New methods for identification of disinfection byproducts of toxicological relevance: Progress and future directions

Disinfection byproducts (DBPs) represent a ubiquitous source of chemical exposure in disinfected water. While over 700 DBPs have been identified, the drivers of toxicity remain poorly understood. Additionally, ever evolving water treatment practices have led to a continually growing list of DBPs. Advancement of analytical technologies have enabled the identification of new classes of DBPs and the quantification of these chemically diverse sets of DBPs. Here we summarize advances in new workflows for DBP analysis, including sample preparation, chromatographic separation with mass spectrometry (MS) detection, and data processing. To aid in the selection of techniques for future studies, we discuss necessary considerations for each step in the strategy. This review focuses on how each step of a workflow can be optimized to capture diverse classes of DBPs within a single method. Additionally, we highlight new MS-based approaches that can be powerful for identifying novel DBPs of toxicological relevance. We discuss current challenges and provide perspectives on future research directions with respect to studying new DBPs of toxicological relevance. As analytical technologies continue to advance, new strategies will be increasingly used to analyze complex DBPs produced in different treatment processes with the aim to identify potential drivers of toxicity.     

Effect of fluoride on pH, organic matter and solubility of elements in soils

The effect of NaF addition on pH, organic matter and the solubilities of fifteen elements was investigated on twenty-eight surface soil samples. Four concentrations of NaF were added: 0, 10(-2.7), 10(-1.7) and 10(-1.0)m F in solution. Addition of NaF increased the pH and the solubility of organic matter for all soils. The magnitude of these increases was higher for acid than for alkaline soils. Aluminum, Fe and Ca showed the greatest increases in solubility while Mg, K, Mn and P showed intermediate increases. The elements Cd, Cr, Ni, Cu, Zn, B, Mo and Ba showed only slight increases in solubility. Another experiment was conducted to test whether the effects of NaF on pH, organic matter and the solubilities of various elements were due to F or Na. Four levels of NaCl similar to those for NaF were added to three acid and two alkaline soils. The results confirmed the effects of F on soil pH, organic matter and the solubilities of all elements investigated except those of K, Ca and Mg. Addition of Na as NaF resulted in release of K, Ca and Mg from the exchange sites on solid surfaces into solution.     

Divergence between populations of a monogamous polychaete with male parental care: Premating isolation and chromosome variation

Low dispersal and sexual selection are characteristic of the coastal polychaeteNereis acuminata Ehlers 1868 [also known asNereis arenaceodentata Moore 1903 andNereis (Neanthes) caudata Delle Chiaje 1841]. We assessed levels of premating isolation between populations of this polychaete. Four North American populations were used, two from the Atlantic and two from the Pacific. Worms from all sites (1) were collected in 1987 and 1988 from the same habitat type, (2) were morphologically similar and keyed out asN. acuminata, and (3) reproduced monogamously and exhibited male parental care, an extremely rare reproductive mode in marine invertebrates. There was no evidence from 10-min or 36-h trials of premating isolation between the two Pacific populations. Incomplete premating isolation was found between the two Atlantic populations. High aggression and non-pairing occurred in some 10-min trials between males and females. However, in 36-h trials males and females from the two Atlantic populations always paired to mate. Complete premating isolation was found between Atlantic and Pacific populations. During 10-min trials, males and females from different oceans often attacked and then avoided each other, and they never paired to mate. Nor did they pair to mate in longer, 36-h trials. One Pacific and one Atlantic population were compared for tolerance to cold temperature. Pacific individuals were less able to tolerate cold water than Atlantic individuals. Two Atlantic populations studied had karyotypes with 11 pairs of small acrocentric chromosomes (2n=22), while the two Pacific populations had nine pairs of large metacentric or submetacentric chromosomes (2n=18). Such extreme dissimilarity in karyotype was not expected considering the similarity in morphology, habitat, and reproductive mode. Results suggest strongly that the Atlantic and Pacific populations have been allopatric for a long time, and are different species.     

Anterior regeneration in the spionid polychaetes<Emphasis Type="Italic"> Dipolydora quadrilobata</Emphasis> and<Emphasis Type="Italic"> Pygospio elegans</Emphasis>

Like many other benthic infaunal invertebrates, spionid polychaetes often lose portions of their bodies to predators, which affects their activities. Feeding palp loss and tail loss have been studied in several spionids, but the capacity for anterior tissue regeneration has not been compared in different species. The present study examines anterior tissue regeneration in two species, Dipolydora quadrilobata (Jacobi 1883) and Pygospio elegans Claparède 1863, in two laboratory experiments. Tissue removal treatments included removal of palps only, removal of anterior tissue through the first setiger, anterior tissue through the fifth setiger, all anterior tissue through half of the gill-bearing setigers, and all anterior tissue through the last gill-bearing setiger. Regeneration was monitored by capturing images of the worms and digitizing the area of regenerated anterior tissue or counting the number of segments that grew over time. Worms of both species regenerated anterior tissue regardless of the amount removed. Morphogenesis during regeneration followed a similar pattern in these two species regardless of the amount of anterior tissue lost, progressing from wound healing to formation of a recognizable prostomium and peristomium (“head”) by 6 days post-ablation. Palp and setal growth, addition of segments, and formation of nuchal organs and the ciliated food groove followed so that worms appeared to have re-grown “normal,” but smaller, “heads” and palps by 9–12 days following ablation. Over the course of 16 days, worms that lost more segments regenerated less tissue relative to their initial intact size and did so more slowly. There was no significant palp growth during the first 3 days following ablation. Rate of segment addition was directly related to the degree of tissue loss in D. quadrilobata. P. elegans added segments at similar rates whether 50 or 70% of the original segments was removed.     

