Better Together: Tandem Mass Spectrometry Achieves up to 50 Times Lower Quantification of 62 Disinfection Byproducts in Drinking Water.

Disinfection byproducts (DBPs) are ubiquitous contaminants present in nearly all drinking water and are associated with adverse health effects in human epidemiologic studies. The most toxic DBPs are unregulated and often occur at concentrations well below regulated DBPs; thus, quantification at low parts-per-trillion (ng/L) levels is critical in assessing exposure. We developed a new liquid-liquid extraction-gas chromatography-tandem mass spectrometry (LLE-GC-MS/MS) method with the first analysis by tandem gas chromatography-mass spectrometry of 23 priority unregulated DBPs including 13 haloacetamides, 3 haloacetic acids, 2 haloacetonitriles, 1 haloacetaldehyde, 2 haloketones, and 2 halonitromethanes. When combined with our previous GC-MS/MS method for haloacetic acids and previously reported MS/MS transitions that we optimized for this method, the analysis of 62 regulated and priority unregulated DBPs at lower quantification limits is achieved. Limits of quantification for most DBPs were between 5 and 30 ng/L with r2 > 0.99 and an average of 9 times lower limits of quantification (LOQs) compared to LLE-GC-MS using selected ion monitoring (SIM). Relative standard deviations ranged from 0.7 to 30% for 61 DBPs in spiked samples. This new method was validated using tap waters from four US cities, where individual DBP concentrations ranged from 5 to 126,882 ng/L. This project provides the most comprehensive GC-MS/MS method for DBP analysis to date and is capable of analyzing volatile and semivolatile DBPs across nine different compound classes, including a class not previously analyzed by GC-MS/MS.

Low Parts Per Trillion Detection of Iodinated Disinfection Byproducts in Drinking Water and Urine using Vacuum-Assisted Sorbent Extraction and GC-MS/MS.

Disinfection byproducts (DBPs) are ubiquitous environmental contaminants, which are present in virtually all drinking water and linked to detrimental health effects. Iodinated-DBPs are more cytotoxic and genotoxic than chloro- and bromo-DBPs and are formed during disinfection of iodide-containing source water. Liquid-liquid extraction (LLE) paired with gas chromatography (GC)-mass spectrometry (MS) has been the method of choice in the study of low molecular weight iodinated-DBPs; however, this method is laborious and time-consuming and struggles with complex matrices. We developed an environmentally friendly method utilizing headspace solid phase extraction with the application of vacuum to measure six iodinated-trihalomethanes (I-THMs) in drinking water and urine. Vacuum-assisted sorbent extraction (VASE) has the ability to exhaustively and rapidly extract volatile and semivolatile compounds from liquid matrices without the use of solvent. Using VASE with GC-MS/MS provides improved analyte recovery and reduced matrix interference compared to LLE. Additionally, VASE enables extraction of 30 samples simultaneously with minimal sample handling and improved method reproducibility. Using VASE with GC-MS/MS, we achieved quantification limits of 3-4 ng/L. This technique was demonstrated on drinking water from four cities, where five I-THMs were quantified at levels 10-33 times below comparable LLE methods with 10 times lower volumes of sample (10 mL vs 100 mL).

Chlorination of Emerging Contaminants for Application in Potable Wastewater Reuse: Disinfection Byproduct Formation, Estrogen Activity, and Cytotoxicity.

With increasing water scarcity, many utilities are considering the potable reuse of wastewater as a source of drinking water. However, not all chemicals are removed in conventional wastewater treatment, and disinfection byproducts (DBPs) can form from these contaminants when disinfectants are applied during or after reuse treatment, especially if applied upstream of advanced treatment processes to control biofouling. We investigated the chlorination of seven priority emerging contaminants (17ß-estradiol, estrone, 17α-ethinylestradiol, bisphenol A (BPA), diclofenac, p-nonylphenol, and triclosan) in ultrapure water, and we also investigated the impact of chlorination on real samples from different treatment stages of an advanced reuse plant to evaluate the role of chlorination on the associated cytotoxicity and estrogenicity. Many DBPs were tentatively identified via liquid chromatography (LC)- and gas chromatography (GC)-high resolution mass spectrometry, including 28 not previously reported. These encompassed chlorinated, brominated, and oxidized analogs of the parent compounds as well as smaller halogenated molecules. Chlorinated BPA was the least cytotoxic of the DBPs formed but was highly estrogenic, whereas chlorinated hormones were highly cytotoxic. Estrogenicity decreased by ∼4-6 orders of magnitude for 17ß-estradiol and estrone following chlorination but increased 2 orders of magnitude for diclofenac. Estrogenicity of chlorinated BPA and p-nonylphenol were ∼50% of the natural/synthetic hormones. Potential seasonal differences in estrogen activity of unreacted vs reacted advanced wastewater treatment field samples were observed.

