Occurrence of filamentous fungi and yeasts in three different drinking water sources

In order to determine the occurrence of fungi in different drinking water sources and capture variability in terms of matrix composition and seasonal effects, surface water, spring water, and groundwater samples were collected in numerous sampling events. The occurrence and significance of fungi detected in the different water sources are reported and discussed in terms of colony-forming units per millilitre and by the identification of the most frequently detected isolates, at the species level, based on morphology and other phenotypic characters. All the samples were also analyzed in terms of total coliforms and Escherichia coli that are widely monitored bacteria considered as microbiology indicators of water quality. All the groundwater samples showed significantly lower levels of total coliforms, E. coli, and fungi compared to the surface and spring water samples. No significant correlations were found between the levels of fungi detected in all the matrices and the physico-chemical parameters and bacteria regularly monitored by drinking water utilities. Fifty-two fungi isolates were identified in this study, most of which have never been described to occur in water sources. The results obtained show that fungi occur widely in drinking water sources and that further studies should be conducted to address their biodegradation potential as well as if the drinking water treatment processes currently used are effective in removing these organisms and the potential secondary metabolites produced.     

Derivation of acute ecological risk criteria for chlorite in freshwater ecosystems

Chlorine dioxide has been proposed as an alternative to chlorine because it is a powerful disinfection agent that does not react with ammonia or chlorinated organics to form chloramines or trihalomethanes. The major reduction product formed when chlorine dioxide is added to water is the chlorite ion. Chlorite has been shown to be less toxic than free or combined chlorine. However, previous studies with eight freshwater families produced a US Environmental Protection Agency (USEPA) acute water quality criteria (WQC) lower than the WQC for chlorine. In the current study, an additional 12 families were added to the toxicological database to determine ecological risk criteria (ERC) using both the standard USEPA WQC methodology and the USEPA Office of Pesticide Programs (OPP) probabilistic approach. Chlorite LC50 values for the 20 family database ranged from 0.27 mg/L for the Daphnidae to 208.76 mg/L for the Salmonidae. The Daphnidae were by far the most sensitive family tested, with an LC50 44 times lower than the next most sensitive family tested, the Hyalellidae (LC50=1.19 mg/L) and 214 times lower than the most sensitive fish family tested, the Ictaluridae (LC50=5.79 mg/L). The Criteria Maximum Concentration calculated using the USEPA WQC methodology was 0.025 mg/L while the 95% ERC calculated using the USEPA OPP probabilistic methodology was 0.135 mg/L. The USEPA OPP probabilistic approach yields a criterion more consistent with the overall species sensitivity distribution and is not overly skewed by the low Daphnidae LC50 as is the USEPA WQC approach.     

Assessment of sources of human pathogens and fecal contamination in a Florida freshwater lake

We investigated the potential for a variety of environmental reservoirs to harbor or contribute fecal indicator bacteria (FIB), DNA markers of human fecal contamination, and human pathogens to a freshwater lake. We hypothesized that submerged aquatic vegetation (SAV), sediments, and stormwater act as reservoirs and/or provide inputs of FIB and human pathogens to this inland water. Analysis included microbial source tracking (MST) markers of sewage contamination (Enterococcus faecium esp gene, human-associated Bacteroides HF183, and human polyomaviruses), pathogens (Salmonella, Cryptosporidium, Giardia, and enteric viruses), and FIB (fecal coliforms, Escherichia coli, and enterococci). Bayesian analysis was used to assess relationships among microbial and physicochemical variables. FIB in the water were correlated with concentrations in SAV and sediment. Furthermore, the correlation of antecedent rainfall and major rain events with FIB concentrations and detection of human markers and pathogens points toward multiple reservoirs for microbial contaminants in this system. Although pathogens and human-source markers were detected in 55% and 21% of samples, respectively, markers rarely coincided with pathogen detection. Bayesian analysis revealed that low concentrations (<45 CFU × 100 ml⁻¹) of fecal coliforms were associated with 93% probability that pathogens would not be detected; furthermore the Bayes net model showed associations between elevated temperature and rainfall with fecal coliform and enterococci concentrations, but not E. coli. These data indicate that many under-studied matrices (e.g. SAV, sediment, stormwater) are important reservoirs for FIB and potentially human pathogens and demonstrate the usefulness of Bayes net analysis for water quality assessment.     

