Multiple Contamination Sources Research Articles

Modeling of coastal water contamination in Fortaleza (Northeastern Brazil).

An important tool in environmental management projects and studies due to the complexity of environmental systems, environmental modeling makes it possible to integrate many variables and processes, thereby providing a dynamic view of systems. In this study the bacteriological quality of the coastal waters of Fortaleza (a state capital in Northeastern Brazil) was modeled considering multiple contamination sources. Using the software SisBaHiA, the dispersion of thermotolerant coliforms and Escherichia coli from three sources of contamination (local rivers, storm drains and submarine outfall) was analyzed. The models took into account variations in bacterial decay due to solar radiation and other environmental factors. Fecal pollution discharged from rivers and storm drains is transported westward by coastal currents, contaminating strips of beach water to the left of each storm drain or river. Exception to this condition only occurs on beaches protected by the breakwater of the harbor, where counterclockwise vortexes reverse this behavior. The results of the models were consistent with field measurements taken during the dry and the rainy season. Our results show that the submarine outfall plume was over 2 km from the nearest beach. The storm drains and the Maceió stream are the main factors responsible for the poor water quality on the waterfront of Fortaleza. The depollution of these sources would generate considerable social, health and economic gains for the region.

Performance of different assessment methods to evaluate contaminant sources and fate in a coastal aquifer.

The present study deals with the application of different monitoring techniques and numerical models to characterize coastal aquifers affected by multiple sources of contamination. Specifically, equivalent freshwater heads in 243 monitoring wells were used to reconstruct the piezometric map of the studied aquifer; flow meter tests were carried out to infer vertical groundwater fluxes at selected wells; deuterium and oxygen isotopes were used to identify the groundwater origin, and tritium was analyzed to estimate the residence time; compound-specific isotope analyses and microbial analyses were employed to track different sources of contamination and their degradation; numerical modelling was used to estimate and verify groundwater flow direction and magnitude throughout the aquifer. The comparison of the information level for each technique allowed determining which of the applied approaches showed the best results to locate the possible sources and better understanding of the fate of the contaminants. This study reports a detailed site characterization process and outcomes for a coastal industrial site, where a comprehensive conceptual model of pollution and seawater intrusion has been built using different assessment methods. Information and results from this study encourages combining different methods for the design and implementation of the monitoring activities in real-life coastal contaminated sites in order to develop an appropriate strategy for control and remediation of the contamination.

Impact of environmental curium on plutonium migration and isotopic signatures.

Plutonium (Pu), americium (Am), and curium (Cm) activities were measured in sediments from a former radioactive waste disposal basin located on the Savannah River Site, South Carolina, and in subsurface aquifer sediments collected downgradient from the basin. In situ Kd values (Pu concentration ratio of sediment/groundwater) derived from this field data and previously reported groundwater concentration data compared well to laboratory Kd values reported in the literature. Pu isotopic signatures confirmed multiple sources of Pu contamination. The ratio of (240)Pu/(239)Pu was appreciably lower for sediment samples compared to the associated groundwater. This isotopic ratio difference may be explained by the following: (1) (240)Pu produced by decay of (244)Cm may exist predominantly in high oxidation states (Pu(V)O2(+) and Pu(VI)O2(2+)) compared to Pu derived from the disposed waste effluents, and (2) oxidized forms of Pu sorb less to sediments than reduced forms of Pu. Isotope-specific Kd values calculated from measured Pu activities in the sediments and groundwater indicated that (240)Pu, which is derived primarily from the decay of (244)Cm, had a value of 10 ± 2 mL g(-1), whereas (239)Pu originating from the waste effluents discharged at the site had a value of 101 ± 8 mL g(-1). One possible explanation for the isotope-specific sorption behavior is that (240)Pu likely existed in the weaker sorbing oxidation states, +5 or +6, than (239)Pu, which likely existed in the +3 or +4 oxidation states. Consequently, remediation strategies for radioactively contaminated systems must consider not only the discharged contaminants but also their decay products. In this case, mitigation of Cm as well as Pu will be required to completely address Pu migration from the source term.

