Geology topics

W.L. Cranor

Publications and source records attributed to W.L. Cranor.

10 recordsLinked to original sources

USGS2009

Reproductive health of bass in the potomac, USA, drainage: Part 2. Seasonal occurrence of persistent and emerging organic contaminants

The seasonal occurrence of organic contaminants, many of which are potential endocrine disruptors, entering the Potomac River, USA, watershed was investigated using a two-pronged approach during the fall of 2005 and spring of 2006. Passive samplers (semipermeable membrane device and polar organic chemical integrative sampler [POCIS]) were deployed in tandem at sites above and below wastewater treatment plant discharges within the watershed. Analysis of the samplers resulted in detection of 84 of 138 targeted chemicals. The agricultural pesticides atrazine and metolachlor had the greatest seasonal changes in water concentrations, with a 3.1 - to 91 -fold increase in the spring compared with the level in the previous fall. Coinciding with the elevated concentrations of atrazine in the spring were increasing concentrations of the atrazine degradation products desethylatrazine and desisopropylatrazine in the fall following spring and summer application of the parent compound. Other targeted chemicals (organochlorine pesticides, polycyclic aromatic hydrocarbons, and organic wastewater chemicals) did not indicate seasonal changes in occurrence or concentration; however, the overall concentrations and number of chemicals present were greater at the sites downstream of wastewater treatment plant discharges. Several fragrances and flame retardants were identified in these downstream sites, which are characteristic of wastewater effluent and human activities. The bioluminescent yeast estrogen screen in vitro assay of the POCIS extracts indicated the presence of chemicals that were capable of producing an estrogenic response at all sampling sites. ?? 2009 SETA.

Environmental Toxicology and Chemistry↗

USGS2009

Semivolatile organic compounds in residential air along the Arizona - Mexico border

Concerns about indoor air quality and the potential effects on people living in these environments are increasing as more reports about the toxicities and the potential indoor air exposure levels of household-use chemicals and chemicals fromhousingandfurnishingmanufactureinairarebeingassessed. Gas chromatography/mass spectrometry was used to confirm numerous airborne contaminants obtained from the analysis of semipermeable membrane devices deployed inside of 52 homes situated along the border between Arizona and Mexico. We also describe nontarget analytes in the organochlorine pesticide fractions of 12 of these homes; this fraction is also the most likelytocontainthebroadestscopeofbioconcentratablechemicals accumulated from the indoor air. Approximately 400 individual components were identified, ranging from pesticides to a wide array of hydrocarbons, fragrances such as the musk xylenes, flavors relating to spices, aldehydes, alcohols, esters and phthalate esters, and other miscellaneous types of chemicals. The results presented in this study demonstrate unequivocally that the mixture of airborne chemicals present indoors is far more complex than previously demonstrated. ?? 2009 American Chemical Society.

Environmental Science & Technology↗

USGS2009

Uptake rate constants and partition coefficients for vapor phase organic chemicals using semipermeable membrane devices (SPMDs)

To fully utilize semipermeable membrane devices (SPMDs) as passive samplers in air monitoring, data are required to accurately estimate airborne concentrations of environmental contaminants. Limited uptake rate constants (k ua ) and no SPMD air partitioning coefficient (K sa ) existed for vapor-phase contaminants. This research was conducted to expand the existing body of kinetic data for SPMD air sampling by determining k ua and K sa for a number of airborne contaminants including the chemical classes: polycyclic aromatic hydrocarbons, organochlorine pesticides, brominated diphenyl ethers, phthalate esters, synthetic pyrethroids, and organophosphate/organosulfur pesticides. The k ua s were obtained for 48 of 50 chemicals investigated and ranged from 0.03 to 3.07??m 3 ??g -1 ??d -1 . In cases where uptake was approaching equilibrium, K sa s were approximated. K sa values (no units) were determined or estimated for 48 of the chemicals investigated and ranging from 3.84E+5 to 7.34E+7. This research utilized a test system (United States Patent 6,877,724 B1) which afforded the capability to generate and maintain constant concentrations of vapor-phase chemical mixtures. The test system and experimental design employed gave reproducible results during experimental runs spanning more than two years. This reproducibility was shown by obtaining mean k ua values (n??=??3) of anthracene and p,p???-DDE at 0.96 and 1.57??m 3 ??g -1 ??d -1 with relative standard deviations of 8.4% and 8.6% respectively.