Indoor levels of volatile organic compounds at Florentine museum environments in Italy

Indoor Air Quality monitoring in cultural institutions is of particular concern to protect these places and the cultural heritage content. An indoor monitoring campaign was performed in three museums in Florence (Italy) to determine the occurrence and levels of volatile organic compounds (VOCs). VOCs of interest included BTEX (benzene, toluene, ethylbenzene, xylenes), terpenes, aldehydes, organic acids, and cyclic volatile methyl siloxanes (cVMS). The most abundant VOCs in all samples analyzed were BTEX, which were strictly related to the traffic source, followed by siloxanes and terpenes. Among BTEX, toluene was always the most abundant followed by xylenes, ethylbenzene, and benzene. cVMS in exhibition rooms with the presence of visitors showed higher values compared to samples collected when the museums were closed. Terpenes showed not only the influence of vegetation-biogenic sources surrounding a museum but could also be related to the wood used for the construction of showcases and furniture and the use of cleaning products. Data obtained also showed the presence of organic acids and aldehydes whose source can be traced back to exhibits themselves and wood-based furniture. Assessing the levels of organic acids in museums is important because, over time, it can cause deterioration of the artifacts.     

Effects of ferric hydroxide on the anaerobic biodegradation kinetics and toxicity of vegetable oil in freshwater sediments

Biodegradation of vegetable oil in freshwater sediments exhibits self-inhibitory characteristics when it occurs under methanogenic conditions but not under iron-reducing conditions. The basis of the protective effect of iron was investigated by comparing its effects on oil biodegradation rate and the toxicity of oil-amended sediments to those of clay and calcium, which reduce the toxicity of oil-derived long-chain fatty acids by adsorption and precipitation, respectively. Kinetic parameters for an integrated mixed-second-order model were estimated by nonlinear regression using cumulative methane production as the response variable and used to compare the effects of the three treatment factors on the rate of oil biodegradation. Ferric hydroxide was the only factor that significantly (P<0.05) increased the rate of methane production from canola oil, whereas calcium significantly reduced the oil biodegradation rate. Measurement of sediment toxicity using the Microtox Solid-Phase Test showed that inhibitory products formed within 5 days of oil addition, but the sediment toxicity decreased over time as the extent of oil mineralization increased. None of the other amendments significantly reduced the toxicity of oil-containing sediments. Since ferric hydroxide stimulated the rate of oil biodegradation without affecting the toxicity of oiled sediments, it must operate through a mechanism that is different from those previously described for clay and calcium.     

Assessment of pollution from livestock and poultry breeding in China

Livestock and poultry husbandry is a major source of agricultural pollution in China. Thus far, national-scale approaches to estimating pollutant loads from livestock and poultry rearing remain limited. This impedes effective water quality assessment and relevant policy making. Applying unit load and export coefficient modelling, we estimated pollutant loads from livestock and poultry raising from 2000 to 2010. Results show that the total annual pollutant loads generated from the faeces and urine of livestock and poultry in 2010 had a chemical oxygen demand of 78.2?million metric tonnes; biochemical oxygen demand of 72.7?million tonnes; ammonia nitrogen of 7.4?million tonnes; total phosphorus of 6.0?million tonnes; and total nitrogen of 18.0?million tonnes. Livestock and poultry husbandry has been one of the main pollution sources in China. The significant contributors are pigs and cattle. In particular, pollution from livestock and poultry raising in China spatially overlaps with industrial and domestic pollution. South eastern regions face the difficult challenge of controlling and managing agricultural, industrial and domestic pollution.     

Antimicrobial resistance and species composition of Enterococcus spp. isolated from waters and sands of marine recreational beaches in Southeastern Brazil

Density, species composition and antimicrobial resistance in bacteria of the Enterococcus genus were evaluated in seawater and sands from 2 marine recreational beaches with different levels of pollution. The 2 beaches showed predominance of Enterococcus faecalis and Enterococcus faecium, in the water and the sand. Dry sand presented higher densities of Enterococcus sp. and higher frequency of resistant strains than wet sand and seawater. The beach with a higher degree of pollution presented higher percentages of resistant strains (66.7% and 61.5%, in sand and in water, respectively) and resistance to a larger number of antimicrobials compared with the less polluted beach, Ilha Porchat (35.7% and 31.25% of resistant strains in sand and water, respectively). In water samples, the highest frequencies of resistance were obtained against streptomycin (38.5%) and erythromycin (25%), whilst in sand, the highest frequencies were observed in relation to erythromycin and tetracycline (38.1% and 14.3%, respectively). These results show that water and sands from beaches with high indexes of faecal contamination of human origin may be potential sources of contamination by pathogens and contribute to the dissemination of bacterial resistance.     