Airborne hydrocarbon contamination from laboratory atmospheres

Hydrocarbon contamination of organic-lean rocks is thought to occur principally during lubricant-assisted core drilling and improper sample storage, while in-laboratory contamination can be monitored and controlled via the use of procedural blanks. Contamination by fine particles settling from the air inside laboratories has not been considered a serious threat. We have used passive silica gel samplers to show that laboratory atmospheres can contain airborne hydrocarbons that preferentially accumulate in fume hoods. The molecular inventory consisted of a range of mature hydrocarbons, including diagnostic hopanes, steranes and, oddly, aryl isoprenoids. Accumulation rates were linear and reached a level that could pose a threat to lean samples after exposure for as little as 24h. Temporal and spatial variability indicated multiple contaminant sources. During common laboratory operation no single source could be identified and hydrocarbons probably represented a blend of rock dust produced in previous projects and oil used in roughing pumps. During floor waxing, performed as building maintenance on a regular basis in some laboratories, we observed that common background levels were raised by a factor of ca. 10 and shifted towards a different molecular fingerprint. This aspect of sample contamination has failed to be acknowledged hitherto but might explain some of the false positive hydrocarbon signatures reported from otherwise overmature rocks.

A fast model for identifying multiple indoor contaminant sources by considering sensor threshold and measurement error

In an emergency where a hazardous contaminant is abruptly released into indoor air, identifying the characteristics of contaminant source promptly and accurately is very important to eliminate source, control contamination and protect people. An identification model is presented in this study for quickly identifying the exact locations and emissions rates of multiple indoor contaminant sources with constant emissions rates and known release time, by considering sensor thresholds and measurement errors. Through case studies in a three-dimensional room, the model was numerically demonstrated and validated, and thorough analyses were made on the effects of the sensor threshold and measurement error on model performance. The results suggest that the model has the potential to obtain accurate results in real-time allowing for high levels of sensor data loss and measurement error. Practical application: The presented identification model is applicable to a wide variety of indoor environments involving multiple continuous contaminant sources, such as the emission of volatile compounds from building materials or furniture, the leakage of toxic or inflammable gases from pipeline or vessels in trace amount. This study will hopefully contribute to developing more realistic source identification techniques with unknown release time and real sensor use.

Rapid identification of multiple constantly-released contaminant sources in indoor environments with unknown release time

The sudden release of airborne hazardous contaminants in an indoor environment can potentially lead to severe disasters, such as the spread of toxic gases, fire, and explosion. To prevent and mitigate these disasters it is critical to rapidly and accurately identify the characteristics of the contaminant sources. Although remarkable achievements have been made in identifying a single indoor contaminant source in recent years, the issues related to multiple contaminant sources are still challenging. This study presents a method for identifying the exact locations, emission rates, and release time of multiple indoor contaminant sources simultaneously released at constant rates, by considering sensor thresholds and measurement errors. The method uses a two-stage procedure for rapid source identification. Before the release of contaminants, only a limited number of time-consuming computational fluid dynamics (CFD) simulations need to be conducted. After the release of contaminants, the method can be executed in real-time. Through case studies in a three-dimensional office the method was numerically demonstrated and validated, and the results show that the method is effective and feasible. The effects of sensor threshold, measurement error and total sampling time on the source identification performance were analysed, and the limitations and applicability of the method were also discussed.

An integrated assessment of seawater intrusion in a small tropical island using geophysical, geochemical, and geostatistical techniques

In this study, geophysics, geochemistry, and geostatistical techniques were integrated to assess seawater intrusion in Kapas Island due to its geological complexity and multiple contamination sources. Five resistivity profiles were measured using an electric resistivity technique. The results reveal very low resistivity <1 Ωm, suggesting either marine clay deposit or seawater intrusion or both along the majority of the resistivity images. As a result, geochemistry was further employed to verify the resistivity evidence. The Chadha and Stiff diagrams classify the island groundwater into Ca-HCO3, Ca-Na-HCO3, Na-HCO3, and Na-Cl water types, with Ca-HCO3 as the dominant. The Mg(2+)/Mg(2+)+Ca(2+), HCO3 (-)/anion, Cl(-)/HCO3 (-), Na(+)/Cl(-), and SO4 (2-)/Cl(-) ratios show that some sampling sites are affected by seawater intrusion; these sampling sites fall within the same areas that show low-resistivity values. The resulting ratios and resistivity values were then used in the geographical information system (GIS) environment to create the geostatistical map of individual indicators. These maps were then overlaid to create the final map showing seawater-affected areas. The final map successfully delineates the area that is actually undergoing seawater intrusion. The proposed technique is not area specific, and hence, it can work in any place with similar completed characteristics or under the influence of multiple contaminants so as to distinguish the area that is truly affected by any targeted pollutants from the rest. This information would provide managers and policy makers with the knowledge of the current situation and will serve as a guide and standard in water research for sustainable management plan.

