Carbon monoxide poisoning--a public health perspective

Spectrum of delayed post-hypoxic leukoencephalopathy syndrome: A systematic review

BACKGROUND

Delayed post hypoxic leukoencephalopathy syndrome (DPHLS), also known as Grinker’s myelinopathy, is a rare but significant neurological condition that manifests days to weeks after a hypoxic event. Characterized by delayed onset of neurological and cognitive deficits, DPHLS presents substantial diagnostic and therapeutic challenges.

AIM

To consolidate current knowledge on pathophysiology, clinical features, diagnostic approaches, and management strategies for DPHLS, providing a comprehensive overview and highlighting gaps for future research.

METHODS

Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyzes guidelines, we systematically searched PubMed, ScienceDirect and Hinari databases using terms related to delayed post-hypoxic leukoencephalopathy. Inclusion criteria were original research articles, case reports, and case series involving human subjects with detailed clinical, neuroimaging, or pathological data on DPHLS. Data were extracted on study characteristics, participant demographics, clinical features, neuroimaging findings, pathological findings, treatment, and outcomes. The quality assessment was performed using the Joanna Briggs Institute critical appraisal checklist.

RESULTS

A total of 73 cases were reviewed. Common comorbidities included schizoaffective disorder, bipolar disorder, hypertension, and substance use disorder. The primary causes of hypoxia were benzodiazepine overdose, opioid overdose, polysubstance overdose, and carbon monoxide (CO) poisoning. Symptoms frequently include decreased level of consciousness, psychomotor agitation, cognitive decline, parkinsonism, and encephalopathy. Neuroimaging commonly revealed diffuse T2 hyperintensities in cerebral white matter, sometimes involving the basal ganglia and the globus pallidus. Magnetic resonance spectroscopy often showed decreased N-acetylaspartate, elevated choline, choline-to-creatinine ratio, and normal or elevated lactate. Treatment is often supportive, including amantadine, an antioxidant cocktail, and steroids. Hyperbaric oxygen therapy may be beneficial in those with CO poisoning. Parkinsonism was often treated with levodopa. Most of the patients had substantial recovery over the course of months and many cases had some residual neurocognitive deficits.

CONCLUSION

DPHLS remains a complex and multifaceted condition with various etiologies and clinical manifestations. Early recognition and appropriate management are crucial to improving patient outcomes. Future research should focus on standardizing diagnostic criteria, using advanced imaging techniques, and exploring therapeutic interventions to improve understanding and treatment of DPHLS. Conducting prospective cohort studies and developing biomarkers for early diagnosis and monitoring will be essential to advance patient care.

Theoretical study of adsorption of gas (CO, CO2, NH3) by metal (Au, Ag, Cu)-doped single-layer WS2

CONTEXT

The adsorptions of gas (CO, CO2, NH3) by metal (Au, Ag, Cu)-doped single layer WS2 are studied by density functional theory. The doping of metal atoms makes WS2 behave as n-type semiconductors. The final adsorption sites for CO, CO2, and NH3 are close to the atomic sites of the doped metal. The adsorptions of CO and NH3 gases on Cu/WS2, Ag/WS2, and Au/WS2 are dominated by chemisorption. The doped metal atoms enhance the hybridization of the substrate with the gas molecular orbitals, which contributes to the charge transfer and enhances the adsorption of the gas with the material surface. The adsorptions of CO and NH3 on Cu/WS2 and Ag/WS2 allow favorable desorption in a short time after heating. The single-layer Cu/WS2 is proved to have the potential to be used as a reliable recyclable sensor for CO. This work provides a theoretical basis for developing high-performance WS2-based gas sensors.

METHODS

In this paper, the adsorption energy, electronic structure, charge transfer, and recovery time of CO, CO2, and NH3 in the doped system have been investigated based on the CASTEP code of density functional theory. The exchange correlation function used is the Perdew-Burke-Ernzerhof (PBE) generalized gradient approximation (GGA). The TS (Tkatchenko-Scheffler) dispersion correction method was used to involve the effects of van der Waals interaction on the adsorption energies for all adsorption system. The ultrasoft pseudopotentials are chosen and the plane-wave cut-off energies are set to 500 eV. The k-point mesh generated by the Monkhorst package scheme is used to perform the numerical integration of the Brillouin zone and 5 × 5 × 1 k-point grid is used. The tolerances of total energy convergence, maximum ionic force, ionic displacement, and stress component are 1.0 × 10-5 eV/atom, 0.03 eV/Å, 0.001 Å, and 0.05 GPa, respectively.