Model-based analysis and simulation of airflow control systems of ventilation units in building environments

Model-based analysis and simulation of the airflow control system of ventilation units is of primary importance for the design and maintenance of the entire HVAC system in building environments. In this paper, we develop a mathematical model to simulate such airflow control systems. The model is implemented and a systematic analysis of the system is carried out, including its dynamic simulations in SIMULINK. The simulation results are compared with data obtained from analytical predictions as well as with experimental results available for a lab-scale ventilation unit. Finally, based on the combination of temperature and airflow regulations with conventional PI controllers, we provide the results of simulations of the entire ventilation unit control system for two different types of loading conditions.     

滇池现代沉积物中总磷和磁化率研究

通过对滇池（外海）现代沉积物柱状样中的总磷（TP）浓度和磁化率的测试,对两者的相关性进行了测试分析,以期为滇池治理污染现状提供资料依据。     

An analysis of bioclimatic zones and implications for design of outdoor built environments in Egypt

Climate considerations are essential dimensions in the assessment of quality of outdoor built environments. This paper provides an analysis of bioclimatic classification of Egypt to help the environmental design of wide range of purposes, including: climate responsive design; energy conservation and thermal comfort in the outdoor built environments. The analysis of this classification uses a bioclimatic approach in which the comfort zone and monthly climatic lines were determined and plotted on the psychrometric chart. Since the mean radiant temperature (T_mrt) is the most important input parameter for the energy balance in outdoor environments, the charts apply the ASHRAE 55-2004 standard considering the operative temperature as a function of T_mrt. Analysis for each bioclimatic zone determines the potential of passive design strategies to maintain thermal comfort in outdoor spaces and to contribute to energy efficient built environment. Finally, this study suggests a design guideline matrix for landscape architectural design for the different bioclimatic zones.     

Vulnerability of coastal environments to land use and abuse: the example of southeast Florida

The Atlantic coastal zone of subtropical southeast Florida supports nearly 7 million inhabitants. Since the mid‐19th century urbanization intensified along the shore and spread westward into freshwater marshlands. Population densities approaching 2500 persons per km^?2 and dredge and fill operations to create urban land in western marshes has degraded coastal environments bringing environmental sustainability into question. Efforts to maintain environmental integrity initially focused on shore protection via ‘hard’ engineering works, which later included massive beach renourishment projects along developed coasts subject to critical erosion. Marine algal blooms, degraded coastal water quality and the deterioration of coral reefs indicate environmental problems more serious than beach erosion. Recognition of a potential eco‐catastrophe prompted the Everglades Restoration Project, the largest single environmental recovery effort in the world. The cleanup of terrestrial systems is essential to sustainability of marine ecosystems now jeopardized by nutrient loading.     

Experimental measurements,integral modeling and smoke detection of early fire in thermally stratified environments

Building fires go through a series of stages. They start with a fire plume period during which buoyant fire smoke rises to the ceiling. A second stage is the following enclosure smoke-filling period. In this paper, the first stage is the subject, especially for the fire plume behavior in thermally stratified environments in large volume spaces. In NFPA 92B, Morton's integral equation was introduced for calculating the maximum plume rise, and beam smoke detectors were recommended for smoke detection design. In this work, experiments and CFD simulations were conducted in a small-scale enclosure and a large space to investigate early fire movements in temperature-stratified ambients. The results show that in a thermally stratified environment, the axial temperature and velocity of a fire plume decrease more quickly along the vertical axis than in uniform environment, and in some cases the fire plume ceases to rise. The previous integral equation was shown to underestimate the actual maximum height of a fire smoke plume, and also was unable to explain the differences of the maximum heights of low-density and high-density smoke plumes with the same stratification and outlet conditions. The integral equation was improved by introducing two correction factors, and extended for non-linear temperature stratified environments. A light section smoke detection method with three space-protected area was suggested and discussed.     