Emission study of a diesel engine fueled with higher alcohol-biodiesel blended fuels

This work examines the effect of butanol (higher alcohol) on the emission pattern of neat neem oil biodiesel (NBD100) fueled diesel engine. Single-cylinder, 4-stroke, research diesel engine was employed to conduct the trial. Blends comprising the mixture of biodiesel and higher alcohol were prepared by employing an ultrasonic agitator. Four test fuels such as neat neem oil biodiesel, diesel, and two blends of higher alcohol/neem oil biodiesel: 10% and 20% (by volume). Experimental result showed that increasing alcohol content to biodiesel brought down the various emissions such as Smoke, NO_x, HC, and CO by 6.8%, 10.4%, 8.6%, and 5.9%, respectively, at all loads. It was also concluded from the trail that a 20% higher alcohol/neem oil biodiesel blends show the promising signs in reducing all the emissions associated with biodiesel fuelled diesel engine.     

Nontargeted identification of peptides and disinfection byproducts in water

A broad range of organic compounds are known to exist in drinking water sources and serve as precursors of disinfection byproducts(DBPs).Epidemiological findings of an association of increased risk of bladder cancer with the consumption of chlorinated water has resulted in health concerns about DBPs.Peptides are thought to be an important category of DBP precursors in water.However,little is known about the actual presence of peptides and their DBPs in drinking water because of their high sample complexity and low concentrations.To address this challenge and identify peptides and non-chlorinated/chlorinated peptide DBPs from large sets of organic compounds in water,we developed a novel high throughput analysis strategy,which integrated multiple solid phase extraction(SPE),high performance liquid chromatography(HPLC)separation,and non-target identification using precursor ion exclusion(PIE)high resolution mass spectrometry(MS).After MS analysis,structures of candidate compounds,particularly peptides,were obtained by searching against the Human Metabolome Database(HMDB).Using this strategy,we successfully detected 625 peptides(out of 17,205 putative compounds)and 617 peptides(out of 13,297)respectively in source and finished water samples.The source and finished water samples had 501 peptides and amino acids in common.The remaining 116 peptides and amino acids were unique to the finished water.From a subset of 30 putative compounds for which standards were available,25 were confirmed using HPLC-MS analysis.By analyzing the peptides identified in source and finished water,we successfully confirmed three disinfection reaction pathways that convert peptides into toxic DBPs.     

A guide to prenatal counseling regarding neurodevelopment in congenital heart disease

Advances in cardiac surgical techniques taking place over the past 50 years have resulted in the vast majority of children born with congenital cardiac malformations now surviving into adulthood. As the focus shifts from survival to the functional outcomes of our patients, it is increasingly being recognized that a significant proportion of patients undergoing infant cardiac repair experience adverse neurodevelopmental (ND) outcomes. The etiology of abnormal brain development in the setting of congenital heart disease is poorly understood, complex, and likely multifactorial. Furthermore, the efficacy of therapies available for the learning disabilities, attention deficit, and hyperactivity disorders and other ND deficits complicating congenital heart disease is currently uncertain. This situation presents a challenge for prenatal counseling as current antenatal testing does not usually provide prognostic information regarding the likely ND trajectories of individual patients. However, we believe it is important for parents to be informed about potential issues with child development when a new diagnosis of congenital heart disease is disclosed. Parents deserve a comprehensive and thoughtful approach to this subject, which conveys the uncertainties involved in predicting the severity of any developmental disorders encountered, while emphasizing the improvements in outcomes that have already been achieved in infants with congenital heart disease. A balanced approach to counseling should also discuss what local arrangements are in place for ND follow-up. This review presents an up-to-date overview of ND outcomes in patients with congenital heart disease, providing possible approaches to communicating this information to parents during prenatal counseling in a sensitive and accurate manner.     

Both texting and eating are associated with impaired simulated driving performance

Objective: Distracted driving is a known contributor to traffic accidents, and many states have banned texting while driving. However, little is known about the potential accident risk of other common activities while driving, such as eating. The objective of the current study was to examine the adverse impact of eating/drinking behavior relative to texting and nondistracted behaviors on a simulated driving task. Methods: A total of 186 participants were recruited from undergraduate psychology courses over 2 semesters at Kent State University. We utilized the Kent Multidimensional Assessment Driving Simulation (K-MADS) to compare simulated driving performance among participants randomly assigned to texting (N = 45), eating (N = 45), and control (N = 96) conditions. Multivariate analyses of variance (MANOVA) were conducted to examine between-group differences on simulated driving indices. Results: MANOVA analyses indicated that groups differed in simulated driving performance, F(14, 366) = 7.70, P < .001. Both texting and eating produced impaired driving performance relative to controls, though these behaviors had approximately equal effect. Specifically, both texting and eating groups had more collisions, pedestrian strikes, and center line crossings than controls. In addition, the texting group had more road edge excursions than either eating or control participants and the eating group missed more stop signs than controls. Conclusions: These findings suggest that both texting and eating are associated with poorer simulated driving performance. Future work is needed to determine whether these findings generalize to real-world driving and the development of strategies to reduce distracted driving.