Fungi in fabricated soils

Fabricated soil (FS) is usually used for landscape rehabilitation, and is an excellent example of environmental remediation. These soils were used to revitalise damaged and eroded soils caused by acid mine drainage, a common site in Western Pennsylvania. The ratio of bacterial and fungal microbiota contributes to the health, fertility and sustainability of the soil. The structure and function of the soils foodweb have been suggested for numerous times as a prime indicator of ecosystem health (Bongers, 1990; Coleman et al., 1992; Kalevitch et al., 2003). The measurement of disrupted soil processes, decreased bacterial or fungal activity or decreased fungal or bacterial biomass can indicate a problem long before the natural vegetation is lost (Bongers, 1990). After the exposure of FS to the natural habitat, we evaluated the bacterial and fungal activity in soil as this is an important indicator of soil health. Details on bacterial presence and specifics in application of FS are described in previous publications (Kalevitch et al., 2003, 2004a, 2004b). In this paper, we will concentrate on the role of fungal biomass in FS.     

The EU-project ERAPharm. Incentives for the further development of guidance documents?

- Triggered by the detection of a large variety of pharmaceuticals in surface waters, soils and groundwaters across the world (e.g. Halling- Sørensen et al. 1998, Daughton & Ternes 1999, Jones et al. 2001, Heberer 2002) and the widespread occurrence of endocrine active compounds and related effects in the environment (e.g. Purdom et al. 1994, Tyler et al. 1998, Vethaak et al. 2002), pharmaceuticals in the environment have become an issue for both the scientific and the public community. During the last few years, our understanding of the fate and effects of pharmaceuticals in the environment has progressed significantly. However, there are still a number of uncertainties concerning the effects of pharmaceuticals on the environment and the assessment of potential exposure (e.g. Hanisch et al. 2004, Salomon 2005). These uncertainties will be addressed by the EU-project ‘Environmental risk assessment of pharmaceuticals’ (ERAPharm). This project, a specific targeted research project, is carried out within the priority ‘Global change and ecosystems’ of the 6th framework programme of the European Union. ERAPharm has started on 1st October 2004; the project duration is three years.     

Concentration of global fallout 99Tc in rice paddy soils collected in Japan

Analysis of global fallout 99Tc in environmental samples should provide useful information for predicting the nuclide behaviour under natural conditions which is important from the viewpoint of radioecology. Concentrations of 99Tc in rice paddy soils collected in Japan have been studied. After chemical separation, 99Tc in the final solution was measured by ICP-MS. The activity ratio of 99Tc/137Cs was used to understand the 99Tc behaviour in the environment because the fission yields of 99Tc and 137Cs from 235U or 239Pu are almost the same. The theoretical activity ratio from fission which is calculated now is about 3.0 x 10(-4). Our results showed that the range of activity ratios of 99Tc/137Cs in the soil samples was (2.0-5.2) x 10(-3); these ratios were one order of magnitude higher than the theoretical one. 99Tc has been accumulating in rice paddy soil like 137Cs has, although their mechanisms might differ. One of the reasons for the high ratio in the surface soil might be the ratios in the atmospheric samples, which have increased from the order of 10(-3) to 10(-2) (García-León et al., 1993).     

Changes in the biochemical oxygen demand procedure in the 21st edition of Standard Methods for the Examination of Water and Wastewater.

The dilution biochemical oxygen demand (BOD) test has widespread application for design and operation of wastewater treatment processes, evaluating the quality of natural waters, and assessing the effect of wastewater discharges on these waters. While standardization of the BOD-measuring method has become of prime importance in maintaining dependable data acquisition, changes are made as needed in response to questions raised by analysts and to accommodate new applications. The purpose of this article is to describe changes that have been incorporated in the 20th and 21st editions of Standard Methods for the Examination of Water and Wastewater (APHA et al., 1998 and 2004). These changes include changes in text format to clarify the procedural steps, allowance for use of bottle sizes ranging from 60 mL or larger, improvements in quality-control procedures, and improvements in the method of calculating BOD. Other changes include allowance for the use of allylthiourea for nitrification inhibition and broadening the source of seed that can be used for inoculation of BOD samples.     

