Assessment of the Antiviral Properties of Zeolites Containing Metal Ions

The antiviral properties of zeolite (sodium aluminosilicate) powders amended with metal ions were assessed using human coronavirus 229E, feline infectious peritonitis virus (FIPV), and feline calicivirus F-9. Zeolites containing silver and silver/copper caused significant reductions of coronavirus 229E after 1 h in suspension. The silver/copper combination yielded a >5.13-log₁₀ reduction within 24 h. It was also the most effective (>3.18-log₁₀) against FIPV after 4 h. Other formulations were ineffective against FIPV. On plastic coupons with incorporated silver/copper-zeolites, >1.7-log₁₀ and >3.8-log₁₀ reductions were achieved for coronavirus 229E and feline calicivirus within 24 h, respectively. Silver/copper zeolite reduced titers of all viruses tested, suggesting that it may be effective against related pathogens of interest [i.e., SARS coronavirus, other coronaviruses, human norovirus (calicivirus)]. Of note, it was effective against both enveloped and nonenveloped viruses. Metal-zeolites could therefore possibly be used in applications to reduce virus contamination of fomites and thus the spread of viral diseases.     

Contaminant risks from biosolids land application: contemporary organic contaminant levels in digested sewage sludge from five treatment plants in Greater Vancouver,British Columbia

This study examines the potential for environmental risks due to organic contaminants at sewage sludge application sites, and documents metals and various potential organic contaminants (volatile organics, chlorinated pesticides, PCBs, dioxins/furans, extractable petroleum hydrocarbons, PAHs, phenols, and others) in current production biosolids from five wastewater treatment plants (WWTPs) within the Greater Vancouver Regional District (GVRD). There has been greater focus in Europe, North America and elsewhere on metals accumulation in biosolids-amended soil than on organic substances, with the exception of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans. Another objective, therefore, was to evaluate the extent to which management of biosolids re-use based on metal/metalloid levels coincidentally minimizes environmental risks from organic contaminants. Historical-use contaminants such as chlorophenols, PCBs, and chlorinated pesticides were not detected at environmentally relevant concentrations in any of the 36 fresh biosolids samples, and appear to have virtually eliminated from sanitary collection system inputs. The few organic contaminants found in freshly produced biosolids samples that exhibited high concentrations relative to British Columbia and Canadian soil quality benchmarks included p-cresol, phenol, phenanthrene, pyrene, naphthalene, and heavy extractable petroleum hydrocarbons (HEPHs--nCl9-C34 effective carbon chain length). It was concluded that, with the exception of these petroleum hydrocarbon constituents or their microbial metabolites, the mixing of biosolids with uncontaminated soils during land application and based on the known metal concentrations in biosolids from the Greater Vancouver WWTPs investigated provides adequate protection against the environmental risks associated with organic substances such as dioxins and furans, phthalate esters, or volatile organics. Unlike many other organic contaminants, the concentrations of petroleum hydrocarbon derived substances in biosolids has not decreased within the last decade or more in the WWTPs studied, and--unlike persistent chlorinated compounds--the associated PAHs and other hydrocarbon constituents merit careful consideration, especially in the context of repeated land-application of biosolid.     

Beyond the environmental Kuznets curve: Do combined impacts of air transport and rail transport matter for environmental sustainability amidst energy use in E7 economies?

Environment, Development and Sustainability - This study is motivated by the United Nations Sustainable Development Goals (UN-SDG-7,8,11,12 and 13) on the need for clean and responsible energy...     

Attenuation of landfill leachate by UK Triassic sandstone aquifer materials: 2. Sorption and degradation of organic pollutants in laboratory columns

