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We characterized the elemental and C and N stable isotope compositions of Tillandsia fasciculata Sw., Tillandsia balbisiana Schult. & Schult.f. and Tillandsia recurvata (L.) L. samples collected in Cienfuegos (Cuba). Results showed high enrichment factors for S, Hg, Cd, Pb, P, Zn, Cu, Mo, Sb and Ca in all Tillandsia species, indicating inputs from local anthropogenic activities (road traffic, industries and cement production). Carbon concentrations and δ13C varied from 38.3–47.7 % and –20.4 to –13.4 ‰ within the three species, respectively. δ13C showed seasonal dependence with the dry and wet periods and more 13C-depleted values in urban/industrial areas, coherent with the input of anthropogenic emissions. Nitrogen concentrations (0.4–1.3 %) and δ15N values (–9.9–4.4 ‰) exhibit larger variations and are positively correlated in the three species. The most positive δ15N in T. recurvata (–0.2–4.4 ‰) are attributed to contributions from industrial activities and road traffic. In fact, both δ15N and total nitrogen (TN) values increase in sites with higher road traffic and show significant correlations with typical road traffic and industrial tracers. Finally, we calculate an average total nitrogen deposition rate of 4.4 ± 2.3 kg ha–1 a–1 from N content in T. recurvata, similar to the existing values determined in the region by field measurements, but higher than the global terrestrial average. [ABSTRACT FROM AUTHOR]

Road dust is an indicator widely used when monitoring contamination and evaluating environmental and health risks in urban ecosystems. We conducted an exhaustive characterization of road dust samples coupling their chemical characteristics and stable isotope compositions (C and N) with the aim of evaluating the levels and spatial distribution of local contamination as well as to identify its main source(s) in the coastal city of Cienfuegos (Cuba). Results indicate that the concentrations of several elements (total nitrogen, S, Ca, V, Cu, Zn, Mo, Sn, Hg, and Pb) exceed the background values reported for both Cuban soils and the upper continental crust (UCC) and showed a high variability among the sampling sites. We show that road dust contamination in Cienfuegos induces high associated ecological risks. Among the studied elements, Cd and Hg are the major contributors to the environmental contamination in the city, mainly along busy roads and downtown. δ13C and δ15N, coupled to a multivariate statistical analysis, help associate the studied elements to several local sources of contamination: mineral matter derived from local soils, cement plant and related activities, road pavement alteration, power plant, road traffic, and resuspension of particulate organic matter (POM). Our results suggest that incorporating the chemical and isotope monitoring of road dust may help implement more effective environmental management measures in order to reduce their adverse impact on ecosystems and human health. [ABSTRACT FROM AUTHOR]

• First report on the chemical composition of Tillandsia recurvata (L.) L. in Cuba. • T. recurvata and top soils are good indicators of pollution in Caribbean urban areas. • Road traffic, oil combustion and industrial emissions detected in both indicators. This work provides a comprehensive report on the chemical composition of 47 major and trace elements in Tillandsia recurvata (L.) L. and top soil samples from the cities of Cienfuegos and Santa Clara in Cuba. The main aims were to provide new information on the urban pollution degree in Caribbean urban regions where the availability of data of urban health indicators are very limited and to identify the main pollution sources. The abundance of the analyzed elements at both type of samples were different at each urban regions suggesting the influence of various sources. Top soils were slightly contaminated with Zn, V, Ba, Pb, Ni, Cr, Cu, Co and Hg and seriously contaminated with Ni and Cr in Santa Clara. These and other elements such as Se, S, P, Cd, Mo and Ca where highly enriched in T. recurvata indicating a significant impact of anthropogenic sources in the air quality of both urban areas. Cluster analysis helped us associate most of the elements with an anthropogenic origin with three main pollution sources: road traffic, industrial emissions and oil combustion. The spatial variability was particularly useful to identify some of these sources including the emissions from diesel and fuel oil combustion in power stations, biomass burning and metallurgic industries. The results also showed that V and Ni were strongly associated to the oil combustion and that V/Ni ratio indices in both indicators can be used to trace this type of sources. The results presented in this study confirmed the conclusion that both T. recurvata and top soils can be used as feasible indicators of the health of Caribbean urban ecosystems and the distribution of the main pollution sources that are affecting them. [ABSTRACT FROM AUTHOR]

In this study, PM 10 aerosol samples were collected at 4 urban and 1 rural sites in the region of Cienfuegos (Cuba) and analyzed for their chemical compositions (total carbon (TC), total nitrogen (TN), NH 4 +, Cl−, NO 3 − and SO 4 2−) and their stable carbon (δ13C) and nitrogen (δ15N), and radioactive (210Pb, 7Be, 137Cs and 40K) isotope systematics, in order to better constrain both their sources of pollution and their atmospheric dynamics. The average PM 10 concentrations varied from 21.67 ± 8.54 μg m−3 at the rural site to 39.01 ± 8.23 μg m−3 at an urban site characterized by high road traffic. Chemical compositions showed low variability and similar abundances of the ionic species, but we observed strong correlations between i) NH 4 + and SO 4 2− that indicates the formation of secondary ammonium bisulfate (NH 4 HSO 4), and ii) between PM 10 and TC highlighting the significant influence of carbonaceous aerosols. We are reporting here the first 210Pb aerosol concentrations in this region and demonstrate that, coupled with the corresponding 7Be concentrations, they allow characterizing the dynamics of the regional continental air masses. δ13C values in PM 10 appear to be controlled by i) emissions from different types of combustion sources, including fossil fuel and biomass burning and ii) carbonate inputs from the industrial activities located around the limestone quarries, east of the city. δ15N values presented large isotope variations that can be explained by kinetic processes and the exchange between gas (NH 3) and particle (NH 4 +) phases during the formation of secondary NH 4 HSO 4 , a reaction that was enhanced as Cl− concentrations decreased, revealing the preponderant role of local emissions in the budget of the aerosol nitrogen. This study confirms that isotope analysis is reliable for tracing the origin of aerosols and highlight the importance of a multi-isotope approach. • Multi-isotopic approach of PM 10 samples improve source discrimination. • Continental air masses can be traced combining 210Pb and 7Be concentrations. • δ13C identifies emissions from combustion sources and activities in limestone quarries. • 15N-enrichments are controlled by NH 4 HSO 4 formation and enhanced by local emissions. [ABSTRACT FROM AUTHOR]