Temporal changes in chromium allergy in Denmark between 2002 and 2017.

BACKGROUND: In 2012, Danish authorities submitted a proposal to the European Chemical Agency restricting the content of hexavalent chromium to a maximum of 3 ppm in leather goods. Following its adoption, this proposal was implemented in 2015 as a directive in the EU. OBJECTIVES: To examine the temporal trend of chromium contact allergy in adult dermatitis patients patch tested between 2002 and 2017, and to determine clinical characteristics and causative exposures in these patients. METHODS: All adult dermatitis patients patch tested between 2002 and 2017 were included. Patch test data were reviewed retrospectively. Comparisons were performed with the χ 2 test and logistic regression analysis. RESULTS: A total of 13 379 adults aged 18 to 99 years were patch tested between 2002 and 2017. The overall prevalence of chromium allergy was 2.2%. An overall decreasing trend was found for the prevalence of chromium allergy (Ptrend = 0.00002). Specifically, a significant difference was found for the study periods 2010 to 2013 (Ptrend = 0.002) and 2014 to 2017 (Ptrend < 0.0001) as compared with 2002 to 2005. Leather remained the most important single cause of allergic contact dermatitis caused by chromium. The proportion of clinically relevant leather exposures increased from 42.3% during 2002 to 2009 to 54.8% during 2010 to 2017 (P = 0.04). CONCLUSIONS: The prevalence of chromium allergy is decreasing. The EU Directive restricting the use of hexavalent chromium in leather goods is thought to be playing a central role in this change.

Hexavalent and trivalent chromium in leather: What should be done?

Trivalent chromium compounds are used for leather tanning, and chromium may be released during use of leather goods. In certain instances, small amounts of hexavalent chromium can be formed and released. Both trivalent and hexavalent chromium can elicit allergic skin reaction in chromium sensitised subjects, the latter being significantly more potent. Induction of sensitisation only occurs after exposure to hexavalent chromium. A minority of subjects are sensitised to chromium, and in a fraction of these subjects allergic skin reaction have been described after wearing leather shoes or, less frequently, other leather goods. The evidence that in all these cases the reaction is related to hexavalent chromium is not always strong. The content of hexavalent chromium in leather is regulated in European Union, but rate of release rather than content is relevant for allergic skin reaction. The role of trivalent chromium appear much less relevant if at all. Modern tanning procedure do not pose significant risk due to either hexavalent or trivalent chromium. Dismissing bad quality and worn-off leather goods is relevant in reducing or eliminating the skin reaction. It should also be pointed out that shoe components or substances other than chromium in leather may cause allergic/irritative skin reactions.

UV emissions from artificial tanning devices and their compliance with the European technical standard.

Use of ultraviolet radiation-emitting tanning devices has been classified as "carcinogenic to humans" (group 1) by the International Agency for Research on Cancer. Following this classification, the knowledge of typical ultraviolet emission levels from tanning devices can be of interest for evaluating their impact on health. In this work, the results of an extensive measurement campaign on artificial tanning appliances are presented. Ultraviolet emissions from 94 tanning appliances produced by 15 different manufacturers were characterized by onsite spectroradiometric measurements. The measured radiometric quantities were compared with reference values fixed in the European technical standard EN 60335-2-27 "Household and similar electrical appliances-Safety. Part 2: Particular requirements for appliances for skin exposure to ultraviolet and infrared radiation." Measurement results indicate that 88% of the examined appliances had ultraviolet emissions not compliant with the technical standard. Among the considered appliances, tanning devices equipped with low pressure lamps showed higher ultraviolet levels of effective irradiance and less compliance with standard requirements. In particular, UV emissions from 100% of low pressure appliances and from 78% of high pressure appliances exceeded the irradiance limit of 0.3 Wm set by the European technical standard.

Policy framework for formulating environmental management strategy for sustainable development of tanneries in India.

