Molecular Detection of Adenoviruses in Lakes and Rivers of Goiânia,Goiás,Brazil

Adenoviruses are a highly important public health issue, since they are among the most persistent and ubiquitous viruses present in water and associated with a variety of clinical manifestations. The aim of this study was to use molecular techniques for the detection of adenovirus in public and recreational water supplies in Goiania, Brazil. From December 2007 to November 2008, 54 water samples were collected in 5 different sites in 2 lakes and 2 rivers of the city. The samples were filtered in a positively charged nylon membrane, and the DNA was extracted using the phenol–chloroform–isoamyl alcohol method. Semi-nested PCR was used to detect adenovirus DNA, and sequence analysis of the semi-nested PCR products was performed to identify the recovered viruses. Adenovirus DNA was detected in 43% (24 of 54) of samples collected. Considering all examined sites, MP1 presented the highest occurrence of adenovirus (6 positive from 10 collected samples), followed by MP2 (3 positive from 6 collected samples), JL (10 positive from 21 collected samples), VB (3 positive from 9 collected samples), and BB (2 positive from 8 collected samples), respectively. The methodology employed proved to be feasible, fast, low-cost, and suitable to be used as screening approach on adenovirus detection in water for public sanitation companies.     

A distance dependent contagion function for vector-based data

Landscape pattern is of primary interest to landscape ecologists and landscape metrics are used to quantify landscape pattern. Metrics are commonly defined and calculated on raster-based land cover maps. One metric is the contagion, existing in several versions, e.g., unconditional and conditional, used as a measure of fragmentation. However, mapped data is sometimes in vector-based format or there may be no mapped data but only a point sample. In this study a definition of contagion for such cases is investigated. The metric is an extension of the usual contagion, based on pairs of points at varying distances and gives a function of the distance. In this study the extended contagion is calculated for vector-based delineated real landscapes and for simulated ones. Both unconditional and conditional contagions are studied using two classification systems. The unconditional contagion function was decreasing and convex, with upper and lower limits highly correlated to the Shannon diversity index, thus carrying only area proportion information. The spatial information lies in the speed by which the function converges to the lower limit; using a proxy function this can be expressed by a single parameter b, with high values for fragmented landscapes. No proxy function was found for the conditional contagion, for which only qualitative information was found. The extended contagion is applicable both in patch mosaic models of landscapes and in gradient-based models, where landscape characteristics change continuously without distinct borders between patches. The extended contagion can be useful in sample based surveys where there no map of the entire landscape is available.     

Content, distribution and fate of 33 elements in sediments of rivers receiving wastewater in Hanoi, Vietnam

Untreated industrial and domestic wastewater from Hanoi city is discharged into rivers that supply water for various agricultural and aqua-cultural food production systems. The aim of this study was to assess the content, distribution and fate of 33 elements in the sediment and pore water of the main wastewater receiving rivers. The sediment was polluted with potentially toxic elements (PTEs) with maximum concentrations of 73 As, 427 Cd, 281 Cr, 240 Cu, 218 Ni, 363 Pb, 12.5 Sb and 1240 Zn mg kg(-1) d.w. Observed distribution coefficients (log(10) K(d,obs)) were calculated as the ratio between sediment (mg kg(-1) d.w.) and pore water (mg L(-1)) concentrations. Maxima log(10) K(d,obs) were >4.26 Cd, >6.60 Cu, 4.78 Ni, 7.01 Pb and 6.62 Zn. The high values show a strong PTE retention and indicate the importance of both sorption and precipitation as retention mechanisms. Sulphide precipitation was a likely mechanism due to highly reduced conditions.     

Aspects on the analysis of 210Po

There has been little development regarding analysis of polonium (Po) in environmental samples since the 1960ies. This is due to the straightforward spontaneous deposition of this element on silver (Ag), nickel (Ni) or copper (Cu) without any radiochemical separation. For many years, no radiochemical yield determinant was used and it was generally supposed that the yield was 100% after two depositions. Counting was often done using ZnS scintillation counter coupled to a photomultiplier tube. However, the use of the yield determinants ²⁰⁸Po and ²⁰⁹Po and the development of alpha spectrometry showed that the yield was lower. Furthermore, the tendency of Po to volatilize at low temperatures constrains the sample preparation techniques; dry-ashing cannot be used. But during the wet-ashing procedure, there are still some losses.The aim of this study was to evaluate the Po losses during wet-ashing by the use of a double-tracer technique. We have found that the losses were about 30% when open glass beakers were used and about 17% when the samples were digested in microwave oven. When long-necked bottles (Kjeldahl flasks) were used, a loss of about 20% was registered.It has also been observed that ²¹⁰Pb to some extent is plating out together with its daughter nuclide Po during the electrochemical deposition. This will result in a systematic error since an unknown amount of supported ²¹⁰Po will be produced from the ²¹⁰Pb decay depending on the fraction of ²¹⁰Pb being deposited on the disc and the waiting time between deposition and measurement of the sample. A further consequence of this is that in the assessment of the ²¹⁰Pb content in the sample, very often the remaining liquid is stored after deposition for build-up of ²¹⁰Po. Since some ²¹⁰Pb is lost on the disc, the result for ²¹⁰Pb will be too low. Both these systematic errors give rise to a too high ²¹⁰Po/²¹⁰Pb ratio. The fraction of ²¹⁰Pb which is plating out has been assessed in this study for different matrices and is about 50-90%. During the measurement by solid state Si-detectors, some Po is evaporated in the vacuum conditions contaminating the detectors. Experiments have here been done by heating the discs after deposition which indicate that less Po is evaporated from Ag than from Ni. The losses from Ag are less than that from the other metals probably due to a deeper penetration into the surface of Po. We conclude that in most aspects, Ag is better to use than the other plating metals.     

