Contaminated Sites Research Articles

The effect of interactions between soil compaction and phenol contamination on plant growth characteristics: Implications for scaling bioremediation at industrial sites

In phenol contaminated soils from an industrial site, soil compaction and soil chemical contaminants influenced germination, emergence, and early plant growth (roots and shoots) for Thrift (Ameria maratima) and Blackbutt oats (Avena sativa). The specific effects were of soil compaction (low, 100 psi and high, 800 psi) at two concentrations of phenol (biotreated, ∼200 mg kg−3; untreated, ∼1150 mg kg−3). Plant responses to compaction and phenol varies between the two species. Emergence of Thrift showed greater sensitivity to increasing soil compaction but only under high phenol concentrations. Low phenol inhibited Thrift root length, as is the case with Balckbutt oats, although high phenol had no significant impact on Thrift. While shoot length of Blackbutt oats is not significantly affected by increasing soil compaction, it is negatively impacted at the increased phenol concentrations in the untreated soils indicating an interaction effect with compaction. This is the first study that examines the impact of soil contamination on oats. The oat variety tested had known drought tolerance and hardiness indicating an ability to withstand compaction, and which may explain those characteristics. Thrift was most resistant to contamination which is consistent with its previously reported tolerance of pollutants. Implications of the study are that Blackbutt oats represent a potential candidate species for land rehabilitation under high compaction conditions such as at degraded soil sites at decommissioned mining operations, polluted industrial sites, or degraded (compacted) agricultural land.

Delineation of necroleachate pathways using electrical resistivity tomography (ERT): Case study on a cemetery in Brazil

Cemeteries can be considered as potential sources of soil and groundwater contamination in burial sites where there is no collection and treatment system for necroleachate, an effluent rich in organic matter and inorganic elements produced during the decomposition of corpses. Brazilian cemeteries are mostly located in the interior of cities, where collective or family deposits with the absence of necroleachate collection devices predominates. The tropical climate, the recurrence, and the distribution of corpses, combined with soil permeability, are decisive elements in the percolation and distribution of necroleachate in the subsurface. An important tool for the diagnosis and evaluation of organic and inorganic contamination in soil and shallow aquifers is geophysics, through research methods related to the contrast of physical properties in the presence of this type of contaminant. This research consists of a geophysical investigation in a medium-sized cemetery in the southeastern Brazil, using the DC resistivity method using three different electrodes arrays: Wenner, Schlumberger and Dipole-Dipole. Additionally, results were combined with the history of burials in the 5 years prior to the geophysical study. The 2D inversion models confirm the presence of low resistivity anomalies related to the presence of ionic compounds. 3D visualization models with results of the three acquisition arrays are compared to the amount of burial by compartmentalized areas of the cemetery, which clearly reveals a relationship of areas with high and recent recurrence of burials and areas of low resistivity in depth. The results do not present significant differences between arrays, with similarities in terms of location and dimension of the most significant areas of low resistivity.

Evaluating backward probability model under various hydrogeologic and hydrologic conditions

Contaminant source identification improves the understanding of contaminant source characteristics including location and release time, which can lead to more effective remediation and water resources management plans. The backward probability model can provide probabilities of source locations and release times under various contaminant properties and hydrogeologic conditions. The backward probability model has been applied to numerous synthetic and real contamination sites for locating possible contaminant sources, but it is also important to evaluate the reliability of the backward probability model through rigorous verification analyses. Here, we present a model verification framework for the backward probability model using a stepwise approach from simple to complex model settings: comparison with previous studies, transient saturated flow under various hydrogeologic conditions, and transient variably-saturated flow conditions. As a simple condition, one-dimensional homogeneous problems under steady-state and transient flow conditions were verified by comparing with previous studies. Model verifications with complex conditions were conducted by comparing forward and backward probability simulation results. The verification results demonstrate that the backward probability model performs well for homogeneous problems. For heterogeneous problems, the backward probability model results in slightly different backward travel times due to differences in solute decay and boundary conditions assigned for both forward and backward probability simulations, but the backward travel time at the maximum probability can be reproduced well.