OBJECTIVES: The leather industry is one of the main examples of industries which play an important role in the Indian economy in terms of exports and employment opportunities, while being blamed for environmental pollution. The objective of this study was to find the advances or improvements in the Japanese leather industry which are not found in typical leather industries in developing countries. We examined the Japanese leather industry in this context because Japan is a developed country in which tanning processes have been a traditional business from ancient times, and also the leather industry has played an important role in the process of economic development of Japan. METHODS: The study was based both on information collected from various areas related to the leather industry or leather industry stakeholders, and also on a review of published information. Information was collected through site visits, interviews, questionnaires, and detailed discussions with these stakeholders, as well as from their websites. RESULTS: The framework of a typical leather industry is discussed in three sections: pollution prevention, pollution control, and pollution mitigation related to sources, processes, and impact possibilities, respectively. Eleven basic differences were noted between the Japanese and Indian leather industries. The availability of melting centers is the main important feature of the Japanese leather sector. CONCLUSION: Guidelines are suggested which focus on some changes that are expected to lead to both environmental and economic benefits, with better pollution management, which should lead to continuous improvement of the environmental performance of the industry, and, finally, sustainable development.

Assessment on major factors that cause skin rejection at Modjo export tannery, Ethiopia.

A study was conducted from November 2009 to March 2010 with the objective of identifying the major causes of skin rejection on fresh, pickled, and wet blue skins at Modjo Mesaco Global tannery. A total of 401 fresh and 1,873 pickled and wet blue skins from the routine production system of the tannery were used. Overall, high prevalence of sheep ked (100%) followed by biting louse (64.4%), tick (50%), and sucking louse (45.8%) were observed on fresh sheep pelts, while, on fresh goat pelts, a high prevalence of sucking louse (54.5%), followed by tick (50%), and biting louse (35.5%) were observed. From the total of 90 rejected pickled and wet blue skins of sheep and goats, 98.8% were "ekek" and scratch, 85.6% sheep and goat pox, 74% poor substance, 73.3% heat, 72.2% scar, and 52.2% knife cut-in skins. Large number of skins rejections was recorded in large-sized skins (29.8%), and the lowest observed was in medium-sized skins (11.1%). There were highly statistically significant association (p < 0.05) between size and grades of shoat skins. Ekek and scratches together with sheep and goat pox were the common skin defects that hamper skin quality. However, there was no significant association (p > 0.05) between sheep and goat skins. Ekek and scratch caused high rejection of skin and entailed serious economic loss in terms of foreign exchange earning to Ethiopia. Therefore, the main causes of skin rejection and factors that cause downgrading of skin should be controlled.

Optimization of a novel enzyme treatment process for early-stage processing of sheepskins.

An enzyme treatment process for early-stage processing of sheepskins has been previously reported by the Leather and Shoe Research Association of New Zealand (LASRA) as an alternative to current industry operations. The newly developed process had marked benefits over conventional processing in terms of a lowered energy usage (73%), processing time (47%) as well as water use (49%), but had been developed as a "proof of principle''. The objective of this work was to develop the process further to a stage ready for adoption by industry. Mass balancing was used to investigate potential modifications for the process based on the understanding developed from a detailed analysis of preliminary design trials. Results showed that a configuration utilising a 2 stage counter-current system for the washing stages and segregation and recycling of enzyme float prior to dilution in the neutralization stage was a significant improvement. Benefits over conventional processing include a reduction of residual TDS by 50% at the washing stages and 70% savings on water use overall. Benefits over the un-optimized LASRA process are reduction of solids in product after enzyme treatment and neutralization stages by 30%, additional water savings of 21%, as well as 10% savings of enzyme usage.

Effects of leather industry on health and recommendations for improving the situation in Pakistan.

The leather industry and its associated sectors contribute significantly to the Pakistani economy. There are around 600 tanneries in Pakistan that are concentrated in 3 major cities (Kasur, Karachi, Sialkot). Waste discharge from tanneries pollutes the air, soil, and water, causing serious health problems. Exposure to such contaminated environmental milieu has been seen to culminate in a multiple array of disease processes such as asthma, dermatitis, hepatic and neurological disorders, and various malignancies. An overall dearth of research on the occupational hazards of employment in the leather industry as well as its effects on pediatric population was observed during literature review with particular reference to Pakistan. It is recommended that research should be conducted about the health hazards in the leather industry in Pakistan as well as globally to gather data that can be translated into effective prevention programs for both adults as well as pediatric populations.

