Chemical characterization of PM_(10) samples collected simultaneously at a rural and an urban site in the Caribbean coast: Local and long-range source apportionment

摘要

The deterioration of the air quality is a global concern. Daily PM10samples were simultaneously collected and chemically characterized at an urban and a rural site in Cienfuegos, Cuba between January 2015 and January 2016. A source apportionment study was conducted in order to identify and quantify the main contributions of both local and long-range sources.Concentrations of PM10varied similarly at the urban and rural site, with annual averages of 35.4 and 24.8 μg m−3, respectively. The highest concentrations were observed between March and August at both sites, when a strong influence of Saharan dust was identified. The PM10daily limit (50 μg m−3) established in the Cuban legislation for air quality was exceeded by 3 and 8 times in the rural and urban site, respectively. The chemical characterization of PM10showed important contributions of mineral matter, total carbon and secondary inorganic compounds in the region, with the highest concentrations observed at the urban site. Marine contribution, by contrast, was higher at the rural site. The highest EFs were obtained for the typical road traffic tracers Mo and Cu. Positive matrix factorization (PMF) analysis coupled with conditional bivariate probability function (CBPF) and concentration weighted trajectory (CWT) identified 5 main sources in the studied sites: Saharan intrusions, marine aerosol, combustion sources and secondary aerosols, road traffic and cement plant. The Saharan dust contribution was quantified for the first time in Cuba, proving to be one of the major components of PM10at both sites. Its daily contribution, indeed, explained more than 60% of the PM10recorded in 10 of the 11 exceedance events.This study reports the first simultaneous evaluation of PM10and its chemical composition in urban and rural areas of Cuba, and provides the basis for environmental managers to adopt control strategies to reduce the impact of PM10pollution in the region.