Guaiacol hydrotreating with in-situ generated hydrogen over ni/modified zeolite supports

Catalytic hydrotreating of guaiacol as a model compound was investigated using bifunctional catalysts constituted of Ni supported on chemically modified zeolites with increased mesoporosity. In the reaction conditions, the hydrogen required for the process was generated in situ by the Zn–H2O redox system, which represents a promising green alternative to the use of gaseous hydrogen. The guaiacol hydrotreating conversion using as support zeolites with increased mesoporosity, is largely higher than that obtained with the original ones. The introduction of mesopores through desilication treatment with NaOH and TBAOH significantly increased the mass transfer of guaiacol and improved the accessibility of the active sites, accordingly enhancing the catalytic performance. The alkaline treatment notably increased the mesopore volume of Ni/HZSM-5 and Ni/HBeta by 5.6 and 3.8 times, respectively. Ni supported on desilicated HBeta zeolite displayed high hydrodeoxygenation and hydrodearomatization efficiencies with values of 69.37% and 62.82%, respectively. The reusability of this catalyst was investigated, showing a decrease in the performance after three consecutive runs due to the oxidation of Ni active site, coking and zinc oxide contamination. The main of guaiacol conversion products are cyclohexane, cyclohexanone, cyclohexanol, benzene and phenol. A reaction pathway of guaiacol hydrotreating using Ni-zeolites catalysts is proposed.

Life in extreme habitats: the number of prepupae per nest of the crabronid wasp Pemphredon fabricii is constant even under pressure from high concentrations of toxic elements.

Anthropogenic habitats that are contaminated by toxic elements were recently shown to host abundant and diverse assemblages of bees and wasps (Hymenoptera: Aculeata), including numerous threatened species. However, toxic elements adversely affect insect fitness. We address the effects of toxic elements on aculeate inquilines that occupy Lipara lucens-induced galls on the common reed, Phragmites australis. We hypothesized that contamination of potential nesting and feeding habitats is associated with adverse changes in bee and wasp populations that are attracted in these environments. To address this hypothesis, we analyzed the contents of As, Cd, Cu, Pb, Zn, Fe, and S in site-matched samples of soil, reed galls, and crabronid wasp bodies and correlated them with abundance and species richness of aculeate hymenopterans in reed galls and with the number of larvae in nests of the eudominant hymenopteran, Pemphredon fabricii. The common reed was present at all the examined sites, and L. lucens-induced galls were present at all but one sampling site; the single exception was the sampling site with the highest contents of four of the seven analyzed elements. The alpha diversity of gall-associated aculeate inquilines, abundance of P. fabricii, and number of prepupae per nest of P. fabricii were not correlated with the contents of any of the seven analyzed toxic elements. We found P. fabricii to be abundantly present in habitats with extreme concentrations of toxic elements. Exposed P. fabricii accumulated Cd, Cu, and Pb, while they eliminated Fe and Zn. The obtained data did not support the hypothesis that heavy metal contamination of anthropogenic sites affects P. fabricii and other reed gall-associated aculeates.

Using prototypes to enable development of commercially viable field scale contaminated site remediation processes

Soil structure was damaged from solvents and localised heating after a large fire which had potential to limit bioremediation of an industrial site. Laboratory prototypes (biopile, bioflushing, bioreactor, slurry reactor) for treating the site contamination were developed. After successful laboratory testing (96% removal of main contaminant, phenol), the bioflushing prototype was then applied in the field. Field prototype removed 95% phenol using a small scale 2000 L bioreactor. Field trial was then scaled to commercial clean-up. Intensive soil grid sampling after 600 days treatment revealed hotspots of solvents remaining as well as the heterogeneity in the subsurface, however overall concentrations were substantially decreased below the initial assessment. The process decreased initial soil phenol concentrations of approximately 500 mg/kg (pre-treatment area average) to 75 mg/kg across the most contaminated areas. Phenol toxicity increased with depth and is linked to increasing oxygen deficit. The study demonstrated the prototyping process enabling site clean-up and scaling for bioremediation at the industrial site, provided certainty for site owner on treatment elements and achieving improved environmental and commercial outcomes.

