PM10 mass concentration characteristics in a coastal mediterranean site: a yearly study of seasonality and sources with short term elemental analysis

Abstract

PM₁₀ mass concentrations were measured online for one year at the Akrotiri monitoring station in Chania (Greece). PM₁₀ concentrations ranged from 7.3 to 287.5 µg m^− 3 with highest concentrations measured in April, due to intense dust episodes. Overall, a total of 50 events days were identified with most episodes taking place during the first semester of the year. The majority of PM₁₀ exceedances (80%), using the World Health Organization air quality guidelines (45 µg m⁻³), were mainly due to dust episodes and secondarily due to anthropogenic activities. Increased concentrations of PM₁₀ in winter were due to domestic heating, in spring due to frequent and intense dust episodes, in summer due to touristic activities and in autumn due to vehicular traffic and road dust resuspension. Diurnal analysis demonstrated higher concentrations of PM₁₀ during morning and midday on weekdays and during afternoon and evening on weekends, all associated with peak hours. Gravimetric sampling of PM₁₀ for one month has verified previous observations at the study site. Particularly, PM₁₀ particles were enriched withNa, Cl and Br when windblown arrived from the sea whilst crustal elements such as Mg, Si, Ca, K and Al, were significantly increased during dust episodes. On the other hand, heavy metals such as V and Ni were linked with shipping activities from the nearby port Zn was associated with non-exhaust vehicle emissions and Pb with engine related sources.