Model approach for estimating potato pesticide bioconcentration factor

We presented a model that estimates the bioconcentration factor (BCF) of pesticides in potatoes supposing that the pesticide in the soil solution is absorbed by the potato by passive diffusion, following Fick's second law. The pesticides in the model are nonionic organic substances, traditionally used in potato crops that degrade in the soil according to a first-order kinetic equation. This presents an expression that relates BCF with the pesticide elimination rate by the potato, with the pesticide accumulation rate within the potato, with the rate of growth of the potato and with the pesticide degradation rate in the soil. BCF was estimated supposing steady state equilibrium of the quotient between the pesticide concentration in the potato and the pesticide concentration in the soil solution. It is suggested that a negative correlation exists between the pesticide BCF and the soil sorption partition coefficient. The model was built based on the work of Trapp et al. [Trapp, S., Cammarano, A., Capri, E., Reichenberg, F., Mayer, P., 2007. Diffusion of PAH in potato and carrot slices and application for a potato model. Environ. Sci. Technol. 41 (9), 3103-3108], in which an expression to calculate the diffusivity of persistent organic substances in potatoes is presented. The model consists in adding to the expression of Trapp et al. [Trapp, S., Cammarano, A., Capri, E., Reichenberg, F., Mayer, P., 2007. Diffusion of PAH in potato and carrot slices and application for a potato model. Environ. Sci. Technol. 41 (9), 3103-3108] the hypothesis that the pesticide degrades in the soil. The value of BCF suggests which pesticides should be monitored in potatoes.     

Modelling the migration of contaminants through variably saturated dual-porosity, dual-permeability chalk

In the Hesbaye region in Belgium, tracer tests performed in variably saturated fissured chalk rocks presented very contrasting results in terms of transit times, according to artificially controlled water recharge conditions prevailing during the experiments. Under intense recharge conditions, tracers migrated across the partially or fully saturated fissure network, at high velocity in accordance with the high hydraulic conductivity and low effective porosity (fracture porosity). At the same time, a portion of the tracer was temporarily retarded in the almost immobile water located in the matrix. Under natural infiltration conditions, the fissure network remained inactive. Tracers migrated downward through the matrix, at low velocity in relation with the low hydraulic conductivity and the large porosity of the matrix. Based on these observations, Brouyère et al. (2004a) [Brouyère, S., Dassargues, A., Hallet, V., 2004a. Migration of contaminants through the unsaturated zone overlying the Hesbaye chalky aquifer in Belgium: a field investigation, J. Contam. Hydrol., 72 (1-4), 135-164, doi: 10.1016/j.conhyd.2003.10.009] proposed a conceptual model in order to explain the migration of solutes in variably saturated, dual-porosity, dual-permeability chalk. Here, mathematical and numerical modelling of tracer and contaminant migration in variably saturated fissured chalk is presented, considering the aforementioned conceptual model. A new mathematical formulation is proposed to represent the unsaturated properties of the fissured chalk in a more dynamic and appropriate way. At the same time, the rock water content is partitioned between mobile and immobile water phases, as a function of the water saturation of the chalk rock. The groundwater flow and contaminant transport in the variably saturated chalk is solved using the control volume finite element method. Modelling the field tracer experiments performed in the variably saturated chalk shows the adequacy and usefulness of the new conceptual, mathematical and numerical model.     

Validating a nondestructive optical method for apportioning colored particulate matter into black carbon and additional components

Exposure of black carbon (BC) is associated with a variety of adverse health outcomes. A number of optical methods for estimating BC on Teflon filters have been adopted but most assume all light absorption is due to BC while other sources of colored particulate matter exist. Recently, a four-wavelength-optical reflectance measurement for distinguishing second hand cigarette smoke (SHS) from soot-BC was developed (Brook et al., 2010; Lawless et al., 2004). However, the method has not been validated for soot-BC nor SHS and little work has been done to look at the methodological issues of the optical reflectance measurements for samples that could have SHS, BC, and other colored particles. We refined this method using a lab-modified integrating sphere with absorption measured continuously from 350 nm to 1000 nm. Furthermore, we characterized the absorption spectrum of additional components of particulate matter (PM) on PM(2.5) filters including ammonium sulfate, hematite, goethite, and magnetite. Finally, we validate this method for BC by comparison to other standard methods. Use of synthesized data indicates that it is important to optimize the choice of wavelengths to minimize computational errors as additional components (more than 2) are added to the apportionment model of colored components. We found that substantial errors are introduced when using 4 wavelengths suggested by Lawless et al. to quantify four substances, while an optimized choice of wavelengths can reduce model-derived error from over 10% to less than 2%. For environmental samples, the method was sensitive for estimating airborne levels of BC and SHS, but not mass loadings of iron oxides and sulfate. Duplicate samples collected in NYC show high reproducibility (points consistent with a 1:1 line, R(2) = 0.95). BC data measured by this method were consistent with those measured by other optical methods, including Aethalometer and Smoke-stain Reflectometer (SSR); although the SSR looses sensitivity at filter loadings above 90 ng/mm(2). Furthermore, positive correlations (R(2) = 0.7) were observed between EC measured by NIOSH Method 5040 on quartz filters and BC measured in co-located Teflon filter samples collected from both heating and non-heating seasons. Overall, the validation data demonstrates the usefulness of this method to evaluate BC from archived Teflon filters while potentially providing additional component information.     

