Leather, pollution effect

Materials and Structures. Building materials have become soiled and blackened by smoke, and damage by chemical attack from acid gases in the air has led to the deterioration of many marble statues in western Europe. Metals are also affected by air pollution for example, S02 causes many metals to corrode at a faster rate. Ozone is known to oxidize rubber products, and one of the effects of Los Angeles smog is cracking of rubber tires. Fabrics, leather, and paper are also affected by S02 and sulfuric acid, causing them to crack, become brittle, and tear more easily. 

Synthetic dyes are extensively used in many up-to-date industrial processes and research, mainly in the preparation of textile, food, and leather products, as well as in cosmetics and medicine. The widespread application of synthetic dyes has resulted in serious environmental pollution Their occurrence in ground water and waste-water and the accumulation in sediment, soil, and various biological tissues has often been observed and reported. Dyes and intermediates can cause abnormal reproductive function in males and show marked toxic effects toward bacteria. The rate of biodegradation of the majority of synthetic dyes is very low, enhancing the toxicological hazard and environmental impact. 

Abstract Indoor contamination is one source of exposure to toxic pollutants and has been classified as a high environmental risk. Epidemiological research linked health effects including childhood leukemia and neuroblastoma to the indoor occurrence of pesticides. Pesticides in indoor environments contribute to human exposure via inhalation, non dietary ingestion and dermal contact. Sources for pesticides indoors are direct applications, pesticides used in varnishes, colors, adhesives, etc., or in finishing textiles, leather, carpets, etc., and pesticides brought in from outdoors. Results for pesticides in indoor environments from different countries and obtained under different conditions are compiled in this chapter. They are discussed by applying two approaches (1) the comparison with reference values... 

In the 1930s, a major study was undertaken to determine the effects of different environmental conditions on over a hundred commercially- and experimentally-prepared leathers. Duplicate sets of books were bound with these. One set was shelved in the British Library, representative of conditions in a polluted urban atmosphere and the others in the National Library of Wales in Aberystwyth, a clean rural setting. The books were examined at regular intervals over a period of nearly 50 years for evidence of degradation. 

It can be concluded that chemical degradation of vegetable-tanned leather will occur in both polluted and unpolluted environments, and that both oxidative and hydrolytic reactions are always involved. The preponderant mechanism will depend on the exact conditions to which the leather is subjected. It should also be noted that the rate of decay of leathers exposed to the mainly hydrolytic effects of acidic urban atmospheres is much greater than the oxidative deterioration found with leathers held in cleaner rural surroundings. 

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