The use of uric acid as a method of tracing domestic sewage discharges in riverine, estuarine and coastal water environments

The chemical tracking of sewage effluents discharged into fresh and saline waters presents difficulties, especially in estuaries. The main difficulty is caused by the dissolved constituents being used to monitor the effluent also occurring naturally at similar levels. Uric acid is present at significant levels in untreated sewage and is not normally found in unpolluted waters. Until now no suitable routine method has been available for uric acid estimation in fresh and saline waters at levels normally encountered in the environment. In this paper we describe a recently developed technique using high-performance liquid chromatography which estimates uric acid in both fresh and saline waters in the range 1–10,000 μg l⁻¹ with a precision (2σ) of ±20% at 2 μg l⁻¹, ±4% at 40 μg l⁻¹ and ±2% at 10 mg l⁻¹.     

Effects of stream acidification on fungal biomass in decaying beech leaves and leaf palatability

We examined the effect of surface water acidification on rates of decomposition, ergosterol concentrations (as a measure of fungal biomass), and palatability to shredders of common beech leaves (Fagus sylvatica L.) in five mountain streams (pH 4.7-7.1). Leaf decomposition was significantly faster in the circumneutral streams (pH 6.4-7.1; k > or = 0.00175 d(-1)), when compared to acidic streams (pH 4.7-4.9; k < or = 0.00100 d(-1)). Fungal biomass showed no particular trend along the acidification gradient except that it peaked earlier in the stream closest to neutrality. Leaf palatability, measured as the feeding activity of the leaf-shredding amphipod Gammarus fossarum Koch, varied with the exposure time in the streams. Except for the higher palatability of leaves exposed during 6 weeks at the highest pH, patterns among streams were mostly similar. These results suggest that reduced processing rates in the most acidic streams were not related to differences in fungal biomass associated with decomposing leaves and that microbial conditioning was only slightly delayed by acidification. Possible effects of low pH and related variables (Ca, Al) on microbial decomposition and detritivorous macroinvertebrates are discussed to clarify the inhibition of beech leaf decomposition in the studied systems.     

Ventilation and health in non-industrial indoor environments: report from a European multidisciplinary scientific consensus meeting (EUROVEN)

Scientific literature on the effects of ventilation on health, comfort, and productivity in non-industrial indoor environments (offices, schools, homes, etc.) has been reviewed by a multidisciplinary group of European scientists, called EUROVEN, with expertise in medicine, epidemiology, toxicology, and engineering. The group reviewed 105 papers published in peer-reviewed scientific journals and judged 30 as conclusive, providing sufficient information on ventilation, health effects, data processing, and reporting, 14 as providing relevant background information on the issue, 43 as relevant but non-informative or inconclusive, and 18 as irrelevant for the issue discussed. Based on the data in papers judged conclusive, the group agreed that ventilation is strongly associated with comfort (perceived air quality) and health [Sick Building Syndrome (SBS) symptoms, inflammation, infections, asthma, allergy, short-term sick leave], and that an association between ventilation and productivity (performance of office work) is indicated. The group also concluded that increasing outdoor air supply rates in non-industrial environments improves perceived air quality; that outdoor air supply rates below 25 l/s per person increase the risk of SBS symptoms, increase short-term sick leave, and decrease productivity among occupants of office buildings; and that ventilation rates above 0.5 air changes per hour (h-1) in homes reduce infestation of house dust mites in Nordic countries. The group concluded additionally that the literature indicates that in buildings with air-conditioning systems there may be an increased risk of SBS symptoms compared with naturally or mechanically ventilated buildings, and that improper maintenance, design, and functioning of air-conditioning systems contributes to increased prevalence of SBS symptoms.     

