A Field Technique Measuring Virus Decay and Potential Aerosol Hazard from Wastewater Sprinkler Irrigation

The increased use of domestic wastewater for irrigation purposes has stimulated a growing practice of sprinkler irrigating from oxidation ponds and other domestic wastewaters. Aerosols generated from these sprinkler irrigation systems may contain potentially hazardous pathogens. Subsequently, the aerosols can contain infective viruses which can be carried through the air to surrounding populations. Thus, a public health hazard can be created by sprinkler irrigating domestic wastewater. This study is an investigation of a means by which the virus decay rate of viruses in aerosols and the potentials hazard of sprinkler irrigation aerosol clouds may be examined. A means of injection of a human and animal virus stimulant, MS-2 bacteriophage, is described. In addition, the factors which are known to effect the survival of viruses in aerosols are discussed. The ambient air factors that are known to effect virus survival and which are discussed include relative humidity, air temperature, solar radiation, and aerosol age. The suspending fluid factors that are known to effect virus survival and which are discussed include dissolved inorganic salt contact, dissolved organic content, filterable solids and pH. The decay rate of the aerosolized MS-2 was measured with an all-glass impinger (AGI-30) when the wind velocity and distance of the sampler from the sprinkler system, and the initial and final concentrations of aerosolized MS-2 virus were known. The aerosol hazard of a domestic wastewater sprinkler irrigation system is defined in terms of the likelihood of infective aerosol particles to be inhaled and penetrate the human lung. Thus, the aerosol hazard is a function of aerosol particle size. The aerosol particle size distribution of the infective aerosol cloud was measured wit the Andersen sampler. A high and homogeneous concentration of the virus in the wastewater was insured by using pressure differentials in the sprinkler irrigation delivery line. By injecting the MS-2 virus into the line at a constant rate along with a tracer, Bacillus subtilus var niger (Bacillus globigii) spores, the decay rate of the virus during airborne exposure to environmental factors could be determined. The decay rate was determined assuming the environmental factors had no affect on the concentration of the tracer. It was proposed that the environmental engineer, after knowing the virus decay rates under varying environmental conditions, can define buffer zones which would be required around sprinkler irrigation sites. The buffer zone would reduce the possibility of contaminating humans by prohibiting access. The usefulness of the filed technique was demonstrated and the MS-2 was found to undergo a 33.3 percent decay per minute in the dark (no solar radiation) at 33 percent relative humidity, 70.6 percent dissolved organic material, 29.4 percent dissolved inorganic salts, 30.1 mg/1 filterable solids, and 17 degree C air temperature. The aerosol cloud resulting from the spray irrigation process appeared potentially hazardous because the Andersen sampler collected 84.2 percent of the virus infective droplets in the size range that could be inhaled

CD55 is over-expressed in the tumour environment

CD55 is a protein that protects cells from complement-mediated attack. 791Tgp72 is an antigen which has been used succesfully as a target for both tumour imaging and cancer vaccines. 791Tgp72 has recently been identified as CD55. Quantitative expression of CD55 in the tumour environment was therefore studied. Tumour cells showed a 4–100-fold increase in CD55 cell surface expression when compared to normal cells. Immunohistochemical staining of colorectal tumours also revealed high expression of CD55 in the stroma. To examine the source of this stromal CD55 the ability of both epithelial cells and endothelial cells to produce extracellular CD55 was measured. Tumour cell lines deposit CD55 into their extracellular matrix (ECM) in direct proportion to their cell surface expression. In contrast the ECM from HUVEC cells contained large amounts of CD55 despite expressing low levels of CD55 on their cell surface. Furthermore expression of CD55 on HUVEC cells was increased by exposure to VEGF. Although it remains unclear why CD55 is upregulated in the tumour environment its high level of expression on tumour cells and associated endothelium may explain why it is a good target for both imaging and immunotherapy. © 2001 Cancer Research Campaign http://www.bjcancer.co

Kinematics of chromodynamic multicomponent lattice Boltzmann Simulation with a large density contrast