Development and Performance of Underwater Gamma-Ray Spectrometry for Riverbed Monitoring

Ji, Y.-Y.; Joung, S.; Min, B.I., and Suh, K.-S., 2021. Development and performance of underwater gamma-ray spectrometry for riverbed monitoring. In: Lee, J.L.; Suh, K.-S.; Lee, B.; Shin, S., and Lee, J. (eds.), Crisis and Integrated Management for Coastal and Marine Safety. Journal of Coastal Research, Special Issue No. 114, pp. 330–334. Coconut Creek (Florida), ISSN 0749-0208. The atmospheric release and fallouts of radionuclides have produced the radioactive contamination over wide area in the accident at the Fukushima Daiichi nuclear power plant (FDNPP). They still affect the environment around the Fukushima Prefecture, such as resident area, fields, mountainous area, river and stream, and reservoir. In JAEA (Japan Atomic Energy Agency), diverse monitoring platforms have been developing and successfully applying to the assessment of environmental radiation and deposited nuclides. Especially, there are about 3,700 irrigation reservoirs around the Fukushima Prefecture, which can be effected from direct fallouts in reservoirs as well as dispersions of the contamination in the other sites, depending on weather conditions. Underwater survey system is an important tool to assess the radioactive contamination in the river, stream and reservoir, including the bottom sediments. In this study, underwater gamma-ray spectrometry, named as MARK-U1, was developed to rapidly estimate the underwater radioactivity for the emergency preparedness, according to the lesson learned from the nuclear accident of FDNPP. A 3”φx3” NaI(Tl) detector is equipped in this underwater system and the lateral shielding around a detector was also designed using lead with a thickness of 1 cm to confine the field of view. Finally, its performance test was conducted by evaluating the natural radioactivity of 214Bi, 208Tl, and 40K in the riverbed of reservoir.

AN OVERVIEW OF VISCERAL LEISHMANIASIS IN THE CITY OF GURUPI, SOUTH REGION OF TOCANTINS

Visceral leishmaniasis (VL) is an endemic disease in the region of Gurupi, with higher prevalence in the pediatric age group, aggravated by the high morbidity and low prophylaxis and prevention strategies of this anthropozoonosis. Objective: To characterize the data reported in the municipality of Gurupi - TO in the years 2013 to 2020 and to outline the epidemiological profile of the disease by determining the risk factors for high prevalence of the disease in this locality. Methods: This is a cross-sectional descriptive epidemiological research, retrospective and documental based, extracted from the database of SINAN (Notifiable Diseases Information System) of Gurupi in the interval between 2013 and 2020. Evaluative questionnaires were applied to all patients notified and found, analyzing the variables described in the study and subsequent statistical application of the chi-square test. Results: In the city of Gurupi, the most affected age group was between 2 and 9 years (37.29%); the most affected gender was male (66.10%); the year of highest prevalence was the year 2017 a total of 37.28% of cases in the analyzed period; and the location of highest prevalence in the municipality were the neighborhoods farthest from the city center. As for the probable sites for contamination, most people point to their own home as a source of contamination. Conclusion: The epidemiological cut shows the prevalence of VL in the city of Gurupi and highlights the need for preventive intervention protocols for the prevention of the disease in endemic areas to decrease morbidity and mortality and control the number of cases.

Signs of life: Oxygen sensors confirm viability, measure oxygen consumption and provide rapid, effective contamination monitoring for field‐based tissue culture

Abstract Understanding the ecology and evolution of wildlife and domesticated species requires knowledge of their physiological responses to environmental change and the constraints under which they operate. However, whole animal experiments are often limited in sample size and can be logistically and ethically challenging. Culture techniques represent a powerful approach, but are used infrequently in field research due to practical constraints. We used minimal tissue culture equipment in a remote field site for in vitro explant experiments using blubber from wild grey seals Halichoerus grypus. Assessing explant viability and detecting microbial contamination in remote field sites, where facilities are often small, unspecialised and more vulnerable to bacterial or fungal infection, present major challenges. We investigated whether oxygen‐sensitive planar optodes (OSPO) in closed system respirometry could be used to assess oxygen consumption by blubber explants from suckling and fasting wild seal pups as a proxy for viability. We also explored whether OSPOs could provide rapid information on whole animal relevant physiological metrics by determining whether explant oxygen consumption correlated with the nutritional state of the animal, blubber depth and other tissue metabolic properties, including glucose uptake, lactate production and lipolysis. Vials containing blubber explants consumed significant amounts of oxygen compared to controls, showing tissues were metabolically active. Oxygen consumption differed between nutritional states and blubber tissue depth. These differences were reflected in other tissue metabolic properties. Dissolved oxygen levels remained consistent over 24 hr in 94% of control vials containing only culture media. In 6% of control vials extremely rapid oxygen consumption preceded, by 2–3 days, colour changes in the phenol‐red containing media that indicate lactic acidosis from microbial metabolic activity. Oxygen use in control vials was, therefore, an effective monitoring system that provided vital early warning of media contamination, allowing stocks to be discarded, which prevented erroneous results and avoided waste of valuable field time and irreplaceable samples. OSPO are thus a useful tool for simultaneously assessing tissue oxygen consumption, investigating functional physiological differences and monitoring microbiological contamination in culture experiments, particularly in field laboratories studying live tissues from wildlife.