Atmospheric Environment↗

USGS2008

Chemical and toxicologic assessment of organic contaminants in surface water using passive samplers

Passive sampling methodologies were used to conduct a chemical and toxicologic assessment of organic contaminants in the surface waters of three geographically distinct agricultural watersheds. A selection of current-use agrochemicals and persistent organic pollutants, including polycyclic aromatic hydrocarbons, polychlorinated biphenyls, and organochlorine pesticides, were targeted using the polar organic chemical integrative sampler (POCIS) and the semipermeable membrane device passive samplers. In addition to the chemical analysis, the Microtox assay for acute toxicity and the yeast estrogen screen (YES) were conducted as potential assessment tools in combination with the passive samplers. During the spring of 2004, the passive samplers were deployed for 29 to 65 d at Leary Weber Ditch, IN; Morgan Creek, MD; and DR2 Drain, WA. Chemical analysis of the sampler extracts identified the agrochemicals predominantly used in those areas, including atrazine, simazine, acetochlor, and metolachlor. Other chemicals identified included deethylatrazine and deisopropylatrazine, trifluralin, fluoranthene, pyrene, cis- and trans-nonachlor, and pentachloroanisole. Screening using Microtox resulted in no acutely toxic samples. POCIS samples screened by the YES assay failed to elicit a positive estrogenic response. Copyright ?? 2008 by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America. All rights reserved.

Journal of Environmental Quality↗

USGS2004

A holistic passive integrative sampling approach for assessing the presence and potential impacts of waterborne environmental contaminants

As an integral part of our continuing research in environmental quality assessment approaches, we have developed a variety of passive integrative sampling devices widely applicable for use in defining the presence and potential impacts of a broad array of contaminants. The semipermeable membrane device has gained widespread use for sampling hydrophobic chemicals from water and air, the polar organic chemical integrative sampler is applicable for sequestering waterborne hydrophilic organic chemicals, the stabilized liquid membrane device is used to integratively sample waterborne ionic metals, and the passive integrative mercury sampler is applicable for sampling vapor phase or dissolved neutral mercury species. This suite of integrative samplers forms the basis for a new passive sampling approach for assessing the presence and potential toxicological significance of a broad spectrum of environmental contaminants. In a proof-of-concept study, three of our four passive integrative samplers were used to assess the presence of a wide variety of contaminants in the waters of a constructed wetland, and to determine the effectiveness of the constructed wetland in removing contaminants. The wetland is used for final polishing of secondary-treatment municipal wastewater and the effluent is used as a source of water for a state wildlife area. Numerous contaminants, including organochlorine pesticides, polycyclic aromatic hydrocarbons, organophosphate pesticides, and pharmaceutical chemicals (e.g., ibuprofen, oxindole, etc.) were detected in the wastewater. Herein we summarize the results of the analysis of the field-deployed samplers and demonstrate the utility of this holistic approach.

Chemosphere↗

USGS2004

Purification of triolein for use in semipermeable membrane devices (SPMDs)

Analyses of triolein-containing semipermeable membrane devices (SPMDs) have sometimes been impeded by interferences caused by impurities endemic to triolein that codialyze with the analytes. Oleic acid and methyl oleate have been the most troublesome of these impurities because of their relatively high concentrations in triolein and because significant residues of both can persist even after size exclusion chromatographic (SEC) fractionation. These residues have also been blamed for false-positive signals during bioindicator testing of SPMD dialysates. To prevent these problems, a simple, cost-effective procedure was developed for purifying triolein destined for use in SPMDs: the bulk triolein is repeatedly (6×) partitioned against methanol. Tests of the procedure show that 14 C-oleic acid is completely removed from the triolein. After SEC fractionation, dialysates of standard-size SPMDs made with the purified triolein contain less than 5 μg of methyl oleate as compared to sometimes more than 500 μg for dialysates (also after SEC) of SPMDs made with unpurified triolein. Gas chromatographic analyses with flame ionization and electron capture detection show that the purification treatment also greatly reduces the number and size of peaks caused by unidentified contaminants in the triolein. Microtox basic assay of dialysates of SPMDs shows that those made with the purified triolein have lower acute toxicities than dialysates of SPMDs made with unpurified triolein. Yeast estrogen screen (YES) testing of SPMDs fabricated with unpurified and purified triolein demonstrates that the purification process removes all background estrogenic activity.

Chemosphere↗

USGS2003

Comparisons of coarse and fine versions of two carbons for reducing the bioavailabilities of sediment-bound hydrophobic organic contaminants

Coarse (whole) and finely ground Ambersorb 1500 and coarse and fine coconut charcoal were compared as to their efficiencies in scavenging organic contaminants desorbed from sediment. Aqueous slurries of a test sediment spiked (1 ppm) with p,p???-DDE (DDE), 2,2???,5,5???-tetrachlorobiphenyl (TCB), naphthalene (NAP), or phenanthrene (PHEN), and containing 1% levels of the test carbons were treated by shaking at 35 ??C while exposed to clusters of low-density polyethylene membrane (detox spiders). Controls consisted of spiked sediments and detox spiders but no added carbon of any kind and thus represented unimpeded bioavailabilities (to the spiders). After the treatments - agitation periods from 2.5 to 60 h, depending on contaminant hydrophobicity - the exposed detox spiders were analyzed. The fine carbon of either type was more effective than its coarser variant in obstructing contaminant bioavailabilities. The finer variants of both carbons obstructed the bioavailabilities of NAP and PHEN equally well as did the coarser variants of both. Whole Ambersorb 1500 and coarse coconut charcoal were similarly ineffective in intercepting TCB and DDE. Ground Ambersorb 1500 obstructed virtually all bioavailability of all four contaminants and was far more effective than fine coconut charcoal in intercepting DDE and TCB. An additional experiment compared the effectiveness of ground Ambersorb 1500 and fine coconut charcoal in obstructing the bioavailabilities from sediment of a broad array of spiked organochlorine pesticides. The performance of ground Ambersorb 1500 was again found to be superior; the bioavailable levels of each of the 27 pesticides were markedly lower in the presence of ground Ambersorb 1500 than in the presence of fine coconut charcoal.