Measuring waning protection from seasonal influenza vaccination during nine influenza seasons, Ontario, Canada, 2010/11 to 2018/19.

BackgroundWaning immunity from seasonal influenza vaccination can cause suboptimal protection during peak influenza activity. However, vaccine effectiveness studies assessing waning immunity using vaccinated and unvaccinated individuals are subject to biases.AimWe examined the association between time since vaccination and laboratory-confirmed influenza to assess the change in influenza vaccine protection over time.MethodsUsing linked laboratory and health administrative databases in Ontario, Canada, we identified community-dwelling individuals aged ≥ 6 months who received an influenza vaccine before being tested for influenza by RT-PCR during the 2010/11 to 2018/19 influenza seasons. We estimated the adjusted odds ratio (aOR) for laboratory-confirmed influenza by time since vaccination (categorised into intervals) and for every 28 days.ResultsThere were 53,065 individuals who were vaccinated before testing for influenza, with 10,264 (19%) influenza-positive cases. The odds of influenza increased from 1.05 (95% CI: 0.91-1.22) at 42-69 days after vaccination and peaked at 1.27 (95% CI: 1.04-1.55) at 126-153 days when compared with the reference interval (14-41 days). This corresponded to 1.09-times increased odds of influenza every 28 days (aOR = 1.09; 95% CI: 1.04-1.15). Individuals aged 18-64 years showed the greatest decline in protection against influenza A(H1N1) (aORper 28 days = 1.26; 95% CI: 0.97-1.64), whereas for individuals aged ≥ 65 years, it was against influenza A(H3N2) (aORper 28 days = 1.20; 95% CI: 1.08-1.33). We did not observe evidence of waning vaccine protection for individuals aged < 18 years.ConclusionsInfluenza vaccine protection wanes during an influenza season. Understanding the optimal timing of vaccination could ensure robust protection during seasonal influenza activity.

Endoscopic surveillance with systematic random biopsy for the early diagnosis of hereditary diffuse gastric cancer: a prospective 16-year longitudinal cohort study.

BACKGROUND: Hereditary diffuse gastric cancer, generally caused by germline pathogenic variants in CDH1, presents with early-onset signet ring cell carcinoma. Prophylactic total gastrectomy is the definitive treatment. Endoscopic surveillance can inform the timing of prophylactic total gastrectomy through detection of microscopic signet ring cell carcinoma foci. However, evidence is scarce about the optimal endoscopic sampling technique and characterisation of signet ring cell carcinoma foci in hereditary diffuse gastric cancer. We aimed to formally assess the diagnostic yield of different sampling strategies and to identify criteria for the characterisation of endoscopic lesions. METHODS: For this prospective longitudinal cohort study, we included individuals aged 18 years or older at the Cambridge University Hospitals National Health Service (NHS) Foundation Trust who fulfilled testing criteria for hereditary diffuse gastric cancer between June 1, 2005, and July 31, 2021. The primary outcome was detection of intramucosal signet ring cell carcinoma foci. We assessed the detection rate and anatomical location of signet ring cell carcinoma in random biopsy samples taken according to a systematic protocol compared with biopsies targeted to endoscopic findings. Endoscopic lesions were examined with white-light and narrow band imaging with magnification to assess the likelihood of cancerous foci. FINDINGS: 145 individuals were included, of whom 68 (47%) were male and 92 (63%) carried the CDH1 pathogenic variant. 58 (40%) patients were diagnosed with invasive signet ring cell carcinoma over a median follow-up time of 51 months (IQR 18-80). The first diagnosis of signet ring cell carcinoma was most commonly made from random biopsies (29 [50%] of 58 patients), rather than targeted biopsies (15 [26%] patients). The anatomical distribution of signet ring cell carcinoma foci detected by random biopsies more accurately reflected those identified in prophylactic total gastrectomy specimens than did targeted biopsies. Omitting random biopsies in our cohort would have led to an under-diagnosis rate of 42%. Using a novel panel of endoscopic criteria, gastric lesions containing signet ring cell carcinoma were predicted with a sensitivity of 67·3% and a specificity of 90·2%. INTERPRETATION: Random biopsies enhance the early detection of signet ring cell carcinoma and are complementary to targeted biopsies in surveillance of hereditary diffuse gastric cancer. This sampling method should be the standard of care when performing all surveillance endoscopies for individuals with hereditary diffuse gastric cancer. FUNDING: UK Medical Research Council.

