed workers as a result of a high concentration of environmental Cr at the work place.

Investigation of water pollution in the Yalvac basin into Egirdir Lake, Turkey

The aim of this study is to understand the effects of pollution of anthropogenic origin on water quality in Yalvac Basin, part of the Egirdir Lake catchment. Surface discharge from the basin to the lake is 63 m3/year and underground discharge is 114 m3/year. Possible water pollution is categorized into domestic, industrial and agricultural origin. Domestic and industrial wastewaters, including effluents from leather tanneries are discharged, without being purified, into Yalvac Stream, which flows into Egirdir Lake directly or via the drainage canal. Surface waters flowing into the lake are used in winter for irrigation of agricultural areas. In agricultural areas natural and synthetic fertilizers and pesticides are used extensively. Lake Egirdir is used as a source of drinking water. Sampling sites were established for surface and underground waters, taking into account the known point sources of pollution. These sites were sampled in May and October of 2002, and analysed chemically. Cr3+ and Pb2+ concentrations exceed standard limits, meaning that pollution caused by effluent from the tanneries is adversely affecting the water quality in the lake.

The chromium issue in soils of the leather tannery district in Italy

Among heavy metals, up to now chromium has received little attention. The reasons for this lack of interest are diverse. One is that Cr was considered a “local source” contaminant, thus constituting a non-widespread environmental problem. A second reason is that the dominant naturally occurring form of chromium, Cr 2O 3, is considered essentially immobile in the environment, in contrast with the highly mobile and toxic Cr(VI). Based on these assumptions, we have started a research program aimed at assessing the actual chromium accumulation in soils and plants of a tannery industrial district in NE Italy. Further objectives of our study were: • to highlight possible contamination of soils, plants and waters; • to ascertain the potential risk to human health. Large differences in Cr concentration were observed in the area investigated, with a very scattered distribution. Mean Cr concentration in soils is 210 mg/kg (range 50–10,000). Most of the investigated sites present surface Cr concentrations higher than subsurface, suggesting local sources of Cr to be responsible for soil contamination. Chromium concentrations in selected plants ( Taraxacum officinale, Plantago lanceolata) present wide ranges in both the species examined, with little translocation from roots to leaves (barrier effect). To determine the groundwater pollution hazard in the surveyed district, we have compared the soil Cr concentration with the soil vulnerability map. Surface soils having the highest Cr concentration correspond to sites with very high to high vulnerability. Therefore, considering the present soil Cr concentrations and the pollution hazard, precaution and control acts are needed, in order to avoid more damage to land and waters. Moreover, considering all the above items, hazard for human health by direct contact with soil, ingestion, and inhalation should be taken in consideration by decision makers.

Wastewater Toxicity of Tannin- Versus Chromium-Based Leather Tanneries in Marrakesh, Morocco

The toxicity of leather tanning wastewater from a traditional tannery (TT), which is based on vegetable tannin (VT), was compared with wastewater from a tannery combining the use of chromium-based tanning (CT) with VT-based tanning operations. Wastewater samples from a TT and a CT plant as well as from five sewer sampling points were collected in Marrakesh, Morocco, and the concentrations of VT and some selected inorganics were measured. A set of bioassays were used to test wastewater toxicity in sea urchin (Paracentrotus lividus) embryos and sperm, in Daphnia magna, and in marine microalgae (Dunaliella tertiolecta). Toxicity end points included: (1) developmental defects, embryonic mortality, sperm fertilization success, and offspring damage in sea urchins; (2) D. magna immobilization; and (3) algal growth rate inhibition. Toxicity tests on TT and CT effluents (TTE and CTE) were run at dilutions ranging from 0.1% to 2% (sea urchins and algae) or up to 12% in D. magna. Parallel bioassays were run on VT extract (VTE) at nominal tannin concentrations ranging from 0.1 to 10 mg l(-1). The results showed higher toxicity of CTE compared with TTE. CTE toxicity in sea urchins and algae showed concentration-related trends, whereas TTE exerted hormetic effects at levels of 0.1% to 0.2% and toxic effects at levels >or=1%. The same trends were observed for VTE, suggesting a prevailing role of tannin in TTE-associated effects. The moderate wastewater toxicity of VT-based tanneries might prompt interest in the VT tanning process.