Identification of Multiple Sources of Groundwater Contamination by Dual Isotopes

Chlorinated solvents are one of the most commonly detected groundwater contaminants in industrial areas. Identification of polluters and allocation of contaminant sources are important concerns in the evaluation of complex subsurface contamination with multiple sources. In recent years, compound-specific isotope analyses (CSIA) have been employed to discriminate among different contaminant sources and to better understand the fate of contaminants in field-site studies. In this study, the usefulness of dual isotopes (carbon and chlorine) was shown in assessments of groundwater contamination at an industrial complex in Wonju, Korea, where groundwater contamination with chlorinated solvents such as trichloroethene (TCE) and carbon tetrachloride (CT) was observed. In November 2009, the detected TCE concentrations at the study site ranged between nondetected and 10,066 µg/L, and the CT concentrations ranged between nondetected and 985 µg/L. In the upgradient area, TCE and CT metabolites were detected, whereas only TCE metabolites were detected in the downgradient area. The study revealed the presence of separate small but concentrated TCE pockets in the downgradient area, suggesting the possibility of multiple contaminant sources that created multiple comingling plumes. Furthermore, the variation of the isotopic (δ(13) C and δ(37) Cl) TCE values between the upgradient and downgradient areas lends support to the idea of multiple contamination sources even in the presence of detectable biodegradation. This case study found it useful to apply a spatial distribution of contaminants coupled with their dual isotopic values for evaluation of the contaminated sites and identification of the presence of multiple sources in the study area.

Ecotoxicological assessment of sediments from an urban marine protected area (Xixová-Japuí State Park, SP, Brazil)

This study aimed to evaluate the environmental quality of the marine portion of Xixová-Japuí State Park (XJSP), an urban marine protected area, which is influenced by multiple contamination sources, by using ecotoxicological and geochemical analyses. Sediments were predominantly sandy, with low CaCO3 and organic matter contents, and presented contamination by metals (Cd,Cu,Zn). Acute toxicity was detected in three tested samples, and copepod exposed to sediments from four stations exhibited lower fecundities, despite the absence of significant effects. Contamination and toxicity seemed to be associated, suggesting that the environment is degraded and presents risks to the biota. Whole sediment TIE indicated ammonia as a main responsible for toxicity, suggesting sewage is a main contributor to sediment degradation. As external contamination sources seem to be negatively influencing the sediment quality, the park conservation objectives are not being fully reached, demanding actions to mitigate impacts.

Transplantation of epiphytic bioaccumulators (Tillandsia capillaris) for high spatial resolution biomonitoring of trace elements and point sources deconvolution in a complex mining/smelting urban context

Monitoring atmospheric trace elements (TE) levels and tracing their source origin is essential for exposure assessment and human health studies. Epiphytic Tillandsia capillaris plants were used as bioaccumulator of TE in a complex polymetallic mining/smelting urban context (Oruro, Bolivia). Specimens collected from a pristine reference site were transplanted at a high spatial resolution (∼1 sample/km2) throughout the urban area. About twenty-seven elements were measured after a 4-month exposure, also providing new information values for reference material BCR482. Statistical power analysis for this biomonitoring mapping approach against classical aerosols surveys performed on the same site showed the better aptitude of T. Capillaris to detect geographical trend, and to deconvolute multiple contamination sources using geostatistical principal component analysis. Transplanted specimens in the vicinity of the mining and smelting areas were characterized by extreme TE accumulation (Sn > Ag > Sb > Pb > Cd > As > W > Cu > Zn). Three contamination sources were identified: mining (Ag, Pb, Sb), smelting (As, Sn) and road traffic (Zn) emissions, confirming results of previous aerosol survey.

