Monthly variations of unregulated brominated disinfection by-products in chlorinated water are correlated with total bromine.

Brominated disinfection by-products (Br-DBPs) can form during the chlorination of drinking water in treatment plants (DWTP). Regulations exist for a small subset of Br-DBPs; however, hundreds of unregulated Br-DBPs have been detected, and limited information exists on their occurrence, concentrations, and seasonal trends. Here, a data-independent precursor isolation and characteristic fragment (DIPIC-Frag) method were optimized to screen chlorinated waters for Br-DBPs. There were 553 Br-DBPs detected with m/z values ranging from 170.884 to 497.0278 and chromatographic retention times from 2.4 to 26.2 min. With MS2 information, structures for 40 of the 54 most abundant Br-DBPs were predicted. The method was then applied to a year-long study in which raw, clear well, and finished water were analyzed monthly. The 54 most abundant unregulated Br-DBPs were subjected to trend analysis. Br-DBPs with higher oxygen-to-carbon (O/C) and bromine-to-carbon (Br/C) ratios increased as water moved from the clear well to the finished stage, which indicated the dynamic formation of Br-DBPs. Monthly trends of unregulated Br-DBPs were compared to raw water parameters, such as natural organic matter, temperature, and total bromine, but no correlations were observed. It was found that total concentrations of bromine (TBr) in finished water (0.04-0.12 mg/L) were consistently and significantly greater than in raw water (0.013-0.038 mg/L, P < 0.001), suggesting the introduction of bromine during the disinfection process. Concentrations of TBr in treatment units, rather than raw water, were significantly correlated to 34 of the Br-DBPs at α = 0.05. This study provides the first evidence that monthly trends of unregulated Br-DBPs can be associated with the concentration of TBr in treated waters.

Etizolam Blood Concentrations in 191 Forensic Cases in Ontario, Canada (2019-2020).

Although not used clinically in North America, etizolam has been identified in forensic samples as an illicit 'designer' benzodiazepine. As a central nervous system depressant, analysis for etizolam has probative value in both death investigations and forensic cases where incapacitation or human psychomotor performance is relevant. This report examines toxicological findings and demographic data in a series of authentic forensic cases analyzed between November 2019 and December 2020 in which etizolam was quantified by liquid chromatography-tandem mass spectrometry analysis. Blood concentrations were determined in 191 individuals aged 1-75 years. In living individuals (i.e., impaired driving and sexual assaults), etizolam concentrations ranged from <5 to 767 ng/mL which overlapped with the range of <5 to 260 ng/mL reported in death investigations. In all but one case, other drugs were detected in combination with etizolam. Fentanyl was the most common co-occurring drug and was present in 164 cases (86%). Additional case details are provided for cases of forensic interest: two deaths involving children <3 years of age, two deaths involving body packing and an individual arrested for drug-impaired driving with, to our knowledge, the highest reported etizolam concentration to date.

Characterizing imidacloprid and metabolites in songbird blood with applications for diagnosing field exposures.

Neonicotinoids are the most widely used insecticides globally, but their rapid metabolism in vertebrates makes diagnosing wildlife exposure challenging. More detailed information on the pattern of imidacloprid metabolites over time could be used to better approximate the timing and level of exposure. Here, we applied recently developed sensitive analytical methods to measure imidacloprid (IMI) parent compound along with an expanded suite of metabolites (5-OH-IMI, IMI-olefin, desnitro-IMI, IMI-urea, 6-chloronicotinic acid, 5-AMCP, 6-OH nicotinic acid) and six other neonicotinoids in adult red-winged blackbirds (Agelaius phoeniceus) that were experimentally exposed to one of two field-realistic concentrations of imidacloprid (0.8 or 6.9 mg/kg bw). We measured concentrations in small (25 µL) plasma samples collected pre-exposure and at 1-, 6-, 24- and 48-h post-exposure. Imidacloprid was rapidly absorbed and metabolized within 48 h at both doses, with the largest decrease within 6 h post-exposure. The average proportion of parent IMI decreased from 68% of total detectable residues at 1-h to 34% at 6-h post-exposure. Two primary metabolites in blood were 5-OH-IMI and IMI-olefin, and 5-OH-IMI was the most persistent marker of exposure at 48-h. Desnitro-IMI was consistently detected following very recent (≤ 1-h) IMI exposure, and a higher ratio of parent IMI to metabolites also indicated recent exposure. Other metabolites were only detected in the higher dose group, and could be used as indicators of exposure to higher IMI concentrations. This sensitive analytical method and the observed metabolite patterns could be used to inform a growing body of field studies linking neonicotinoid exposure and effects in free-living birds.

A novel Peptide-binding motifs inference approach to understand deoxynivalenol molecular toxicity.

Deoxynivalenol (DON) is a type B trichothecene mycotoxin that is commonly detected in cereals and grains world-wide. The low-tolerated levels of this mycotoxin, especially in mono-gastric animals, reflect its bio-potency. The toxicity of DON is conventionally attributed to its ability to inhibit ribosomal protein biosynthesis, but recent advances in molecular tools have elucidated novel mechanisms that further explain DON's toxicological profile, complementing the diverse symptoms associated with its exposure. This article summarizes the recent findings related to novel mechanisms of DON toxicity as well as how structural modifications to DON alter its potency. In addition, it explores feasible ways of expanding our understating of DON-cellular targets and their roles in DON toxicity, clearance, and detoxification through the utilization of computational biology approaches.