Baseline values and environmental assessment for metal(loid)s in soils under a tropical rainy climate in a Colombian region.

The baseline values for metal(loid)s in soils are known as a tool for the evaluation, prevention, and monitoring of the environmental quality of the soil. The main aim is to propose baseline values for metal(loid)s through the analysis of the concentrations in soils within natural areas; additionally, this study attempts to assess the environmental quality of soils in agricultural areas. The study was developed in the Piedemonte Llanero from Colombia a region with more than 5000 mm year-1 of pluviometry. A total of 90 soil samples were collected in agricultural and natural areas. Chemical analysis was conducted by acid digestion following the method EPA 3050B and determined the metal(loid)s (Al, As, Fe, Cd, Cr, Cu, Mg, Mn, Ni, Pb, and Zn) through ICP-OES. This is the first time that baseline values are proposed for a region in Colombia. The values proposed (expressed in mg kg-1) are Cd (0.3), As (2.8), Cu (9.9), Ni (10.2), Pb (11.3), Cr (21.1), Zn (28.2), Mn (83.8), Mg (348), Fe (22,775), and Al (28,975). These values are comparatively lower than those reported for other regions in Latin America and the rest of the world. Also, agricultural soils are not contaminated. The possible explanation is as a consequence of the intense washing caused by the intense rainfall of the place. The results also demonstrated that the soils in this region are not contaminated. Finally, these advances will allow public and private organizations to establish criteria for the environmental and sustainable management of soils, especially on agricultural activities.

Using genotoxic and haematological biomarkers as an evidence of environmental contamination in the Ocoa River native fish, Villavicencio-Meta, Colombia.

The studies evaluating the impact of environmental pollution on aquatic organisms have had a growing concern in recent decades. The Ocoa River runs through Villavicencio city, receiving the wastewater produced in the city. To date studies reporting the effect and the consequences of Ocoa River pollution on aquatic organisms inhabiting this water body are unknown. Haematological and genotoxicity biomarkers were evaluated in peripheral blood of two native fish species Astyanax gr. bimaculatus and Aequidens metae during rainy and dry season at three different sites of Ocoa River called Nacimiento (site 1, before entering the city), Centauros (site 2, inside the city), Caño Seco (site 3, after the city). Also, fish from a reference site with little likelihood of contamination were sampled. Alterations such as decrease in erythrocyte count, lymphocytes, haemoglobin concentration and haematocrit percentage, and increased thrombocytes and neutrophils counts, together with nuclear abnormalities in erythrocytes such as increased frequency of micronuclei, lobed, blebbed and notched nuclei and binucleate cells were observed in fish from the site 3, followed by the site 2 in rainy season. These results shown that during rainy season, sites 2 and 3 receive domestic and industrial wastewater leading to genotoxic and haematological changes in the monitored organisms.