Oil and gas produced waters fail to meet beneficial reuse recommendations for use as dust suppressants.

Produced water from conventional oil and gas wells (O&G PW) is beneficially reused as an inexpensive alternative to commercial dust suppressants which minimize inhalable particulate matter (PM10) from unpaved roads. The efficacy and environmental impacts of using O&G PW instead of commercial products have not been extensively investigated, although O&G PW has been used for dust suppression for decades and often has elevated concentrations of environmental pollutants. In this study, the effectiveness of O&G PW is compared to commercial products under variable humidity conditions by measuring total generated PM10 emissions from treated road aggregate discs. To measure environmental impacts, model roadbeds were treated with six O&G PW and commercial products then subjected to a simulated two-year, 24-h storm event. Generated runoff water was collected and characterized. In efficacy studies, O&G PW offered variable dust reduction (10-85 %) compared to rainwater controls under high humidity (50 %) conditions but performed similarly or worse than controls when humidity was low (20 %). Conversely, all but two commercial products reduced dust emissions by over 90 % regardless of humidity. In rainfall-runoff experiments, roads treated with O&G PWs and CaCl2 Brine generated runoff that was hypersaline, indicating that mobilization of soluble salts could contribute to freshwater salinization. Though most runoff concentrations were highest from roadbeds treated with CaCl2 Brine, runoff from roadbeds treated with O&G PW had the highest concentrations of combined radium (83.6 pCi/L), sodium (3560 mg/L), and suspended solids (5330 mg/L). High sodium concentrations likely dispersed clay particles, which increased road mass loss by 47.2 kg solids/km/storm event compared to rainwater controls. Roadbeds treated with CaCl2 Brine, which had low sodium concentrations, reduced solid road mass loss by 98.1 kg solids/km/storm event. Based on this study, O&G PW do not perform as well as commercial products and pose unique risks to environmental health.

Efficacy of oil and gas produced water as a dust suppressant.

The effectiveness of oil and gas produced water (OGPW) applied to unpaved roads to reduce particulate matter (PM10) generation has not been well-characterized. Here we quantify the efficacy of OGPW compared to commercial and alternative byproducts as dust suppressants applied to unpaved roads and estimate efficacy of a dust suppressant extrapolated from both lab experiments and published data for OGPW across U.S. states. Both treated and untreated OGPW, simulated brines, and commercial dust suppressants were characterized by major and trace element composition and then applied to road aggregate in the laboratory. PM10 generation after treatment was quantified, both before and after simulated rain events to assess the need for multiple applications. We found the dust suppression efficacy of all OGPW to be less than commercial products and alternative byproducts such as waste soybean oil. In addition, OGPW lost efficacy following simulated rain events, which would require repeated applications of OGPW to maintain dust suppression. The dust suppression efficacy of OGPW can be estimated based on two chemical measurements, the sodium absorption ratio (SAR) and the total dissolved solids (TDS). OGPW with the lowest SAR and highest TDS performed best as dust suppressants while high SAR and lower TDS led to greater dust generation.

Evaluating flow cytometer performance with weighted quadratic least squares analysis of LED and multi-level bead data.

We developed a fully automated procedure for analyzing data from LED pulses and multilevel bead sets to evaluate backgrounds and photoelectron scales of cytometer fluorescence channels. The method improves on previous formulations by fitting a full quadratic model with appropriate weighting and by providing standard errors and peak residuals as well as the fitted parameters themselves. Here we describe the details of the methods and procedures involved and present a set of illustrations and test cases that demonstrate the consistency and reliability of the results. The automated analysis and fitting procedure is generally quite successful in providing good estimates of the Spe (statistical photoelectron) scales and backgrounds for all the fluorescence channels on instruments with good linearity. The precision of the results obtained from LED data is almost always better than that from multilevel bead data, but the bead procedure is easy to carry out and provides results good enough for most purposes. Including standard errors on the fitted parameters is important for understanding the uncertainty in the values of interest. The weighted residuals give information about how well the data fits the model, and particularly high residuals indicate bad data points. Known photoelectron scales and measurement channel backgrounds make it possible to estimate the precision of measurements at different signal levels and the effects of compensated spectral overlap on measurement quality. Combining this information with measurements of standard samples carrying dyes of biological interest, we can make accurate comparisons of dye sensitivity among different instruments. Our method is freely available through the R/Bioconductor package flowQB. © 2017 International Society for Advancement of Cytometry.

