18 research outputs found
Including Pathogen Risk in Life Cycle Assessment of Wastewater Management. 1. Estimating the Burden of Disease Associated with Pathogens
The environmental performance of wastewater and sewage sludge management is commonly assessed using life cycle assessment (LCA), whereas pathogen risk is evaluated with quantitative microbial risk assessment (QMRA). This study explored the application of QMRA methodology with intent to include pathogen risk in LCA and facilitate a comparison with other potential impacts on human health considered in LCA. Pathogen risk was estimated for a model wastewater treatment system (WWTS) located in an industrialized country and consisting of primary, secondary, and tertiary wastewater treatment, anaerobic sludge digestion, and land application of sewage sludge. The estimation was based on eight previous QMRA studies as well as parameter values taken from the literature. A total pathogen risk (expressed as burden of disease) on the order of 0.2–9 disability-adjusted life years (DALY) per year of operation was estimated for the model WWTS serving 28 600 persons and for the pathogens and exposure pathways included in this study. The comparison of pathogen risk with other potential impacts on human health considered in LCA is detailed in part 2 of this article series
Influence of Sacarose and Sodium Chloride in the Toxicity Evaluation of Environmental Samples Using V. Fischeri
The acute toxicity assay using the marine bacteria Vibrio fischeri requires osmotic adjustment for testing samples with low salt content. Two kinds of compounds can be used for this purpose, sodium chloride (NaCl) or sucrose. It is known that this osmotic adjustment can cause changes in the toxicity for some substances like some metals and ammonia. The toxicity of 29 environmental samples that included raw waters, industrial effluents, sediments, solid wastes and foams deriving from polluted water bodies was evaluated using NaCl and sucrose, in parallel. The two methods of osmotic adjustment showed a good agreement in terms of the qualitative responses for all samples analyzed. Only for five samples, the CE50 values were lower in sucrose than in NaCl, in agreement with the results of zinc and ammonia. The results obtained for the environmental samples tested with both methods suggest that NaCl can be used routinely. Additional analysis with sucrose can be especially helpful when metals like zinc and ammonia are suspected to be the key toxicant in the samples
Microbiological quality assessment of sand and water from three selected beaches of South Coast, Sao Paulo State, Brazil
This study aimed to assess the sanitary quality of water, and wet and dry sand from three beaches located in the South Coast region of Sao Paulo State, Brazil, selected taking into account the frequency of tourists and the water quality (good, fair and poor). Thirty-six water samples each of wet and dry sand and seawater were collected monthly over a period of one year and analyzed for fecal indicator bacteria (FIB: thermotolerant coliforms, Escherichia coli, and enterococci), presumptive Staphylococcus aureus, Pseudomonas aeruginosa, Candida albicans and dermatophytes. The results revealed FIB concentrations more elevated in dry sand followed by wet sand and water. P. aeruginosa and presumptive S. aureus were detected with a similar frequency in water and sand samples, but maximum concentrations and geometric means were higher in dry sand. C. albicans was detected only in water samples whereas the dermatophyte Microsporum sp. was isolated exclusively from dry and wet sand samples. This evaluation showed also that the environment had a significant influence on P. aeruginosa but not on presumptive S. aureus concentrations. According to threshold values proposed in the literature for E. coli and enterococci dry sand densities, none of the beaches would be considered of sufficient quality for recreational activities
Molecular and Phenotypic Characterization of a Highly Evolved Type 2 Vaccine-Derived Poliovirus Isolated from Seawater in Brazil, 2014
<div><p>A type 2 vaccine-derived poliovirus (VDPV), differing from the Sabin 2 strain at 8.6% (78/903) of VP1 nucleotide positions, was isolated from seawater collected from a seaport in São Paulo State, Brazil. The P1/capsid region is related to the Sabin 2 strain, but sequences within the 5'-untranslated region and downstream of the P1 region were derived from recombination with other members of Human Enterovirus Species C (HEV-C). The two known attenuating mutations had reverted to wild-type (A481G in the 5'-UTR and Ile143Thr in VP1). The VDPV isolate had lost the temperature sensitive phenotype and had accumulated amino acid substitutions in neutralizing antigenic (NAg) sites 3a and 3b. The date of the initiating OPV dose, estimated from the number of synonymous substitutions in the capsid region, was approximately 8.5 years before seawater sampling, a finding consistent with a long time of virus replication and possible transmission among several individuals. Although no closely related type 2 VDPVs were detected in Brazil or elsewhere, this VDPV was found in an area with a mobile population, where conditions may favor both viral infection and spread. Environmental surveillance serves as an important tool for sensitive and early detection of circulating poliovirus in the final stages of global polio eradication.</p></div
Reproductive capacity of VDPV2 isolate 44624 and Sabin 2 strain at different temperatures (RCT marker).
<p>The RCT value is defined as the difference between the log 10 virus titer of the viral stock measured at the optimal temperature 36,5°C and supraoptimal temperature 40°C. The values are expressed as log 10 TCID50 / 0,1ml. Virus were considered thermosensitive if the ΔRCT value was greater or equal to 2, and thermo resistant when RCT value was inferior to 2.00.</p
Amino acid substitutions in the capsid protomer of isolate 44624.
<p>VP1, VP2, VP3 and VP4 are represented as a 3-dimensional structured protomer. The image was generated using the software Swiss-PdbViewer [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0152251#pone.0152251.ref024" target="_blank">24</a>], based on X-ray crystallographic analysis of type 2 poliovirus strain Lansing (Protein Data Bank accession number 1EAH.pdb) [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0152251#pone.0152251.ref023" target="_blank">23</a>]. Colour codes: Substitutions at known antigenic sites, brown. Substitutions elsewhere, pink. The BC-loop of VP1 is not visible in this model.</p
Draft Genome Sequence of Non-O1 and Non-O139 Vibrio cholerae Strain VCC19
Pathway between enclosure all on the right and the tower area, with pergola arching overhead; Located at the end of two dead-end streets, the Xeros residence is positioned upon the upward slope of a 50’x 250’ double lot facing the North Phoenix Mountain Preserve to the north and the city center to the south. The building includes a two-story lower level design studio that descends down into the earth with a single story residence that exists above the studio that is accessed solely by an external stair. The primary building material is exposed steel (as structure, cladding, and shading) that is allowed to weather naturally and meld with the color of the surrounding hills. Called 'Xeros' (from the Greek for 'dry') as a reminder that all design solutions should be in a direct response to the environment. Source: ArchDaily; http://www.archdaily.com/ (accessed 5/15/2013
Analysis of nucleotide differences between the genome of isolate 44624 and Sabin 2.
<p>Analysis of nucleotide differences between the genome of isolate 44624 and Sabin 2.</p
Schematic representation of the genome of recombinant aVDPV 44624, isolated in Brazil.
<p>Non-vaccine sequences (HEV-C species) are represented in light blue. Highly mutated Sabin 2 regions are represented in gray.</p