Spatial and temporal (short and long-term) variability of submicron, fine and sub-10 μm particulate matter (PM1, PM2.5, PM10) in Cyprus

Abstract

Long-term particulate matter (PM) mass concentration measurements have been performed in Cyprus at three major cities, one industrial area and two remote stations covering the entire southern part of the island in an effort to assess; i) the spatial and temporal variability of sub-10 μm (PM10), fine (PM2.5) and submicron (PM1) particulate matter in the eastern Mediterranean, ii) the main source areas contributing to their levels and iii) the relative contribution of regional and local anthropogenic and natural sources to PM levels. It was found that dust is responsible for the 33.6 ± 5.2% or about 10 μg m−3 of the annual PM10 levels reported in background stations; the latter underlines the significant contribution of natural sources on the ambient PM10 amounts in the eastern Mediterranean region. A significant (p < 0.001) decreasing trend of 0.7 ± 0.1 μg m−3 y−1 was observed when both PM10 and PM2.5 annual values are considered, indicating contribution from both natural and anthropogenic sources to this tendency. By considering the PMx (with x = 1, 2.5 and 10) mass concentrations obtained at the background station of Agia Marina as representative of the regional influence, the local influence of the urban and industrial sites on the measured PMx levels can be estimated. On average, 36–44% of the observed PM10 levels at the urban and industrial locations is estimated to originate from local anthropogenic and/or natural emissions including vehicle, biomass-burning, shipping emissions (in Limassol), airport related emissions (in Larnaca), resuspension of dust and sea-salt (in coastal locations). These local emissions are almost equally distributed in the fine and coarse fractions as 40–50% of the local PM10 amounts are due to fine particles emissions. The above results highlight significant emissions from both fine mode (e.g. residential heating and traffic) and coarse mode urban emissions (e.g. dust resuspension, wear and tear in brakes and tires, respectively) in urban and industrial locations in Cyprus.