Storage of natural water samples for total and reactive mercury analysis in PET bottles

Poly(ethylene terephthalate) (PET) bottles used in commercially available mineral water were compared to Teflon bottles for sampling and storage of river water samples prior to mercury determination. The metal concentration was in the range 0.3-2.0 ng L-1 for the reactive species, and in the range 1-9 ng L-1 for total mercury. A paired t-test showed no significant difference in the results for both reactive (p = 0.011) and total Hg (p = 0.024). Storage time was studied for PET bottles, using synthetic samples spiked with 10 ng L-1 Hg2+ ions, using two different types of preservation: (a) by freezing at -18 degrees C, and (b) by the addition of BrCl solution. Both procedures yielded the same results up to the 14th day of storage (ANOVA, p = 0.72 for BrCl and p = 0.12 for freezing). The freezing procedure proved to be more suitable for longer storage times, i.e., up to 40 d (significance level of 0.03, ANOVA).125354955

Islet Endothelial Activation and Oxidative Stress Gene Expression Is Reduced by IL-1Ra Treatment in the Type 2 Diabetic GK Rat

Inflammation followed by fibrosis is a component of islet dysfunction in both rodent and human type 2 diabetes. Because islet inflammation may originate from endothelial cells, we assessed the expression of selected genes involved in endothelial cell activation in islets from a spontaneous model of type 2 diabetes, the Goto-Kakizaki (GK) rat. We also examined islet endotheliuml/oxidative stress (OS)/inflammation-related gene expression, islet vascularization and fibrosis after treatment with the interleukin-1 (IL-1) receptor antagonist (IL-1Ra)

'Statins in retinal disease'

Statins are known for their blood cholesterol-lowering effect and are widely used in patients with cardiovascular and metabolic diseases. Research over the past three decades shows that statins have diverse effects on different pathophysiological pathways involved in angiogenesis, inflammation, apoptosis, and anti-oxidation, leading to new therapeutic options. Recently, statins have attracted considerable attention for their immunomodulatory effect. Since immune reactivity has been implicated in a number of retinal diseases, such as uveitis, age-related macular degeneration (AMD) and diabetic retinopathy, there is now a growing body of evidence supporting the beneficial effects of statins in these retinopathies. This review evaluates the relationship between statins and the pathophysiological basis of these diseases, focusing on their potential role in treatment. A PubMed database search and literature review was conducted. Among AMD patients, there is inconsistent evidence regarding protection against development of early AMD or delaying disease progression; though they have been found to reduce the risk of developing choroidal neovascular membranes (CNV). In patients with retinal vein occlusion, there was no evidence to support a therapeutic benefit or a protective role with statins. In patients with diabetic retinopathy, statins demonstrate a reduction in disease progression and improved resolution of diabetic macular oedema (DMO). Among patients with uveitis, statins have a protective effect by reducing the likelihood of uveitis development

Is the Negro River Basin (Amazon) impacted by naturally occurring mercury?

In order to investigate the major sources and cycling of mercury in the Negro River Basin (Amazon), total metal measurements were carried out in soils, in river and lake waters, in the atmosphere, and in bulk precipitation during the period 1995 throughout 1998. Median values of 1.3 ng m(-3) in the atmosphere, 172 mug kg(-1) in soils, 4.6-7.5 ng l(-1) in three different lakes, 4.5 ng l(-1) in 17 different Negro River tributaries and 20.3 mug m(-2) year(-1) in bulk precipitation were found. Mercury concentrations in rivers and lakes waters, as well as in soils and bulk precipitation were high, considering the scarcity of anthropogenic point sources in the region. Mercury leaching from soil, the largest regional reservoir of this metal, was considered to be the major pathway to mercury enrichment in the region. (C) 2001 Elsevier Science B.V. All rights reserved.27541699718

Mercury in the Waters of the Jundiai River, SP, Brazil: The Role of Dissolved Organic Matter

