CHAPETR I INTRODUCTION Over the past century

CHAPETR I
INTRODUCTION
Over the past century, there has been increasing of various new chemical substances that are produced with advanced technology which cause major effects on environment. The personal care products are one of the foremost substances that are widely used by anthropogenically for personal or household use such as detergents, food storage containers etc. There are many chemicals like, phthalates, parabens, fragrances, atenolol, caffeine, carbamazepine, ibuprofen, trimethoprim etc (Paulsen, 2015) that are used in personal care products that destroys environment through direct discharge. In those chemicals, Triclosan 5-chloro-2-(2,4-dichlorophenoxy)phenol is a chlorinated chemical having antimicrobial properties, which was introduced about more than 50 years ago and used as preservatives and antiseptic agent in most consumer products, such as soaps, cosmetics, dental products, textiles, toys, paints, furniture and other household products (Sabaliunas et al., 2002) and also it has been categorized as halogenated aromatic hydrocarbon having phenolic, diphenyl ether and polychlorinated biphenyl (PCB) substances which related to toxicity (Ahn et al., 2008).
Antibacterial soaps, detergents contains the triclosan concentrations of 0.1 – 0.3% by weight. The usage of antimicrobial products is steadily increasing in worldwide. Due to their continual usage, Triclosan is frequently detected in sewage effluents, biosolids and soils of waste water treatment plants (WWTPs) and also in rivers, lakes and sea water (Kumar et al., 2010). Suddenly it is transformed into methyl-triclosan and dioxin compounds when it’s heated. Triclosan bioaccumulates in aquatic plants, animals and poses various ecological risks. Then it also enters into the food chain from contaminated water and agricultural runoff. In soil, sludge and sediments, Triclosan is readily degraded in the environment through photodegradation or sunlight irrandiance with a half-life of a week in aerobic and a month to years in anerobic conditions, forming other compounds like, chlorophenols, chloroforms and dioxins (Latch et al., 2005). In atmosphere, Triclosan has been degraded with a half-life of 8 hours based on the reaction of photochemically produced hydroxyl radicals.
At low doses, it is bacteriostatic and at higher doses, it acts as a bactericidal agent. Triclosan also inhibits fatty acid synthesis in plants and other living organisms. When it enters the cell, it poisons a specific enzyme called enoyl-acyl carrier protein reductase (ENR) preventing bacteria from synthesizing fatty acids required for building their cell membranes. It also has genotoxic and cytotoxic effects in algae and tends to bioaccumulate in algae, fish and enters into food chain (Brain et al., 2008) and it also found to have synergistic effects when combined with other common contaminants of water, which potentially making triclosan more toxic to environment. (Rodricks et al., 2010) suggested that TCS has adverse effects on endocrine function, thyroid hormones and antibiotic resistance. The carcinogenicity of TCS has been studied in rats and mice which indicate that it cause liver pathogenesis, particularly tumour formation which studied in mice.

The aim of this present study is to find out the Assessment of Triclosan and its derivatives in sewage, sludge and contaminated soils of Coimbatore, Madurai and Chennai to generate the information of Triclosan and its persistency in environment in Indian condition. Hence, there is no any Indian data among Triclosan concentration in sewage and sludge. In this study, the behaviour of Triclosan and its concentration in aqueous and non-aqueous region is explained with the objectives of,
Collection and characterization of sewage, sludge and soil samples in Sewage treatment sites of Coimbatore, Madurai and Chennai.

Assessment of concentration of triclosan and its derivatives (Methyl triclosan, Chloroform, Chlorophenol and Dioxin) in sewage, sludge and soil samples of sewage treatment sites in Coimbatore, Madurai and Chennai.