Refinements on the age-dependent half-life model for estimating child body burdens of polychlorodibenzodioxins and dibenzofurans

We modified our prior age-dependent half-life model to characterize the range of child (ages 0-7) body burdens associated with dietary and environmental exposure to polychlorodibenzodioxins and furans (PCDD/Fs). Several exposure scenarios were evaluated. Infants were assumed to be either breast-fed or formula-fed from birth to 6 months of age. They then received intakes of PCDD/Fs through age 7 from foods based on weighted means estimates [JECFA, 2001. Joint FAO/WHO Committee on Food Additives. Fifty-seventh meeting, Rome, June 5-14 , 2001, pp. 24-40], and with or without exposures (ingestion and dermal) to urban residential soils at 1ppb TCDD toxic equivalents (TEQ). A one-compartment (adipose volume) toxicokinetic model for TCDD described by Kreuzer [Kreuzer, P.F., Csanady, Gy.A., et al., 1997. 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) and congeners in infants. A toxicokinetic model of human lifetime body burden by TCDD with special emphasis on its uptake by nutrition. Arch. Toxicol. 71, 383-400] was expanded to include the key non-TCDD congeners in human breast milk and adipose tissues, and two model parameter refinements were examined: (1) use of updated and more detailed age-correlated body fat mass data [CDC, 2000. Centers for Disease Control. CDC Growth Charts: United States. Advance Data from Vital and Health Statistics of the Centers for Disease Control and Prevention, National Center for Health Statistics, Number 314, December 2000]; (2) use of breast milk PCDD/F concentration data from sampling completed in 2000-2003 [Wittsiepe, J., Fürst, P., et al., 2004. PCDD/F and dioxin-like PCB in human blood and milk from German mothers. Organohalogen Compd. 66, 2865-2872]. The updated body fat mass data nearly halved the predicted peak body burden for breast-feeding and lowered the time-weighted average (TWA) body burdens from ages 0-7 by 30-40% for breast-fed and formula-fed infants. Combined use of the updated breast milk PCDD/F concentration and body fat mass data increased the contribution of breast-feeding but reduced TWA body burdens from diet and soil. We conclude that further refinements are needed, but reliance on these better data sets for body fat mass and breast milk PCDD/F concentration significantly improves the model's ability to accurately predict body burdens during early childhood.     

Comments on "Sorption of triazoles to soil and iron minerals" by Y. Jia et al. [Chemosphere 67 (2007) 250-258

This letter suggests possible improvements on the discussion of the adsorptive removal of triazoles by iron minerals which are possible corrosion products of elemental iron materials (Fe0) in a recent article by Jia et al. [Jia, Y., Aagaard, P., Breedveld, G.D., 2007. Sorption of triaxoles to soil and iron materials. Chemosphere 67, 250-258]. Also recalled is the importance of the adsorption of organics by iron corrosion products which is not properly addressed in the iron technology literature when the contaminants are redox-sensitive.     

Catalytic oxidative treatment of diluted black liquor at mild conditions using copper oxide/cerium oxide catalyst.