Simple and Sensitive Method for Synchronous Quantification of Regulated and Unregulated Priority Disinfection Byproducts in Drinking Water.

Due to their elevated concentrations in drinking water, compared to other emerging environmental contaminants, disinfection byproducts (DBPs) have become a global concern. To address this, we have created a simple and sensitive method for simultaneously measuring 9 classes of DBPs. Haloacetic acids (HAAs) and iodo-acetic acids (IAAs) are determined using silylation derivatization, replacing diazomethane or acidic methanol derivatization with a more environmentally friendly and simpler treatment process that also offers greater sensitivity. Mono-/di-haloacetaldehydes (mono-/di-HALs) are directly analyzed without derivatization, along with trihalomethanes (THMs), iodo-THMs, haloketones, haloacetonitriles, haloacetamides, and halonitromethanes. Of the 50 DBPs studied, recoveries for most were 70-130%, LOQs for most were 0.01-0.05 µg/L, and relative standard deviations were <30%. We subsequently applied this method to 13 home tap water samples. Total concentrations of 9 classes of DBPs were 39.6-79.2 µg/L, in which unregulated priority DBPs contributed 42% of total DBP concentrations and 97% of total calculated cytotoxicity, highlighting the importance of monitoring their presence in drinking water. Br-DBPs were the dominant contributors to total DBPs (54%) and total calculated cytotoxicity (92%). Nitrogenous DBPs contributed 25% of total DBPs while inducing 57% of total calculated cytotoxicity. HALs were the most important toxicity drivers (40%), particularly four mono-/di-HALs, which induced 28% of total calculated cytotoxicity. This simple and sensitive method allows the synchronous analysis of 9 classes of regulated and unregulated priority DBPs and overcomes the weaknesses of some other methods especially for HAAs/IAAs and mono-/di-HALs, providing a useful tool for research on regulated and unregulated priority DBPs.

Confocal endomicroscopy diagnostic criteria for early signet-ring cell carcinoma in hereditary diffuse gastric cancer.

BACKGROUND: Recognition of early signet-ring cell carcinoma (SRCC) in patients with hereditary diffuse gastric cancer (HDGC) undergoing endoscopic surveillance is challenging. We hypothesized that probe-based confocal laser endomicroscopy (pCLE) might help diagnose early cancerous lesions in the context of HDGC. The aim of this study was to identify pCLE diagnostic criteria for early SRCC. METHODS: Patients with HDGC syndrome were prospectively recruited and pCLE assessment was performed on areas suspicious for early SRCC and control regions during an endoscopic surveillance procedure. Targeted biopsies were taken for gold standard histologic assessment. In Phase I two investigators assessed video sequences off-line to identify pCLE features related to SRCC. In Phase II pCLE diagnostic criteria were evaluated in an independent video set by the investigators blinded to the histologic diagnosis. Sensitivity, specificity, accuracy, and interobserver agreement were calculated. RESULTS: Forty-two video sequences from 16 HDGC patients were included in Phase I. Four pCLE patterns associated to SRCC histologic features were identified: (A) glands with attenuated margins, (B) glands with spiculated or irregular shape, (C) heterogenous granular stroma with sparse glands, (D) enlarged vessels with tortuous shape. In Phase II, 38 video sequences from 15 patients were assessed. Criteria A and B and C had the highest diagnostic accuracy, with a κ for interobserver agreement ranging from 0.153 to 0.565. A panel comprising these 3 criteria with a cut-off of at least one positive criterion had a sensitivity of 80.9% (95%CI:58.1-94.5%) and a specificity of 70.6% (95%CI:44.0-89.7%) for a diagnosis of SRCC. CONCLUSIONS: We have generated and validated off-line pCLE criteria for early SRCC. Future real-time validation of these criteria is required.

