RESUMO
Sea urchin species are ecologically important in the Gulf of California and are becoming popular as a local fishery due to their commercial value. The most abundant species are Echinometra vanbrunti, Eucidaris thouarsii, and Tripneustes depressus. The objective of this study was to evaluate cadmium, lead, copper, zinc, and iron concentrations, as well as stable isotope values in these sea urchin species in the Santa Rosalia mining area (STR), in three sites: Punta Gorda, Punta el Aterrizaje, and Punta Salina. The highest Fe concentration (100.2 mg kg-1) was found in E. vanbrunti, while the highest concentrations of Pb (15.1 mg kg-1), Cu (14.5 mg kg-1), and Zn (347.7 mg kg-1) were recorded in E. thouarsii, and the highest Cd concentration (10.8 mg kg-1) was found in T. depressus. The main health risk of trace metal pollution in STR may be caused by Cd and Pb. δ15N and δ13C values were higher in E. thouarsii and T. depressus, respectively; E. thouarsii has the highest trophic position. Specimen size was not related to metal concentrations, but a positive relationship was observed between specimen size and isotopic values in T. depressus. The three species showed different bioaccumulation patterns for the metals analyzed. Additionally, collection sites and seasons play an important role in the variability of metal concentration.
Assuntos
Monitoramento Ambiental , Ouriços-do-Mar , Poluentes Químicos da Água , Animais , Poluentes Químicos da Água/análise , Metais Pesados/análise , Cadeia Alimentar , MéxicoRESUMO
Laboratory ecotoxicological tests are important tools for the management of environmental changes derived from anthropogenic activities. Folsomia candida is usually the model species used in some procedures. However, this species may not be sufficiently representative of the sensitivity of the other collembolan species. This study aimed to evaluate (i) the effects of soils naturally rich in potentially toxic elements (PTE) and soil characteristics on the reproduction and survival of different collembolan species, (ii) whether the habitat function of these soils is compromised, and (iii) to what extent F. candida is representative of the other collembolan species. For this, reproduction tests with six collembolan species were conducted in 14 different samples of soils. In general, collembolan reproduction was not completely inhibited in none of the natural tested soils. Even soils with high pollution load index values did not negatively affect collembolan reproduction for most of the species. In contrast, the lowest collembolan reproduction rates were found in a visually dense soil (lowest volume/weight ratio), highlighting that soil attributes other than total PTE concentration also interfere in the reproduction of collembolans. Our results support the idea that the F. candida species might not be representative of other collembolan species and that laboratory tests to assess soil contaminations should be conducted using diverse collembolan species.
Assuntos
Artrópodes , Poluentes do Solo , Animais , Solo , Poluentes do Solo/análise , Poluição Ambiental , ReproduçãoRESUMO
During the operation of the landfills, leachate should be managed with caution to avoid possible negative environmental impacts. Considering this, the present study aims to evaluate the relationship between different variables in the leachate composition and elucidate the transformation processes through which this effluent passes during the landfill's period of operation. The study was conducted with eight sanitary landfills from the state of Minas Gerais, in southeastern Brazil, and used descriptive statistical analysis, principal component analysis (PCA), correlation analysis, and calculation of the leachate pollution index (LPI). The biochemical oxygen demand (BOD5)/chemical oxygen demand (COD) ratio was between 0.20 and 0.60. We also observed a significant correlation of 0.45 between Cl- and N-NH4+, which reflects the biological degradation processes that contribute to the presence of both variables. The PCA showed that inorganic variables and organic matter dominated the first component, with coefficients above 0.65, indicating the importance of those variables in determining the general data variability. The LPI values were between 15.26 and 25.97, with BOD5, COD, and N-NH4+ having sub-indexes above 35, being the main variables that increase the pollution potential of the leachate. On the other hand, trace metals present sub-indexes below 7 due to precipitation caused by increased pH and the characteristics of the waste discarded in landfills. The study provides essential information regarding the landfill leachate characteristics and its variation over time, which can contribute to the definition of treatment technologies for this affluent in different scenarios.