The utility of an enhanced chromodynamic, color gradient or phase-field multicomponent lattice Boltzmann (MCLB) equation for immiscible fluids with a density difference was demonstrated by Wen et al. [Phys. Rev. E 100, 023301 (2019)] and Ba et al. [Phys. Rev. E 94, 023310 (2016)], who advanced earlier work by Liu et al. [Phys. Rev. E 85, 046309 (2012)] by removing certain error terms in the momentum equations. But while these models' collision scheme has been carefully enhanced by degrees, there is, currently, no quantitative consideration in the macroscopic dynamics of the segregation scheme which is common to all. Here, by analysis of the kinetic-scale segregation rule (previously neglected when considering the continuum behavior) we derive, bound, and test the emergent kinematics of the continuum fluids' interface for this class of MCLB, concurrently demonstrating the circular relationship with—and competition between—the models' dynamics and kinematics. The analytical and numerical results we present in Sec. V confirm that, at the kinetic scale, for a range of density contrast, color is a material invariant. That is, within numerical error, the emergent interface structure is isotropic (i.e., without orientation dependence) and Galilean-invariant (i.e., without dependence on direction of motion). Numerical data further suggest that reported restrictions on the achievable density contrast in rapid flow, using chromodynamic MCLB, originate in the effect on the model's kinematics of the terms deriving from our term F1i in the evolution equation, which correct its dynamics for large density differences. Taken with Ba's applications and validations, this result significantly enhances the theoretical foundation of this MCLB variant, bringing it somewhat belatedly further into line with the schemes of Inamuro et al. [J. Comput. Phys. 198, 628 (2004)] and the free-energy scheme [see, e.g., Phys. Rev. E. 76, 045702(R) (2007), and references therein] which, in contradistinction to the present scheme and perhaps wisely, postulate appropriate kinematics a priori

Field studies on coliphages and coliforms as indicators of airborne animal viral contamination from wastewater treatment facilities

The occurrence of animal viruses in the aerosol emissions of wastewater treatment facilities was evaluated by direct assay and by the use of coliforms and coliphages as indicator organisms. Coliforms and coliphages were compared and evaluated with regard to their suitability as indicators of airborne animal viral contamination from wastewater treatment facilities. Two plants, one with treatment by activated sludge and the other by trickling filtration, were studied. Field air sampling procedures used large-volume air samplers, with recirculation devices, and Andersen samplers. Airborne viruses were enumerated by a most probable number (MPN) procedure. Partially treated liquid sewage contained about 1.0 x 102 pfu l-1 of animal viruses assayed on Buffalo Green Monkey (BGM) cells, 3.6 x 105 and 5.0 x 105 pfu l-1 of coliphages, depending upon the E. coli host strain used for assay, and 2.0 x 109 colonies l-1 of coliform bacteria. No airborne animal viruses were recovered, airborne coliphage levels averaged 2.3 x 10-1 and 3.0 x 10-1 MPN m-3, coliforms from aerosol emissions were 2.1 x 102 colonies m-3. Ratios of coliphages to animal viruses indicate that wastewater treatment plants may be continuous sources of low level concentrations of animal virus aerosols. Evidence shows coliforms to be much less stable than coliphages in the airborne state. Coliphages may be a more acceptable indicator of airborne animal viral contamination than coliforms.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/23037/1/0000608.pd

Molecular expression patterns in the synovium and their association with advanced symptomatic knee osteoarthritis

Objective: Osteoarthritis (OA) is a major source of knee pain. Mechanisms of OA knee pain are incompletely understood but include synovial pathology. We aimed to identify molecular expression patterns in the synovium associated with symptomatic knee OA.Design: Snap frozen synovia were from people undergoing total knee replacement (TKR) for advanced OA, or from post-mortem (PM) cases who had not sought help for knee pain. Associations with OA symptoms were determined using discovery and validation samples, each comprising TKR and post mortem (PM) cases matched for chondropathy (Symptomatic or Asymptomatic Chondropathy). Associations with OA were determined by comparing age matched TKR and PM control cases. Real-time quantitative PCR for 96 genes involved in inflammation and nerve sensitisation used TaqMan® Array Cards in discovery and validation samples, and protein expression for replicated genes was quantified using Luminex bead assay.Results: Eight genes were differentially expressed between asymptomatic and symptomatic chondropathy cases and replicated between discovery and validation samples (P3-fold change). Of these, matrix metalloprotease (MMP)-1 was also increased whereas interleukin-1 receptor 1 (IL1R1) and vascular endothelial growth factor (VEGF) were decreased at the protein level in the synovium of symptomatic compared to asymptomatic chondropathy cases. MMP1 protein expression was also increased in OA compared to PM controls.Conclusion: Associations of symptomatic OA may suggest roles of MMP1 expression and IL1R1 and VEGF pathways in OA pain. Better understanding of which inflammation-associated molecules mediate OA pain should inform refinement of existing therapies and development of new treatments