Transformation of Algal Toxins during the Oxidation/Disinfection Processes of Drinking Water: From Structure to Toxicity.

With the increase of algal blooms worldwide, drinking water resources are threatened by the release of various algal toxins, which can be hepatotoxic, cytotoxic, or neurotoxic. Because of their ubiquitous occurrence in global waters and incomplete removal in conventional drinking water treatment, oxidation/disinfection processes have become promising alternative treatment options to destroy both the structures and toxicity of algal toxins. This Review first summarizes the occurrence and regulation of algal toxins in source water and drinking water. Then, the transformation kinetics, disinfection byproducts (DBPs)/transformation products (TPs), pathways, and toxicity of algal toxins in water oxidation/disinfection processes, including treatment by ozonation, chlorination, chloramination, ultraviolet-based advanced oxidation process, and permanganate, are reviewed. For most algal toxins, hydroxyl radicals (HO•) exhibit the highest oxidation rate, followed by ozone and free chlorine. Under practical applications, ozone and chlorine can degrade most algal toxins to meet water quality standards. However, the transformation of the parent structures of algal toxins by oxidation/disinfection processes does not guarantee a reduction in toxicity, and the formation of toxic TPs should also be considered, especially during chlorination. Notably, the toxicity variation of algal toxins is associated with the chemical moiety responsible for toxicity (e.g., Adda moiety in microcystin-LR and uracil moiety in cylindrospermopsin). Moreover, the formation of known halogenated DBPs after chlorination indicates that toxicity in drinking water may shift from toxicity contributed by algal toxins to toxicity contributed by DBPs. To achieve the simultaneous toxicity reduction of algal toxins and their TPs, optimized oxidation/disinfection processes are warranted in future research, not only for meeting water quality standards but also for effective reduction of toxicity of algal toxins.

Unravelling High-Molecular-Weight DBP Toxicity Drivers in Chlorinated and Chloraminated Drinking Water: Effect-Directed Analysis of Molecular Weight Fractions.

As disinfection byproducts (DBPs) are ubiquitous sources of chemical exposure in disinfected drinking water, identifying unknown DBPs, especially unknown drivers of toxicity, is one of the major challenges in the safe supply of drinking water. While >700 low-molecular-weight DBPs have been identified, the molecular composition of high-molecular-weight DBPs remains poorly understood. Moreover, due to the absence of chemical standards for most DBPs, it is difficult to assess toxicity contributions for new DBPs identified. Based on effect-directed analysis, this study combined predictive cytotoxicity and quantitative genotoxicity analyses and Fourier transform ion cyclotron resonance mass spectrometry (21 T FT-ICR-MS) identification to resolve molecular weight fractions that induce toxicity in chloraminated and chlorinated drinking waters, along with the molecular composition of these DBP drivers. Fractionation using ultrafiltration membranes allowed the investigation of <1 kD, 1-3 kD, 3-5 kD, and >5 kD molecular weight fractions. Thiol reactivity based predictive cytotoxicity and single-cell gel electrophoresis based genotoxicity assays revealed that the <1 kD fraction for both chloraminated and chlorinated waters exhibited the highest levels of predictive cytotoxicity and direct genotoxicity. The <1 kD target fraction was used for subsequent molecular composition identification. Ultrahigh-resolution MS identified singly charged species (as evidenced by the 1 Da spacing in 13C isotopologues), including 3599 chlorine-containing DBPs in the <1 kD fraction with the empirical formulas CHOCl, CHOCl2, and CHOCl3, with a relative abundance order of CHOCl > CHOCl2 ≫ CHOCl3. Interestingly, more high-molecular-weight CHOCl1-3 DBPs were identified in the chloraminated vs chlorinated waters. This may be due to slower reactions of NH2Cl. Most of the DBPs formed in chloraminated waters were composed of high-molecular-weight Cl-DBPs (up to 1 kD) rather than known low-molecular-weight DBPs. Moreover, with the increase of chlorine number in the high-molecular-weight DBPs detected, the O/C ratio exhibited an increasing trend, while the modified aromaticity index (AImod) showed an opposite trend. In drinking water treatment processes, the removal of natural organic matter fractions with high O/C ratio and high AImod value should be strengthened to minimize the formation of known and unknown DBPs.

