Particle Pollution: Trends, Sources, Components and Health

Eastern Mediterranean (EM) region experience poor air quality because it is highly influenced by local and transported pollution. For this reason, we examined the particulate pollution in Cyprus, an EU-member country located in the EM region. First, we analyzed daily PM10 (particulate matter with aerodynamic diameter less than 10 μm) data collected in an urban and background site for sixteen years (1993-2008). We investigated long term trends using a Generalized Additive Model (GAM) after controlling for day of week, month, temperature, wind speed, and relative humidity. Annual PM10 (50.4-63.8 μg/m3) exceeded the 2005 EU annual standard (40 μg/m3) every year at the urban station, and dust storms were responsible for a small fraction of the daily exceedances. However, urban PM10 levels decreased from 59.4 μg/m3 in 1993 to 49.0 μg/m3 in 2008, probably in part as a result of traffic emission control policies. We then collected PM10 and PM2.5 samples (particulate matter with aerodynamic diameter less than 2.5 μm) in the four main cities in Cyprus using Harvard Impactors, during the year of 2012. We analyzed them for mass concentration and chemical composition, and conducted a source apportionment analysis. For PM2.5, seven source types were identified including regional sulfur (>30%), traffic emissions, biomass, re-suspended soil, oil combustion, road dust, and sea salt. For PM10-2.5 (coarse particles with aerodynamic diameter between 2.5 and 10 μm) three sources were identified, which include road dust, soil, and sea salt. Last, since the mortality effect estimates for PM2.5 components and mortality vary across studies and locations, we performed a meta-regression analysis to estimate their association using city specific estimates from time-series and case-crossover studies. We found significant associations between mortality and elements from combustion sources such as traffic, biomass burning, and oil combustion. Furthermore, PM2.5 effect estimates varied across regions, and further research is needed to explore the possible factors that modify or confound their association