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At least 55 records · Page 3Linked to original sources
USGS2022

Minimum requirements for publishing hydrogen, carbon, nitrogen, oxygen and sulfur stable-isotope delta results (IUPAC Technical Report)

Stable hydrogen, carbon, nitrogen, oxygen and sulfur (HCNOS) isotope compositions expressed as isotope-delta values are typically reported relative to international standards such as Vienna Standard Mean Ocean Water (VSMOW), Vienna Peedee belemnite (VPDB) or Vienna Cañon Diablo Troilite (VCDT). These international standards are chosen by convention and the calibration methods used to realise them in practice undergo occasional changes. To ensure longevity and reusability of published data, a comprehensive description of (1) analytical procedure, (2) traceability, (3) data processing, and (4) uncertainty evaluation is required. Following earlier International Union of Pure and Applied Chemistry documents on terminology and notations, this paper proposes minimum requirements for publishing HCNOS stable-isotope delta results. Each of the requirements are presented with illustrative examples.

Pure and Applied Chemistry↗
USGS2006

Description, Properties, and Degradation of Selected Volatile Organic Compounds Detected in Ground Water--A Review of Selected Literature

This report provides abridged information describing the most salient properties and biodegradation of 27 chlorinated volatile organic compounds detected during ground-water studies in the United States. This information is condensed from an extensive list of reports, papers, and literature published by the U.S. Government, various State governments, and peer-reviewed journals. The list includes literature reviews, compilations, and summaries describing volatile organic compounds in ground water. This report cross-references common names and synonyms associated with volatile organic compounds with the naming conventions supported by the International Union of Pure and Applied Chemistry. In addition, the report describes basic physical characteristics of those compounds such as Henry's Law constant, water solubility, density, octanol-water partition (log Kow), and organic carbon partition (log Koc) coefficients. Descriptions and illustrations are provided for natural and laboratory biodegradation rates, chemical by-products, and degradation pathways.

Open-File Report↗
USGS2013

Managing the effects of endocrine disrupting chemicals in wastewater-impacted streams

A revolution in analytical instrumentation circa 1920 greatly improved the ability to characterize chemical substances. This analytical foundation resulted in an unprecedented explosion in the design and production of synthetic chemicals during and post-World War II. What is now often referred to as the 2nd Chemical Revolution has provided substantial societal benefits; with modern chemical design and manufacturing supporting dramatic advances in medicine, increased food production, and expanding gross domestic products at the national and global scales as well as improved health, longevity, and lifestyle convenience at the individual scale. Presently, the chemical industry is the largest manufacturing sector in the United States (U.S.) and the second largest in Europe and Japan, representing approximately 5% of the Gross Domestic Product (GDP) in each of these countries. At the turn of the 21st century, the chemical industry was estimated to be worth more than $1.6 trillion and to employ over 10 million people, globally. During the first half of the 20th century, the chemical sector expanded rapidly, the chemical industry enjoyed a generally positive status in society, and chemicals were widely appreciated as fundamental to individual and societal quality of life. Starting in the 1960s, however, the environmental costs associated with the chemical industry increasingly became the focus, due in part to the impact of books like “Silent Spring” and “Our Stolen Future” and to a number of highly publicized environmental disasters. Galvanizing chemical industry disasters included the 1976 dioxin leak north of Milan, Italy, the Love Canal evacuations in Niagara, New York beginning in 1978, and the Union Carbide leak in Bhopal, India in 1984. Understanding the environmental impact of synthetic compounds is essential to any informed assessment of net societal benefit, for the simple reason that any chemical substance that is in commercial production or use will eventually find its way to the environment. Not surprisingly given the direct link to profits, manufacturers intensely investigate and routinely document the potential benefits of new chemicals and chemical products. In contrast, the environmental risks associated with chemical production and uses are often investigated less intensely and are poorly communicated. An imbalance in the risk-benefit analysis of any synthetic chemical substance or naturally occurring chemical, which presence and concentration in the environment largely reflects human activities and management, is a particular concern owing to the fundamental link between chemistry and biology. Biological organisms are intrinsically a homeostatic balance of innumerable internal and external chemical interactions and, thus, inherently sensitive to changes in the external chemical environment.