Wet-air oxidation of diluted black liquor (chemical oxygen demand [COD] approximately 3250 to 14 500 mg/L) was performed at mild operating conditions (temperature = 388 to 423 K and total pressure = 0.6 MPa) in the presence of heterogeneous 60% copper oxide (CuO)/ 40% cerium oxide (CeO2) catalyst. Maximum COD reduction of 77.3% was obtained at 423 K at pH 3.0, which was marginally higher than that obtained at 413 K temperature (77.1%). In the acidic environment (pH < or = 3), most of the COD was removed in the form of settleable solids during the transient heating of the wastewater from room temperature to the desired one. The solid residue obtained after the reaction has a heating value of 20.1 MJ/kg, which is comparable with that of Indian coal. Thermal degradation kinetic determination suggested that thermal characteristics of the solid residue are well represented by a power law model with Agarwal and Sivasubramanian approximation (Safi et al., 2004).     

The variability of free tropospheric ozone over Beltsville,Maryland (39N, 77W) in the summers 2004–2007

Ozone profiles are often used to investigate day-to-day and year-to-year variability in origins of free tropospheric ozone. With this in mind, more than 50 ozonesonde launches were conducted in Beltsville, MD, during the summers of 2004 through 2007. Budgets of free tropospheric ozone were calculated for each ozone profile in the four summers using a laminar identification (LID) method and unusual episodes were analyzed with respect to meteorological variables. The laminar method showed that stratosphere-to-troposphere transport (ST) accounted for greater than 50% of the free tropospheric ozone column on 17% of days sampled, a more pronounced influence than regional convective and lightning (RCL) sources. The ST origins were confirmed with trajectories, and tracers (water vapor and potential vorticity). The amount of free tropospheric ozone from ST and RCL sources varied from year-to-year (up to 13%) and can be explained by differences in mean meteorological patterns. On average, almost 30% of the free tropospheric column was attributed to ST influence, about twice as much as RCL, although the LID method may not capture weeks-old lightning influences as in a chemical model. The prevalence of ST ozone in summertime Beltsville soundings was similar to six sounding sites in the IONS-04 campaign [Thompson, A.M., et al., 2007b. Intercontinental Transport Experiment Ozonesonde Network Study (IONS, 2004): 1. Summertime upper tropospheric/lower stratosphere ozone over northeastern North America. J. Geophys. Res. 112, D12S12; Thompson, A.M., et al., 2007c. Intercontinental Transport Experiment Ozonesonde Network Study (IONS, 2004): 2. Tropospheric ozone budgets and variability over northeastern North America. J. Geophys. Res. 112, D12S13.] and to statistics from a 30 year climatology of European soundings [Collette, A., Ancellet, G., 2005. Impact of vertical transport processes on the tropospheric ozone layering above Europe. Part II: Climatological analysis of the past 30 years. Atmos. Environ. 39, 5423–5435]. The Beltsville record also demonstrated the value of soundings for air quality forecasting in an urban area. The 22 nighttime soundings collected over Beltsville in 2004–2007 can be divided into distinct polluted and unpolluted subsets, the former 20 ppbv higher in residual layer ozone (1 km) than the latter. These distinctions propagated to daytime differences of 10 ppbv at the surface in the Washington, DC, area, with the high-ozone residual layers leading to non-attainment of the National Ambient Air Quality Standard for ozone. More frequent ozone observations aloft appear essential for better understanding ozone variability and for enabling air quality modelers to achieve more accurate ozone forecasts.     

Fabricated soils for landscape restoration: an example for scientific contribution by a public-private partnership effort

Public-private partnership efforts are working towards creating green landscapes from abandoned industrial sites. Fabricated soils, potentially an essential element of such landscapes, are designed to substitute for top-soil on the areas free from ground cover and plant community. The aluminosilicate matrix and humus form the soil micelle – the primary unit of any soil complex. Humus formation is a process based on carbon–nitrogen interaction. Sources of carbon can be materials rich in easily composted products like cellulose and polyphenols (plant leaves) or aged lignin polymers (saw dust from different woody plants). The pathways of carbon–nitrogen complexes are discussed. Properties of the fabricated soil components were examined by bio-tests and plant models.     

The Correlation between Light Scattering and Mass Concentration of Tobacco Smoke

Reports by others^1,2 have pointed to tobacco smoke as a significant source of air pollution in indoor spaces. Studies by Charlson, et al., ³ Kretzschmar,⁴ and Eccleston, et al. ⁵ have yielded mass concentration-light scattering correlations for several natural aerosols. This note presents a value for the mass concentration/ light scattering ratio for tobacco smoke. This ratio provides a means of assessing air quality in indoor spaces using an instrument with a fairly short (?1 min) time constant.     