Exploring the Sources of Bacterial Spoilers in Beefsteaks by Culture-Independent High-Throughput Sequencing

Microbial growth on meat to unacceptable levels contributes significantly to change meat structure, color and flavor and to cause meat spoilage. The types of microorganisms initially present in meat depend on several factors and multiple sources of contamination can be identified. The aims of this study were to evaluate the microbial diversity in beefsteaks before and after aerobic storage at 4°C and to investigate the sources of microbial contamination by examining the microbiota of carcasses wherefrom the steaks originated and of the processing environment where the beef was handled. Carcass, environmental (processing plant) and meat samples were analyzed by culture-independent high-throughput sequencing of 16S rRNA gene amplicons. The microbiota of carcass swabs was very complex, including more than 600 operational taxonomic units (OTUs) belonging to 15 different phyla. A significant association was found between beef microbiota and specific beef cuts (P<0.01) indicating that different cuts of the same carcass can influence the microbial contamination of beef. Despite the initially high complexity of the carcass microbiota, the steaks after aerobic storage at 4°C showed a dramatic decrease in microbial complexity. Pseudomonas sp. and Brochothrix thermosphacta were the main contaminants, and Acinetobacter, Psychrobacter and Enterobacteriaceae were also found. Comparing the relative abundance of OTUs in the different samples it was shown that abundant OTUs in beefsteaks after storage occurred in the corresponding carcass. However, the abundance of these same OTUs clearly increased in environmental samples taken in the processing plant suggesting that spoilage-associated microbial species originate from carcasses, they are carried to the processing environment where the meat is handled and there they become a resident microbiota. Such microbiota is then further spread on meat when it is handled and it represents the starting microbial association wherefrom the most efficiently growing microbial species take over during storage and can cause spoilage.

Dioxin-related compounds in house dust from New York State: Occurrence, in vitro toxic evaluation and implications for indoor exposure

This study analysed sulphuric-acid-treated extracts of house dust from New York State with DR-CALUX assay and HRGC-HRMS to elucidate the total dioxin-like (DL) activities, the occurrence of various dioxin-related compounds (DRCs), including PBDD/Fs, and their toxic contribution. The DL activities were 30–8000, median 210 pg CALUX-TEQ/g. PCDD/Fs, PBDD/Fs and DL-PCBs were detected with a large variation in concentrations (0.12–80, 0.33–150, 0.46–35, medians 1.7, 2.1 and 5.6 ng/g, respectively) and profiles, indicating the existence of multiple contamination sources in homes. PCDD/Fs, PBDD/Fs and DL-PCBs with known potency theoretically contributed <1%–130%, <1%–21% and <1%–6.8%, respectively, of the measured CALUX-TEQs. These results and those from DR-CALUX assays with fractionated dust extracts indicated that a substantial portion of the CALUX-TEQs could be caused by unknown dust contaminants. Considering that the DRC intake from indoor dust ingestion can be significant, identification of unknown DL contaminants in indoor dust is necessary.

Sediment quality assessment in a tropical estuary: The case of Ceará River, Northeastern Brazil

The present study aimed to assess the sediment quality in a tropical estuary located in the northeast of Brazil under semi-arid conditions and multiple sources of contamination, using both toxicity bioassays and metal distribution. The metal distribution followed a concentration gradient decreasing one order of magnitude from the inner station toward the outer estuary, with amounts in the following order: Fe > Al > Zn > Cr > Pb > Cu. The index of geoaccumulation indicated a metal enrichment in the Ceará river sediment, mainly at inner sites, considered from moderately to strongly contaminated by Al, Cu, Cr and Zn. Sediment samples were considered toxic by means of whole sediment tests with copepods (reproduction) and amphipods (survival), and also elutriate fraction and sediment–water interface with sea urchin embryos (development). Acute and chronic toxicity did not exhibit a significant correlation with metals, emphasizing the influence of other contaminants mainly related to the pollution sources installed in the mid-estuary.