Book chapter↗
USGS2001

Aircraft and runway deicers at General Mitchell International Airport, Milwaukee, Wisconsin, USA. 1. Biochemical oxygen demand and dissolved oxygen in receiving streams

Aircraft and runway deicers are used during cold weather at many of the world's airports to facilitate safe air travel. Propylene glycol-, ethylene glycol-, and urea-based deicers are known to have very high biochemical oxygen demand. At General Mitchell International Airport (GMIA) in Milwaukee, Wisconsin, USA, deicer application, water chemistry, and dissolved oxygen (DO) data were collected for two deicing seasons in order to evaluate and define premanagement water quality parameters prior to the implementation of a glycol management program. Calculations using stream-monitoring data during a controlled release of deicer provided an estimate of 0.8/d for the first-order decay rate constant, substantially higher than published laboratory test results. For eight precipitation events with deicing activities, between 2.4 and 99% of propylene and ethylene glycol applied to aircraft was delivered directly to receiving streams. The percentage of glycol runoff during an event increased with increasing storm-flow volume. Elevated concentrations of glycol and biochemical oxygen demand were measured downstream from the airport. However, the frequency of low DO concentrations in the receiving streams is comparable with that at an upstream reference site. This is possibly due to slowed bacteria metabolism at low water temperatures, short travel times, and dilution from downstream tributaries.

Wisconsin↗
USGS2000

Atrazine and its metabolites as indicators of stream-aquifer interaction in Kansas, USA

A survey of atrazine and its metabolites in Kansas ground water indicated that ground-water quality was impacted by stream-aquifer interaction between rivers in the Kansas River basin and their adjacent alluvial aquifers. Atrazine was detected in 19 of the 78 samples. The most common metabolite, deethylatrazine, was detected in 25 samples, 18 of which also had atrazine. The deethylatrazine/atrazine ratio (DAR) of < 1.0 indicates rapid movement of agricultural chemicals to ground water. In this study, 12 of 18 samples had DAR values < 1.0, suggesting rapid recharge to the aquifers. Hydroxyatrazine is seldom detected in ground water. In this study hydroxyatrazine was detected primarily in wells sited in alluvium of rivers. These rivers contain atrazine in varying concentrations. Results of the study suggest that stream-aquifer interaction is a process contributing to the presence of both atrazine and its metabolites in ground water in these areas.A survey of atrazine and its metabolites in Kansas ground water indicated that ground water quality was impacted by stream-aquifer interaction between rivers in the Kansas River basin and their adjacent alluvial aquifers. Atrazine was detected in 19 of the 78 samples. The most common metabolite, deethylatrazine, was detected in 25 samples, 18 of which also had atrazine. The deethylatrazine/attrazine ratio (DAR) of < 1.0 indicates rapid movement of agricultural chemicals to ground water. In this study, 12 of 18 samples had DAR values < 1.0, suggesting rapid recharge to the aquifers. Hydroxyatrazine is seldom detected in ground water. In this study hydroxyatrazine was detected primarily in wells sited in alluvium of rivers. These rivers contain atrazine in varying concentration. Results of the study suggest that stream-aquifer interaction is a process contributing to the presence of both attrazine and its metabolites in ground water in these areas.

