BTEX Profile in Ambient Air of in and around Gangtok (Sikkim) – North-East Himalayan Region

The present study aims to provide an indication of ambient levels of BTEX, a group of VOCs in and around Gangtok (Sikkim) for the first time in the history of North-East Himalayan Region of India. The study on VOCs particularly BTEX are important because they can present a health risk to humans, animals, and vegetations. Benzene is classified as a “Group A, known human carcinogen of medium carcinogenic hazard” by the United States – Environmental Protection Agency (Beim et al, 1998). Chronic (long-term) exposure to benzene is associated with haemotoxicity, genotoxicity, and carcinogenicity. For monitoring of BTEX levels, five sites were selected based on land use pattern i.e. Remote area, Commercial area, Residential area, Traffic Intersection area and Industrial area. The BTEX levels were observed for two years on monthly basis at these sites using passive sampling. The levels of pollutants were highest in the winter season, at traffic Intersection area and lowest in monsoon season, at remote area. The annual average concentration of benzene was slightly higher at traffic Intersection area in Gangtok (Sikkim) during June-2015 to May-2016 (II year) of measurement than its prescribed limit i.e. 5 μg/m³ as per National Ambient Air Quality Standards 2009 (NAAQS) of Central Pollution Control Board, Delhi. So, this is an alarming situation to ecosensitive and fragile environment of Gangtok (Sikkim).