RESEARCH ARTICLE Monitoring trace elements generated by automobiles: air pollutants with possible health impacts Khaleeq Anwar & Sohail Ejaz & Muhammad Ashraf & Nisar Ahmad & Aqeel Javeed Received: 24 September 2012 / Accepted: 29 November 2012 / Published online: 21 December 2012 # Springer-Verlag Berlin Heidelberg 2012 Abstract Major transformations in the environmental com- position are principally attributable to the combustion of fuels by automobiles. Motorized gasoline-powered two- stroke auto-rickshaws (TSA) and compressed natural gas (CNG)-powered four-stroke auto-rickshaws (FSA) are po- tential source of air pollution in south Asia and produce toxic amount of particulate matter (PM) to the environment. In this study, we attempted to characterize elemental pollu- tants from the PM of TSA and FSA using proton-induced X- ray emission (PIXE) analysis. The observations of the exist- ing investigation recognized significant increase in Al (P <0.05), P (P <0.01), and Zn (P <0.01) from the PM samples of FSA. In addition, the concentrations of Cu, Fe, K, Mg, Na and S were also observed exceeding the recommended National Institute for Environmental Studies limits. On the contrary, increased concentration of Sr and V were observed in the PM samples from TSA. It is generally believed that FSA generates smaller amount of PM but data obtained from FSA are clearly describing that emissions from FSA comprised potentially more toxic substances than TSA. The current research is specific to metropolitan population and has evidently revealed an inconsistent bur- den of exposure to air pollutants engendered by FSA in urban communities, which could lead to the disruption of several biological activities and may cause severe damage to entire ecological system. Keywords Air pollution . PIXE . Auto-rickshaw . CNG Introduction Air pollution is the contamination of air environment with diverse air pollutants that cause damage to living organisms and natural environment. Air pollutant, by definition, is any material which has potential to harm humans, animals, and vegetation (Kampa and Castanas 2008). Air pollutants largely affect human population and may contribute to seri- ous infirmity leading to increase mortality of the inhabitants, thus, posing a potential hazard to human health. The diverse nature, composition, exposure doses, and duration of expo- sure to air pollutants can lead to drastic impacts on human health ranging from nausea, dyspnea, skin allergies, birth defects (Ejaz et al. 2009a, c; Ejaz and Woong 2006), growth retardation (Ejaz and Lim 2005a, b; Ejaz et al. 2005a, b, c), damaged immune system, stroke, heart failure, and cancer, which may also persuade normal functioning of other vital systems (Cohen et al. 2005; Sawyer et al. 2010). Despite the fact that different natural/physical activities, e.g., volcanic eruption, forest fires, etc. may emit diverse air pollutants to the environment, anthropogenic activities are considered to be the foremost contributor of environmental air pollution (Kampa and Castanas 2008). The major trans- formations in the environmental composition are principally Responsible editor: Vera Slaveykova Khaleeq Anwar, Sohail Ejaz, and Muhammad Ashraf contributed equally to this work. K. Anwar : M. Ashraf (*) : A. Javeed Department of Pharmacology and Toxicology, University of Veterinary and Animal Sciences, Abdul Qadir Jilani Road, Lahore, Pakistan 54600 e-mail: drashraf2001@yahoo.com S. Ejaz (*) Department of Clinical Neurosciences, Neurology Unit, Stroke Research Group, Addenbrooke’ s Hospital, University of Cambridge, Cambridge, UK e-mail: se298@cam.ac.uk N. Ahmad Accelerator and Laser Lab, Centre of Advanced Studies in Physics, Government College University, Lahore, Pakistan Environ Sci Pollut Res (2013) 20:4574–4586 DOI 10.1007/s11356-012-1383-1