Abstract
A campaign took place in Wales (UK) in the spring of 2006 to characterize emissions from a major steelworks through atmospheric measurements. At no time during the measurements was the 24-h air quality standard for PM10 exceeded. However, real-time measurements of single particles by aerosol time-of-flight mass spectrometry (ATOFMS) allowed detection of particulate matter from the steelworks, which could be associated with specific emission areas within the works from measurements of wind direction. Three main wind sectors were identified with possible sources of emissions of fine nonmetallic particulate matter (PM < 1 mu m). Characterization of the aerosol composition by a high resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS) of the nonrefractory material associated with the specific plumes is also reported, along with results from other real-time techniques. The ATOFMS detected for the first time a unique elemental sulfur-rich particle type, likely to originate from the blast furnaces. AMS results, supported also by laboratory studies, confirm this finding by reporting elevated mass ratios m/z 64/48 and m/z 64/80. Two other novel ATOFMS particulate types were found to be associated with steelworks emissions. One was characterized by nitrogen-containing organic species, aromatic compounds, and high-molecular-weight (MW) polycyclic aromatic hydrocarbons (PAHs) and was associated with the sources in the area of the hot and cold mills. The second was found to be rich in organic carbon internally mixed with elemental carbon, nitrate, sulfate, and PAHs with lower MW. These particle types were likely related to the coke ovens and the basic oxygen steelmaking plant.