Dams are known to trap pollutants such as metals and PCBs in the sediment that accumulates within their reservoirs. As more attention is paid to microplastics, an emerging contaminant in waterways ...worldwide, and how they move along rivers, whether microplastic particles also accumulate behind dams is an important question for informing estimates of global river inputs to oceans. In this study, we measured microplastic concentrations above, below, and within the reservoirs of six dams near Ithaca, NY USA. Samples were processed following the wet peroxide oxidation method and visual counting, followed by Raman Spectroscopy validation. We found that microplastic concentrations in sediment within reservoirs was significantly higher than in sediment above the dams (p = 0.005), and in water samples, concentrations within reservoirs was significantly lower (p = 0.02). Plastic fibers were the dominant plastic type, but in within-reservoir sediment samples, less abundant plastic types such as plastic fragments were found in higher proportions. These results show that the sediment collecting behind dams is one sink for microplastics in river systems at long timescales, indicating that accounting for dams may be important when modeling global riverine microplastic transport.
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•Studied how microplastic concentrations differ in the presence of dams.•Paired sediment and water samples were collected upstream and downstream of dams.•Concentration trends were investigated at individual dams and across many in series.•Reservoir sediments contain highest concentrations of microplastics.•Dams in series do not cumulatively reduce microplastic concentrations.
In today's chemically dependent society, environmental studies demonstrate that drinking water in developed countries contains numerous industrial chemicals, pesticides, pharmaceuticals and chemicals ...from water treatment processes. This poses a real threat. As a result of the ever-expanding list of chemical and biochemical products industry, current drinking water standards that serve to preserve our drinking water quality are grossly out of date. Environmental Science of Drinking Water demonstrates why we need to make a fundamental change in our approach toward protecting our drinking water. Factual and circumstantial evidence showing the failure of current drinking water standards to adequately protect human health is presented along with analysis of the extent of pollution in our water resources and drinking water. The authors also present detail of the currently available state-of-the-art technologies which, if fully employed, can move us toward a healthier future.* Addresses the international problems of outdated standards and the overwhelming onslaught of new contaminants. * Includes new monitoring data on non-regulated chemicals in water sources and drinking water. * Includes a summary of different bottled waters as well as consumer water purification technologies.
Microplastic pollution is measured with a variety of sampling methods. Field experiments indicate that commonly used sampling methods, including net, pump, and grab samples, do not always result in ...equivalent measured concentration. We investigate the comparability of these methods through a meta-analysis of 121 surface water microplastic studies. We find systematic relationships between measured concentration and sampled volume, method of collection, mesh size used for filtration, and waterbody sampled. Most significantly, a strong log–linear relationship exists between sample volume and measured concentration, with small-volume grab samples measuring up to 104 particles/L higher concentrations than larger volume net samples, even when sampled concurrently. Potential biasing factors explored included filtration size (±102 particles/L), net volume overestimation (±101 particles/L), fiber loss through net mesh (unknown magnitude), intersample variability (±101 particles/L), and contamination, the potential factor with an effect large enough (±103 particles/L) to explain the observed differences. On the basis of these results, we caution against comparing concentrations across multiple studies or combining multiple study results to identify regional patterns. Additionally, we emphasize the importance of contamination reduction and quantification strategies, namely that blank samples from all stages of field sampling be collected and reported as a matter of course for all studies.
Laser-induced breakdown spectroscopy (LIBS) is an atomic emission spectroscopic technique which uses a focused pulsed laser beam to generate plasma from the material. The plasma contains atoms, ions ...and free electrons which emit electromagnetic radiation as the plasma cools down. The emitted light is resolved by a spectrometer to form a spectrum. Recently, LIBS has become an emerging analytical technique for characterisation and identification of materials; its multi-elemental analysis, fast response, remote sensing, little to no sample preparation, low running cost and ease of use make LIBS a promising technique for the food sector.
The present article reviews the feasibility of LIBS for food analysis. It presents recent progress and applications of LIBS as an efficient and reagent-free, at-line tool capable of replacing traditional time-consuming analytical methods for assessing the quality and composition of food products. An overview of LIBS fundamentals, instrumentation and statistical data analysis is also provided.
Although LIBS technology shows many advantages, challenges remain in terms of sample preparation, matrix effects, spectral pre-processing, model calibration and instrument development.
•Laser-induced breakdown spectroscopy (LIBS) is an optical technique capable of fast multi-elemental analysis of food samples.•The feasibility of laser-induced breakdown spectroscopy for the food sector has been reviewed.•Adulteration and mineral composition of food have an impact on global human health.•The request for healthy, functional and safe consumer food, mobilises research with new analytical techniques.