Characteristics of total gaseous mercury concentrations at a coastal area of the Yangtze Delta,China

In this study, we report on total gaseous mercury (TGM) field observations made in the rural area of Shanghai, Chongming Island, China, from September 2009 to April 2012. The average TGM was 2.65 ± 1.73 ng m^?3 in Chongming Island, which is higher than the TGM background value of the Northern Hemisphere (1.5–1.7 ng m^?3); this indicates that to some extent, the Chongming area has been affected by anthropogenic mercury emissions. The observed TGM follows a seasonal pattern; concentrations are highest in winter, followed by autumn, summer, and spring. There is also a clear diurnal variation in TGM. All peak values appear between 7:00 and 9:00 in all four seasons; this appears to be the result of the height change in the atmospheric boundary layer that occurs between day and night. TGM concentrations in Chongming remain high in the westerly wind direction, especially in the southwest direction because of its low frequency, so the greatest source contribution to TGM in Chongming lies to the northwest. Wind speed is also a significant factor affecting TGM, and was negatively correlated with TGM concentrations. TGM is also closely related to carbon monoxide (CO) concentrations, indicating that TGM is impacted by human activities. The slope of the linear fitting of TGM and CO demonstrates that the contribution of noncoal source emissions to TGM in summer is greater than in autumn, mainly because the high temperature and intensive sunlight in summer increase mercury emissions from natural sources.

Implications: Except for some studies in the coastal areas (e.g., Kang Hwa Island by Kim et al., 2006, An–Myun Island by Kim et al., 2002, and Okinawa by Chan et al., 2008), data specifically for coastal areas are lacking. Monitoring of total gaseous mercury (TGM) in the rural area of Shanghai, Chongming Island, can help us understand mercury distribution.     

Sensor transition failure in the high flow sampler: Implications for methane emission inventories of natural gas infrastructure

Quantification of leaks from natural gas (NG) infrastructure is a key step in reducing emissions of the greenhouse gas methane (CH₄), particularly as NG becomes a larger component of domestic energy supply. The U.S. Environmental Protection Agency (EPA) requires measurement and reporting of emissions of CH₄ from NG transmission, storage, and processing facilities, and the high-flow sampler (or high-volume sampler) is one of the tools approved for this by the EPA. The Bacharach Hi-Flow Sampler (BHFS) is the only commercially available high-flow instrument, and it is also used throughout the NG supply chain for directed inspection and maintenance, emission factor development, and greenhouse gas reduction programs. Here we document failure of the BHFS to transition from a catalytic oxidation sensor used to measure low NG (~5% or less) concentrations to a thermal conductivity sensor for higher concentrations (from ~5% to 100%), resulting in underestimation of NG emission rates. Our analysis includes both our own field testing and analysis of data from two other studies (Modrak et al., 2012; City of Fort Worth, 2011). Although this failure is not completely understood, and although we do not know if all BHFS models are similarly affected, sensor transition failure has been observed under one or more of these conditions: (1) Calibration is more than ~2 weeks old; (2) firmware is out of date; or (3) the composition of the NG source is less than ~91% CH₄. The extent to which this issue has affected recent emission studies is uncertain, but the analysis presented here suggests that the problem could be widespread. Furthermore, it is critical that this problem be resolved before the onset of regulations on CH₄ emissions from the oil and gas industry, as the BHFS is a popular instrument for these measurements.

Implications: An instrument commonly used to measure leaks in natural gas infrastructure has a critical sensor transition failure issue that results in underestimation of leaks, with implications for greenhouse gas emissions estimates as well as safety.     