Kansas↗
USGS2006

Use of field-applied quality control samples to monitor performance of a Goulden large-sample extractor/GC-MS method for pesticides in water

Since 1985, the Goulden large-sample extractor (GLSE) has been used to isolate a broad array of trace-organic contaminants from large volumes of water. In this study, field-applied quality control measures, including matrix and surrogate spikes and blanks, were used to monitor method performance from GLSE extraction through GC-MS analysis. The method was applied to the determination of multiple classes of pesticides isolated from 4- to 112-L filtered surface-water samples. Average recoveries of six surrogate compounds ranged from 84 ?? 18% for [2H10]diazinon to 15 ?? 13% for 4,4'-[2H8]DDT, the low recoveries for which were largely a result of unmonitored breakdown of this surrogate by the GC injection system. Field-matrix-spike samples were prepared by fortifying 10-L, 35-L, and 110-L filtered surface-water samples with 68 pesticides to amended concentrations of 11- to 50-ng/L each. Recoveries ranged from not detected to greater than 100%. Variability in pesticide recoveries from triplicate 10-L water samples collected at one site averaged 5.7% relative standard deviation and did not exceed 19%.Since 1985, the Goulden large-sample extractor (GLSE) has been used to isolate a broad array of trace-organic contaminants from large volumes of water. In this study, field-applied quality control measures, including matrix and surrogate spikes and blanks, were used to monitor method performance from GLSE extraction through GC-MS analysis. The method was applied to the determination of multiple classes of pesticides isolated from 4- to 112-L filtered surface-water samples. Average recoveries of six surrogate compounds ranged from 84 ?? 18% for [2H10]diazinon to 15 ?? 13% for 4,4???-[2H8]DDT, the low recoveries for which were largely a result of unmonitored breakdown of this surrogate by the GC injection system. Field-matrix-spike samples were prepared by fortifying 10-L, 35-L, and 110-L filtered surface-water samples with 68 pesticides to amended concentrations of 11- to 50-ng/L each. Recoveries ranged from not detected to greater than 100%. Variability in pesticide recoveries from triplicate 10-L water samples collected at one site averaged 5.7% relative standard deviation and did not exceed 19%.

International Journal of Environmental Analytical ↗
USGS2001

Regional water-quality analysis of 2,4-D and dicamba in river water using gas chromatography-isotope dilution mass spectrometry

Gas chromatography with isotope dilution mass spectrometry (GC-MS) and enzyme-linked immunosorbent assay (ELISA) were used in regional National Water Quality Assessment studies of the herbicides, 2,4-D and dicamba, in river water across the United States. The GC-MS method involved solid-phase extraction, derivatized with deuterated 2,4-D, and analysis by selected ion monitoring. The ELISA method was applied after preconcentration with solid-phase extraction. The ELISA method was unreliable because of interference from humic substances that were also isolated by solid-phase extraction. Therefore, GC-MS was used to analyzed 80 samples from river water from 14 basins. The frequency of detection of dicamba (28%) was higher than that for 2,4-D (16%). Concentrations were higher for dicamba than for 2,4-D, ranging from less than the detection limit (7lt; 0.05 μg/L) to 3.77μg/L, in spite of 5 times more annual use of 2,4-D as compared to dicamba. These results suggest that 2,4-D degrades more rapidly in the environment than dicamba.

International Journal of Environmental Analytical ↗
USGS2005

Occurrence of antibiotics in water from 13 fish hatcheries, 2001-2003

A 2-year study of extensive and intensive fish hatcheries was conducted to assess the general temporal occurrence of antibiotics in aquaculture. Antibiotics were detected in 15% of the water samples collected during the 2001-2002 collection period and in 31% of the samples during the 2003 collection period. Antibiotics were detected more frequently in samples from the intensive hatcheries (17 and 39%) than in samples from the extensive hatcheries (14 and 4%) during the 2001-2002 and 2003 collection periods, respectively. The maximum ormetoprim, oxytetracycline, and sulphadimethoxine concentrations were higher in samples from the intensive hatcheries (12, 10, and 36 &micro;g L-1), respectively, than in samples from the extensive hatcheries (<0.05, 0.31, and 1.2 &micro;g L-1), respectively. Sulphadimethoxine persisted for a longer period of time (up to 48 days) than ormetoprim (up to 28 days) and oxytetracycline (less than 20 days).

