In June, 2022, 25 scientists from eight countries met at the International Agency for Research on Cancer (IARC) in Lyon, France, to finalise their evaluation of the carcinogenicity of occupational ...exposure as a firefighter. Firefighters can be exposed to combustion products from fires (eg, polycyclic aromatic hydrocarbons PAHs and particulates), building materials (eg, asbestos), chemicals in firefighting foams (eg, perfluorinated and polyfluorinated substances PFAS), flame retardants, diesel exhaust, and other hazards (eg, night shift work and ultraviolet or other radiation). Dermal absorption of chemicals can occur even in firefighters wearing PPE due to limitations of its design, fit, maintenance, or decontamination. Since the previous classification of firefighting (as “possibly carcinogenic to humans,” Group 2B) by the IARC Monographs in 2007,2 many new studies have investigated the association between occupational exposure as a firefighter and cancer risk in humans. Airway and systemic inflammatory markers, such as IL-6 and IL-8, were associated with firefighting-related exposures. ...declines in lung function associated with changes in inflammatory markers and exposure-associated bronchial hyperreactivity were reported in firefighters.
Abstract
Excretion of toxicants accumulated from firefighter exposures through breastmilk represents a potential hazard. We investigated if firefighting exposures could increase the concentration of ...polybrominated diphenyl ethers (PBDEs) and aryl hydrocarbon receptor (AhR) activation in excreted breastmilk. Firefighters and nonfirefighters collected breastmilk samples prior to any firefighting responses (baseline) and at 2, 8, 24, 48, and 72 h after a structural fire (firefighters only). Five PBDE analytes (BDEs 15, 28, 47, 99, and 153) detected in at least 90% of samples were summed for analyses. The AhR in vitro DR CALUX bioassay assessed the mixture of dioxin-like compounds and toxicity from breastmilk extracts. Baseline PBDEs and AhR responses were compared between firefighters and nonfirefighters. Separate linear mixed models assessed changes in sum of PBDEs and AhR response among firefighters over time and effect modification by interior or exterior response was assessed. Baseline PBDE concentrations and AhR responses did not differ between the 21 firefighters and 10 nonfirefighters. There were no significant changes in sum of PBDEs or AhR response among firefighters over time postfire, and no variation by interior or exterior response. Plots of sum of PBDEs and AhR response over time demonstrated individual variation but no consistent pattern. Currently, our novel study results do not support forgoing breastfeeding after a fire exposure. However, given study limitations and the potential hazard of accumulated toxicants from firefighter exposures excreted via breastfeeding, future studies should consider additional contaminants and measures of toxicity by which firefighting may impact maternal and child health.
Arsenic exposure from drinking water is associated with adverse respiratory outcomes, but it is unknown whether arsenic affects pulmonary microbiota. This exploratory study assessed the effect of ...exposure to arsenic in drinking water on bacterial diversity in the respiratory tract of non-smokers. Induced sputum was collected from 10 subjects with moderate mean household water arsenic concentration (21.1 ± 6.4 ppb) and 10 subjects with low household water arsenic (2.4 ± 0.8 ppb). To assess microbiota in sputum, the V6 hypervariable region amplicons of bacterial 16s rRNA genes were sequenced using the Ion Torrent Personal Genome Machine. Microbial community differences between arsenic exposure groups were evaluated using QIIME and Metastats. A total of 3,920,441 sequence reads, ranging from 37,935 to 508,787 per sample for 316 chips after QIIME quality filtering, were taxonomically classified into 142 individual genera and five phyla. Firmicutes (22%), Proteobacteria (17%) and Bacteriodetes (12%) were the main phyla in all samples, with Neisseriaceae (15%), Prevotellaceae (12%) and Veillonellacea (7%) being most common at the genus level. Some genera, including Gemella, Lactobacillales, Streptococcus, Neisseria and Pasteurellaceae were elevated in the moderate arsenic exposure group, while Rothia, Prevotella, Prevotellaceae Fusobacterium and Neisseriaceae were decreased, although none of these differences was statistically significant. Future studies with more participants and a greater range of arsenic exposure are needed to further elucidate the effects of drinking water arsenic consumption on respiratory microbiota.
The goal of the Mu2e experiment at Fermilab is to search for charged-lepton flavor violation by looking for neutrino-less muon to electron conversion in the field of the nucleus. The Mu2e ...experimental apparatus utilizes a complex magnetic field in the muon generation and momentum and charge selection process. Precise knowledge of the magnetic field is crucial. It is planned to map the solenoid field with calibrated three-dimensional (3-D) Hall probes up to 10 -5 accuracy. This article describes a new design of a Hall probe calibration system that will be used to calibrate 3-D Hall probes to better than 10 -5 accuracy for the Mu2e solenoid field mapping system.
Mu2e Solenoid Field Mapping System Design Feher, Sandor; DeLurgio, Patrick; Elementi, Luciano ...
IEEE transactions on applied superconductivity,
04/2018, Letnik:
28, Številka:
3
Journal Article
Recenzirano
Odprti dostop
The Mu2e experiment at Fermilab plans to search for charged-lepton flavor violations by looking for neutrino-less muon to electron conversions in the field of the nucleus. A complex solenoid system ...and precise knowledge of its magnetic field play a major role in the experimental approach Mu2e has chosen. It is essential to map the solenoid field up to 10 -4 accuracy. This article describes the design of the Field Mapping System Mu2e will use to measure the magnetic field. Two different mechanical mapper systems, a survey-based position determination of the in-house calibrated three-dimensional Hall probes, a motion control system, and a data acquisition and readout system are presented.
The transcriptional underpinnings of brain development remain poorly understood, particularly in humans and closely related non-human primates. We describe a high-resolution transcriptional atlas of ...rhesus monkey (Macaca mulatta) brain development that combines dense temporal sampling of prenatal and postnatal periods with fine anatomical division of cortical and subcortical regions associated with human neuropsychiatric disease. Gene expression changes more rapidly before birth, both in progenitor cells and maturing neurons. Cortical layers and areas acquire adult-like molecular profiles surprisingly late in postnatal development. Disparate cell populations exhibit distinct developmental timing of gene expression, but also unexpected synchrony of processes underlying neural circuit construction including cell projection and adhesion. Candidate risk genes for neurodevelopmental disorders including primary microcephaly, autism spectrum disorder, intellectual disability, and schizophrenia show disease-specific spatiotemporal enrichment within developing neocortex. Human developmental expression trajectories are more similar to monkey than rodent, although approximately 9% of genes show human-specific regulation with evidence for prolonged maturation or neoteny compared to monkey.
1. The physiological significance of communication through gap junction channels has been difficult to assess because channel activity cannot be experimentally modulated in a specific manner. To ...address this problem we have constructed chimeric connexins that function as dominant-negative inhibitors of intercellular channel activity.
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