Rapid assessment of environmental health risks posed by mining operations in low- and middle-income countries: selected case studies

Previous studies have evaluated associated health risks and human exposure pathways at mining sites. Others have provided estimates of the scale of the issue based in part on surveys. However, a global census of mining-related hazardous waste sites has been lacking. The Toxic Sites Identification Program (TSIP) implemented by Blacksmith Institute (New York, NY, USA) since 2009 is an ongoing effort to catalogue a wide range of chemically contaminated sites with a potential human health risk (Ericson et al., Environ Monit Assess doi:10.1007/s 10661-012-2665-2, 2012). The TSIP utilizes a rapid assessment instrument, the Initial Site Screening (ISS), to quickly and affordably identify key site criteria including human exposure pathways, estimated populations at risk, and sampling information. The resulting ISS allows for comparison between sites exhibiting different contaminants and pollution sources. This paper explores the results of a subset of ISSs completed at 131 artisanal and small-scale gold mining areas and 275 industrial mining and ore processing sites in 45 countries. The authors show that the ISS captures key data points, allowing for prioritization of sites for further investigation or remedial activity.     

Evidence of one-dimensional scale-dependent fractional advection-dispersion

A semi-analytical inverse method and the corresponding program FADEMain for parameter estimation of the fractional advection-dispersion equation (FADE) were developed in this paper. We have analyzed Huang et al.'s [Huang, K., Toride, N., van Genuchten, M.Th., 1995. Experimental investigation of solute transport in large homogeneous and heterogeneous saturated soil columns. Trans. Porous Media 18, 283-302.] laboratory experimental data of conservative solute transport in 12.5-m long homogeneous and heterogeneous soil columns to test the non-Fickian dispersion theory of FADE. The dispersion coefficient was calculated by fitting the analytical solution of FADE to the measured data at different transport scales. We found that the dispersion coefficient increased exponentially with transport scale for the homogeneous column, whereas it increased with transport scale in a power law function for the heterogeneous column. The scale effect of the dispersion coefficient in the heterogeneous soil was much more significant comparing to that in the homogeneous soil. The increasing rate of dispersion coefficient versus transport distance was smaller for FADE than that for the advection-dispersion equation (ADE). Finite difference numerical approximations of the scale-dependent FADE were established to interpret the experimental results. The numerical solutions were found to be adequate for predicting scale-dependent transport in the homogeneous column, while the prediction for the heterogeneous column was less satisfactory.     

Simulation of the tropospheric distribution of carbon monoxide during the 1984 MAPS experiment

A global, three-dimensional tropospheric chemistry model was used to perform simulations of the tropospheric distribution of carbon monoxide (CO) coinciding with NASA's Measurement of Air Pollution from Satellites (MAPS) experiment which took place during 5–13 October 1984. Archived meteorological data for September and October, 1984, were obtained from the European Centre for Medium-Range Weather Forecasting and used to drive the offline chemical transport model simulations. Base-case CO emissions were generated by applying emission factors to compiled inventories for related or co-emitted trace species. Simulation results from September and October have been compared with a recent re-release of the 1984 MAPS data and with in situ correlative data taken during the MAPS mission. Because of unrealistically large spatial variability in N₂O mixing ratios measured concurrently by MAPS, model results were also compared with an adjusted CO data set generated by assuming that errors in N₂O measured mixing ratios were correlated with errors in the MAPS CO data. These comparisons, in conjunction with simulations probing model sensitivities, led to the conclusion that biomass burning CO emissions from central and southern Africa may have been larger during September and October, 1984, than our initial best estimate based on the CO₂ emissions data of Hao et al. (1990. Fire in the Tropical Biota; Ecosystem Processes and Global Challenges. Springer, Berlin, pp. 440–462; 1994. Global Biogeochemical Cycles 8, 495–503). This result is in disagreement with recent estimates of biomass burning emissions from Africa (Scholes et al., 1996, Journal of Geophysical Research 101, 23677–23682) which are smaller than previously thought for emissions from this region. Although unknown model deficiencies cannot be conclusively ruled out, model sensitivity studies indicate that increased CO emissions from central and southern Africa offer the best explanation for reducing observed differences between model results and MAPS data for this time period. Our results, in combination with a disparity in recent CO emission estimates from this region (Scholes et al., 1996; Hao et al., 1996, Journal of Geophysical Research 101, 23577–23584), and in light of recent indications of highly variable biomass burning activities from the tropical western Pacific (Folkins et al., 1997, Journal of Geophysical Research 102, 13291–13299), seem to suggest that biomass burning emissions exhibit significant year-to-year variability. This large variability of emissions sources makes the accurate simulation of specific time periods very difficult and suggests that biomass burning trace species inventories may have to be developed specifically for each simulated time period, employing satellite-derived information on fire coverage and flame intensity.