International Journal of Environmental Analytical ↗
USGS2007

Input, flux, and persistence of six select pesticides in San Francisco Bay

Temporal patterns of pesticide inputs to San Francisco Bay were identified and correlated with timing of application and transport mechanism. Fluxes were calculated from measured concentrations and estimated flow. Persistence of the pesticides under typical riverine or estuarine conditions were estimated from laboratory experiments. Simazine was detected most frequently and had the highest flux into the Bay, which could be explained by its continuous use and long half-life. In comparison, diazinon was detected at lower concentrations and had a lower flux which corresponded to its lower use and shorter half-life. The order-of-magnitude lower fluxes of carbofuran and methidathion corresponded to their lower use and expected hydrolysis. Molinate was detected at the highest concentration but its flux was lower than expected, considering its very high use and persistence in the laboratory experiments. Additional loss of molinate is likely to occur from volatilization and photodegradation on the rice fields. Although thiobencarb had the second highest use, it had the lowest flux of the six pesticides, which can be attributed to its loss via hydrolysis, photodegradation, volatilization, and sorption to sediments. Fluxes into San Francisco Bay were equal to or greater than those reported for other estuaries, except for the Gulf of Mexico.

California↗
USGS2007

Use of a watershed model to characterize the fate and transport of fluometuron, a soil-applied cotton herbicide, in surface water

The Soil and Water Assessment Tool (SWAT) was used to characterize the fate and transport of fluometuron (a herbicide used on cotton) in the Bogue Phalia Basin in northwestern Mississippi, USA. SWAT is a basin-scale watershed model, able to simulate hydrological, chemical, and sediment transport processes. After adjustments to a few parameters (specifically the SURLAG variable, the runoff curve number, Manning's N for overland flow, soil available water capacity, and the base-flow alpha factor) the SWAT model fit the observed streamflow well (the Coefficient of Efficiency and R2 were greater than 60). The results from comparing observed fluometuron concentrations with simulated concentrations were reasonable. The simulated concentrations (which were daily averages) followed the pattern of observed concentrations (instantaneous values) closely, but could be off in magnitude at times. Further calibration might have improved the fit, but given the uncertainties in the input data, it was not clear that any improvement would be due to a better understanding of the input variables. ?? 2007 Taylor & Francis.

International Journal of Environmental Analytical ↗
USGS2007

Development and evaluation of a gas chromatographic method for the determination of triazine herbicides in natural water samples

A multi-residue method is described for the determination o triazine herbicides in natural water samples. The technique uses solvent extraction followed by gas chromatographic separation and detection employing nitrogen-selective devices. Seven compounds can be determined simultaneously at a nominal detection limit of 0.1 μg/L in a 1-litre sample. Three different natural water samples were used for error analysis via evaluation of recovery efficiencies and estimation of overall method precision. As an alternative to liquid-liquid partition (solvent extraction) for removal of compounds of interest from water, solid-phase extraction (SPE) techniques employing chromatographic grade silicas with chemically modified surfaces have been examined. SPE is found to provide rapid and efficient concentration with quantitative recovery of some triazine herbicides from natural water samples. Concentration factors of 500 to 1000 times are obtained readily by the SPE technique.

International Journal of Environmental Analytical ↗
USGS2006

A laboratory and field evaluation of a portable immunoassay test for triazine herbicides in environmental water samples

The usefulness and sensitivity, of a portable immunoassay test for the semiquantitative field screening of water samples was evaluated by means of laboratory and field studies. Laboratory results indicated that the tests were useful for the determination of atrazine concentrations of 0.1 to 1.5 &mu;g/L. At a concentration of 1 &mu;g/L, the relative standard deviation in the difference between the regression line and the actual result was about 40 percent. The immunoassay was less sensitive and produced similar errors for other triazine herbicides. After standardization, the test results were relatively insensitive to ionic content and variations in pH (range, 4 to 10), mildly sensitive to temperature changes, and quite sensitive to the timing of the final incubation step, variances in timing can be a significant source of error. Almost all of the immunoassays predicted a higher atrazine concentration in water samples when compared to results of gas chromatography. If these tests are used as a semiquantitative screening tool, this tendency for overprediction does not diminish the tests' usefulness. Generally, the tests seem to be a valuable method for screening water samples for triazine herbicides.