Abstract Purpose Recent results suggests the risk of a new onset of depression increases with longer duration of opioid analgesic use. It is unclear whether new-onset depression related to opioid ...analgesic use is a function of the dose prescribed or the duration of use or both. Methods Using a retrospective cohort design, we collected patient data from 2000 to 2012 from the Veterans Health Administration (VHA), and from 2003 to 2012 from both Baylor Scott & White Health (BSWH) and the Henry Ford Health System (HFHS). Patients (70,997 VHA patients, 13,777 BSWH patients, and 22,981 HFHS patients) were new opioid users, aged 18 to 80 years, without a diagnosis of depression at baseline. Opioid analgesic use duration was defined as 1 to 30, 31 to 90, and more than 90 days, and morphine equivalent dose (MED) was defined as 1 to 50 mg/d, 51 to 100 mg/d, and greater than 100 mg/d of analgesic. Pain and other potential confounders were controlled for by inverse probability of treatment–weighted propensity scores. Results New-onset depression after opioid analgesic use occurred in 12% of the VHA sample, 9% of the BSWH sample, and 11% of the HFHS sample. Compared with 1- to 30-day users, new-onset depression increased in those with longer opioid analgesic use. Risk of new-onset depression with 31 to 90 days of opioid analgesic use ranged from hazard ratio HR = 1.18 (95% CI, 1.10–1.25) in VHA to HR = 1.33 (95% CI, 1.16–1.52) in HFHS; in opioid analgesic use of more than 90 days, it ranged from HR = 1.35 (95% CI, 1.26–1.44) in VHA to HR = 2.05 (95% CI, 1.75–2.40) in HFHS. Dose was not significantly associated with a new onset of depression. Conclusions Opioid-related new onset of depression is associated with longer duration of use but not dose. Patients and practitioners should be aware that opioid analgesic use of longer than 30 days imposes risk of new-onset depression. Opioid analgesic use, not just pain, should be considered a potential source when patients report depressed mood.
The habitat amount hypothesis (HAH) stresses the importance of total patch amount over the size of individual patches in determining species richness within a local landscape. However, the absence of ...some species from patches too small to contain a territory would be inconsistent with the HAH. Using the association of territory size with body size and the circle as optimal territory shape, we tested several HAH predictions of threshold patch occupancy and richness of 19 guilds of primarily insectivorous breeding birds. We characterized 16 guild-associated patch types at high spatial resolution and assigned one type to each guild. We measured functional patch size as the largest circle that fit within each patch type occurring in a local landscape. Functional patch size was the sole or primary predictor in regression models of species richness for 15 of the 19 guilds. Total patch amount was the sole or primary variable in only 2 models. Quantifying patch size at high resolution also demonstrated that breeding birds should be absent from patches that are too small to contain a territory and larger species should occur only in larger patches. Functional patch size is a readily interpretable metric that helps explain the habitat basis for differences in species composition and richness between areas. It provides a tool to assess the combined effects of patch size, shape and perforation on threshold habitat availability, and with total patch amount can inform design and/or evaluation of conservation, restoration or enhancement options for focal taxa or biodiversity in general.
This paper considers the ethical justification for the use of harm minimisation approaches with individuals who self-injure. While the general issues concerning harm minimisation have been widely ...debated, there has been only limited consideration of the ethical issues raised by allowing people to continue injuring themselves as part of an agreed therapeutic programme. I will argue that harm minimisation should be supported on the basis that it results in an overall reduction in harm when compared with more traditional ways of dealing with self-injurious behaviour. It will be argued that this is an example of a situation where healthcare professionals sometimes have a moral obligation to allow harm to come to their patients.
Microplastics, particles less than 5 mm in size, are an emerging contaminant in waterways worldwide. Most microplastic studies focus on spatial trends in concentration, but in systems as dynamic as ...rivers, to draw conclusions from existing spatial studies, we must first examine how microplastic concentrations may change with time and flow conditions. In this study, we investigate how microplastic concentrations change over a 24-h period and between seasonally high and low flows. We do this in two streams, controlling for wastewater treatment strategy: one stream in a watershed where waste is treated with septic systems and the other receiving wastewater treatment plant effluent. We hypothesized that a stream with wastewater treatment plant effluent would exhibit higher and more variable microplastic concentrations than a stream in a watershed with septic systems. Results indicate, however, that there is no significant difference between the two streams despite their differing treatment strategies. Additionally, no significant variation in concentrations was measured over two 24-h sampling campaigns. There was, however, significantly higher concentrations measured in summer low flow conditions relative to spring high flow conditions across both sampled streams (
p
value <0.001), indicating that increases in stream discharge unrelated to storm events dilute and decrease measured microplastic concentrations. From this, we learn that pairing measured concentrations with a description of flow conditions at sampling time is a requisite for a robust microplastic literature that allows for comparisons between existing spatial studies and extrapolations to global loads.
In this trial in patients with lumbar central stenosis and moderate-to-severe leg pain and disability, epidural injection of glucocorticoids plus lidocaine offered minimal or no short-term benefit ...over epidural injection with lidocaine alone with respect to disability and pain.
Lumbar spinal stenosis, a common cause of spine-related disability, is the leading reason for spinal surgery in older adults.
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Degenerative changes resulting in narrowing of the spinal canal and nerve-root compression can cause back and leg pain, lower-extremity paresthesias, and weakness.
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The treatment of symptomatic lumbar stenosis remains controversial.
Symptoms of lumbar stenosis are commonly treated with epidural glucocorticoid injections. These injections typically contain a glucocorticoid and an anesthetic, which are thought to relieve pain by reducing nerve-root inflammation and ischemia.
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An estimated 25% of all epidural glucocorticoid injections administered in the Medicare population and 74% of those . . .
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