Highly time-resolved measurements of element concentrations in PM<sub>10</sub> and PM<sub>2.5</sub>: comparison of Delhi, Beijing, London, and Krakow

Abstract. We present highly time-resolved (30 to 120 min) measurements of size-fractionated (PM10 and PM2.5) elements in two cities Asia (Delhi Beijing) Europe (Krakow London). For most elements, the mean concentrations PM10 PM2.5 are higher Asian (up 24 28 times, respectively) than Krakow often Delhi Beijing. Among European cities, shows elemental 20 27 London. Hourly maximum Pb Zn reach up 1 µg m?3 Delhi, substantially at other sites. The enrichment factor an element together with size distribution allows for a rough classification by major source. define five groups: (1) dust emissions, (2) non-exhaust traffic (3) solid fuel combustion, (4) mixed traffic/industrial (5) industrial/coal/waste burning last group exhibiting site-to-site variability. demonstrate that high time resolution size-segregated dataset can be powerful tool assess aerosol composition sources urban environments. Our results highlight need consider distributions toxic diurnal patterns targeted local vs. regional effects formulating effective environmental policies protect public health.