A sustainability assessment-based methodology for the prioritization of contaminated site risk management options.

Contaminated site management is a multiple objective decision-making that generally involves different factors, such as performance of technology, environmental effects, cost, and social influence. In this study, we developed a sustainability assessment-based methodology for the prioritization of contaminated site risk management options. We integrate remediation sustainable assessment and redevelopment sustainable assessment in one framework and allow the optimization of indicators. The framework started with the definition of site management type, then investigating site characterization, screening indicators, quantifying of indicator, selecting assessment model, selecting primary options, assessment with uncertainty analysis, and determining of preferred options. To demonstrate the utility of the framework, results are presented in a contaminate site in southwest China for two risk management decisions, site remediation and site redevelopment. We used different approaches to evaluate the stability and robustness of assessment results, including Monte Carlo simulation, scenario analysis, and sensitivity analysis. The demonstration showed that attention has to be paid to the proper description of the site, the principles of the procedure, and the decision criteria.

Model-Based Assessment of Groundwater Contamination with PFOS due to Fire-Training Activities

Aqueous film-forming foams (AFFFs) containing perfluoro-octane sulfonate (PFOS) were commonly used in fire trainings until the awareness of their toxicity started to increase in the 2000s. Our objective was to build a modeling framework for estimating groundwater pollution with PFOS, utilizing dual-permeability modeling still novel for groundwater studies. The framework was applied to an existing contamination site. According to the results, only 27% of PFOS released from the fire-training area reached the aquifer. Adsorption to unburnt fuels and removal via oil separation wells before discharging to the aquifer can substantially reduce the PFOS contamination of groundwater. Despite this, the PFOS concentration in a groundwater intake area 1.9 km from the pollutant source was predicted to exceed the limits set for drinking water, in contrast to earlier predictions based solely on monitoring. The study demonstrates the importance of modeling for groundwater management as the data on AFFF usage and composition, and on soil and groundwater contamination with perfluorinated compounds and co-pollutants typically are limited in terms of the spatial and temporal scale of contamination.

PFAS in American Indian and Alaska Native Communities

BACKGROUND AND AIM: Systemic environmental health disparities exist for residents of U.S. Tribal lands including access to safe public drinking water and differences in drinking water quality as compared to non-Tribal lands. Per- and polyfluoroalkyl substances (PFAS) are a leading emerging concern for drinking water. However, knowledge about PFAS contamination on Tribal lands is lacking, a shortcoming in environmental health research given the extent of PFAS contamination. METHODS: We comprehensively identified existing PFAS water testing programs, including academic institutions and federal agencies, to identify all existing testing of drinking and/or groundwater on Tribal lands and to understand factors that prompted testing. We examined the proximity of Indian Reservations to active U.S. military installations. Military installations, Indian Reservations, and known PFAS contamination site levels were mapped with ArcGIS using publicly available data. RESULTS:We identified limited existing PFAS testing on Tribal lands, including partnerships with academic research institutions, and completed and planned testing by government entities. Spatial analysis identified 58 Reservations were within six miles of an active military installation, including at least 18 installations with identified PFAS contamination and six with over 100,000 ppt PFAS detected in groundwater. CONCLUSIONS:Tribal Nations and their public water systems have been overlooked for systematic testing of PFAS, a large data gap. Tribal lands near military installations may be at increased risk of contamination. While efforts for increased testing by federal agencies exist, current programs are voluntary with little incentive for Tribal Nations to participate. While the EPA’s 2023-2025 testing under the Unregulated Contaminant Monitoring Rule will have increased Tribal PWS inclusion, there is need for timelier PFAS testing. Recognition of the risks posed by PFAS contamination should inform policy change to protect American Indian and Alaska Native health. KEYWORDS: PFAS, environmental disparities, policy

