Abstract
Abstract. We present highly time-resolved (30 to 120 min) measurements of size-fractionated (PM10 and PM2.5) elements in two cities in Asia (Delhi and Beijing) and Europe (Krakow and London). For most elements, the mean concentrations in PM10 and PM2.5 are higher in the Asian cities (up to 24 and 28 times, respectively) than in Krakow and often higher in Delhi than in Beijing. Among European cities, Krakow shows higher elemental concentrations (up to 20 and 27 times, respectively) than London. Hourly maximum concentrations of Pb and Zn reach up to 1 µg m−3 in Delhi, substantially higher than at the other sites. The enrichment factor of an element together with the size distribution allows for a rough classification of elements by major source. We define five groups: (1) dust emissions, (2) non-exhaust traffic emissions, (3) solid fuel combustion, (4) mixed traffic/industrial emissions, and (5) industrial/coal/waste burning emissions, with the last group exhibiting the most site-to-site variability. We demonstrate that the high time resolution and size-segregated elemental dataset can be a powerful tool to assess aerosol composition and sources in urban environments. Our results highlight the need to consider the size distributions of toxic elements, diurnal patterns of targeted emissions, and local vs. regional effects in formulating effective environmental policies to protect public health.
Highlights
The percentage of the global population living in urban areas with more than 1 million inhabitants has been steadily increasing over the last decades (Krzyzanowski et al, 2014).Published by Copernicus Publications on behalf of the European Geosciences Union.P
In Krakow and London, concentrations are mostly elevated during rush hour and during daytime in general (from 08:00 until 18:00 local time (LT))
Five groups are identified based on these metrics, with Groups 1–3 having low enrichment factor (EF) with increasing PM2.5/PM10 and Groups 4–5 having high EFs with increasing PM2.5/PM10
Summary
Particle toxicity depends on PM composition (Kelly and Fussell, 2012), with identified toxic constituents including elemental and organic carbon and metals Transition metals such as Fe, V, Ni, CrVI, Cu, and Zn are of particular concern due to their potential to produce reactive oxygen species (ROS) in biological tissue (Manke et al, 2013). Elements are recognized as effective markers for source apportionment (SA), especially for anthropogenic emissions in urban areas (e.g., traffic, industry, and power production). Emissions from these sources vary on timescales of a few hours or less, and such rapid changes cannot be resolved by conventional 24 h filter measurements. Time-resolved and size-segregated measurements are required for the determination of elemental PM sources and health effects within urban areas under varying meteorological conditions
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