Polyprodrug nanomedicine for chemiexcitation-triggered self-augmented cancer chemotherapy and gas therapy

Carbon monoxide (CO) has emerged as a potential antitumor agent by inducing the dysfunction of mitochondria and the apoptosis of cancer cells. However, it remains challenging to deliver appropriate amount of CO into tumor to ensure efficient tumor growth suppression with minimum side effects. Herein we developed a CO prodrug-loaded nanomedicine based on the self-assembly of camptothecin (CPT) polyprodrug amphiphiles. The polyprodrug nanoparticles readily dissociate upon exposure to endogenous H2O2 in the tumor, resulting in rapid release of CPT and generation of high-energy intermediate dioxetanedione. The latter can transfer the energy to neighboring CO prodrugs to activate CO production by chemiexcitation, while CPT promotes the generation of H2O2 in tumors, which in turn facilitates cascade CPT and CO release. As a result, the polyprodrug nanoparticles display remarkable tumor suppression in both subcutaneous and orthotopic breast tumor-bearing mice owing to the self-augmented CPT release and CO generation. In addition, no obvious systemic toxicity was observed in mice treated with the metal-free CO prodrug-loaded nanomedicine, suggesting the good biocompatibility of the polyprodrug nanoparticles. Our work provides new insights into the design and construction of polyprodrug nanomedicines for synergistic chemo/gas therapy.

Early and late adverse clinical outcomes of severe carbon monoxide intoxication: A cross-sectional retrospective study

BACKGROUND

Carbon monoxide (CO) results from incomplete combustion of carbon-based materials, causing symptoms such as headaches, dizziness, nausea, chest pain, confusion, and, in severe cases, unconsciousness. Normobaric oxygen therapy (NBOT) is the standard therapy, whereas hyperbaric oxygen therapy (HBOT) is recommended in severe cases of organ damage. This study examined the early and late adverse outcomes in patients with severe CO poisoning.

MATERIALS AND METHODS

This study analyzed severe cases of CO poisoning among patients admitted to the emergency department between January 2020 and May 2022. The demographic, clinical, and laboratory data of symptomatic individuals and those requiring HBOT were examined. The study recorded early outcomes, such as intubation and in-hospital mortality, and late outcomes, such as delayed neurological sequelae and 1-year mortality. Chi-square tests, Spearman's rho correlation tests, and logistic regression analyses were performed to identify factors affecting these outcomes.

RESULTS

Patients who received HBOT showed a significant difference in delayed neurological sequelae (DNS) compared to those who received NBOT (p = 0.037). Significant differences were observed in the need for intubation, in-hospital mortality, and 1-year mortality between patients based on COHb levels, but no significant differences were found in DNS. The 1-year mortality probability was significantly influenced by COHb level (odds ratio = 1.159, 95% CI [1.056-1.273]). Patients receiving NBOT had a higher odds ratio for DNS risk than those receiving HBOT (odds ratio = 8.464, 95% [1.755-40.817], p = 0.008).

CONCLUSION

The study showed no differences in intubation, in-hospital mortality, and 1-year mortality rates between the HBOT and NBOT groups. However, significant differences in DNS suggest that treatment modalities have different effects on neurological outcomes. High COHb levels are associated with an increased risk of intubation, and mortality underscores the significance of monitoring COHb levels in clinical evaluations.

Different effects of air pollutant concentrations on influenza A and B in Sichuan, China

BACKGROUND

The detrimental effects of air pollution on the respiratory system are well documented. Previous research has established a correlation between air pollutant concentration and the frequency of outpatient visits for influenza-like illness. However, studies investigating the variations in infection among different influenza subtypes remain sparse. We aimed to determine the correlation between air pollutant levels and different influenza subtypes in Sichuan Province, China.

METHODS

A generalized additive model and distributed lag nonlinear model were employed to assess the association between air pollutants and influenza subtypes, utilizing daily influenza data obtained from 30 hospitals across 21 cities in Sichuan Province. The analysis considered the temporal effects and meteorological factors. The study spanned from January 1, 2017, to December 31, 2019. To provide a more precise evaluation of the actual impact of air pollution on different subtypes of influenza, we also performed subgroup analyses based on factors such as gender, age, and geography within the population.

RESULTS

During the investigation, 17,462 specimens from Sichuan Province tested positive for influenza. Among these, 12,607 and 4855 were diagnosed with Flu A and B, respectively. The related risk of influenza A infection significantly increased following exposure to PM2.5 on Lag2 days (RR=1.008, 95 % confidence interval [CI]: 1.000-1.016), SO2 and CO on Lag1 days (RR=1.121, 95 % CI: 1.032-1.219; RR=1.151, 95 % CI: 1.030-1.289), and NO2 on Lag0 day (RR=1.089, 95 % CI: 1.035-1.145). PM10 and SO2 levels on Lag0 day, PM2.5 levels on Lag1 day, and CO levels on Lag6 day, with a reduced risk of influenza B (RR=0.987, 95 % CI: 0.976-0.997; RR=0.817, 95 % CI: 0.676-0.987; RR=0.979, 95 % CI: 0.970-0.989; RR=0.814, 95 % CI: 0.561-0.921).