Overlooked Iodo-Disinfection Byproduct Formation When Cooking Pasta with Iodized Table Salt.

Iodized table salt provides iodide that is essential for health. However, during cooking, we found that chloramine residuals in tap water can react with iodide in table salt and organic matter in pasta to form iodinated disinfection byproducts (I-DBPs). While naturally occurring iodide in source waters is known to react with chloramine and dissolved organic carbon (e.g., humic acid) during the treatment of drinking water, this is the first study to investigate I-DBP formation from cooking real food with iodized table salt and chloraminated tap water. Matrix effects from the pasta posed an analytical challenge, necessitating the development of a new method for sensitive and reproducible measurements. The optimized method utilized sample cleanup with Captiva EMR-Lipid sorbent, extraction with ethyl acetate, standard addition calibration, and analysis using gas chromatography (GC)-mass spectrometry (MS)/MS. Using this method, seven I-DBPs, including six iodo-trihalomethanes (I-THMs) and iodoacetonitrile, were detected when iodized table salt was used to cook pasta, while no I-DBPs were formed with Kosher or Himalayan salts. Total I-THM levels of 11.1 ng/g in pasta combined with cooking water were measured, with triiodomethane and chlorodiiodomethane dominant, at 6.7 and 1.3 ng/g, respectively. Calculated cytotoxicity and genotoxicity of I-THMs for the pasta with cooking water were 126- and 18-fold, respectively, compared to the corresponding chloraminated tap water. However, when the cooked pasta was separated (strained) from the pasta water, chlorodiiodomethane was the dominant I-THM, and lower levels of total I-THMs (retaining 30% of the I-THMs) and calculated toxicity were observed. This study highlights an overlooked source of exposure to toxic I-DBPs. At the same time, the formation of I-DBPs can be avoided by boiling the pasta without a lid and adding iodized salt after cooking.

AAPM BTSC Report 377: Physicist Brachytherapy Training in 2021-A survey of therapeutic medical physics residency program directors.

BACKGROUND: Brachytherapy (BT) was the first radiotherapeutic technique used to treat human disease and remains an essential modality in radiation oncology. A decline in the utilization of BT as a treatment modality has been observed and reported, which may impact training opportunities for medical physics residents. A survey of therapeutic medical physics residency program directors was performed as part of an assessment of the current state of BT training during residency. METHODS: In March 2021, a survey consisting of 23 questions was designed by a working unit of the Brachytherapy Subcommittee of the American Association of Physicists in Medicine (AAPM) and approved for distribution by the Executive Committee of the AAPM. The survey was distributed to the directors of the Commission on Accreditation of Medical Physics Education Programs (CAMPEP)-accredited therapeutic medical physics residency programs by the AAPM. The participant response was recorded anonymously in an online platform and then analyzed using MATLAB and Microsoft Excel software. RESULTS: The survey was distributed to the program directors of 110 residency programs. Over the course of 6 weeks, 72 directors accessed the survey online, and 55 fully completed the survey. Individual responses from the directors (including partial submissions) were evaluated and analyzed. Nearly all participating programs (98%) utilize high dose rate BT treatments with 74% using low dose rate BT techniques. All programs treated gynecological sites using BT, and the next most common treatment sites were prostate (80%) and breast (53%). Overall, the residency program directors had a positive outlook toward BT as a radiotherapeutic treatment modality. Caseload and time limitations were identified as primary barriers to BT training by some programs. CONCLUSIONS: Based on the responses of the program directors, it was identified that the residency programs might benefit from additional resources such as virtual BT training, interinstitutional collaborations as well as resident fellowships. Programs might also benefit from additional guidance related to BT-specific training requirements to help program directors attest Authorized Medical Physicist eligibility for graduating residents.