Minimization of the environmental impact of chrome tanning: a new process with high chrome exhaustion.

In all tanning technology operations wastes are generated. These reach the environment as residual waters, solid and liquid waste as well as atmospheric emissions and odours. This study tests an alternative method to the traditional tanning method at an industrial level. The new method is based on tanning without float and by significantly increasing the temperature at the end of the tanning process. The properties of the leathers obtained using the two methods have been compared and the results indicate that those leathers have similar physical, chemical, and organoleptic properties. However, the differences existing from the environmental point of view are significant. It is not necessary to use clean water for this tanning. Moreover, there is a 75% reduction of the residual float, a 91% reduction of the chrome discharged, and a 94% reduction of the chlorides discharged. A financial assessment was carried out to demonstrate that the newly proposed system is 32% more economic than the traditional one.

Assessing the impact of leather industry to water quality in the Aojing watershed in Zhejiang Province, China.

The development of the leather industry in the Aojiang watershed of Zhejiang province increased the release of waste water. In the waste water, ammonium nitrogen (NH(+) (4)-N) and germanium (Ge) are the main pollutants. In recent years, literature has documented that the intake of high concentrations of NH(+) (4)-N and Ge harms human health and biological species. This paper focuses on assessing the trends of NH(+) (4)-N and Ge concentrations in the released waste water in Aojiang watershed and on understanding their relationships with the released waste water using regression and correlation statistics. The paper also utilizes the integrated pollution index to evaluate the water quality in the watershed. Preliminary results show that, from 1992 to 1998, the concentrations of NH(+) (4)-N and total Ge increased 13 and 14 times, respectively, and they decreased somewhat after 1998. The concentrations of NH(+) (4)-N and total Ge are positively correlated to the amount of released waste water. These concentrations of NH(+) (4)-N and Ge, respectively, exceed 12 and 3 times, of the water standards. The water quality in the watershed degraded from Type III in 1992 to over Type V in 2003 when they were compared with the national water quality standards. It appeared that the pollution had positive correlation with leather industry production. The degraded water has no doubt affected human health and the ecosystem health. These results can provide scientific information for the local government to reasonably adjust the industry structure and reduce the pollution to protect the environment.

Reversing the conventional leather processing sequence for cleaner leather production.

Conventional leather processing generally involves a combination of single and multistep processes that employs as well as expels various biological, inorganic, and organic materials. It involves nearly 14-15 steps and discharges a huge amount of pollutants. This is primarily due to the fact that conventional leather processing employs a "do-undo" process logic. In this study, the conventional leather processing steps have been reversed to overcome the problems associated with the conventional method. The charges of the skin matrix and of the chemicals and pH profiles of the process have been judiciously used for reversing the process steps. This reversed process eventually avoids several acidification and basification/neutralization steps used in conventional leather processing. The developed process has been validated through various analyses such as chromium content, shrinkage temperature, softness measurements, scanning electron microscopy, and physical testing of the leathers. Further, the performance of the leathers is shown to be on par with conventionally processed leathers through bulk property evaluation. The process enjoys a significant reduction in COD and TS by 53 and 79%, respectively. Water consumption and discharge is reduced by 65 and 64%, respectively. Also, the process benefits from significant reduction in chemicals, time, power, and cost compared to the conventional process.

High-performance liquid chromatographic method for the comparison of tanning capacity of tannic acid batches used in the manufacture of pregnancy testing kits.

A high-performance liquid chromatographic (HPLC) method was developed for the quantitative comparison of various batches of tannic acid from the same manufacturer used to aid the binding of human chorionic gonadotropin to sheep erythrocytes in the manufacture of pregnancy testing kits. The tannic acids were separated by reversed-phase HPLC on a C18 column using gradient elution with aqueous methanolic eluents at low pH. A portion of the chromatogram corresponding to the compounds involved in the tanninisation process was integrated and a linear relationship was established between this peak area and tannic acid concentration. The correlation coefficient was greater than 0.993 even in the absence of an internal standard. Tanning capacity was evaluated on the basis of the amount of tannic acid which remained following incubation with a known quantity of erythrocytes. The application of this procedure to three batches of tannic acid is demonstrated.