The use of polyacrylamides (PAMs) for removing natural organic matter (NOM) from Paraiba do Sul River (Brazil)

This work assesses the efficiency of polyacrylamides for natural organic matter (NOM) removal from Paraiba do Sul River (Brazil) raw water for drinking purposes. Jar tests were performed following an experimental design protocol. Three kinds of polyacrylamides (anionic, cationic, and non-ionic) at 0.2 mg L(-1) were tested. After coagulation, turbidity, DOC, UVA(254) and SCAN (UV-absorbing material) were determined. Color and pH were also measured. It was found that polyacrylamides did not reduce the amounts of alum and lime needed in the process and that the amount of alum alone for removing UV-absorbing organic matter is significantly higher. Efficiency of the coagulation process decreased as follows: non-ionic -> cationic -> anionic -> no polyacrylamide. Removal efficiencies for the best case were: 100%, 90%, 83%, and 68% for turbidity, DOC, UVA(254), and SCAN, respectively.

Mässingslegeringar med låg blyhalt för svarvade komponenter ämnade för dricksvatten

This thesis is about brass alloys with low lead levels for manufacturing of turned components destined for human consumption. Is it technically possible, economically viable and environmentally necessary to produce lead-free brass alloys? Turning tests and leaching tests has been carried out in low-lead brass. The result of the tests carried out show that it is technically possible to produce faucets in low-leaded brass, but since these alloys are harder and less ductile, it takes more power and more cooling when it is processed. There should be more reality-based tests in regular machines that belong in the line of manufacturing. Tests is needed to find out which tool materials, cutting angles, cooling, etc. which are needed to manufacture products with the right surface, dimensions, durability, etc. One thing that no one knows today is the lifetime of a faucet made of low-lead brass. If these faucet’s do not have a higher life than that made in CW 602 N, it is a major strain on nature to produce these in low-lead brass, then to maintain production of the faucets as it is today. No information has come from the Boverket of tougher requirements for lead content in brass. This makes it difficult to know how much effort that is needed to replace lead. A legal requirement or to lose market areas is otherwise a good motivation to move forward.

Riskfyllt vatten : Hur individen skapar sig en förståelse av oväntad parasitförekomst i dricksvattnet

Risky water How the individual makes sense of unexpected parasites in the drinking water This quick response study was carried out with the aim to study how individuals made sense of the outbreak of the parasite Cryptosporidium in the drinking water in Ostersund. In total 24 interviews were made with people in Ostersund. The result shows that the interviewees related to social as well as spatial dimensions when they made sense of this risky situation, which can be understood in relation to the concept of sensemaking of risk. Six groups among the interviewees emerged in the analysis, illustrating how different aspects of the risk where focused in the process of sensemaking. Further, the study shows that the process of sensemaking was built upon direct as well as indirect social relations, where the interviewees made sense of the risk by relating to people who were close to them as well as to people to whom they had no personal relation. These indirect social relations were defined as: elderly, children and people in other countries, which also points at the fact that the interviewees made sense of the risk in a global context. Finally, the results suggest that social relations could be further explored in future studies in sensemaking of risk.

Regulation of redox and DNA repair genes by arsenic : low dose protection against oxidative stress?

We have evaluated the molecular responses of human epithelial cells to low dose arsenic to ascertain how target cells may respond to physiologically relevant concentrations of arsenic. Data gathered in numerous experiments in different cell types all point to the same conclusion: low dose arsenic induces what appears to be a protective response against subsequent exposure to oxidative stress or DNA damage, whereas higher doses often provoke synergistic toxicity. In particular, exposure to low, sub-toxic doses of arsenite, As(III), causes coordinate up-regulation of multiple redox and redox-related genes including thioredoxin (Trx) and glutathione reductase (GR). Glutathione peroxidase (GPx) is down-regulated in fibroblasts, but up-regulated in keratinocytes, as is glutathione S-transferase (GST). The maximum effect on these redox genes occurs after 24 h exposure to 5–10 mM As(III). This is 10-fold higher than the maximum As(III) concentrations required for induction of DNA repair genes, but within the dose region where DNA repair genes are co-ordinately down-regulated. These changes in gene regulation are brought about in part by changes in DNA binding activity of the transcription factors activating protein-1 (AP-1), nuclear factor kappa-B, and cAMP response element binding protein (CREB). Although sub-acute exposure to micromolar As(III) up-regulates transcription factor binding, chronic exposure to submicromolar As(III) causes persistent down-regulation of this response. Similar long-term exposure to micromolar concentrations of arsenate in drinking water results in a decrease in skin tumour formation in dimethylbenzanthracene (DMBA)/phorbol 12-tetradecanoate 13-acetate (TPA) treated mice. Altered response patterns after long exposure to As(III) may play a significant role in As(III) toxicology in ways that may not be predicted by experimental protocols using short-term exposures.