AAPM medical physics practice guideline 13.a: HDR brachytherapy, part A.

The American Association of Physicists in Medicine (AAPM) is a nonprofit professional society whose primary purposes are to advance the science, education, and professional practice of medical physics. The AAPM has more than 8000 members and is the principal organization of medical physicists in the United States. The AAPM will periodically define new practice guidelines for medical physics practice to help advance the science of medical physics and to improve the quality of service to patients throughout the United States. Existing medical physics practice guidelines (MPPGs) will be reviewed for the purpose of revision or renewal, as appropriate, on their fifth anniversary or sooner. Each medical physics practice guideline represents a policy statement by the AAPM, has undergone a thorough consensus process in which it has been subjected to extensive review, and requires the approval of the Professional Council. The medical physics practice guidelines recognize that the safe and effective use of diagnostic and therapeutic radiology requires specific training, skills, and techniques, as described in each document. Reproduction or modification of the published practice guidelines and technical standards by those entities not providing these services is not authorized. The following terms are used in the AAPM practice guidelines: (1) Must and must not: Used to indicate that adherence to the recommendation is considered necessary to conform to this practice guideline. (2) Should and should not: Used to indicate a prudent practice to which exceptions may occasionally be made in appropriate circumstances. Approved by AAPM's Executive Committee April 28, 2022.

A Practical Workflow for the Identification of Aspergillus, Fusarium, Mucorales by MALDI-TOF MS: Database, Medium, and Incubation Optimization.

There is an increasing body of literature on the utility of MALDI-TOF MS in the identification of filamentous fungi. However, the process still lacks standardization. In this study, we attempted to establish a practical workflow for the identification of three clinically important molds: Aspergillus, Fusarium, and Mucorales using MALDI-TOF MS. We evaluated the performance of Bruker Filamentous Fungi database v3.0 for the identification of these fungi, highlighting when there would be a benefit of using an additional database, the MSI-2 for further identification. We also examined two other variables, namely, medium effect and incubation time on the accuracy of fungal identification. The Bruker database achieved correct species level identification in 85.7% of Aspergillus and 90% of Mucorales, and correct species-complex level in 94.4% of Fusarium. Analysis of spectra using the MSI-2 database would also offer additional value for species identification of Aspergillus species, especially when suspecting species with known identification limits within the Bruker database. This issue would only be of importance in selected cases where species-level identification would impact therapeutic options. Id-Fungi plates (IDFP) had almost equivalent performance to Sabouraud dextrose agar (SDA) for species-level identification of isolates and enabled an easier harvest of the isolates with occasional faster identification. Our study showed accurate identification at 24 h for Fusarium and Mucorales species, but not for Aspergillus species, which generally required 48 h.

A Prolonged Outbreak of Human Adenovirus A31 (HAdV-A31) Infection on a Pediatric Hematopoietic Stem Cell Transplantation Ward with Whole Genome Sequencing Evidence of International Linkages.

A surge in hematopoietic stem cell transplantation (HSCT) human adenovirus A31 (HAdV-A31) infections was initially observed in late 2014/2015 at SickKids (SK) Hospital, Toronto, Canada. In response, enhanced laboratory monitoring for all adenovirus infections was conducted. Positive samples underwent genotyping, viral culture, and, in selected cases, whole-genome sequencing (WGS). HAdV-A31 specimens/DNA obtained from four international pediatric HSCT centers also underwent WGS. During the SK outbreak period (27 October 2014 to 31 October 2018), 17/20 HAdV-A31 isolates formed a distinct clade with 0 to 8 mutations between the closest neighbors. Surveillance before and after the outbreak detected six additional HAdV-A31 HSCT cases; three of the four sequenced cases clustered within the outbreak clade. Two SK outbreak isolates were identical to sequences from two patients in an outbreak in England. Three SK non-outbreak sequences also had high sequence similarity to strains from three international centers. Environmental PCR testing of the HSCT ward showed significant adenovirus contamination. Despite intense infection control efforts, we observed re-occurrence of infection with the outbreak strain. Severe but nonfatal infection was observed more commonly with HAdV-A31 compared to other genotypes, except HAdV-C1. Our findings strongly implicate nosocomial spread of HAdV-A31 over 10 years on a HSCT unit and demonstrate the value of WGS in defining and mapping the outbreak. Close linkages among strains in different countries suggest international dissemination, though the mechanism is undetermined. This large, extended outbreak emphasizes the pre-eminent role of HAdV-A31 in causing intractable pediatric HSCT outbreaks of severe illness worldwide.

