A comparative study of BTEX profile in ambient air of Gangtok Sikkim and Delhi

Abstract

Air is an integral factor for our survival on Earth and when this air is polluted by VOCs (Volatile Organic Compounds) like BTEX, they can present a health risk to humans, animals, vegetation and environment. Compounds such as Benzene, formaldehyde and polynuclear aromatic hydrocarbons (PAHs) like benzopyrene are grouped in the category of potential carcinogens, which pose a high risk to public health. Ethylbenzene is suspected carcinogen. Toluene and Xylene are not carcinogens to human beings, though in recent studies, there are some evidences of carcinogenicity in experimental animals at high concentrations. VOCs can be emitted from anthropogenic as well as natural sources. For maintaining healthy air quality, knowledge of ambient levels of VOCs is necessary but miserably the information on VOCs levels for Indian cities is lacking. newlineIn urban atmosphere BTEX, a group of aromatic VOCs constitute up to 60% of non-methane VOCs. This group acts as one of the major polluter, proving it to be an efficient indicator of pollution arising from road traffic (because of increased global consumption of gasoline). Among all the aromatic hydrocarbons which are constituted in the class of BTEX, Benzene has been chosen a prime target for assessment of pollution levels in the urban atmosphere. BTEX are found naturally in petroleum products such as crude oil, diesel fuel and gasoline. Benzene is used in the production of synthetic materials and consumer products such as synthetic rubber, plastics, nylon, insecticides and paints. Toluene is used as a solvent for paints, coatings, gums, oils and resins. Ethylbenzene is a gasoline and aviation fuel additive as well as also used extensively in manufacturing processes. Ethylbenzene may be present in consumer products such as paints, inks, plastics, and pesticides. Xylenes are used as a solvent in printing, rubber, and leather industries. The majority of BTEX released into the environment enter the atmosphere directly. BTEX may be introduced into water by industrial effluents and atmosp