Fenton and photo-Fenton treatment of a synthetic tannin used in leather tannery: a multi-approach study

The aim of this work was to compare the behaviour of Fenton and photo-Fenton (UV-A, UV-C) processes to treat synthetic tannin (syntan) used in leather tannery which is one of the most polluting industries, releasing many xenobiotics. Both oxidation processes were performed at pH 3.0 and temperature 40-45 degrees C, which is the original temperature of the re-tanning process, in synthetic solutions containing 100 and 300 mg/L of COD equivalent of syntan. The efficiency of the applied oxidation processes was monitored by chemical oxygen demand (COD), oxidation redox potential (ORP) and aromaticity (UV280) and double bond (UV254) absorbance measurements. Acute toxicity test on Daphnia magna was performed to monitor toxicity in untreated and treated syntan solution. Gas chromatography-mass spectrometry (GC-MS) was applied to identify by-products of partial oxidation occurring in treated samples. The effective ratio of H2O2/FeSO4 for photo-Fenton processes was found to be feasible in terms of reagents used in the process.

Lessons learned for a more efficient knowledge and technology transfer to South American countries in the fields of solid waste and contaminated sites management

The present paper describes the development, performance and conclusions derived from three know-how and technology transfer projects to South American countries. The first project comprised a collaborative study by European and South American universities to find sustainable solutions for Chilean and Ecuadorian leather tanneries which had underachieving process performances. The second project consisted of investigations carried out in a Brazilian municipality to enhance its municipal solid waste management system. The final collaborative programme dealt with the initial identification, evaluation and registration of suspected contaminated sites in an industrial region of Chile. The detailed objectives, methods and procedures applied as well as the results and conclusions obtained in each of the three mentioned projects are presented, giving special attention to the organizational aspects and to the practical approach of each programme, concluding with their main advantages and disadvantages for identifying a set of qualitative and quantitative suggestions, and to establish transferable methods for future applications.

Prevalence and determinants of asthma in adult male leather tannery workers in Karachi, Pakistan: A cross sectional study

BackgroundThis study aimed to estimate the prevalence and to identify some risk factors of adult asthma in male leather tannery workers in Karachi, Pakistan.MethodsA cross sectional study was conducted from August 2003 to March 2004 on leather tannery workers of Karachi, Pakistan. Data were collected from 641 workers engaged in 95 different tanneries in Korangi industrial area selected as sample of convenience. Face to face interviews were performed using a structured pre-tested questionnaire by trained data collectors.ResultsPrevalence of adult asthma was 10.8% (69/641) in this study population. The prevalence of perceived work-related asthma was 5.3% (34/641). Multivariable logistic regression model showed that after taking into account the age effect, the leather tannery worker were more likely to be asthmatic, if they were illiterate (adjusted OR = 2.13, 95% CI: 1.17–3.88), of Pathan ethnicity (adjusted OR = 2.69; 95% CI: 1.35–5.36), ever-smoked (adjusted OR = 2.22, 95% CI: 1.16–4.26), reportedly never used gloves during different tanning tasks (OR = 3.28; 95% CI : 1.72–6.26). Also, the final model showed a significant interaction between perceived allergy and duration of work. Those who perceived to have allergy were more likely to have asthma if their duration of work was 8 years (adjusted OR = 2.26; 95% CI: 1.19 – 4.29) and this relationship was even stronger if duration was 13 years (adjusted OR = 3.67; 95% CI: 1.98–6.79).ConclusionPrevalence of asthma in leather tannery workers appears to be high and is associated with educational status, ethnicity, smoking, glove use, perceived to have allergy and duration of work.