The use of a video laryngoscope by emergency medicine residents is associated with a reduction in esophageal intubations in the emergency department.

OBJECTIVES: The purpose of this investigation was to compare the incidence of esophageal intubations (EIs) when emergency medicine (EM) residents used a direct laryngoscope (DL) versus a video laryngoscope (VL) for intubation attempts in the emergency department (ED). METHODS: Prospectively collected continuous quality improvement data on tracheal intubations performed by EM residents in an academic ED over a 6-year period were retrospectively analyzed. Following each intubation, EM residents completed a data form with patient, intubation, and operator characteristics. Data collected included the method of intubation, drugs used, device(s) used, number of attempts, outcome of each attempt, occurrence of EIs, and occurrence of adverse events (hypoxemia, aspiration, dysrhythmia, hypotension, and cardiac arrest). The incidence of EI was compared between intubation attempts with a DL and with a VL (GlideScope(®) or C-MAC(®) ). Propensity score matching and conditional logistic regression were used to analyze the association between the intubation device (DL vs. VL) and EI. RESULTS: Over the 6-year period, 2,677 patients underwent 3,425 intubation attempts by EM residents with a DL or a VL. A DL was used in 1,530 attempts (44.7%) and a VL was used in 1,895 attempts (55.3%). There were 96 recognized EIs (2.8%). The incidence of EI when using a DL was 78 of 1,530 attempts (5.1%; 95% confidence interval [CI] = 4.1% to 6.3%) and when using a VL was 18 of 1,895 attempts (1.0%; 95% CI = 0.6% to 1.5%). Based on the propensity score matched analysis, the odds ratio for the occurrence of an EI for DL versus VL was 6.9 (95% CI = 3.3 to 14.4). Patients who had inadvertent EIs had a higher incidence of adverse events (49.5%; 95% CI = 38.9% to 60.0%) than patients in which EI did not occur (19.8%; 95% CI = 18.3% to 21.4%). CONCLUSIONS: The use of a VL by EM residents during an intubation attempt in the ED was associated with significantly fewer EIs compared to when a DL was used. Patients who had inadvertent EIs had significantly more adverse events than those who did not have EIs. EM residency training programs should consider using VLs for ED intubations to maximize patient safety when EM residents are performing intubation.

NFATc3-induced reductions in voltage-gated K+ currents after myocardial infarction.

Reductions in voltage-activated K+ (Kv) currents may underlie arrhythmias after myocardial infarction (MI). We investigated the role of beta-adrenergic signaling and the calcineurin/NFAT pathway in mediating the reductions in Kv currents observed after MI in mouse ventricular myocytes. Kv currents were produced by the summation of 3 distinct currents: I(to), I(Kslow1), and I(Kslow2). At 48 hours after MI, we found a 4-fold increase in NFAT activity, which coincided with a decrease in the amplitudes of I(to), I(Kslow1), and I(Kslow2). Consistent with this, mRNA and protein levels of Kv1.5, 2.1, 4.2, and 4.3, which underlie I(Kslow1), I(Kslow2), and I(to), were decreased after MI. Administration of the beta-blocker metoprolol prevented the activation of NFAT and the reductions in I(to), I(Kslow1), and I(Kslow2) after MI. Cyclosporine, an inhibitor of calcineurin, also prevented the reductions in these currents after MI. Importantly, Kv currents did not change after MI in ventricular myocytes from NFATc3 knockout mice. Conversely, chronic beta-adrenergic stimulation or expression of an activated NFATc3 decreased Kv currents to a similar extent as MI. Taken together, these data indicate that NFATc3 plays an essential role in the signaling pathway leading to reduced I(to), I(Kslow1), and I(Kslow2) after MI. We propose that increased beta-adrenergic signaling after MI activates calcineurin and NFATc3, which decreases I(to), I(Kslow1), and I(Kslow2) via a reduction in Kv1.5, Kv2.1, Kv4.2, and Kv4.3 expression.