Journal of Environmental Protection, 2011, 2, 21-36 doi:10.4236/jep.2011.21003 Published Online March 2011 (http://www.SciRP.org/journal/jep) Copyright © 2011 SciRes. JEP 21 Ambient Air Non-Methane Volatile Organic Compound (NMVOC) Study Initiatives in India - a Review Amrita Talapatra, Anjali Srivastava NEERI, Kolkata Zonal Laboratory, I-8, Sector ‘C’, East Kolkata Area Development Project, Kolkata, India. Email: talapatra_amrita@yahoo.co.in Received September 14 th , 2010; revised November 8 th , 2010; accepted December 23 rd , 2011. ABSTRACT Different aspects of Volatile Organic Compounds (VOCs) are being investigated in details by different research groups in Indian institutes. The spectrum covers measuring technologies, source apportionment and variability studies, all these are in due process of preparing a guideline for the sustainable development in terms of industrial, infrastructural as well as overall growth of the country. Both the outdoor and indoor air quality has significant impact on human health. With special concentration on BTEX and HAPs, the health related investigations are conducted as part of inter- disciplinary studies of environmental science. Newer technologies to remove VOCs under specific industrial and prac- tical conditions are getting emerged as a comparatively new era. It addresses fields like adsorption, condensation, per- vaporation, biodegradation and catalytic combustion. Besides, different kinds of biofilters have drawn significant atten- tion nowadays. The final selection of appropriate technology depends on type and concentrations of VOCs, extent of separation required and cost involved. All these technologies are although well studied, but could not be adopted for regular commercial usage till date. There is scope to explore new horizons as well as regular monitoring on the intro- duced pathways to limit VOC emission in the ambient air. This review aims at a concise discussion on all the areas that come under the umbrella of non-methane VOC technologies. Keywords: VOC, India, BTEX, HAP, Biofilters, Catalytic Combustion 1. Introduction Volatile organic compounds (VOC) are ubiquitous at- mospheric species of both natural and anthropogenic sources. These are wide range of chemicals including aliphatic and aromatic hydrocarbons, alcohols, aldehydes, ketones, esters and halogenated compounds sharing the same characteristics of high volatility in the ambient en- vironment and result in alteration of the chemistry of atmosphere. On the global scale natural emissions of nonmethane hydrocarbons (NMHCs) and VOCs exceed anthropogenic emissions. Among the natural sources, vegetation is the dominant source. Oceanic and microbial production of these species is minimal as compared to other sources of input. On the other hand, anthropogenic sources are the result of urbanization and industrializa- tion. This rapid urbanization and industrialization, at some places in a most unorganized way, is the general picture in developing countries around the world. The main concern of VOCs is the role they play in the forma- tion of ozone and photochemical smog and increased risk of cancer. Thereby it is quite evident that although in rural areas natural vegetation causes VOC emission, due to lower NO x concentration, O 3 production is less; which is not the case in urban atmosphere, where due to the industrial and vehicular pollution the relative concentra- tion of NO x reaches up to a level so that it easily contrib- utes to production of O 3 even in small concentration of NMHCs. In polluted areas with relatively high concen- tration of NO x , photochemical oxidants of NMHCs, initi- ate a complex series of photochemical reactions that lead to the production of O 3 and other secondary oxidant pol- lutants [1]. The emission of VOCs thus have much more detrimental effect in urban areas and the percentage con- centration of VOCs in ambient air, their source profile identification and effect on health due to exposure should be well understood to undertake a successful planning of metropolis or establishment of industrial belt. India being a leading giant among developing coun-