Geochemical and ecotoxicological assessment for estuarine surface sediments from Southern Brazil

Sediments from Guaratuba Bay (PR, Brazil), a marine protected area, were collected and evaluated for geochemistry and toxicity. High levels of P and acute toxicity were observed in some samples. Concentrations of Cu, Cd, Pb and Zn were relatively low; however, Cd levels eventually exceeded Threshold Effect Level. Toxicities were associated to nutrients and metals enrichment. Results suggest that impacts are incipient and occur only at specific sites, associated to multiple contamination sources. Despite sediments quality seems to range between good and fair, attention is required to land-use planning around Guaratuba Bay and controlling local pollution sources.

‘It’s always dark in front of the pickaxe’: Organizing ignorance in the long-term remediation of contaminated land

This article departs from the view in which ignorance is seen as necessarily detrimental and analyses how specified ignorance (here called ‘nonknowledge’) can even serve as a productive resource. By using the example of cleaning up contaminated land in a timely and effective manner, it is argued that nonknowledge is a useful resource; in some instances, on a par with knowledge in its importance. The article discusses some of the strategies used to cope with ongoing situations involving ignorance in the remediation of areas containing multiple contaminant sources and plumes. Analysis of these processes indicates that planning and policymaking may benefit when limits to knowledge are openly acknowledged.

Legacy Problems in Urban Geochemistry

Research Article| December 01, 2012 Legacy Problems in Urban Geochemistry Stefano Albanese; Stefano Albanese 1University of Napoli “Federico II”, Department of Earth SciencesVia Mezzocannone 8, 80134 Napoli, ItalyE-mail: stefano.albanese@unina.it Search for other works by this author on: GSW Google Scholar Domenico Cicchella Domenico Cicchella 2University of Sannio, Department of Biological, Geological and Environmental SciencesVia dei Mulini 59/A, 82100 Benevento, ItalyE-mail: cidom@unisannio.it Search for other works by this author on: GSW Google Scholar Author and Article Information Stefano Albanese 1University of Napoli “Federico II”, Department of Earth SciencesVia Mezzocannone 8, 80134 Napoli, ItalyE-mail: stefano.albanese@unina.it Domenico Cicchella 2University of Sannio, Department of Biological, Geological and Environmental SciencesVia dei Mulini 59/A, 82100 Benevento, ItalyE-mail: cidom@unisannio.it Publisher: Mineralogical Society of America First Online: 09 Mar 2017 Online ISSN: 1811-5217 Print ISSN: 1811-5209 © 2012 by the Mineralogical Society of America Elements (2012) 8 (6): 423–428. https://doi.org/10.2113/gselements.8.6.423 Article history First Online: 09 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Stefano Albanese, Domenico Cicchella; Legacy Problems in Urban Geochemistry. Elements 2012;; 8 (6): 423–428. doi: https://doi.org/10.2113/gselements.8.6.423 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyElements Search Advanced Search Abstract Modern cities are affected by multiple sources of contamination and pollution, the effects of which overlap in space and time. Toxic metal contamination, organic pollution, smog, acid rain, and greenhouse gas accumulation are the most widespread legacies of an often uncontrolled growth that has deeply changed the geochemical character of the urban environment over the last four millennia. Even though progress has changed human habits and positively influenced the quality of city life, the past is frequently a hidden source of environmental problems with the potential to affect the health of current and future urban residents. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.

Fast Identification of Multiple Indoor Constant Contaminant Sources by Ideal Sensors: A Theoretical Model and Numerical Validation

If hazardous contaminants are suddenly released indoors, quickly identifying the pollutants characteristics, such as the locations and emission rates, of the contaminant sources is critical for developing fast and effective response measures. This study presents a theoretical model for quickly identifying the locations and emission rates of multiple constant sources indoors using a single or limited number of ideal sensors. The model combines a linear programming model with an analytical expression of indoor contaminant dispersion that was presented in our previous study. Before the release of contaminants, only a limited number of time-consuming computational fluid dynamics (CFD) simulations need to be conducted to cover a large number of possible scenarios because of the analytical expression integrated into the model. After the release of contaminants, the model can be solved in real-time. Through case studies of sixteen contaminant release scenarios in a three-dimensional office, the effectiveness of the model was numerically demonstrated and validated. The results revealed that the identification accuracy of the presented model was closely related to the sensor layouts and the total sampling time, rather than the sampling interval.