Arsenic, mode of action at biologically plausible low doses : what are the implications for low dose cancer risk?

Arsenic is an established human carcinogen. However, there has been much controversy about the shape of the arsenic response curve, particularly at low doses. This controversy has been exacerbated by the fact that the  mechanism(s) of arsenic carcinogenesis are still unclear and because there are few satisfactory animal models for arsenic-induced carcinogenesis. Recent epidemiological studies have shown that the relative risk for cancer among populations exposed to ≤60 ppb As in their drinking water is often lower than the risk for the unexposed control population. We have found that treatment of human keratinocyte and fibroblast cells with 0.1 to 1 μM arsenite (As^III) also produces a low dose protective effect against oxidative stress and DNA damage. This response includes increased transcription, protein levels and enzyme activity of several base excision repair genes, including DNA polymerase β and DNA ligase I. At higher concentrations (> 10 μM), As induces down-regulation of DNA repair, oxidative DNA damage and apoptosis. This low dose adaptive (protective) response by a toxic agent is known as hormesis and is characteristic of many agents that induce oxidative stress. A mechanistic model for arsenic carcinogenesis based on these data would predict that the low dose risk for carcinogenesis should be sub-linear. The threshold dose where toxicity outweighs protection is hard to predict based on in vitro dose response data, but might be estimated if one could determine the form (metabolite) and concentration of arsenic responsible for changes in gene regulation in the target tissues.

Heterozygous tx mice have an increased sensitivity to copper loading: implications for Wilson's Disease carriers

Wilson's disease carriers constitute 1% of the human population. It is unknown whether Wilsons disease carriers are at increased susceptibility to copper overload when exposed to chronically high levels of ingested copper. This study investigated the effect of chronic excess copper in drinking water on the heterozygous form of the Wilson’s disease mouse model – the toxic milk (tx) mouse. Mice were provided with drinking water containing 300 mg/l copper for 4–7, 8–11, 12–15 or 16–20 months. At the completion of the study liver, spleen, kidney and brain tissue were analyzed by atomic absorption spectroscopy to determine copper concentration. Plasma ceruloplasmin oxidase activity and liver histology were also assessed. Chronic copper loading resulted in significantly increased liver copper in both tx heterozygous and tx homozygous mice, while wild type mice were resistant to the effects of copper loading. Copper loading effects were greatest in tx homozygous mice, with increased extrahepatic copper deposition in spleen and kidney – an effect absent in heterozygote and wild type mice. Although liver histology in homozygous mice was markedly abnormal, no histological differences were noted between heterozygous and wild type mice with copper loading. Tx heterozygous mice have a reduced ability to excrete excess copper, indicating that half of the normal liver Atp7b copper transporter activity is insufficient to deal with large copper intakes. Our results suggest that Wilsons disease carriers in the human population may be at increased risk of copper loading if chronically exposed to elevated copper in food or drinking water.

Angiotensin converting enzyme inhibition from birth reduces body weight and body fat in Sprague-Dawley rats

In vitro studies have demonstrated that angiotensin II (ANG II) induces adipocyte hyperplasia and hypertrophy. The aim of the present study was to determine the effect of angiotensin-converting enzyme inhibition on body weight, adiposity and blood pressure in Sprague–Dawley rats. From birth half of the animals (n = 15) were given water to drink, while the remainder were administered perindopril in their drinking water (2 mg/kg/day). Food intake, water intake and body weight were measured weekly. Blood pressure was measured by tail cuff plethysmography at 11-weeks. Body fat content and distribution were assessed using dual energy X-ray absorptiometry and Magnetic Resonance Imaging at 12 weeks. Animals administered with perindopril had a body fat proportion that was half that of controls. This was consistent with, but disproportionately greater than the observed differences in food intake and body weight. Perindopril treatment completely removed hypertension. We conclude that the chronic inhibition of ANG II synthesis from birth specifically reduces the development of adiposity in the rat.