Wastelanding and Racialized Reproductive Labor: “Long Dyings” in East Chicago from Urban Renewal to Superfund Remediation

Abstract This article examines the gendered valence of environmental racism and white privilege as it unfolded in the history of urban renewal, public housing, and Superfund remediation in East Chicago, Indiana. Offering a deep history of the US Smelter and Lead Refinery Superfund site, it demonstrates that the historical process of “wastelanding” in the Calumet region relied on the exploitation of reproductive labor. The nonprofit Purdue-Calumet Development Foundation (PCDF)—led by Purdue University administrators and supported by East Chicago municipal administrators, academic researchers, and local business executives—spearheaded East Chicago’s urban renewal program. Through the course of executing these renewal measures, the PCDF co-opted Black and Brown women’s reproductive labor to accomplish their goals and relied on metaphors of feminized labor—particularly women’s stereotyped tasks of cleaning and nurturing—to explain and sanitize the social cost of slum removal. These historical legacies of politicizing reproductive labor are visible today in government officials’ continued disproportionate burdening of East Chicago’s minority women as the city navigates its lead poisoning epidemic. Housing and environmental government agencies (alongside their partners in industry) have reinscribed their reliance on traditional gender roles from the urban renewal era through the distant futurities of Superfund contamination sites. Tracing the long history of the city’s mismanagement of toxic environmental exposures reveals the need for environmental historians to study the important role of racialized reproductive labor in both the perpetuation of environmental injustices as well as the resilience of environmental justice communities as they work to survive devastating health impacts and social trauma.

"The Sky Is Falling," Government Is Not Responding, What Can Scientists Do?

"The Sky Is Falling," Government Is Not Responding, What Can Scientists Do?

Simultaneous immobilization of aqueous co-contaminants using a bismuth layered material

The remediation of co-located contaminants in the vadose zone can be challenging due to accessibility and responses of different contaminants to remedial actions. At the Hanford Site (WA, USA), multiple radionuclides and other hazardous contaminants are present in the vadose zone and groundwater, including iodine-129 (I), technetium-99 (Tc), uranium-238 (U), chromium (Cr), and nitrate (NO3−). We evaluated a layered Bi oxyhydroxide material for its potential to remove individual and co-located contaminants with a series of batch experiments that investigated a range of plume conditions, followed by solid phase characterization of the reacted bismuth material. The results demonstrated successful removal of four contaminants (>98% removal of I, Tc, U, and Cr from the aqueous phase after 30 days) when tested individually. When contaminants were combined, a slight decrease in Tc removal occurred (−6%p). The addition of sediment decreased the removal for Tc and I, but U and Cr removal was unaffected. The results of these batch tests demonstrated that the bismuth based oxy-hydroxide material is a promising material for sequestering multiple contaminants in situ.

Activating the Basal Plane of 2H-MoS2 by Doping Phosphor for Enhancement in the Photocatalytic Degradation of Organic Contaminants.

The 2H phases of MoS2 (2H-MoS2) monolayers present a wealth of new opportunities in photocatalysis owing to their photoinduced catalyzing ability and excellent charge carrier mobility. However, the complete release of their catalytic activities is restricted by their inert basal planes. Although the inert base planes of 2H-MoS2 are known to be activated by atomic doping, the operational principle of the exotic atoms remains vague. In this study, the unutilized inert base sites of MoS2 were activated via an oxygen-aided P-substituted method (denoted as POMS). Molecular structural tests and analyses of POMS indicated that the inert MoS2 substrate is activated when the inerratic crystal phases transform to amorphous phases in the P-doping process. The fully activated inert base planes provide sufficient reaction sites for photo-oxidized water contaminants. The designed POMS presented superior activity in organic degradation and completely removed sulfamethoxazole within 20 min. Uncovering these operational principles provides a theoretical basis for designing effective catalysts.

What Is the Proper Antibiotic Prophylaxis Regimen for Dental Implant Placement?

What Is the Proper Antibiotic Prophylaxis Regimen for Dental Implant Placement?

Should we be prepping the foot? Stockinette use and drape contamination during hip arthroplasty: An experimental study.