Many developing countries have regions of high demographic density, where untreated residuary waters from different sources are often discharged into rivers, streams and other water bodies. This paper discusses the reducing action of organic matter of anthropic origin on the mercury redox cycle in the Jundiai River impacted by discharged wastes, and on the Pirai River, a non-impacted water body. The total mercury concentrations in these locations vary from 1.7 to 32 ng L-1 in the former and from 0.6 to 10.6 ng L-1 in the latter. Dissolved organic carbon concentrations of up to 68.3 and 6.5 mg L-1 were observed, confirming the higher impact on the Jundiai River. It was found that an inverse correlation between the concentration of dissolved organic carbon and total mercury was stronger in the Jundiai River, given that it receives higher organic loads, suggesting that organic matter exerts a reducing action on mercury, which is released as gas into the atmosphere. This correlation was not observed in the Pirai River, where the organic matter of natural origin is probably not sufficiently labile to act intensely upon the Hg redox cycle, favoring the metal transport.18544545

Degradation of formaldehyde by advanced oxidation processes

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)The degradation of formaldehyde in an aqueous solution (400 mg L-1) was studied using photolysis, peroxidation and advanced oxidation processes (UV/H2O2, Fenton and photo-Fenton). Photolysis was the only process tested that did not reduce formaldehyde concentration; however, only advanced oxidation processes (AOPs) significantly decreased dissolved organic carbon (DOC). UV/H2O2 and photo-Fenton AOPs were used to degrade formaldehyde at the highest concentrations (1200-12,000 mg L-1); the processes were able to reduce CH2O by 98% and DOC by 65%. Peroxidation with ultraviolet light (UV/H2O2) improved the efficiency of treatment of effluent from an anatomy laboratory. The effluent's CH2O content was reduced by 91%, DOC by 48%, COD by 46% and BOD by 53% in 420 min of testing. (C) 2012 Elsevier Ltd. All rights reserved.10796101Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)FAPESP [02/12017-0

Mercury biomagnification in a tropical black water, Rio Negro, Brazil

The population living along the riverbanks of the Amazon basin depends heavily on fish for nutritional support. Mono-methyl-mercury (MMHg) concentrates in fish, which can contaminate humans, the risk depending not only on fish MMHg concentration but also on the amount of fish consumed. We sampled nine locations of the Rio Negro basin, differing in water pH, Hg concentrations, and dissolved organic carbon (DOC), and determined total Hg from 951 fish samples of species representative of the food web: herbivorous, detritivorous, omnivorous, and piscivorous. Mercury concentrations varied widely in all species but showed a trend that depended on fish feeding strategies. The highest mean concentration was found in the piscivorous species (688.90 ng/g(-1)), followed by omnivorous (190.30 ng/g(-1)), detritivorous (136.04 ng/g(-1)), and herbivorous (70.39 ng/g(-1)). Fish Hg concentrations exceeding current safe limits (500 ng/g(-1)) for human consumption were found mainly in the piscivorous species (60%). Significant positive correlation between fish weight and Hg concentration was seen for the piscivorous Serrasalmus spp. (n = 326; r = 0.3977; p, < 0.0001), Cichla spp. (n = 125; r = 0.4600: p < 0.0001), and Pimelodus spp. (n = 12; r = 0.8299; p = 0.0008). known locally as Piranha, Tucunare, and Mandi, respectively. However, a negative correlation was seen for non-piscivorous Potamorhina latior (n = 30; r -0.3763; p = 0.0404) and Leporinus spp. (n = 44; r = -3987; p = 0.0073), known as Branquinha (detritivorous) and Aracu (omnivorous). Fish-Hg concentrations in the acidic waters (pH range, 4.09-6.31) of the Rio Negro habitat, with its wide gradient of Hg concentrations (3.4-11.9 mug/L-1) and DOC (1.85-15.3 mg/L-1)-but no history of gold mining activity-are comparable to other Amazonian rivers. Opportunity fish catches in the Rio Negro habitat show high muscle-Hg derived from natural sources, but no systematic association with site-dependent geochemistry.45223524