Comparison of tissue dosimetry in the mouse following chronic exposure to arsenic compounds

Several chronic bioassays have been conducted in multiple strains of mice in which various concentrations of arsenate or arsenite were administered in the drinking water without a tumorigenic effect. However, one study (Ng et al., 1999) reported a significant increase in tumor incidence in C57Bl/6J mice exposed to arsenic in their drinking water throughout their lifetime, with no tumors reported in controls. A physiologically based pharmacokinetic model for arsenic in the mouse has previously been developed (Gentry et al., 2004) to investigate potential differences in tissue dosimetry of arsenic species across various strains of mice. Initial results indicated no significant differences in blood, liver, or urine dosimetry in B6C3F1 and C57Bl/6 mice for acute or subchronic exposure. The current work was conducted to compare model-predicted estimates of tissue dosimetry to additional kinetic information from the (C57Bl/6 x CBA)F1 and TgAc mouse. The results from the current modeling indicate that the pharmacokinetic parameters derived based on information in the B6C3F1 mouse adequately describe the measured concentrations in the blood/plasma, liver, and urine of both the (C57Bl/6 x CBA)F1 and TgAc mouse, providing further support that the differences in response observed in the chronic bioassays are not related to strain-specific differences in pharmacokinetics. One significant finding was that no increases in skin or lung concentrations of arsenic species in the (C57Bl/6 x CBA)F1 strain were observed following administration of low concentrations (0.2 or 2 mg/L) of arsenate in the drinking water, even though differences in response in the skin were reported. These data suggest that pharmacodynamic changes may be observed following exposure to arsenic compounds without an observable change in tissue dosimetry. These results provided further indirect support for the existence of inducible arsenic efflux in these tissues.

A provisional database for the silicon content of foods in the United Kingdom

Si may play an important role in bone formation and connective tissue metabolism. Although biological interest in this element has recently increased, limited literature exists on the Si content of foods. To further our knowledge and understanding of the relationship between dietary Si and human health, a reliable food composition database, relevant for the UK population, is required. A total of 207 foods and beverages, commonly consumed in the UK, were analysed for Si content. Composite samples were analysed using inductively coupled plasma–optical emission spectrometry following microwave-assisted digestion with nitric acid and H2O2. The highest concentrations of Si were found in cereals and cereal products, especially less refined cereals and oat-based products. Fruit and vegetables were highly variable sources of Si with substantial amounts present in Kenyan beans, French beans, runner beans, spinach, dried fruit, bananas and red lentils, but undetectable amounts in tomatoes, oranges and onions. Of the beverages, beer, a macerated whole-grain cereal product, contained the greatest level of Si, whilst drinking water was a variable source with some mineral waters relatively high in Si. The present study provides a provisional database for the Si content of UK foods, which will allow the estimation of dietary intakes of Si in the UK population and investigation into the role of dietary Si in human health.

Enforcement in environmental law: an economic analysis of citizen suits

Previous to 1970, state and federal agencies held exclusive enforcement responsibilities over the violation of pollution control standards. However, recognizing that the government had neither the time nor resources to provide full enforcement, Congress created citizen suits. Citizen suits, first amended to the Clean Air Act in 1970, authorize citizens to act as private attorney generals and to sue polluters for violating the terms of their operating permits. Since that time, Congress has included citizen suits in 13 other federal statutes. The citizen suit phenomenon is sufficiently new that little is known about it. However, we do know that citizen suits have increased rapidly since the early 1980's. Between 1982 and 1986 the number of citizen suits jumped from 41 to 266. Obviously, they are becoming a widely used method of enforcing the environmental statutes. This paper will provide a detailed description, analysis and evaluation of citizen suits. It will begin with an introduction and will then move on to provide some historic and descriptive background on such issues as how citizen suit powers are delegated, what limitations are placed on the citizens, what parties are on each side of the suit, what citizens can enforce against, and the types of remedies available. The following section of the paper will provide an economic analysis of citizen suits. It will begin with a discussion of non-profit organizations, especially non-profit environmental organizations, detailing the economic factors which instigate their creation and activities. Three models will be developed to investigate the evolution and effects of citizen suits. The first model will provide an analysis of the demand for citizen suits from the point of view of a potential litigator showing how varying remedies, limitations and reimbursement procedures can effect both the level and types of activities undertaken. The second model shows how firm behavior could be expected to respond to citizen suits. Finally, a third model will look specifically at the issue of efficiency to determine whether the introduction of citizen enforcement leads to greater or lesser economic efficiency in pollution control. The database on which the analysis rests consists of 1205 cases compiled by the author. For the purposes of this project this list of citizen suit cases and their attributes were computerized and used to test a series of hypotheses derived from three original economic models. The database includes information regarding plaintiffs, defendants date notice and/or complaint was filed and statutes involved in the claim. The analysis focuses on six federal environmental statutes (Clean Water Act} Resource Conservation and Recovery Act, Comprehensive Environmental Response Compensation and Liability Act, Clean Air Act, Toxic Substances Control Act, and Safe Drinking Water Act) because the majority of citizen suits have occurred under these statutes.

