Research Outputs
Habitat type drives the distribution of non-indigenous species in fouling communities regardless of associated maritime traffic
Biological invasions and changes in land and sea use are among the five major causes of global biodiversity decline. Shipping and ocean sprawl (multiplication of artificial structures at the expense of natural habitats) are considered as the major forces responsible for marine invasions and biotic homogenization. And yet, there is little evidence of their interplay at multiple spatial scales. Here, we aimed to examine this interaction and the extent to which the type of artificial habitat alters the distribution of native and non‐indigenous biodiversity. Location: Southeast Pacific—Central Chilean coastline.
Contenido de metales (Ba, Cd, Co, Cr, Cu, Ni, Pb y Zn) en organismos bentónicos de áreas prístinas: Campos de hielo sur (48°- 52° lat. Sur), Chile
Se analizó el contenido de metales totales en organismos bentónicos recolectados en Campos de Hielo Sur, con el objeto de establecer patrones de abundancia de metales en los organismos y concentración de referencia de metales (línea base) en una zona de aguas prístinas. Se estudiaron seis especies 5 moluscos bivalvos y un erizo. Los análisis se realizaron utilizando un espectrómetro de emisión atómica acoplado a plasma (ICP-AES). Se estableció un ranking de abundancia de metales para los analitos y fue similar para las diferentes especies: Zn > Ba > Cu > Co > Cd > Cr > Ni > Pb e independiente de los valores de concentración de cada metal en particular. Se estableció por comparación que la concentración de metales informada fue semejante a otros sistemas no alterados antrópicamente.
Sources analysis and health risk assessment of trace elements in urban soils of Hualpen, Chile
Urban soils are a key component of urban ecosystems as they support biodiversity, provide foundation for infrastructure and play an important role in maintaining the environmental quality, being both a sink and a source of pollutants that have an effect in human health. The objectives of this study were (1) to determine the concentrations background of As, Co, Cr, Cu, Ni, Pb, V and Zn in the urban soils of Hualpen (Chile); (2) to assess the level of contamination in the urban soil based on different pollution indices; (3) to identify natural or anthropogenic sources in order to determine a spatial pattern of the pollutants and (4) to assess the health risks of trace metals in surface soils of Hualpen. A total of 153 samples were collected from the study area as follows: 51 topsoil samples (TS) (0–10 cm), 51 subsoil samples (SS) (10–20 cm) and 51 deep soil samples (DS) (150 cm). Multivariate statistics combined with spatial analysis were implemented in order to distinguish the sources. Several simple and robust statistical methods were applied to datasets in order to explore their potential in the evaluation of a useful and robust background values. The degree of contamination along with pollution indices were also evaluated. The median soil pseudo total concentrations of the elements were as follows: As 3 mg kg−1, Co 15 mg kg−1, Cr 14 mg kg−1, Cu 25 mg kg−1, Ni 36 mg kg−1, Pb 5 mg kg−1, V 97 mg kg−1 and Zn 51 mg kg−1. Multivariate analysis suggests that Cr, Pb, V and Zn are contributed by external sources. The spatial distribution of these elements displays a spatial pattern extending along industrial environments and emission sources. While the other elements show a spatial pattern with a few anthropogenic hot spots dispersed across Hualpen, they were influenced by both anthropogenic and geogenic inputs. The estimate background values determined with the DS samples with median absolute deviation (MAD) method were for As 5 mg kg−1, Co 20 mg kg−1, Cr 18 mg kg−1, Cu 33 mg kg−1, Ni 45 mg kg−1, Pb 3 mg kg−1, V 108 mg kg−1 and Zn 48 mg kg−1. The ecological indices register a moderate to considerable contamination in some soil samples. It was noted that the soils of Hualpen pose no carcinogenic risk, neither by inhalation nor by ingestion.
Spatial distribution of potentially harmful elements in urban soils, city of Talcahuano, Chile
The objective of this study is to ascertain the spatial distribution of Cu, Pb and Zn in order to determine the degree of contamination in urban soils from Talcahuano (Chile) and to identify the influence of possible contamination sources. A total of 420 samples were collected from the study area based on the following criteria: 140 topsoil samples (TS) (0–10 cm), 140 subsoil samples (SS) (10–20 cm) and 140 deep soil samples (DS) (150 cm). The soils were characterized for their physical characteristics such as grain size distribution, pH, organic matter content etc. and the concentrations of Cu, Pb and Zn were analyzed by Atomic Absorption Photospectrometry following Aqua Regia digestion. Correlations combined with spatial analysis were implemented in order to distinguish the sources of the trace metals and whether they are geogenic or anthropogenic of origin. Several simple and robust statistical methods were applied to the data sets in order to evaluate useful and robust background values. The degree of contamination along with the geoaccumulation index, enrichment factors and contamination factors were also evaluated. The median concentrations obtained for the studied trace metals includes: Cu 23.1 mg kg− 1, Pb 10.2 mg kg− 1 and Zn 56.7 mg kg− 1. In general, the concentrations of Cu, Pb and Zn decrease with depth however, in certain sites the subsoil samples (SS) levels show higher concentrations than topsoil samples (TS). A possible explanation could be related to the uncontrolled clandestine landfill sites using both construction material debris and/or industrial solid wastes. Correlation analysis suggests that Cu, Pb and Zn are contributed by external sources. The spatial distribution of Cu, Pb and Zn in topsoil samples (TS) displays a spatial pattern extending along major roadway environments and emission sources. Estimated background values determined with the iterative 2σ-technique yields 43.7 mg kg− 1 for Cu, 17.5 mg kg− 1 for Pb and 91.7 mg kg− 1 for Zn respectively. The geochemical index, enrichment factor and the contamination factor all register a moderate to high contamination level in some of the soil samples.