Assessment of panfungal PCR performance with formalin-fixed paraffin-embedded tissue specimens†.

We reviewed the performance of a panfungal ITS-2 PCR and Sanger sequencing assay performed on 88 FFPE specimens at The Hospital for Sick Children (Toronto, Canada) in 2019. A potential fungal pathogen was identified by ITS PCR in 62.7 and 2.9% of positive and negative direct slide examination of tissue specimens, respectively. ITS amplicons were detected in 87/88 specimens, with 53/88 (60.2%) considered as 'positive-contaminants' and 34/88 (38.6%) as 'positive-potential pathogen' upon sequencing. Potential pathogens included Blastomyces dermatitidis (17.1%), Cryptococcus neoformans (17.1%), Histoplasma capsulatum (14.3%) and Mucormycetes (11.4%). Laboratories should only perform ITS PCR on FFPE tissues if fungal elements have been confirmed on histopathology slides. LAY SUMMARY: In this study, we examined how well a DNA-based test could detect DNA from fungi in archived human biopsy tissues. The best performance was achieved if fungi were seen in the tissue under a microscope before being tested. Our results indicate that we should only use this test if these conditions are met.

Halocyclopentadienes: An Emerging Class of Toxic DBPs in Chlor(am)inated Drinking Water.

Although >700 disinfection by-products (DBPs) have been identified to date, most DBPs in drinking water are still unknown. Identifying unknown DBPs is an important step for improving drinking water quality because known DBPs do not fully account for the adverse health effects noted in epidemiologic studies. Using gas chromatography high-resolution mass spectrometry, six chloro- and bromo-halocyclopentadienes (HCPDs) were identified in chlorinated and chloraminated drinking water via non-target analysis; five HCPDs are reported for the first time as new alicyclic DBPs. Formation pathways were also proposed. Simulated disinfection experiments with Suwannee River natural organic matter (NOM) confirm that NOM is a precursor for these new DBPs. Further, HCPDs are more abundant in chlorinated drinking water (real and simulated) when compared to chloraminated drinking water due to the higher reactivity of chlorine. Of these new DBPs, 1,2,3,4,5,5-hexachloro-1,3-cyclopentadiene is approximately 100,000× more toxic (in vivo) than regulated trihalomethanes (THMs) and haloacetic acids (HAAs) and 20-2000× more toxic than halobenzoquinones, halophenols, and halogenated pyridinols using the available median lethal dose (LD50) and concentration for 50% of maximal effective concentration (EC50) of DBPs to aquatic organisms. The predicted bioconcentration factors of these HCPDs range from 384 to 3980, which are 2-3 orders of magnitude higher than those for regulated and priority DBPs (including THMs, HAAs, halobenzoquinones, haloacetonitriles, haloacetamides, halonitromethanes, haloacetaldehydes, iodo-THMs, and iodo-HAAs). Thus, HCPDs are an important emerging class of DBPs that should be studied to better understand their impact on drinking water quality and long-term human health exposure.

Feel the Burn: Disinfection Byproduct Formation and Cytotoxicity during Chlorine Burn Events.

