Volume No. 12 Issue No.: 4 Page No.: 483-492 April-June 2018




Karishma Hussain* and Subhash Medhi

Department of Bioengineering and Technology, Gauhati University, Guwahati, Assam (INDIA)


Received on : December 29, 2017




Polycyclic Aromatic Hydrocarbons (PAHs) are a distinctive class of organic pollutants containing two or more fused aromatic rings. They are widely investigated compounds and their occurrence has been reported from various places over the world. PAHs are inevitable byproducts of any kind of combustion practice including organic matter and can partition between the gas and the particulate phase. This partitioning process is strongly regulated by particle sizes, PAH species and temperature, and this in turn influences PAH transport, deposition, and degradation as well as health impacts. Health effects of PAH have been extensively evaluated, chiefly due to their potential carcinogenic and mutagenic properties. Dose, duration of exposure, and the individual characteristics such as age, sex, nutritional status, family traits, life style and the state of health mainly determine the level of health effects of PAHs exposure. Ingestion is quantitatively the key route for PAH human exposure. However, inhalation is also a major route because of their ubiquitous presence in the atmosphere. The most lipophilic compounds are primarily combined with the particle fraction, which can build up in the tracheobronchial epithelium, where they amplify PAH concentrations even at low environmental exposures of PAH. On the contrary, PAHs present in the gas phase or those that quickly elute from particles upon inhalation can reach the alveolar epithelium where they can swiftly enter the circulatory system. So, health risk caused by PAHs exposure has been assessed by researchers over the world using various methodologies. In light of the environmental implication of PAH exposure, this review offers an overview of PAH characteristics, gas particle partition in the air, human exposure, and health risk associated with their emission to the atmosphere.


Keywords : Polycyclic aromatic hydrocarbons (PAH), Air, Gas-Particle partition, Human exposure, Health risk