Selective reduction in body fat mass and plasma leptin induced by angiotensin-converting enzyme inhibition in rats

Objective: There is emerging evidence that angiotensin stimulates adipocyte differentiation and lipogenesis. This study tested the hypothesis that inhibition of angiotensin II by treatment with an angiotensin-converting enzyme inhibitor, perindopril, would reduce fat mass in rats. Design: After a 12-day baseline, rats were divided into two groups: one was untreated and the other received perindopril (1.2 mg kg⁻¹ per day) in drinking water for 26 days.Subjects: In total, 16 male Sprague–Dawley rats aged 10 weeks at the start of the study. Measurements: Plasma leptin was measured in samples collected at baseline, half-way through and at the end of treatment. Body weight, food and water intake were measured daily throughout the experiment. Body fat mass, bone and lean mass were determined by dual energy X-ray absorptiometry (DEXA) at the end of the treatment period. Results: Daily food intake was the same in both groups throughout the study. By the end of treatment, animals receiving perindopril showed a modest reduction in weight gain relative to the untreated animals (62.4±5.0 g vs 73.0±4.0 g; P<0.05). DEXA analysis showed that body composition was greatly altered and the perindopril-treated group had 26% less body fat mass than the untreated group (61.0±5.2 g vs 44.4±4.2 g; P<0.01). The reduction in body fat mass was correlated with reductions in the weight of both the epididymal and retroperitoneal fat pads (P<0.001). Similarly, plasma leptin was reduced by perindopril treatment (4.64±0.56 ng ml⁻¹) compared to the untreated group (8.27±1.03 ng ml⁻¹; P<0.001). In contrast, there were no differences in lean or bone mass between the two groups.Conclusion: Oral treatment with perindopril selectively reduced body fat mass without influencing daily food intake. In contrast, there were no differences in lean or bone mass between the two groups

Effect of nitric oxide synthase inhibition on mitochondrial biogenesis in rat skeletal muscle

The purpose of this study was to determine whether nitric oxide synthase (NOS) inhibition decreased basal and exercise-induced skeletal muscle mitochondrial biogenesis. Male Sprague-Dawley rats were assigned to one of four treatment groups: NOS inhibitor NG-nitro-L-arginine methyl ester (L-NAME, ingested for 2 days in drinking water, 1 mg/ml) followed by acute exercise, no L-NAME ingestion and acute exercise, rest plus L-NAME, and rest without L-NAME. The exercised rats ran on a treadmill for 53 ± 2 min and were then killed 4 h later. NOS inhibition significantly (P < 0.05; main effect) decreased basal peroxisome proliferator-activated receptor-{gamma} coactivator 1beta (PGC-1beta) mRNA levels and tended (P = 0.08) to decrease mtTFA mRNA levels in the soleus, but not the extensor digitorum longus (EDL) muscle. This coincided with significantly reduced basal levels of cytochrome c oxidase (COX) I and COX IV mRNA, COX IV protein and COX enzyme activity following NOS inhibition in the soleus, but not the EDL muscle. NOS inhibition had no effect on citrate synthase or beta-hydroxyacyl CoA dehydrogenase activity, or cytochrome c protein abundance in the soleus or EDL. NOS inhibition did not reduce the exercise-induced increase in peroxisome proliferator-activated receptor-{gamma} coactivator 1{alpha} (PGC-1{alpha}) mRNA in the soleus or EDL. In conclusion, inhibition of NOS appears to decrease some aspects of the mitochondrial respiratory chain in the soleus under basal conditions, but does not attenuate exercise-induced mitochondrial biogenesis in the soleus or in the EDL.

Play it again, Sam : How journalists cashed in on Youtube's favourite koala

The world was captivated when footage of a badly burnt koala drinking water from a Victorian firefighter's bottle was uploaded to You Tube in February 2009. When the story of "Sam the Koala" was adopted by the mainstream media, recombinant themes were used to construct her story - from heroism and patriotism to villain vs victim and romance. While scholars have examined the changing role of the journalist in a converged world and the rise of "soft" news, this paper focuses on the way journalists create disjointed narratives around You Tube footage to extend a story s lifespan. We call these new narrative forms "fractured fairy tale news" to describe this emerging phenomenon of convergence culture. Further, we suggest that news media exploit the YouTube community for their own commercial gain and conclude that the fractured fairy tale style is a poor vehicle for the future of news.