Meticulous prepping and draping of the surgical field is paramount to reduce the risk of infection. A consistent technique for draping for hip arthroplasty is not well established. One technique for preparing the operative field utilises a sterile stockinette over an unprepped foot. This study aims to assess surgical site contamination when draping for hip arthroplasty without disinfecting the foot. Ultraviolet (UV) fluorescent powder was used as a surrogate for microbial presence on the foot. Powder was applied to a volunteer's foot to a level where antibacterial prep would stop. The leg was then draped according to three methods; directly with stockinette only, wrapping the foot without using an adhesive seal followed by stockinette, and wrapping the foot with the adhesive seal followed by stockinette. Proximal spread of powder after draping was assessed with UV light. Contamination of the sterile field was found with all draping methods. Spread was particularly noted in the groin, posterior to the thigh and distal to mid-thigh. Wrapping the foot in a small drape without the adhesive seal prior to stockinette application was associated with significantly greater contamination when compared with use of the seal (p= 0.004). Routine formal prepping of the foot during hip arthroplasty is recommended to reduce the risk of surgical site contamination. Surgeons who select not to prep the foot should make use of a small drape with occlusive, adhesive seal prior to stockinette application and consider applying a further U drape to the hip.

Ionizing radiation alters male Acheta domesticus courtship songs that are critical for mating success

The impact of ionizing radiation on overall ecosystem health has become a topic of great interest in recent years due to both several nuclear disasters as well as the growing concern over the normal operating waste associated with nuclear power sites. Here, we aimed to analyse how radiation impacts essential characteristics of invertebrate sexual communication including acoustic signalling and the subsequent impacts to mating success. Specifically, we looked at adult male crickets ( Acheta domesticus ) courtship songs, which are vital for this species’ successful reproduction. We analysed the spectral and temporal patterns of nonirradiated and irradiated male songs (0–12 Gy at the fourth instar) as well as several mating parameters to determine possible impacts of song variation on male mating success. Results indicate alterations of several song parameters in irradiated males, with most variation occurring in low-frequency trills: peak and mean frequency, length of pulse and average entropy were significantly altered in doses 7 Gy and above. Mating success at these doses (7 Gy, 10 Gy, 12 Gy) was consequently significantly impacted, with other mating parameters being only significantly altered at the highest radiation doses. Declines in mating parameters were evident at lower doses but were not significant. Here we show that radiation exposure in early stages of development can result in detrimental impacts to vital components of male acoustic signalling, which may be a key or contributing factor to the evident reduction in the ability of males to mate successfully. These impacts are also vital in understanding the potential impact of radiation contamination sites where populations are being chronically exposed over many generations. • Courtship songs were altered by ionizing radiation in crickets ( A. domesticus ). • Male mating success was reduced in irradiated males. • Altered acoustic signalling is a likely cause of mating success decline in crickets.

Microbial Contamination of Extended Use Ophthalmic Drops in Ophthalmology Clinic.

PurposeThe objectives of this study were to determine the prevalence of microbial contamination of multi-user preserved ophthalmic drops (POD) in Ophthalmology Outpatient Clinic (OOC), to compare the rate of contamination between the dropper tip and the residual contents in the bottle, and to identify the contaminating organisms.MethodsThis was an observational cross-sectional study using a convenience sampling method conducted in the OOC of Universiti Kebangsaan Malaysia Medical Center, Malaysia. The samples of POD bottles were divided into groups obtained after 14 days (T14) and after 30 days (T30) of use. The contamination rate at the dropper tip and in the residual contents was determined and the contaminating organisms were identified.ResultsA total of 140 of 149 extended-use POD bottles were included. The prevalence of contamination was 30%. There was a statistically significant difference in the rate of contamination between samples T14 and T30 (19% and 11%, respectively; p=0.046). Proparacaine and tropicamide showed higher contamination rates in the T14 samples (p=0.027 and p=0.497, respectively) than in the T30 samples. The site of contamination was higher at the dropper tip than in the residual contents (p>0.05). Coagulase-negative Staphylococcus species were the most frequently identified contaminants (89%).ConclusionThe dropper tip was more contaminated than the residual contents, and coagulase-negative Staphylococcus species, which are common commensal flora of the ocular conjunctiva and skin, were the most frequently identified organisms.