Pilot Study of Chromium Exposures in the Mongolian Leather Tanning Industry

MAB3-PD-01 Session Title: Occupational Health (II) Introduction: Livestock-based industries are key economic drivers in Mongolia. Mongolian leather tanneries process 30,000 hides per day. Although regulatory standards exist for this industry, rapid growth in production has fueled concerns about its impact on worker and community health. In 2005, we conducted a pilot investigation of chromium levels among tannery workers and environmental samples from an urban area with high tannery density. Methods: Urine samples were collected from: 51 tannery workers (42 line workers, 9 managers), 32 workers from the industrial pre-treatment plant and the central sewage treatment plant (WWTP workers), and 28 control workers (garment factory, office workers). Samples were collected in acid-cleaned polyethylene bottles, microwave digested, and analyzed for total chromium by AAS (Zeeman 4100ZL, Perkin Elmer, Norwalk, CT). Environmental samples included 11 water and 3 sediment samples from a major river receiving tannery and sewage plant effluent, and 17 wastewater and 6 sludge samples from the 2 WWTPs. Samples were collected in acid-cleaned bottles, microwave digested, and analyzed for total chromium by ICP-AES (Perkin Elmer Optima 3000). Quality control samples included field and laboratory blanks. Statistical analyses were conducted in SAS 9.1 (SAS Institute, Cary, NC). Results: Mean chromium in the field blanks (n = 3) was 6 μg/L; results were blank corrected. Urinary chromium differed significantly among tannery, WWTP, and control workers (Kruskal Wallis P = 0.0004), with 95th percentile concentrations of 18.4 μg/L (tannery), 6.9 μg/L (WWTP), and 10.5 μg/L (control). Among tannery workers, urinary chromium did not differ significantly by job description (Wilcoxon Rank Sum P = 0.1816). Blank correction and method of handling below LOD values did not change test outcomes. Mean chromium was 6208 mg/kg in central WWTP sludge and 5430 mg/kg in pre-treatment plant sludge. Mean levels in wastewater sampled August 2005 from the pre-treatment plant were 1184 mg/L before and 29 mg/L after treatment (removal efficiency ∼97.5%). Removal efficiency dropped to 58% during peak tannery production (November to March). Pre-treatment plant effluent exceeded the Mongolian national standard (5 mg/L) regardless of season. Chromium was not detected in river water samples, and ranged from 15 to 64 mg/kg in sediment samples downstream from the central WWTP outfall. Conclusion: This is the first study to collect data on chromium exposures in the Mongolian leather tanning industry. Biologic sampling showed tannery workers have higher chromium exposures than other workers. High levels of urinary chromium among control workers was surprising; follow-up studies are currently underway.

Prevalence of and Factors Associated with Asthma in Adult Male Leather Tannery Workers of Karachi, Pakistan

Prevalence of and Factors Associated with Asthma in Adult Male Leather Tannery Workers of Karachi, Pakistan

Production of materials with alumina and ashes from incineration of chromium tanned leather shavings: Environmental and technical aspects

The leather tannery industry produces a significant amount of solid and hazardous wastes. Chromium-containing wastes like tanned shavings used to be incinerated in order to recover energy. The incineration process generates ashes that must be disposed of. This paper is a report on the results of the evaluation of technological properties and environmental compatibility of products made of alumina and ashes from incinerated chrome tanned shavings. The raw materials, tannery ashes and alumina were mixed together in different proportions. The ceramic bodies were molded using a hydraulic press and fired with a heating rate of 100 K/h until 1400 °C for 4 h in a muffle furnace. The ceramic specimens were characterized regarding physical, mechanical and thermal properties. Leaching tests, according to Brazilian, German and Dutch regulations, were performed on ceramic bodies containing different additions of ash. Results show that the ceramic materials produced are acceptable for refractory applications.

Retrospective Cohort Study of Cancer Mortality at the Minsk Leather Tannery

The cohort of 768 workers who were actively employed for a minimum of 6 months and died was retrospectively followed from 1 January 1953 to 31 December 2000. There were 328 women and 440 men observed. Proportionate mortality ratios (PMRs) were calculated using the Minsk-city population mortality proportions to generate expected numbers. The significant excess of pancreatic cancer (PMR=366%; 95%CI=134-800) and melanoma and skin cancer (PMR=455%; 95% CI=123-1,164) in women-workers of Dyeing and stuffing workshops was shown. The significantly high mortality from pancreatic cancer among Dyeing and stuffing workshops' female workers hired and discharged between 1958 and 1984 (PMR=1,024%; 95% CI=11-2,109), melanoma and skin cancer (PMR=440%; 95% CI=240-2,327) among Dyeing and stuffing workshops female workers who started before 1970, lip and buccal cavity among men who began working within 1974-1978 (PMR=1,071%; 95% CI=220-3,128), cervix and corpus uteri cancer among workers employed before l960 was found. It should be noted that the significantly high mortality from above noted cancers was indicated for Dyeing and stuffing workshops female workers with seniority more than 10 yr. Thus it was shown for pancreatic cancer (PMR=418%; 95% CI=136-975), for melanoma and skin cancers (PMR=497%; 95% CI=102-1,450), for uterus cancers (PMR=269%; 95% CI=130-496).