Studies on Viruses in Water

A new procedure for the detection of viral antigens in fecal material was developed. The test is performed by first diluting a fecal sample with phosphate buffered saline to give a liquid consistency. The pH is then adjusted to 8.5-9.0 and the solids are allowed to settle for five minutes. Supernatant fluid from above the fecal sediment is placed on the upper surface of a well of an inverted Immulon microtiter plate and incubated for one hour at 37 degrees C to allow virus to adsorb to the plastic. The Immulon plate is then washed three times with a Tween 20 solution and dried. Adsorbed virus is stained with fluorescein labled antiviral antibody containing Evan\u27s Blue dye. The stained preparations are examined by epi-fluorescence microsopy for the presence of viral aggregates and virus-containing cellular membranes. The test is applied in a continuous water monitoring procedure that can be used to upplement methods in which infectious viruses are isolated from water. In another study a protamine sulfate procedure for concentrating and an immunofluorescent cell procedure for assaying infectious virus (IV, reovirus that is infectious without proteolytic enzyme treatment), and potentially infectious virus (PIV, enzyme enhanceable reovirus) from polluted waters have been developed. The presence of PIV inthe environment had not previously been investigated. In following these procedures, protamine sulfate concentratiosn of 0.005 percent for the first precipitation of the sample, and 0.0025 percent for the second were used. With these protamine concentrations and 0.25 percent fetal bovine serum, IV and PIV are concentrations over 500-fold from river water inoculated with virus. Virus recoveries are between 80 and 100 percent. The IV and PIV fractions are assayed respectively before and after treatment with 200 ug fo chymotrypsin per millileter. When PIV is precipitated from river water, and the precipitate is dissolved and stored at 20 degrees C as a protamine-virus concentrate, only 5 percent of the viral infectivity is lost after 14 days. Therefore, reovirus can be precipitated from water at the sampling site, and only the protamine concentrate needs to be taken to the laboratory to be examined for virus content. When reoviruses are treated with chlorine, PIV is more resistant to inactivation thatn IV, and PIV appears to be at least as resistant to chlorination as poliovirus and coxsackievirus A-2. Granular media filtration systems (i.e., sand, anthracite coal and sand; anthracite coal; sand and garnet) are ineffectual in the removal of the acteriophage MS 2 from water when used as in-line direct filters. Batch assays have indicated a 93 percent reduction of MS 2 can occur when polyelectrolytes are added to the water. In addition, alum concentrations of 20, 30, 40, and 50 mg/1 remove 80 to 98 percent of the virus by precipitation. No reduction of MS 2 was observed at alum concentrations from 1 to 10 mg/1

Microbial Aerosols from Food Processing Waste Spray Fields

Federal legislation restricts the discharge of waste from various industrial processes into rivers, lakes, or other waters. For this reason disposal of wastewater by spraying onto cultivated, grassed, or forested lands has come into use. These waste disposal spray systems produce droplets of water containing suspended material that may become aerosolized as particles less than about 20 µ in diameter. Particles of this size will remain suspended in the atmosphere and will travel long distances downwind. The generation of such particles by commercial spray or sprinkler equipment may be presumed because regardless of the size distribution for water droplets leaving the sprinkler nozzle a number of particles of aerosol size will develop through rapid evaporation. Solid materials, including microorganisms, suspended in the water become the nuclei of the aerosol particles. Recent reviews have been published regarding the aerosolization of microorganisms in sprays resulting from the treatment and disposal of wastewater from domestic waste. Microbial aerosol particles were sampled up to 1.2 km downwind of the spray source. Katzenelson and Teltch reported aerosolized coliforms short distances downwind of spray fields for disposal of wastewater containing raw domestic waste and for disposal of effluent from a wastewater settling pond. In this report, studies were made of microbial aerosols downwind from spray fields for the disposal of potato processing wastewater

Failing boys and moral panics: perspectives on the underachievement debate

The paper re-examines the underachievement debate from the perspective of the ‘discourse of derision’ that surrounds much writing in this area. It considers the contradictions and inconsistencies which underpin much of the discourse – from a reinterpretation of examination scores, to the conflation of the concepts of ‘under’ and ‘low’ achievement and finally to the lack of consensus on a means of defining and measuring the term underachievement. In doing so, this paper suggests a more innovative approach for understanding, re-evaluating and perhaps rejecting the notion of underachievement