International Journal of Environmental Analytical ↗
USGS1996

The deethylatrazine/atrazine ratio as an indicator of the onset of the spring flush of herbicides into surface water of the Midwestern United States

The ratio of deethylatrazine to atrazine (DAR) may be used to record the first major runoff of herbicides from non-point-source corn fields to surface water in the Midwestern United States. The DAR dramatically decreases from ∼0.5 to < 0.1 upon application of herbicide and the first major runoff event of a basin. The DAR then gradually increases to values of approximately 0.4–0.6 during the harvest season. Furthermore, the DAR may be used in studies of surface water movement to give a temporal indicator of water moving into reservoirs for possible storage of herbicides. It is hypothesized that deethylatrazine, which accounts for only 6% of the degradation of atrazine, becomes a significant metabolite in surface water (∼ 50% of parent compound) because of its selective removal from soil. This removal process may be an important concept for consideration in studies of herbicide contamination of rivers and reservoirs.

International Journal of Environmental Analytical ↗
USGS1997

Water-quality trends in the Rio Grande/Rio Bravo Basin using sediment cores from reservoirs

Water-quality trends reflect the relation between water quality and human activities, chronicling changes in concentrations of environmental contaminants, introduction of new contaminants, and successful efforts in environmental pollution remediation. Historical data available for analyzing trends often have severe limitations, from questionable accuracy to unknown sampling and analytic methodologies. Where data are unavailable or have such limitations, water-quality trends sometimes can be reconstructed using sediment cores from lakes and reservoirs. The purpose of this fact sheet is to summarize the findings of a study to assess historical changes in surface-water quality in the Rio Grande Basin (known as the R&iacute;o Bravo Basin in Mexico) by analyzing changes in sediment chemistry in cores from three reservoirs: Elephant Butte Reservoir, Amistad International Reservoir, and Falcon International Reservoir (fig. 1). Sediments that erode from the land surface are transported by tributaries into the Rio Grande/R&iacute;o Bravo. Metals and some persistent pesticides and industrial organic compounds sorb to these sediments, which eventually accumulate at the bottom of the reservoirs or are transported to the Gulf of Mexico. Although use of reservoir cores has limitations&mdash;for example, the cores do not record trends in non-persistent compounds&mdash;in many cases the data provide a partial historical record of water quality. In 1991, the U.S. Geological Survey (USGS) began full implementation of the National Water-Quality Assessment (NAWQA) Program (Leahy and others, 1990). Also in 1991, the State of Texas established the Clean Rivers Program (CRP) administered by the Texas Natural Resource Conservation Commission (TNRCC). The coring study reported here was a collaborative effort between the NAWQA Program and the CRP Rio Grande Border Environmental Assessment Team, with additional funding support from the El Paso County Water Improvement District No. 1.

Colorado, New Mexico, Texas↗
USGS2014

Dendrochemical patterns of calcium, zinc, and potassium related to internal factors detected by energy dispersive X-ray fluorescence (EDXRF)

Energy dispersive X-ray fluorescence (EDXRF) provides highly sensitive and precise spatial resolution of cation content in individual annual growth rings in trees. The sensitivity and precision have prompted successful applications to forensic dendrochemistry and the timing of environmental releases of contaminants. These applications have highlighted the need to distinguish dendrochemical effects of internal processes from environmental contamination. Calcium, potassium, and zinc are three marker cations that illustrate the influence of these processes. We found changes in cation chemistry in tree rings potentially due to biomineralization, development of cracks or checks, heartwood/sapwood differentiation, intra-annual processes, and compartmentalization of infection. Distinguishing internal from external processes that affect dendrochemistry will enhance the value of EDXRF for both physiological and forensic investigations.

