Abstract
This study assesses the ambient air concentration of and heavy metals at six different sites (including three sub-urban and three rural) in Roorkee, India. Monthly measurements were carried out continuously between January and March 2007 at all sites. PM concentrations at the rural sites ranged from 37-959 μg/m compared with 151-422 μg/m at sub-urban sites. These concentrations were well above the CPCB (Central Pollution Control Board, Delhi) standards during all sampling months except February. Conversely, lowest concentration during February was the result of removal of particles by heavy rain before the sampling days. In the case of heavy metals, highest concentrations for Cr, Fe, Mn, Zn, and Al were 2.04, 30, 0.80, 7.13, and 15.6 ng/m , respectively, at rural sites compared with 0.28, 0.37, and 0.02 ng/m for Ni, Cu, and Cd, respectively, at an industrial site. Main sources of PM and heavy metals at sub-urban sites were road dust, traffic exhaust, tire abrasion, industrial emissions, and oil lubricants use at vehicle-servicing centers. Heavy metals and PM at the rural sites originate from coal and wood burning, sugar mill and brick furnace emissions, fertilizers use in farming, agricultural activity, road construction activity, and the dust from long-range transport along with naturally occurring resuspended dust. Among all, wood burning was identified as the most significant source of elevated PM concentrations at rural sites. As opposed to the PM that remains a concern, concentrations of all heavy metals were found to be far below the standard limits prescribed by the World Health Organization (WHO) and the United States Environmental Protection Agency (EPA). An integrated assessment of air pollution and health risk is believed to be required to be carried out to draw better conclusions about air quality conditions in study areas. © 2012 American Society of Civil Engineers.