Chemosphere↗

USGS2001

Development of the permeability/performance reference compound approach for in situ calibration of semipermeable membrane devices

Permeability/performance reference compounds (PRCs) are analytically noninterfering organic compounds with moderate to high fugacity from semipermeable membrane devices (SPMDs) that are added to the lipid prior to membrane enclosure. Assuming that isotropic exchange kinetics (IEK) apply and that SPMD-water partition coefficients are known, measurement of PRC dissipation rate constants during SPMD field exposures and laboratory calibration studies permits the calculation of an exposure adjustment factor (EAF). In theory, PRC-derived EAF ratios reflect changes in SPMD sampling rates (relative to laboratory data) due to differences in exposure temperature, membrane biofouling, and flow velocity-turbulence at the membrane surface. Thus, the PRC approach should allow for more accurate estimates of target solute/vapor concentrations in an exposure medium. Under some exposure conditions, the impact of environmental variables on SPMD sampling rates may approach an order of magnitude. The results of this study suggest that most of the effects of temperature, facial velocity-turbulence, and biofouling on the uptake rates of analytes with a wide range of hydrophobicities can be deduced from PRCs with a much narrower range of hydrophobicities. Finally, our findings indicate that the use of PRCs permits prediction of in situ SPMD sampling rates within 2-fold of directly measured values.

Environmental Science & Technology↗

USGS2000

Considerations involved with the use of semipermeable membrane devices for monitoring environmental contaminants

Semipermeable membrane devices (SPMDs) are used with increasing frequency, and throughout the world as samplers of organic contaminants. The devices can be used to detect a variety of lipophilic chemicals in water, sediment/soil, and air. SPMDs are designed to sample nonpolar, hydrophobic chemicals. The maximum concentration factor achievable for a particular chemical is proportional to its octanol–water partition coefficient. Techniques used for cleanup of SPMD extracts for targeted analytes and for general screening by full-scan mass spectrometry do not differ greatly from techniques used for extracts of other matrices. However, SPMD extracts contain potential interferences that are specific to the membrane–lipid matrix. Procedures have been developed or modified to alleviate these potential interferences. The SPMD approach has been demonstrated to be applicable to sequestering and analyzing a wide array of environmental contaminants including organochlorine pesticides, polychlorinated biphenyls, polycyclic aromatic hydrocarbons, polychlorinated dioxins and dibenzofurans, selected organophosphate pesticides and pyrethroid insecticides, and other nonpolar organic chemicals. We present herein an overview of effective procedural steps for analyzing exposed SPMDs for trace to ultra-trace levels of contaminants sequestered from environmental matrices.

Journal of Chromatography A↗

USGS2000

An approach for assessment of water quality using semipermeable membrane devices (SPMDs) and bioindicator tests

As an integral part of our continued development of water quality assessment approaches, we combined integrative sampling, instrumental analysis of widely occurring anthropogenic contaminants, and the application of a suite of bioindicator tests as a specific part of a broader survey of ecological conditions, species diversity, and habitat quality in the Santa Cruz River in Arizona, USA. Lipid-containing semipermeable membrane devices (SPMDs) were employed to sequester waterborne hydrophobic chemicals. Instrumental analysis and a suite of bioindicator tests were used to determine the presence and potential toxicological relevance of mixtures of bioavailable chemicals in two major water sources of the Santa Cruz River. The SPMDs were deployed at two sites; the effluent weir of the International Wastewater Treatment Plant (IWWTP) and the Nogales Wash. Both of these systems empty into the Santa Cruz River and the IWWTP effluent is a potential source of water for a constructed wetland complex. Analysis of the SPMD sample extracts revealed the presence of organochlorine pesticides (OCs), polychlorinated biphenyls (PCBs), and polycyclic aromatic hydrocarbons (PAHs). The bioindicator tests demonstrated increased liver enzyme activity, perturbation of neurotransmitter systems and potential endocrine disrupting effects (vitellogenin induction) in fish exposed to the extracts. With increasing global demands on limited water resources, the approach described herein provides an assessment paradigm applicable to determining the quality of water in a broad range of aquatic systems.

Chemosphere↗