Chemosphere↗
USGS2001

Eruptive stratigraphy of the Tatara-San Pedro complex, 36°S, sourthern volcanic zone, Chilean Andes: Reconstruction method and implications for magma evolution at long-lived arc volcanic centers

The Quaternary Tatara–San Pedro volcanic complex (36°S, Chilean Andes) comprises eight or more unconformity-bound volcanic sequences, representing variably preserved erosional remnants of volcanic centers generated during ∼930 ky of activity. The internal eruptive histories of several dominantly mafic to intermediate sequences have been reconstructed, on the basis of correlations of whole-rock major and trace element chemistry of flows between multiple sampled sections, but with critical contributions from photogrammetric, geochronologic, and paleomagnetic data. Many groups of flows representing discrete eruptive events define internal variation trends that reflect extrusion of heterogeneous or rapidly evolving magma batches from conduit–reservoir systems in which open-system processes typically played a large role. Long-term progressive evolution trends are extremely rare and the magma compositions of successive eruptive events rarely lie on precisely the same differentiation trend, even where they have evolved from similar parent magmas by similar processes. These observations are not consistent with magma differentiation in large long-lived reservoirs, but they may be accommodated by diverse interactions between newly arrived magma inputs and multiple resident pockets of evolved magma and/or crystal mush residing in conduit-dominated subvolcanic reservoirs. Without constraints provided by the reconstructed stratigraphic relations, the framework for petrologic modeling would be far different. A well-established eruptive stratigraphy may provide independent constraints on the petrologic processes involved in magma evolution—simply on the basis of the specific order in which diverse, broadly cogenetic magmas have been erupted. The Tatara–San Pedro complex includes lavas ranging from primitive basalt to high-SiO 2 rhyolite, and although the dominant erupted magma type was basaltic andesite (∼52–55 wt % SiO 2 ) each sequence is characterized by unique proportions of mafic, intermediate, and silicic eruptive products. Intermediate lava compositions also record different evolution paths, both within and between sequences. No systematic long-term pattern is evident from comparisons at the level of sequences. The considerable diversity of mafic and evolved magmas of the Tatara–San Pedro complex bears on interpretations of regional geochemical trends. The variable role of open-system processes in shaping the compositions of evolved Tatara–San Pedro complex magmas, and even some basaltic magmas, leads to the conclusion that addressing problems such as arc magma genesis and elemental fluxes through subduction zones on the basis of averaged or regressed reconnaissance geochemical datasets is a tenuous exercise. Such compositional indices are highly instructive for identifying broad regional trends and first-order problems, but they should be used with extreme caution in attempts to quantify processes and magma sources, including crustal components, implicated in these trends.

Andes Mountains, Tatara-San Pedro Volcanic Complex↗
USGS1999

The types of data needed for assessing the environmental and human health impacts of coal

Coal is one of the most important sources of energy. Its worldwide use will continue to expand during the next several decades, particularly in rapidly developing countries such as China and India. Unfortunately, coal use may bring with it environmental and human health costs. Many of the environmental and health problems attributed to coal combustion are due to mobilization of potentially toxic elements. Some of these problems could be minimized or even avoided if comprehensive databases containing appropriate coal quality information were available to decision makers so that informed decisions could be made regarding coal use. Among the coal quality parameters that should be included in these databases are: C, H, N, O, pyritic sulfur, organic sulfur, major, minor, and trace element concentrations, modes of occurrence of environmentally sensitive elements, cleanability, mineralogy, organic chemistry, petrography, and leachability.Coal is one of the most important sources of energy. Its worldwide use will continue to expand during the next several decades, particularly in rapidly developing countries such as China and India. Unfortunately, coal use may bring with it environmental and human health costs. Many of the environmental and health problems attributed to coal combustion are due to mobilization of potentially toxic elements. Some of these problems could be minimized or even avoided if comprehensive databases containing appropriate coal quality information were available to decision makers so that informed decisions could be made regarding coal use. Among the coal quality parameters that should be included in these databases are: C, H, N, O, pyritic sulfur, organic sulfur, major, minor, and trace element concentrations, modes of occurrence of environmentally sensitive elements, cleanability, mineralogy, organic chemistry, petrography, and leachability.

International Journal of Coal Geology↗