Assuntos
Eliminação de Resíduos , Poluentes Químicos da Água , Monitoramento Ambiental , Poluentes Químicos da Água/análise , Análise da Demanda Biológica de Oxigênio , Instalações de Eliminação de Resíduos , BrasilRESUMO
The physicochemistry and production rate of drinking water treatment residuals (DWTRs) depends on the raw water composition and the plant operational parameters. DWTRs usually contain Fe and/or Al oxyhydroxides, sand, clay, organic matter, and other compounds such as metal(oids), which are relevant in mining countries. This work proposes a simple approach to identify DWTRs reuse opportunities and threats, relevant for public policies in countries with diverse geochemical conditions. Raw water pollution indexes and compositions of DWTRs were estimated for Chile as a model case. About 23% of the raw drinking water sources had moderate or seriously contamination from high turbidity and metal(loid) pollution If the untapped reactivity of clean DWRTs was used to treat resources water in the same water company, the 73 and 64% of these companies would be able to treat water sources with As and Cu above the drinking water regulations, respectively. Integrating plant operational data and the hydrochemical characteristics of raw waters allows the prediction of DWTRs production, chemical composition, and reactivity, which is necessary to identify challenges and opportunities for DWTRs management.
Assuntos
Água Potável , Poluentes Químicos da Água , Purificação da Água , Argila , Monitoramento Ambiental , Metais/análise , Areia , Poluentes Químicos da Água/análiseRESUMO
In recent years, several environmental pollutants have been monitored in surface waters and sediments. However, few studies apply multivariate statistics to identify the main components and correlate them temporally and spatially. In this sense, the present study sought to monitor the quality of water and sediments in the Rio Marrecas/Brazil, through the analysis of physicochemical parameters and trace elements, as well as to identifying sources of contamination, using multivariate statistics. For this purpose, sampling was carried out in nine locations for a period of 12 months. The Total Reflection X-ray Fluorescence (TXRF) technique was used to quantify the 15 elements identified in water and sediment samples. Through multivariate statistical analyses, the most significant elements, their correlations and possible pollutant sources were defined, and the pollution index (HPI) and assessment index (HEI) of heavy metals were applied. The parameters pH and BOD5 do not comply with Brazilian legislation. Based on PCA and Spearman correlation, there was strong evidence of contamination of the water naturally, composed of the elements Ti, V, Mn, Fe, and of anthropogenic origin composed of the elements Ca, Ni, Cu, Zn. These findings provide insights to determine the impacts of heavy metals on human health and the environment.
Assuntos
Metais Pesados , Poluentes Químicos da Água , Brasil , Monitoramento Ambiental/métodos , Sedimentos Geológicos/química , Humanos , Metais Pesados/análise , Medição de Risco , Rios/química , Água/análise , Poluentes Químicos da Água/análiseRESUMO
Trophic transfer and bioaccumulation of trace metals have a profound impact on the structure and function of coastal areas; however, the metal accumulation patterns in detritus-based food webs and the influence of climatic variability have not been thoroughly investigated. The Tampamachoco Lagoon (Gulf of Mexico) is a coastal system impacted by emissions from a thermoelectric plant. We evaluated the spatial-temporal distribution patterns of Al, Cd, Hg, Cr, Cu, and Pb in water, sediments, and in organisms categorized by trophic levels (TLs), trophic guilds, and habitat preferences. The sediments had the highest concentrations of metals with no significant differences between seasons. The indices of geo-accumulation and potential ecological risk classified sediments as "moderately contaminated", evidencing a threat to human health through consumption of detritivores and filter-feeders. The lowest TLs (filter-feeders and detritivorous) reached the maximum Metal Pollution Index in the rainy season. According to discriminant analyses of metals and species, omnivorous and zoobentivorous organisms were associated with Hg during the rainy and dry seasons; while Al, Cd, and Cu were related to low TLs, and seston was associated with Pb. Food web magnification factor analysis showed that: (a) Pb, Cu, and Cr were biodiluted as trophic levels increased; (b) Cd and Hg showed temporal biomagnification trends; (c) Al, Pb, Cu, and Cd showed significant biodilution from the lowest TL to intermediate TLs; and (d) Hg was transferred from the lowest to intermediate TLs with clear biomagnification effects.
Assuntos
Mercúrio , Metais Pesados , Poluentes Químicos da Água , Cádmio/análise , Monitoramento Ambiental , Sedimentos Geológicos/química , Golfo do México , Humanos , Chumbo/análise , Mercúrio/análise , Metais Pesados/análise , Água/análise , Poluentes Químicos da Água/análiseRESUMO
Agricultural activities are highly related to the reduction of the availability of water resources due to the consumption of freshwater for crop irrigation, the use of fertilizers and pesticides. In this study, the water quality of the Adolfo López Mateos (ALM) reservoir was evaluated. This is one of the most important reservoirs in Mexico since the water stored is used mainly for crop irrigation in the most productive agricultural region. A comprehensive evaluation of water quality was carried out by analyzing the behavior of 23 parameters at four sampling points in the period of 2012-2019. The analysis of the spatial behavior of the water quality parameters was studied by spatial distribution graphs using the Inverse Distance Weighting interpolation. Pearson correlation was performed to better describe the behavior of all water quality parameters. This analysis revealed that many of these parameters were significantly correlated. The Principal Components Analysis (PCA) was carried out and showed the importance of water quality parameters. Ten principal components were obtained, which explained almost 90% of the total variation of the data. Additionally, the comprehensive pollution index showed a slight water quality variation in the ALM reservoir. This study also demonstrated that the main source of contamination in this reservoir occurs near sampling point one. Finally, the results obtained indicated that a contamination risk in the waterbody and further severe ecosystem degradations may occur if appropriate management is not taken.