Mercury speciation and mercury isotope fractionation during ore roasting process and their implication to source identification of downstream sediment in the Wanshan mercury mining area, SW China

The environment of Guizhou province of SW China is in part significantly impacted by mercury (Hg) mining activities. The exploitation and processing of Hg-bearing ore in the past have led to multiple sources of Hg contamination, including unprocessed ores and Hg waste calcines and liquid elemental Hg, making source control strategies difficult and expensive to implement. In this study, initially extended X-ray absorption fine structure (EXAFS) spectroscopy was used to determine the Hg species and to estimate the relative proportions of these species present in Hg-bearing wastes from the Wanshan Hg mine (WSMM) of the eastern Guizhou province. The results showed that cinnabar is the dominant Hg species in the unroasted ore samples, while the most prevalent Hg compounds in mine waste calcine is in the following order: meta-cinnabar, cinnabar and mercuric chloride. Our study demonstrated that mass dependent fractionation of Hg isotopes may occur during transformation of cinnabar to by-products (such as meta-cinnabar and mercuric chloride) by the roasting process. Hg stable isotope analysis of unroasted Hg ores and Hg waste calcines showed that Hg waste calcines (0.08±0.20‰, 2ó, n=11) were enriched by ~0.80‰ in δ202Hg values compared to the unroasted Hg ores (−0.74±0.11‰, 2ó, n=14). Finally, using a combined triple mixing model, the source attribution of the downstream sediment in WSMM was estimated. Our study suggested that the Hg isotope could be a useful tool to trace and quantify the source of Hg in the environment.

Disaster Waste Characteristics and Radiation Distribution as a Result of the Great East Japan Earthquake

The compounded impacts of the catastrophes that resulted from the Great East Japan Earthquake have emphasized the need to develop strategies to respond to multiple types and sources of contamination. In Japan, earthquake and tsunami-generated waste were found to have elevated levels of metals/metalloids (e.g., mercury, arsenic, and lead) with separation and sorting more difficult for tsunami-generated waste as opposed to earthquake-generated waste. Radiation contamination superimposed on these disaster wastes has made it particularly difficult to manage the ultimate disposal resulting in delays in waste management. Work is needed to develop policies a priori for handling wastes from combined catastrophes such as those recently observed in Japan.

Multiple Sources of Contamination in Samples from Patients Reported to Have XMRV Infection

Xenotropic murine leukemia virus (MLV)-related retrovirus (XMRV) was reported to be associated with prostate cancer by Urisman, et al. in 2006 and chronic fatigue syndrome (CFS) by Lombardi, et al. in 2009. To investigate this association, we independently evaluated plasma samples from 4 patients with CFS reported by Lombardi, et al. to have XMRV infection and from 5 healthy controls reported to be XMRV uninfected. We also analyzed viral sequences obtained from supernatants of cell cultures found to contain XMRV after coculture with 9 clinical samples from 8 patients. A qPCR assay capable of distinguishing XMRV from endogenous MLVs showed that the viral sequences detected in the CFS patient plasma behaved like endogenous MLVs and not XMRV. Single-genome sequences (N = 89) from CFS patient plasma were indistinguishable from endogenous MLVs found in the mouse genome that are distinct from XMRV. By contrast, XMRV sequences were detected by qPCR in 2 of the 5 plasma samples from healthy controls (sequencing of the qPCR product confirmed XMRV not MLV). Single-genome sequences (N = 234) from the 9 culture supernatants reportedly positive for XMRV were indistinguishable from XMRV sequences obtained from 22Rv1 and XMRV-contaminated 293T cell-lines. These results indicate that MLV DNA detected in the plasma samples from CFS patients evaluated in this study was from contaminating mouse genomic DNA and that XMRV detected in plasma samples from healthy controls and in cultures of patient samples was due to cross-contamination with XMRV (virus or nucleic acid).