The sorption and degradation of dissolved organic matter (DOM) and 13 organic micropollutants (BTEX, aromatic hydrocarbons, chloro-aromatic and -aliphatic compounds, and pesticides) in acetogenic and methanogenic landfill leachate was studied in laboratory columns containing Triassic sandstone aquifer materials from the English Midlands. Solute sorption and degradation relationships were evaluated using a simple transport model. Relative to predictions, micropollutant sorption was decreased up to eightfold in acetogenic leachate, but increased up to sixfold in methanogenic leachate. This behaviour reflects a combination of interactions between the micropollutants, leachate DOM and aquifer mineral fraction. Sorption of DOM was not significant. Degradation of organic fractions occurred under Mn-reducing and SO₄-reducing conditions. Degradation of some micropollutants occurred exclusively under Mn-reducing conditions. DOM and benzene were not significantly degraded under the conditions and time span (up to 280 days) of the experiments. Most micropollutants were degraded immediately or after a lag phase (32–115 days). Micropollutant degradation rates varied considerably (half-lives of 8 to >2000 days) for the same compounds (e.g., TeCE) in different experiments, and for compounds (e.g., naphthalene, DCB and TeCA) within the same experiment. Degradation of many micropollutants was both simultaneous and sequential, and inhibited by the utilisation of different substrates. This mechanism, in combination with lag phases, controls micropollutant degradation potential in these systems more than the degradation rate. These aquifer materials have a potentially large capacity for in situ bioremediation of organic pollutants in landfill leachate and significant degradation may occur in the Mn-reducing zones of leachate plumes. However, degradation of organic pollutants in acetogenic leachate may be limited in aquifers with low pH buffering capacity and reducible Mn oxides. Contaminants in this leachate present a greater risk to groundwater resources in these aquifers than methanogenic leachate.     

Total mercury distribution in different tissues of six species of freshwater fish from the Kpong hydroelectric reservoir in Ghana

Total mercury concentrations were determined in seven tissues of 38 fish samples comprising six species from the Kpong hydroelectric reservoir in Ghana by cold vapour atomic absorption spectrometry technique using an automatic mercury analyzer. Mercury concentration in all the tissues ranged from 0.005 to 0.022 μg/g wet weight. In general, the concentration of mercury in all the tissues were decreasing in the order; liver > muscle > intestine > stomach > gonad > gill > swim bladder. Mercury concentration was generally greater in the tissues of high-trophic-level fish such as Clarotes laticeps, Mormyrops anguilloides and Chrysichthys aurutus whereas low-trophic-level fish such as Oreochromis niloticus recorded low mercury concentration in their tissues. The results obtained for total mercury concentration in the muscle tissues analysed in this study are below the WHO/FAO threshold limit of 0.5 μg/g. This suggests that the exposure of the general public to Hg through fish consumption can be considered negligible.     

Carbon dioxide use by chemoautotrophic endosymbionts of hydrothermal vent vestimentiferans: affinities for carbon dioxide, absence of carboxysomes, and δ13C values

The hydrothermal vent vestimentiferans Riftia pachyptila Jones, 1981 and Ridgeia piscesae Jones, 1985 live in habitats with different abundances of external CO₂. R. pachyptila is found in areas with a high input of hydrothermal fluid, and therefore with a high [CO₂]. R. piscesae is found in a range of habitats with low to high levels of hydrothermal fluid input, with a correspondingly broad range of CO₂ concentrations. We examined the strategies for dissolved inorganic carbon (DIC) use by the symbionts from these two species. R. pachyptila were collected from the East Pacific Rise (9°50′N; 104°20′W) in March 1996, and R. piscesae were collected from the Juan de Fuca Ridge (47°57′N; 129°07′W) during September of 1996 and 1997. The differences in the hosts' habitats were reflected by the internal pools of DIC in these organisms. The concentrations of DIC in coelomic fluid from R. piscesae were 3.1 to 10.5 mM, lower than those previously reported for R. pachyptila, which often exceed 30 mM. When symbionts from both hosts were incubated at in situ pressures, their carbon fixation rates increased with the extracellular concentration of CO₂, and not HCO₃ ⁻, and symbionts from R. piscesae had a higher affinity for CO₂ than those from R. pachyptila (K _1/2 of 7.6 μM versus 49 μM). Transmission electron micrographs showed that symbionts from R. piscesae lack carboxysomes, irrespective of the coelomic fluid [DIC] of their host. This suggests that the higher affinity for CO₂ of R. piscesae symbionts may be their sole means of compensating for lower DIC concentrations. The δ¹³C values of tissues from R. piscesae with higher [DIC] in the coelomic fluid were more positive, opposite to the trend previously described for other autotrophs. Factors which may contribute to this trend are discussed. Received: 24 September 1998 / Accepted: 12 May 1999     

Anaerobic ammonia-oxidizing bacteria in tropical bioaugmented zero water exchange aquaculture ponds

Environmental Science and Pollution Research - Bioaugmented zero water exchange aquaculture production systems (ZWEAPS) maintained with minimal or no water exchange prevent the ammonia accumulation...     

