Physical and chemical characteristics of water from the hydrographic basin of the Poxim River, Sergipe State, Brazil

The Poxim River is one of Sergipe State’s major waterways. It supplies water to the State capital, Aracaju, but is threatened by urban and agricultural developments that compromise both the quantity and the quality of the water. This has direct impacts on the daily lives of the region’s population. In this work, a multivariate analytical approach was used to investigate the physical and chemical characteristics of the water in the river basin. Four sampling campaigns were undertaken, in November 2005, and in February, May, and September 2006, at 15 sites distributed along the Poxim. The parameters analyzed were conductivity, turbidity, color, total dissolved solids, dissolved oxygen, alkalinity, hardness, chlorophyll-a, and nutrients (total phosphorus, dissolved orthophosphate, nitrite, nitrate, ammoniacal nitrogen, and total nitrogen). Dissolved oxygen contents were very low in the Poxim-Açu River (1.0–2.8), the Poxim River (1.6–4.6), and the estuarine region (1.7–5.1), due to the dumping of wastes and discharges of domestic and industrial effluents containing organic matter into fluvial and estuarine regions of the Poxim. Factor analysis identified five components that were indicative of the quality of the water, and that explained 81.73 % of the total variance.     

Chronic genetic damages in <Emphasis Type="Italic">Geophagus brasiliensis</Emphasis> exposed to anthropic impact in Estuarine Lakes at Santa Catarina Coast–Southern of Brazil

Biological monitoring through animals exposed to pollutants using biomarkers provides a promising tool for the identification of pollutants that may cause damage to human health and/or to sustainability of ecosystems. The effects of pollutants in fish tissues are important tools to understand the impact of human activities in natural ecosystems. The aim of this work was to study the water quality of two estuarine lakes in Santa Catarina, Brazil (Camacho Lake and Santa Marta Lake). Geophagus brasiliensis is a species widely distributed in Brazil and was used in this work. Comet assays in peripheral red blood and kidney cells, micronucleus tests in peripheral red blood cells, measurements of acetylcholinesterase activity in axial muscle and histopathological analysis of liver were used as biomarkers. Three sampling campaigns were undertaken in November 2004, June 2005 and November 2005. Thirty adult animals were sampled from each of three different sites (P1—Santa Marta Lake, P2 and P3—Camacho Lake). A negative control was sampled in a non-polluted site at Costa Ecological Park, Paraná. The positive control for genotoxicity was obtained by treating animals with copper sulphate. The results showed that both studied lakes are impacted by potential genotoxic substances. Severe lesions in liver of G. brasiliensis were also observed. The inhibition of acetylcholinesterase activity suggests the presence of pesticides or metals in the studied sites. This work shows that the water quality of Santa Marta and Camacho Lakes have been compromised and further control source of pollutants into these ecosystems is required.     

Mercury concentration in fish from Piracicaba River (Minas Gerais, Brazil)

Mercury emissions from some upstream gold mining areas and recent findings of high natural Hg levels in sediments motivated studies on the Hg cycle in the Minas Gerais state. The study presents the total mercury amount found in Geophagus brasiliensis' muscular tissue (wet weight) and sediments from Piracicaba River. Mercury was analyzed using acid digestion followed by determination of total mercury by cold vapour atomic absorption spectrophotometry. This study was also complemented with the analysis of the limnological parameters (water temperature, conductivity, total dissolved solids, suspended particles, pH, dissolved oxygen, maximum depth, photic index and total carbon). The mercury concentration in sediments samples was higher than the mercury concentration in muscular tissue of fish. The lowest Hg level measured in fish was 0.0147 microg g( - 1), while the highest was 0.101 microg g( - 1). In the sediment samples, the lowest and highest levels were 0.02 microg g( - 1) and 0.16 microg g( - 1), respectively. The Hg concentrations in fish and sediment were both under the maximum limit permitted by the World Health Organization.     

Factors regulating the coastal nutrient filter in the Baltic Sea

Ambio - The coastal zone of the Baltic Sea is diverse with strong regional differences in the physico-chemical setting. This diversity is also reflected in the importance of different...     

Effects of lead on anatomy,ultrastructure and concentration of nutrients in plants Oxycaryum cubense (Poep. & Kunth) Palla: a species with phytoremediator potential in contaminated watersheds

Lead (Pb) has been highlighted as a major pollutant of both terrestrial and aquatic ecosystems, causing negative impacts to these environments. The concentration of Pb in plants has increased in recent decades, mainly due to anthropogenic activities. This study has as a hypothesis that the species Oxycaryum cubense (Poep. & Kunth) Palla, abundant in aquatic environments, has the potential to be used a phytoremediator. The plants were grown in a hydroponic system with Pb in increasing concentrations (0, 4, 8, 16 and 32 mg l^?1) for 15 days. Inductively coupled mass spectrometer (ICP OES) was used to determine the concentration of mineral nutrients and lead. Optical and transmission electron microscopy were used for the analysis of cellular damage induced by lead in roots and leaves. Ultrastructural alterations were observed as disorganization of thylakoids in the chloroplast and disruption of mitochondrial membranes in cells of leaf tissues of plants subjected to increasing Pb concentrations. There was accumulation of Pb, especially in the root system, affecting the absorption and translocation of some mineral nutrients analysed. In roots, there was reduction in the thickness of the epidermis in plants treated with Pb. This species was shown to be tolerant to the Pb concentrations evaluated, compartmentalizing and accumulating Pb mainly in roots. Due to these results, it may be considered a species with phytoremediation capacity for Pb, with potential rizofiltration of this metallic element in contaminated watersheds.     

