Xenobiotic Products & Natural Environments Pollution
Industrial revolution has led to invention of many materials which are man-made and not resembling to natural ones. The term xenobiotic (stranger to life) is derived from the Greek word ‘xenon’ – a strange and ‘bios’ – life. For environmental chemist, xenobiotic means foreign to the biosphere and Anthropogenic is the specific term for man-made. These materials may be the products, intermediates or wastes of our industrial and other activities; at whichever stage they enter into the nature, they cannot become the part of cycle of the matter, because of this simple reason that microorganisms do not find any resemblance between these materials and their natural food habit.
However, all foreign to nature man-made substances need not be non-degradable. Those compounds which are not capable of degrading in nature following their release in the environment even when conditions are adequate for microbial growth, are termed as ‘Recalcitrant Compounds’ which persist in all natural environments, regardless of whether they are inherently degradable or not. Without being biased to any industry, it is the clearly accepted fact that xenobiotic compounds, toxic chemicals and other hazardous wastes come from the petrochemical / pesticide /chemical industry & metal processing.
There is a long list of pollutants which are tough to be biodegraded and pose environmental and health hazard including solvents, wood preservatives chemicals, plasticizers, refrigerants, coulter wastes, biphenyls, polychlorinated/polybrominated biphenyls, synthetic fibers, plastics, polyvinyl chloride, polystyrene, detergents such as alkyl-benzene sulphonates, Oils etc. The first man-made plastic was invented by Alexander Parkes, a British metallurgist, in l862, and the resu1t was publicly displayed at Great International Exhibition in london (Bellis, n.d.).
In 1907, Leo Hendrik Baekeland invented the first fully synthetic resin, called Bakelite, which experienced commercial success (Bellis, n.d.). Later on, the plastic industry greatly expanded during World War II, and continued thereafter (CHF, 20l0). In the modern world, use of plastic is ubiquitous. Plastic has become now the material of choice used in various products which were previously fabricated from metal, glass, wood, or materials derived from plants & animais (e.g., cotton and wool).
It is an undeniable fact that plastic brings convenience to human life due to its versatility, durability, and low cost, and is therefore popular among both manufacturers and consumers. Over 50 years, global production and consumption of plastics have continued to increase. An estimated 299 million tons of plastics were produced in 2013, representing 4% increase over 20l2, and leading to an upward trend Over the past years. In 2008, global plastic consumption worldwide has been estimated at 260 million tons. Plastic is versatile, lightweight, flexible, moisture resistant, strong.