Dry and wet heat transfer through clothing dependent on the clothing properties under cold conditions.

The purpose of this study was to investigate the effect of moisture on the heat transfer through clothing in relation to the water vapour resistance, type of underwear, location of the moisture and climate. This forms part of the work performed for work package 2 of the European Union THERMPROTECT project. Thermal manikin results of dry and wet heat loss are presented from different laboratories for a range of 2-layer clothing with similar dry insulations but different water vapour permeabilities and absorptive properties. The results obtained from the different manikins are generally consistent with each other. For each climate, total wet heat loss is predominately dependent on the permeability of the outer layer. At 10 degrees C, the apparent evaporative heat loss is markedly higher than expected from evaporation alone (measured at 34 degrees C), which is attributed to condensation within the clothing and to increased conductivity of the wet clothing layers.     

Life cycle assessment of the waste hierarchy--a Danish case study on waste paper

The waste hierarchy is being widely discussed these days, not only by cost-benefit analysts, but a growing number of life cycle assessments (LCA) have also begun to question it. In this article, we investigate the handling of waste paper in Denmark and compare the present situation with scenarios of more waste being recycled, incinerated or consigned to landfill. The investigations are made in accordance with ISO 14040-43 and based on the newly launched methodology of consequential LCA and following the recent guidelines of the European Centre on Waste and Material Flows. The LCA concerns the Danish consumption of paper in 1999, totalling 1.2 million tons. The results of the investigation indicate that the waste hierarchy is reliable; from an environmental point of view recycling of paper is better than incineration and landfilling. For incineration, the reason for the advantage of landfilling mainly comes from the substitution of fossil fuels, when incinerators provide heat and electricity. For recycling, the advantage is related to the saved wood resources, which can be used for generating energy from wood, i.e., from renewable fuel which does not contribute to global warming.     

Allium cepa L. as a bioindicator to measure cytotoxicity of surface water of the Quatorze River,located in Francisco Beltrão,Paraná, Brazil

Due to an increase in water consumption in the industrial sector and within the Brazilian population, surface water that receives wastewater from industries, domestic sewage, agricultural industries, and sewage treatment stations can pollute water bodies when not properly treated. The water quality has been linked to catchment characteristics and intensity of agricultural activities. Thus, the aim of this study was to monitor the cytotoxic potential of the water of the Quatorze River, located in the town of Francisco Beltrão, Paraná, Brazil, along its route in the rural area, using the root meristematic cells of Allium cepa L. as a bioindicator. The results showed that the water at points 2, 3, and 4 were not cytotoxic because the rates of A. cepa cell division were unaltered. Point 1 had presented a mitotic index that was statistically larger than the negative control, indicating that this water contained substances with mitogenic capacity, as demonstrated by elevated values in chemical oxygen demand (COD) and biochemical oxygen demand (BOD). However, the mitotic index values decreased along the route of the river (point 1 to point 4), possibly indicating a mechanism of self-purification, despite having received other sources of pollution. Thus, the results of this study show that the water of the Quatorze River should undergo periodic environmental monitoring at different times of the year, including cytotoxicity analysis, to evaluate the principal sources of contamination to maintain the quality of the river water and, consequently, to maintain human health and equilibrium of the entire ecosystem.     

Evaluation of the Effect of Chemical or Enzymatic Synthesis Methods on Biodegradability of Polyesters

This work compares the biodegradability of polyesters produced by an esterification reaction between glycerol and oleic di-acid (D 18:1) issued from green chemical pathways, via either classical thermo-chemical methods, or an enzymatic method using the immobilized lipase of Candida antartica B (Novozym 435). An elastomeric polymer synthesized by enzymatic catalysis is more biodegradable than an elastomeric thermo-chemical polyester synthesized by a standard chemical procedure. This difference lies in percentage of the dendritic motifs, in values of the degree of substitution, and certainly in cross-links inducing an hyper-branched structure less accessible to the lipolytic enzymes in a waste treatment plant. However, when the elastomeric polymer synthesized by enzymatic catalysis is processed at high temperature as required for certain industrial applications, it presents an identical rate of biodegradation than the chemical polyester. The advantages of the thermo-chemical methods are greater speed and lower cost. Enzymatic synthesis appears be suited to producing polyesters, devoid of metallic catalysts, which must be used without processing at high temperature to keep a high biodegradability.