小兴安岭成矿带岩(矿)石磁化率特征分析及应用

岩(矿)石磁性差异是进行航磁资料地质解释的重要依据。为全面了解小兴安岭成矿带岩(矿)石的磁性特征,项目组连续两年深入该区,实测3236个物性点,取得有效磁化率数据96 930个。文章综合前人资料,研究了该区岩(矿)石磁化率的分布情况,分析总结了各岩性的磁性特征,结果表明基性、超基性岩浆岩是引起该区强磁异常的主要因素。在此基础上,对区域磁场进行划分,新圈定隐伏岩体306处,划定火山岩367片,优选重点航磁异常709个,对航磁异常进行综合推断解释。     

Toxicity and sorption kinetics of dissolved cadmium and chromium III on tropical freshwater phytoperiphyton in laboratory mesocosm experiments

The objective of this study was to assess the interactive effects of Cd and Cr III on tropical phytoperiphyton community growth, metal sorption kinetics, as well as Cd and Cr mixtures toxicity to diatom assemblages in laboratory mesocosm experiments. A natural phytoperiphyton community sampled from the Monjolinho River (South of Brazil) was inoculated into seven experimental systems containing clean glass substrates for phytoperiphyton colonization. The communities were exposed to mixtures of dissolved Cd and Cr concentrations of 0.01 and 0.1 mg.L⁻¹ Cd and 0.05 and 0.2 mg.L⁻¹ Cr. Phytoperiphyton chlorophyll a, ash-free dry mass, growth rate, diatom cell density and diatom community composition were analyzed on samples collected after 1, 2 and 3 weeks of colonization. High Cd concentration (0.1 mg.L⁻¹) affects phytoperiphyton growth while high concentration of Cr (0.2 mg.L⁻¹) decreased the toxic effects of Cd on phytoperiphyton growth demonstrating the importance of studying metal mixtures in field studies. Shifts in species composition (development of more resistant species like Achnanthidium minutissimum (Kützing) Czarnecki, and Nitzschia palea (Kützing) Smith and reduction of sensitive ones like Fragilaria capucina Desmazières, Navicula cryptocephala (Grunow) Cleve, Encyonema silesiacum (Bleisch) Mann, Eunotia bilunaris (Ehrenberg) Mills and Gomphonema parvulum (Kützing) Kützing), of phytoperiphyton communities with increasing Cd and Cr concentrations and exposure duration have been demonstrated in this study making phytoperiphyton communities appropriate monitors of metal mixtures in aquatic systems. Good Cd and Cr accumulation capacity by phytoperiphyton was demonstrated with total and intracellular metal content in phytoperiphyton reflecting the effects of dissolved concentrations of metal in the culture media and exposure duration. Increase in both Cd and Cr reduced sequestration of each other, with generally more Cd being sequestered compared to Cr. Field validation of the observed effects remains an interesting subject for further investigations.     

Exploratory analysis of the water governance frameworks regarding the OECD principles in two river basins in Brazil and Portugal

Water is essential for human and economic development, and ecosystem services. Water crises are primarily governance crises, requiring consideration of multiple scales and actors. This article aims to discuss water governance principles proposed by the Organization for Economic Co-operation and Development (OECD) in 2015 and 2018, in Brazil and Portugal, including an exploratory analysis of the OECD indicators’ framework and those used in the Protocol of the Water Management Observatory (OGA) in Brazil in 2019. The main objective was to identify critical dimensions for an adequate assessment of water governance, and drivers for water policy improvement in both countries.     

Impact of urban geometry on outdoor thermal comfort and air quality from field measurements in Curitiba,Brazil

Urban climate can have severe impacts on people who use outdoor spaces within a city. In its essence, urban climate is directly linked to the configuration of street axes, building heights and their attributes. Thus, the role of urban planners can be crucial for guaranteeing outdoor thermal comfort and air quality in open spaces. This paper presents observed and estimated relations between urban morphology and changes in microclimate and air quality within a city center. Two approaches are presented, showing results of field measurements and urban climate simulations using the ENVI-met software suite. From measured microclimatic data and comfort surveys, carried out in downtown Curitiba, Brazil, the impact of street geometry on ambient temperatures and on daytime pedestrian comfort levels was evaluated, using the sky-view factor (SVF) as indicator of the complexity of the urban geometry. The impact of street orientation relative to prevailing winds and the resulting effects of ventilation (air speed and spatial distribution) on the dispersion of traffic-generated air pollutants were additionally analyzed by means of computer simulations. Results show the impact of urban geometry on human thermal comfort in pedestrian streets and on the outcomes of pollutant dispersion scenarios.