Assuntos
Poluentes Químicos da Água , Qualidade da Água , Ecossistema , Monitoramento Ambiental , México , Estações do Ano , Poluentes Químicos da Água/análiseRESUMO
The growing literature on microplastics (MPs) in coastal and marine environs reflects the seriousness of this pollutant category. Diverse litter studies on Colombia's Central Caribbean Coast have not presented detailed study of MPs' typology, magnitude or distribution. This baseline study presents for first time the MPs problem on 23 beaches in 75 km coastal reach between Punta Roca and Galerazamba, on the central Colombian Caribbean Coast. The Microplastics Pollution Index (MPPI) and Coefficient of Microplastic Impact (CMPI) were developed and applied along with the Environmental Status Index (ESI) and their integration through sector analysis, and mapping using Agglomerative Hierarchical Clustering and Multidimensional Scaling, and Principal Components Analysis. Microplastics abundances (densities) ranged from 2457 to 557 MPs/kg, similar to other global beaches and bays. The MPs Index for the 23 beaches classified 8 beaches as "Moderate," 10 beaches as "High" and 5 as "Very High." Microplastic fibers were the dominant typology at 83% of the combined beaches total (ranging from Moderate to Very High for individual beaches).
Assuntos
Microplásticos , Poluentes Químicos da Água , Praias , Região do Caribe , Colômbia , Monitoramento Ambiental , Plásticos , Poluentes Químicos da Água/análiseRESUMO
The objectives of this study was to diagnose Cd and Pb contamination in soil and to identify the main factors that contribute to the transfer of these elements to tomato plants and fruits and contamination levels of the fruits in tropical mountain conditions. Contamination of the study area soils by Cd and Pb was verified. This contamination stemmed from the intensive use of agricultural inputs, mainly organic fertilizers and soluble mineral fertilizers. The relief of the terrain and inadequate soil management influenced the spatial distribution of these two metals. The Cd concentration in tomato fruits was very low, but the Pb contamination detected in approximately 80% of the fruit samples was considerably higher than the limits that pose a danger to human health. The translocation of Pb to the tomato fruits was associated with the use of organic fertilizer, mainly poultry litter.
Assuntos
Cádmio/análise , Chumbo/análise , Poluentes do Solo/análise , Solanum lycopersicum/química , Agricultura , Fertilizantes/análise , Frutas/química , Humanos , Metais Pesados/análise , Minerais , Solo , Fator de TransferênciaRESUMO
Heavy metals and bromine (Br) derived from organic and industrialized fertilizers can be absorbed, transported and accumulated into parts of plants ingested by humans. This study aimed to evaluate in an experiment conducted under no-tillage for 10 years, totaling 14 applications of pig slurry manure (PS), pig deep-litter (PL), dairy slurry (DS) and mineral fertilizer (MF), the heavy metal and Br contents in soil and in whether the grains produced by corn (Zea mays L.) and wheat (Triticum aestivum L.) under these conditions could result in risk to human health. The total contents of As, Cd, Pb, Cr, Ni, Cu, Zn and Br were analyzed in samples of fertilizers, waste, soil, shoots and grains of corn and wheat. Afterwards, enrichment factor (EF), accumulation factor (AF), health risk index (HRI), target hazard quotient (THQ) and target cancer risk (TCR) were determined. Mineral fertilizer exhibited the highest As and Cr content, while the highest levels of Cu and Zn were found in animal waste. The contents of As, Cd, Cr, Cu, Ni, Pb and Zn in soil were below the limits established by environmental regulatory agencies. However, a significant enrichment factor was found for Cu in soil with a history of PL application. Furthermore, high Zn contents were found in shoots and grains of corn and wheat, especially when the plants were grown in soil with organic waste application. Applications of organic waste and mineral fertilizer provided high HRI and THQ for Br and Zn, posing risks to human health. The intake of corn and wheat fertilized with pig slurry manure, swine deep bed, liquid cattle manure and industrialized mineral fertilizer did not present TCR.