10-years records of monthly bulk atmospheric fluxes of Be-7 and Pb-210 (wet + dry, n = 119 samples) at a coastal station in Cienfuegos (Cuba) between 2010 and 2019 were reported and assessed in function of their temporal variability and meteorological influence. Fluxes of Be-7 and Pb-210 ranged from 120 to 15617 and from 29 to 911 mBq m(- 2) day(-1), respectively. Both radionuclides exhibited a similar seasonal trend with highest values during wet months and minimum values during dry months. The removal of Be-7 and Pb-210 from the atmosphere was mainly controlled by wet depositions, while dry deposition was estimated to be more important for Pb-210 (29% of the total bulk deposition) than for Be-7 (12%). The Pb-210/Be-7 ratios (average of 0.10) showed low variability during wet months with abrupt peaks in the driest months with low temperatures and the highest wind speed and pressure, which was mainly attributed to contributions from soil resuspension. The calculated total deposition velocity of aerosols derived from Be-7 (average of 0.48 cm s(- 1)) and Pb-210 (average of 0.47 cm s(- 1)) was in agreement with values reported in the literature. Multiple linear regression models for the monthly fluxes of Be-7 and Pb-210 based on precipitation, temperature and pressure and explaining about 60% of their variances were derived, highlighting the preponderant role of the local and regional conditions on the variability of these radionuclides. The annual fluxes of Be-7 (209-1901 Bq m(- 2) y(-1)) and Pb-210 (35-123 Bq m(- 2) y(-1)) were in the range of variations observed in other coastal stations worldwide, showing fluctuations affected by changes in the amount of precipitation during the wet periods. Be-7 annual variability also evidenced a significant modulation with the solar activity.

Las deposiciones atmosféricas son consideradas la mayor vía mediante la cual la contaminación de la atmósfera se transfiere a los eco-sistemas acuáticos y terrestres. Sin embargo, en Cuba han sido poco estudiadas. En este trabajo se determinaron los flujos atmosféricos anuales de elementos trazas y mayoritarios en tres estaciones del municipio Cienfuegos (rural, urbana y sub-urbana), y se evaluó la va-riabilidad temporal en los últimos años (2011-2021) y sus implicaciones ambientales. Los mayores flujos para los elementos estudiados se obtuvieron en la zona urbana y su periferia, donde se concentran las mayores emisiones asociadas al tráfico y la actividad industrial. Los elementos Br, S, Zn, Pb, Mo, V, Cu, As, P, Ca y Ni presentaron altos enriquecimientos, indicando una marcada influencia antrópica. Se comprobó que los flujos atmosféricos de estos elementos experimentaron un decrecimiento en la última década, similar a la tendencia observada para las precipitaciones anuales. Los flujos de V y Ni, en contraste, experimentaron un crecimiento importante, lo cual parece estar relacionado con un aumento del impacto de las emisiones provenientes de la combustión del petróleo. Estos resultados constituyen el primer reporte exhaustivo en Cuba sobre series temporales de flujos atmosféricos.

Molybdenum (Mo) is a key cofactor in enzymes used for nitrogen (N) fixation and nitrate reduction, and the low availability of Mo can constrain N inputs, affecting ecosystem productivity. Natural atmospheric Mo aerosolization and deposition from sources such as desert dust, sea-salt spray, and volcanoes can affect ecosystem function across long timescales, but anthropogenic activities such as combustion, motor vehicles, and agricultural dust have accelerated the natural Mo cycle. Here we combined a synthesis of global atmospheric concentration observations and modeling to identify and estimate anthropogenic sources of atmospheric Mo. To project the impact of atmospheric Mo on terrestrial ecosystems, we synthesized soil Mo data and estimated the global distribution of soil Mo using two approaches to calculate turnover times. We estimated global emissions of atmospheric Mo in aerosols (<10 mu m in diameter) to be 23 Gg Mo yr(-1), with 40%-75% from anthropogenic sources. We approximated that for the top meter of soil, Mo turnover times range between 1,000 and 1,000,000 years. In some industrialized regions, anthropogenic inputs have enhanced Mo deposition 100-fold, lowering the soil Mo turnover time considerably. Our synthesis of global observational data, modeling, and a mass balance comparison with riverine Mo exports suggest that anthropogenic activity has greatly accelerated the Mo cycle, with potential to influence N-limited ecosystems.

