Accepted Manuscript Determination and source apportionment of major and trace elements in atmospheric bulk deposition in a Caribbean rural area Yasser Morera-Gómez, Jesús Miguel Santamaría, David Elustondo, Esther Lasheras, Carlos Manuel Alonso-Hernández PII:
S1352-2310(19)30041-X
DOI:
https://doi.org/10.1016/j.atmosenv.2019.01.019
Reference:
AEA 16508
To appear in:
Atmospheric Environment
Received Date: 10 August 2018 Revised Date:
12 December 2018
Accepted Date: 5 January 2019
Please cite this article as: Morera-Gómez, Y., Santamaría, J.M., Elustondo, D., Lasheras, E., AlonsoHernández, C.M., Determination and source apportionment of major and trace elements in atmospheric bulk deposition in a Caribbean rural area, Atmospheric Environment, https://doi.org/10.1016/ j.atmosenv.2019.01.019. This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
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Determination and source apportionment of major and trace elements
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in atmospheric bulk deposition in a Caribbean rural area
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Yasser Morera-Gómez1,2*; Jesús Miguel Santamaría2; David Elustondo2; Esther
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Lasheras2; Carlos Manuel Alonso-Hernández1
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59350 Cienfuegos, Cuba.
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Ambiental (LICA), Campus Universitario, 31080, Pamplona, Spain.
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Centro de Estudios Ambientales de Cienfuegos (CEAC), AP 5. Ciudad Nuclear, CP
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Universidad de Navarra, Facultad de Ciencias, Laboratorio Integrado de Calidad
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* Corresponding author: Yasser Morera-Gómez
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email:
[email protected]
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Centro de Estudios Ambientales de Cienfuegos (CEAC), AP 5. Ciudad Nuclear, CP 59350
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Cienfuegos, Cuba. Telf/Fax +53 43965146
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Abstract
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Atmospheric deposition is considered to be the major pathway by which substances
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from the atmosphere enter to the terrestrial and aquatic ecosystems. This study
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constitutes the first exhaustive report on trace metal deposition in Cuba and is aimed
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to determine the monthly atmospheric flux of 47 major and trace elements in a
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Caribbean coastal site and investigate the main sources contributing to deposition.
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ACCEPTED MANUSCRIPT Bulk deposition (average of 46018 µg m-2 day-1) and fluxes of studied elements showed
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a high variability and no seasonality with the dry and wet periods, results that we
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attributed to the fluctuations of the emissions from their main sources rather than to
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meteorological factors controlling the deposition processes. However, stronger
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correlations were found between typical crustal elements, which showed a marked
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seasonality with the presence of African cloud dust in the Caribbean. Lanthanoids
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element (Eu anomalies and LaN/LuN ratios) helped us to confirm the seasonal influence
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of African dust in the geochemical composition of bulk deposition in Cienfuegos. Most
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of the analyzed elements were found in the range of variation of those reported in
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rural environments around the world but, the elements V, Ni, As and Sb reached
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higher levels, typically found in urban and industrial areas. The elements Sb, Pb, W, Sn,
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S, Cu, Mo, Nb and P were moderately enriched (101 and the PCA results were only
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accepted when the sum of those principal components accounted for more than 75%
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of the total variance of the dataset, and all the communality values were greater than
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0.6. Contributions from the identified sources were quantitatively derived applying a
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multi-linear regression analysis (MLRA), using the bulk deposition values as the
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dependent variable and absolute factor scores from the PCA analysis as independent
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variables.
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ACCEPTED MANUSCRIPT Clustering analysis (CA) was also performed to help in the association of the principal
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components (from the PCA results) with the main anthropogenic or natural sources in
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the study area. A Pearson clustering using the Ward method was applied. The
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statistical analyses were carried out using the SPSS 15.0 statistical software package.
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3. Results and discussion 3.1.
Bulk deposition
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Figure 2a show the monthly variation of the bulk deposition and amount of rainfall
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during the study. Monthly fluxes ranged from 23 129 to 97 224 µg m-2 day-1 (averaging
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46 018 µg m-2 day-1). These values were lower than those reported in an urban site in
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Havana (86 460 µg m-2 day-1) (Jomolca-Parra et al., 2014) but comparable to some
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reported in other coastal region around the world (Huston et al., 2012; Rossini et al.,
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2005). Nonetheless, we generally found higher fluxes reported in the literature
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(Castillo et al., 2013b; Kara et al., 2014; Shanquan et al., 2016). As in most of the
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countries, bulk deposition are not regulated in Cuba; nevertheless, we found all our
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monthly depositions to be below the Australian guideline of 4 g m-2 month-1 (130 000
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µg m-2 day-1) for deposited dust (Huston et al., 2012).
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There was no significant correlation (at pK≈Al>Fe>Mg, whereas the average fluxes of trace metals
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were
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P>Zn>Ti>Mn>V>Sr≈Cu>Pb>Ba>Ni>Cr≈Rb≈Sb>As. These rankings are commonly found
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in rural regions around the world with the exception of V and Sb, which presented high
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levels compared with typical values reported in this environment (Castillo et al., 2013b;
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Fernandez-Olmo et al., 2015; Kyllonen et al., 2009).
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Wide variation in the monthly fluxes of all elements was observed, as indicated by
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their high standard deviations. This may be attributed mainly to weather conditions
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(amount of precipitations, height of mixing layers, and the origin of air masses, among
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others) that strongly affected the dispersion and deposition of air pollutants, as well as
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to variation of emission of pollutants. However, similar to the bulk deposition, no
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elements
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ACCEPTED MANUSCRIPT significant correlation (at the 0.05 level) was observed between the monthly fluxes of
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the studied elements and the meteorological variables. Additionally, a t-test showed
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that there were no significant (at the 0.05 level) differences of atmospheric fluxes of
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any studied elements between the wet and dry season. This appeared to suggest that
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the monthly deposition fluxes of the studied elements were mostly affected by
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fluctuations of the emissions from their sources.
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In this way, a similar temporal trend between the flux of the typical crustal elements
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was observed (see Figure 3). In general, atmospheric fluxes of the elements Al, P, Cr,
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Mn, Fe, Co, Rb, Cs, Ba, Th, U, Ti, Ge, Zr, Nb and lanthanoid elements were significantly
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(t-test at the 0.05 level) higher between March and August than during the rest of the
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year. The highest fluxes were obtained in July each year of study and in April 2015. This
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result may indicate a strong association with the seasonality of African dust clouds in
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the Caribbean region (Prospero and Mayol-Bracero, 2013; Rodriguez et al., 2015). The
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presence and characteristics of African clouds dust in Cuba have been reported for
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each province based on the information obtained from different satellites and sensors
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(Mojena López et al., 2015). In the case of Cienfuegos, the presence of the African dust
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clouds was mainly reported from March until August with the highest occurrence in
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June and July, which agree with our results.
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The stronger correlations (r>0.9, p