Survival of Respiratory Viruses on Fresh Produce

In addition to enteric viruses of fecal origin, emerging zoonotic viruses such as respiratory coronaviruses and influenza viruses may potentially be transmitted via contaminated foods. The goal of this study was to determine the recovery efficiencies and the survival of two respiratory viruses, namely, adenovirus 2 (Ad2) and coronavirus 229E (CoV229E), on fresh produce in comparison to the enteric poliovirus 1 (PV1). Adenovirus was recovered with efficiencies of 56.5, 31.8, and 34.8 % from lettuce, strawberries, and raspberries, respectively. Coronavirus was recovered from lettuce with an efficiency of 19.6 % yet could not be recovered from strawberries. Poliovirus was recovered with efficiencies of 76.7 % from lettuce, but only 0.06 % from strawberries. For comparison purposes, the survival of Ad2, CoV229E, and PV1 was determined for periods up to 10 days on produce. The enteric PV1 survived better than both respiratory viruses on lettuce and strawberries, with only ≤1.03 log₁₀ reductions after 10 days of storage at 4 °C compared to CoV229E not being recovered after 4 days on lettuce and reductions of 1.97 log₁₀ and 2.38 log₁₀ of Ad2 on lettuce and strawberries, respectively, after 10 days. Nevertheless, these respiratory viruses were able to survive for at least several days on produce. There is therefore the potential for transfer to the hands and subsequently to the mucosa via rubbing the eyes or nose. In addition, some respiratory coronaviruses (e.g., severe acute respiratory syndrome coronavirus) and adenoviruses are also capable of replication in the gut and there is thus some potential for acquisition through the consumption of contaminated produce.     

COMPARISON OF HSPF OUTPUTS USING FTABLES GENERATED WITH FIELD SURVEY AND DIGITAL DATA1

ABSTRACT: The Hydrological Simulation Program‐FORTRAN (HSPF) describes discharge from a stream reach based on function tables (FTABLES) that relate stream stage, surface area, volume, and discharge. For this study, five FTABLE scenarios were compared to assess their effect on daily discharge rates predicted using HSPF. Four “field‐based” FTABLE scenarios were developed using detailed cross section surveys collected at predefined intervals along 14 reaches in the study watershed. A fifth “digital‐based” scenario was developed using digital elevation models (DEMs) and Natural Resource Conservation Service (NRCS) Regional Hydraulic Geometry Curves. The Smirnov k‐sample test was used to compare average daily discharge rates simulated with HSPF using the five FTABLE scenarios. No significant difference in simulated stream discharge was found (p = 0.99) between the five FTABLE scenarios. Additional examination of the four field‐based scenarios revealed that the number of cross sections per stream reach used to generate FTABLES had little effect on the resulting stage discharge relationship. These findings suggest that FTABLES generated using digital data are a viable option when simulating stream discharge with HSPF and that if field data are used to generate FTABLES, using fewer cross sections will not adversely affect simulated discharge predictions.     

Meiofauna and the thiobios in the east flower garden brine seep

Special hydrodynamic-chemical conditions at the East Flower Garden brine seep have provided the opportunity to examine the community structure of the thiobios and the oxybiotic-thiobiotic boundary. The boundary between the thiobios, whose population maxima occur in sulfidedependent chemoclines and which presumably have an ecologic requirement for sulfide, and the oxybios, which occur in oxidized zones above the chemocline, is controlled by sulfide, not oxygen. The boundary, which may not be at zero sulfide, is determined by a time-concentration phenomenon based on a dynamic interplay of sulfide and oxygen supply rates and the biota's sulfide detoxification capabilities. In Gollum's Canyon, where oxygen is plentiful, the boundary is at 10–40 μg-atoms·l^-1 sulfide. Total abundances of organisms at thiobiotic stations were comparable to total abundances at oxybiotic stations. Highest thiobiotic abundance was 202 051 organisms per m²; highest oxybiotic abundance was 240 572 organisms per m². The thiobios is dominated by representatives of the lower Bilateria (viz. Gnathostomulida, Platyhelminthes and Aschelminthes). These groups accounted for 50–80% of all the organisms present in the thiobiotic stations but less than 20% of all organisms in the oxybiotic stations. At two thiobiotic stations, over 50% of all organisms were gnathostomulids. Thiobios included macrofaunal as well as meiofaunal components. Peak abundances of amphipods were associated with the thiobiotic environment.