With the objective of better understanding the sources and dynamics of carbonaceous fractions of the aerosols present in the atmosphere of Montreal, we implemented here an online wet oxidation/isotope ratio mass spectrometry (IRMS) method to simultaneously measure both water-soluble organic carbon (WSOC) content and the corresponding delta C-13 of aerosol samples collected at four monitoring stations over a 1-year period representing distinct types of environmental conditions (i.e., background, road traffic, industrial, and downtown). We coupled these data with the corresponding concentrations of other carbon fractions: total carbon (TC), elemental carbon plus organic carbon (EC + OC), and carbonates. Results show that TC (6.64 +/- 2.88 mu g m(-3)), EC + OC (4.98 +/- 2.23 mu g m(-3)), and carbonates (1.71 +/- 1.09 mu g m(-3)) were characterized by lower concentrations in winter and higher ones between spring and early autumn, with all fractions expectedly showing significantly lower concentrations for aerosols collected at the background station. We observed a seasonal dependence of the delta C-13(EC) (+) (OC) (-25.31 +/- 0.94 parts per thousand) with the EC + OC/total suspended particles (TSP) ratio: (i) an increase of the ratio during late spring, summer and early autumn associated to road traffic emissions characterized by a delta C-13 of similar to-25 parts per thousand and (ii) lower ratios during the winter months indicating the influence of two distinct emission sources, a first one with a delta C-13 similar to-27 parts per thousand, suggesting the local influence of combined biomass burning from residential heating and of fossil fuel combustion, and a second one with a delta C-13 similar to-21 parts per thousand, likely related to more regional emissions. WSOC (1.14 +/- 0.67 mu g m(-3)) presented a similar seasonal pattern for all monitoring stations, with low concentrations in winter, early spring and late autumn that rapidly increased until summer. Our results indicate that this seasonality is controlled by higher anthropogenic contributions from southern Canada and northeastern United States regions and probably from biogenic emissions during the warm months. Moreover, delta C-13(WSOC) (-25.08 +/- 1.47 parts per thousand) showed a C-13-depletion in summer, indicating higher fossil fuel and biogenic contributions, whereas the higher isotope compositions observed in winter may result from the photochemical aging of regional aerosols. Ultimately, we identified the influence of local industrial emissions late in 2013 as well as the impact of aerosol emissions associated to the Lac-Megantic rail disaster that occurred on July 6, similar to 200 km east of Montreal.

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 co

Carbon and nitrogen stable isotope compositions (delta 13C and delta 15N) of organic matter (OM) and total organic carbon to total nitrogen ratio (Corg/TN) in a sediment core collected in Sagua estuary (Cuba), were investigated to elucidate the origin of the Sedimentary OM (SOM) and changes in its main sources, over the last 100 years. Results showed almost constant values in the elemental and isotope composition of SOM from 1908 to 1970 with an abrupt change after 1970. From 1970 to 2005, delta 13C increased from -21.2 up to -19.3 parts per thousand, while delta 15N declined from 1.5 to values close to 0 parts per thousand. The output of the mass-balance model for the identification of OM sources indicated that delta 13C and Corg/TN values are generally influenced by marine Particulate OM (POM) sources. Between 1900 and 1970, the main OM source in sediments was marine POM (>85 %), with freshwater POM contributing ca. 15%. Since 1970, the establishment of the Alacranes Dam determined drastic environmental changes influencing the OM sources in the area. Mixing models pointed to seagrasses (79 %) as the main contributors to SOM in the first period, while since 1973 onward, the contribution of human-derived sources such as fertilizers and urban discharges became greater. This information can provide baseline data for the environmental management of the Sagua watershed.

This study investigates the contents, distribution patterns, and sources of lanthanoid elements (La to Lu) in aerosols with an aerodynamic diameter <= 10 mu m (PM10) in a coastal Caribbean region in order to better constrain the origin of the atmospheric PM contamination. We sampled and analysed PM10 aerosols during 2015 simultaneously at a rural and an urban site in Cienfuegos (Cuba) as well as particles samples from regional contamination sources. Results showed that the sum of the studied lanthanoids concentrations ranged from 0.03 to 13.42 ng m(-3) and from 0.51 to 18.75 ng m(-3) at the rural and the urban site, respectively. Time variations for the lanthanoid concentrations displayed similar trends and showed that the highest concentrations corresponded to the influence of the African dust for both sites, but presented distinct variability and lower concentrations when dust intrusions were less frequent. The lanthanoid distribution patterns in the rural and urban sites were significantly different, due to the impact of different local combustion sources. Our results were comforted by comparing the degree of fractionation of the lighter and heavier lanthanoids and the delta Eu and delta Ce anomalies between our PM10 samples and those of the local sources of contamination. Ultimately, we highlight the added value of lanthanoid elements as reliable indicators for discriminating emission sources and for tracking the origin of atmospheric particulate matter.

In this study, PM10 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), NH4+, Cl-, NO3- and SO42-) and their stable carbon (delta C-13) and nitrogen (delta N-15), and radioactive (Pb-210, Be-7, Cs-137 and K-40) isotope systematics, in order to better constrain both their sources of pollution and their atmospheric dynamics. The average PMic, concentrations varied from 21.67 +/- 8.54 mu g.m(-3) at the rural site to 39.01 +/- 8.23 mu g 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) NH4+ and SO42- that indicates the formation of secondary ammonium bisulfate (NH4HSO4), and ii) between PM10, and TC highlighting the significant influence of carbonaceous aerosols. We are reporting here the first Pb-210 aerosol concentrations in this region and demonstrate that, coupled with the corresponding Be-7 concentrations, they allow characterizing the dynamics of the regional continental air masses. delta C-13 values in PM10, 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.

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 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 environmental contamination in the city, mainly along busy roads and downtown.¿13Cand¿15N, 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.

Atmospheric deposition is considered to be the major pathway by which substances from the atmosphere enter to the terrestrial and aquatic ecosystems. This study constitutes the first exhaustive report on trace metal deposition in Cuba and is aimed to determine the monthly atmospheric flux of 47 major and trace elements in a Caribbean coastal site and investigate the main sources contributing to deposition.