Healing with animals in a semiarid northeastern area of Brazil

This study presents information on the use of medicinal animals in a semiarid area of northeast Brazil, a region where animals have recognized importance in local popular medicine. The information on the use of animals for medicinal purposes was obtained through semi-structured questionnaires, complemented by free interviews and informal conversations. The results obtained showed that the residents of the area studied utilize a considerable richness of animal species (n = 42) for medicinal purposes, as occurs in other areas of Brazil’s semiarid region, demonstrating that zootherapy represents an alternative form of health care that is important to the inhabitants of the region. There is a need for new investigations on medicinal fauna, aimed at promoting the sustainable use of eventual medicinal species and preserving popular knowledge associated with the use of animal species.     

Application of Fenton, photo-Fenton, solar photo-Fenton, and UV/H2O2 to degradation of the antineoplastic agent mitoxantrone and toxicological evaluation

In the present study, selected advanced oxidation processes (AOPs)—namely, photo-Fenton (with Fe²⁺, Fe³⁺, and potassium ferrioxalate—FeOx—as iron sources), solar photo-Fenton, Fenton, and UV/H₂O₂—were investigated for degradation of the antineoplastic drug mitoxantrone (MTX), frequently used to treat metastatic breast cancer, skin cancer, and acute leukemia. The results showed that photo-Fenton processes employing Fe(III) and FeOx and the UV/H₂O₂ process were most efficient for mineralizing MTX, with 77, 82, and 90 % of total organic carbon removal, respectively. MTX probably forms a complex with Fe(III), as demonstrated by voltammetric and spectrophotometric measurements. Spectrophotometric titrations suggested that the complex has a 2:1 Fe³⁺:MTX stoichiometric ratio and a complexation constant (K) of 1.47 × 10⁴ M^–1, indicating high MTX affinity for Fe³⁺. Complexation partially inhibits the involvement of iron ions and hence the degradation of MTX during photo-Fenton. The UV/H₂O₂ process is usually slower than the photo-Fenton process, but, in this study, the UV/H₂O₂ process proved to be more efficient due to complexing of MTX with Fe(III). The drug exhibited no cytotoxicity against NIH/3T3 mouse embryonic fibroblast cells when oxidized by UV/H₂O₂ or by UV/H₂O₂/FeOx at the concentrations tested.     

Assessment of DNA damage in Brazilian workers occupationally exposed to pesticides: a study from Central Brazil

We evaluated 41 rural workers occupationally exposed to pesticides and 32 subjects as a control group, using the micronucleus (MN) and the comet assay. For the comet assay, we evaluated the peripheral blood, and for the MN, we sampled cells from the oral epithelium. Damage to DNA was measured by tail length, % DNA in tail (% tail), olive tail moment (OTM), and tail moment (TM). The exposed group presented an 8× increase in MN frequency, when compared to the control group (p <0.05). When we contrasted the MN frequencies between the individuals that use and do not use personal protective equipment, we found a mean of 7.5 MN (57 % variance) and 12.1 MN (130 % variance), respectively. The binucleated cells were 0.04 and 0.005, in the exposed and control groups, respectively, indicating 8× increase in the number of binucleated cells, when comparing the groups (p <0.05). In the comet assay, we demonstrated statistically significant differences in three parameters (% DNA, OTM, and TM) indicating that the rural workers presented high levels of genomic damages. Our results indicate that occupational exposure to pesticides could cause genome damage in somatic cells, representing a potential health risk to Brazilian rural workers that deal constantly with agrochemicals without adequate personal protection equipment.     

Investigating the potential of functionalized MCM-41 on adsorption of Remazol Red dye

The modification of MCM-41 was performed with 3-aminopropropyltrimethoxysilane. The structural order and textural properties of the synthesized materials were studied by X-ray diffraction, Fourier transform infrared spectroscopy, thermogravimetry/differential thermogravimetry, nitrogen adsorption, and desorption analysis. The adsorption capacity of NH₂-MCM-41 was studied with Remazol Red dye. The following parameters were studied in the adsorption process: pH, temperature, adsorbent dosage, and initial concentration. The desorption process was studied in different concentrations of NaOH solutions. The Freundlich isotherm model was found to be fit with the equilibrium isotherm data. Kinetics of adsorption follows the modified Avrami rate equation. The maximum adsorption capacity was estimated to be 45.9 mg?g^?1, with removal of the dye of 99.1 %. The NH₂-MCM-41 material exhibited high desorption capacity with 98.1 %.     

Chitosan for direct bioflocculation of wastewater

Environmental Chemistry Letters - Coagulation/flocculation is a major phenomenon occurring during industrial and municipal water treatment to remove suspended particles. Common coagulants are metal...