Nitrification and biofilm growth within distribution systems remain major issues for drinking water treatment plants utilizing chloramine disinfection. Many chloraminated plants periodically switch to chlorine disinfection for several weeks to mitigate these issues, known as "chlorine burns". The evaluation of disinfection byproduct (DBP) formation during chlorine burns beyond regulated DBPs is scarce. Here, we quantified an extensive suite of 80 regulated and emerging, unregulated DBPs from 10 DBP classes in drinking water from two U.S. drinking water plants during chlorine burn and chloramination treatments. Total organic halogen (TOX), including total organic chlorine, total organic bromine, and total organic iodine, was also quantified, and mammalian cell cytotoxicity of whole water mixtures was assessed in chlorine burn waters for the first time. TOX and most DBPs increased in concentration during chlorine burns, and one emerging DBP, trichloroacetaldehyde, reached 99 µg/L. THMs and HAAs reached concentrations of 249 and 271 µg/L, respectively. Two highly cytotoxic nitrogenous DBP classes, haloacetamides and haloacetonitriles, increased during chlorine burns, reaching up to 14.2 and 19.3 µg/L, respectively. Cytotoxicity did not always increase from chloramine treatment to chlorine burn, but a 100% increase in cytotoxicity was observed for one plant. These data highlight that consumer DBP exposure during chlorine burns can be substantial.

Drivers of Disinfection Byproduct Cytotoxicity in U.S. Drinking Water: Should Other DBPs Be Considered for Regulation?

This study reveals key disinfection byproduct (DBP) toxicity drivers in drinking water across the United States. DBPs, which are ubiquitous in drinking water, form by the reaction of disinfectants, organic matter, bromide, and iodide and are generally present at 100-1000× higher concentrations than other contaminants. DBPs are linked to bladder cancer, miscarriage, and birth defects in human epidemiologic studies, but it is not known as to which DBPs are responsible. We report the most comprehensive investigation of drinking water toxicity to date, with measurements of extracted whole-water mammalian cell chronic cytotoxicity, over 70 regulated and priority unregulated DBPs, and total organic chlorine, bromine, and iodine, revealing a more complete picture of toxicity drivers. A variety of impacted waters were investigated, including those impacted by wastewater, agriculture, and seawater. The results revealed that unregulated haloacetonitriles, particularly dihaloacetonitriles, are important toxicity drivers. In seawater-impacted water treated with chloramine, toxicity was driven by iodinated DBPs, particularly iodoacetic acids. In chlorinated waters, the combined total organic chlorine and bromine was highly and significantly correlated with toxicity (r = 0.94, P < 0.01); in chloraminated waters, total organic iodine was highly and significantly correlated with toxicity (r = 0.80, P < 0.001). These results indicate that haloacetonitriles and iodoacetic acids should be prioritized in future research for potential regulation consideration.

Planet Contamination with Chemical Compounds.

The number of known priority pollutants and emerging contaminants of environmental concern currently exceeds several thousand (US EPA Part 423, US EPA Part 401) [...].

Do DBPs swim in salt water pools? Comparison of 60 DBPs formed by electrochemically generated chlorine vs. conventional chlorine.

Disinfectants are added to swimming pools to kill harmful pathogens. Although liquid chlorine (sodium hypochlorite) is the most commonly used disinfectant, alternative disinfection techniques like electrochemically generated mixed oxidants or electrochemically generated chlorine, often referred to as salt water pools, are growing in popularity. However, these disinfectants react with natural organic matter and anthropogenic contaminants introduced to the pool water by swimmers to form disinfection byproducts (DBPs). DBPs have been linked to several adverse health effects, such as bladder cancer, adverse birth outcomes, and asthma. In this study, we quantified 60 DBPs using gas chromatography-mass spectrometry and assessed the calculated cytotoxicity and genotoxicity of an indoor community swimming pool before and after switching to a salt water pool with electrochemically generated chlorine. Interestingly, the total DBPs increased by 15% upon implementation of the salt water pool, but the calculated cytotoxicity and genotoxicity decreased by 45% and 15%, respectively. Predominant DBP classes formed were haloacetic acids, with trichloroacetic acid and dichloroacetic acid contributing 57% of the average total DBPs formed. Haloacetonitriles, haloacetic acids, and haloacetaldehydes were the primary drivers of calculated cytotoxicity, and haloacetic acids were the primary driver of calculated genotoxicity. Diiodoacetic acid, a highly toxic iodinated DBP, is reported for the first time in swimming pool water. Bromide impurities in sodium chloride used to electrochemically generate chlorine led to a 73% increase in brominated DBPs, primarily driven by bromochloroacetic acid. This study presents the most extensive DBP study to-date for salt water pools.