Age and exposure to arsenic alter base excision repair transcript levels in mice

Arsenic (As) induces DNA-damaging reactive oxygen species. Most oxidative DNA damage is countered by base excision repair (BER), the capacity for which may be reduced in older animals. We examined whether age and consumption of As in lactational milk or drinking water influences BER gene transcript levels in mice. Lactating mothers and 24-week-old mice were exposed (24 h or 2 weeks) to As (2 or 50 p.p.m.) in drinking water. Lung tissue was harvested from adults, neonates (initially 1 week old) feeding from lactating mothers and untreated animals 1– 26 weeks old. Transcripts encoding BER proteins were quantified. BER transcript levels decreased precipitously with age in untreated mice but increased in neonates whose mothers were exposed to 50 p.p.m. As for 24 h or 2 weeks. Treatment of 24-week-old mice with 2 or 50 p.p.m. As for 2 weeks decreased all transcript levels measured. Exposure to As attenuated the age-related transcript level decline for only one BER gene. We conclude that aging is associated with a rapid reduction of BER transcript levels in mice, which may contribute to decreased BER activity in older animals. Levels of As that can alter gene expression are transmitted to neonatal mice in lactational milk produced by mothers drinking water containing As, raising concerns about breastfeeding in countries having As-contaminated groundwater. Reduction of BER transcript levels in 24- week-old mice exposed to As for 2 weeks suggests As may potentiate sensitivity to itself in older animals.

Climate change impacts and adaptation in Bangladesh : an agent-based approach

Bangladesh exemplifies the complex challenges facing densely populated coastal regions. The
pressures on the country are immense: around 145 million people live within an area of just 145,000 sq-km at
the confluence of three major river systems: the Ganges, the Brahmaputra and the Meghna. While progress
has been made, poverty remains widespread, with around 39% of children under five malnourished. Most of
its land-mass lies below 10m above sea level with considerable areas at sea level, leading to frequent and
prolonged flooding during the monsoons. Sea level rise is leading to more flooding as storm surges rise off
higher sea levels, pushing further inland. Higher sea levels also result in salt-water intrusion into freshwater
coastal aquifers and estuaries, contaminating drinking water and farmland. Warmer ocean waters are also
expected to lead to an increase in the intensity of tropical storms.
Bangladesh depends on the South Asian summer monsoon for most of its rainfall which is expected to
increase, leading to more flooding. Climate scientists are also concerned about the stability of monsoon and
the potential for it to undergo a nonlinear phase shift to a drier regime. Bangladesh faces an additional
hydrological challenge in that the Ganges and Brahmaputra rivers both rise in the Himalaya-Tibetan Plateau
region, where glaciers are melting rapidly. The Intergovernmental Panel on Climate Change (IPCC)
concluded that rapid melting is expected to increase river flows until around the late-2030s, by which time
the glaciers are expected to have shrunk from their 1995 extent of 500,000 sq-km to an expected 100,000 sqkm.
After the 2030s, river flows could drop dramatically, turning the great glacier-fed rivers of Asia into
seasonal monsoon-fed rivers. The IPCC concluded that as a result, water shortages in Asia could affect more
than a billion people by the 2050s. Over the same period, crop yields are expected to decline by up to 30% in
South Asia due to a combination of drought and crop heat stress. Bangladesh is therefore likely to face
substantial challenges in the coming decades.
In order to adequately understand the complex, dynamic, spatial and nonlinear challenges facing Bangladesh,
an integrated model of the system is required. An agent-based model (ABM) permits the dynamic
interactions of the economic, social, political, geographic, environmental and epidemiological dimensions of
climate change impacts and adaptation policies to be integrated via a modular approach. Integrating these
dimensions, including nonlinear threshold events such as mass migrations, or the outbreak of conflicts or
epidemics, is possible to a far greater degree with an ABM than with most other approaches.
We are developing a prototype ABM, implemented in Netlogo, to examine the dynamic impacts on poverty,
migration, mortality and conflict from climate change in Bangladesh from 2001 to 2100. The model employs
GIS and sub-district level census and economic data and a coarse-graining methodology to allow model
statistics to be generated on a national scale from local dynamic interactions. This approach allows a more
realistic treatment of distributed spatial events and heterogeneity across the country. The aim is not to
generate precise predictions of Bangladesh’s evolution, but to develop a framework that can be used for
integrated scenario exploration. This paper represents an initial report on progress on this project. So far the
prototype model has demonstrated the desirability and feasibility of integrating the different dimensions of
the complex adaptive system and, once completed, is intended to be used as the basis for a more detailed
policy-oriented model.