CONCLUSION

The findings from the overall population and subgroup analyses indicated that the impact of air pollutant concentrations on influenza A and B is inconsistent, with influenza A demonstrating greater susceptibility to these pollutants. Minimizing the levels of SO2, CO, NO2, and PM2.5 can significantly decrease the likelihood of contracting influenza A. Analyzing the influence of environmental contaminants on different influenza subtypes can provide insights into seasonal influenza trends and guide the development of preventive and control strategies.

Short and long-term outcomes of multidimensional physiotherapy in cases with acute compartment syndrome secondary to carbon monoxide poisoning with prolonged forearm compression

BACKGROUND

Compartment syndrome following carbon monoxide (CO) poisoning and compression, can have a devastating impact on neuromuscular structures, depending on a time-based dosage.

PURPOSE

To investigate multidimensional physiotherapy's short-term and long-term outcomes in identical twin cases who developed compartment syndrome due to CO poisoning and prolonged compression.

STUDY DESIGN

Case report.

METHODS

This study was conducted with two male cases, a 21-year-old identical twin. The loss of consciousness due to CO poisoning lasted for 15 hours. Case one had compartment syndrome that caused damage to the median and ulnar nerves in the right forearm, while Case two had compartment syndrome that caused damage to the radial nerve in the left forearm. No surgical intervention was performed (Fasciotomy etc).

RESULTS

The disability, dexterity, hand health status, sensory-motor function, and edema were evaluated. Initial evaluations showed severe sensory and motor dysfunction, disability, and edema. Treatment included Complex decongestive physiotherapy, electrical stimulation, therapeutic ultrasound, orthotics, and exercises. On the 144th day (discharge day), both cases still exhibited weakness in functional strength and sensory loss compared to the uninjured side. At the ninth month, all parameters except strength were similar to the uninjured side in both cases. By the 53rd month, strength also reached normal values.

CONCLUSIONS

Multidimensional physiotherapy effectively manages edema, improves sensory-motor function, and enhances hand function in the short and long term.

Postmortem concentrations for total blood carbon monoxide (TBCO) as a novel biomarker for carbon monoxide (CO) poisonings

Total blood carbon monoxide (TBCO) showed promising results in improving accuracy of CO determinations in blood and presenting better stability to different storage conditions. Therefore, it was proposed as an alternative biomarker to carboxyhemoglobin (COHb) for CO poisoning diagnosis. However, given that current interpretation reference values exist for COHb only, it is difficult to implement TBCO analysis in routine. Therefore, we aimed at determining TBCO reference values for postmortem CO poisoning cases. A previously validated method for TBCO analysis via gas chromatography-mass spectrometry was applied to cardiac, peripheral, cranial and spleen blood samples collected from 92 autopsies. Autopsy cases included 21 non-CO-related and 71 CO-related cases with varying postmortem intervals (PMIs). Statistical analyses were performed using statistical software R Studio. When comparing lower to higher PMIs for non-CO-related cases, no significant differences were found, which suggests that CO formation or degradation at low PMIs does not occur. Spleen blood showed potential as an alternative matrix to CO determinations in cases with sample availability issues but needs to be evaluated for CO-positive cases. Results for cardiac blood in CO-related autopsies showed a positive correlation between COHb and TBCO values (R = 0.78). This value is lower than what is found in the literature, suggesting that even though COHb and TBCO are correlated, a potential underestimation of the true CO exposure might occur if only COHb values are taken into consideration. Samples were divided into CO exposure groups based on COHb concentrations, and with the data obtained, classification into the following TBCO concentration groups is proposed: no significant CO exposure case <6 µmol/mL, medium CO exposure case 6-20 µmol/mL and high CO exposure case >20 µmol/mL. Even if a higher number of samples in each group would enable to increase the confidence, these results are very promising and highlight the importance of TBCO measurement.

Binding of Carbon Monoxide to Hemoglobin in an Oxygen Environment: Force Field Development for Molecular Dynamics

Carbon monoxide (CO) is a byproduct of the incomplete combustion of carbon-based fuels, such as wood, coal, gasoline, or natural gas. As incomplete combustion in a fire accident or in an engine, massively produced CO leads to a serious life threat because CO competes with oxygen (O2) binding to hemoglobin and makes people suffer from hypoxia. Although there is hyperbaric O2 therapy for patients with CO poisoning, the nanoscale mechanism of CO dissociation in the O2-rich environment is not completely understood. In this study, we construct the classical force field parameters compatible with the CHARMM for simulating the coordination interactions between hemoglobin, CO, and O2, and use the force field to reveal the impact of O2 on the binding strength between hemoglobin and CO. Density functional theory and Car-Parrinello molecular dynamics simulations are used to obtain the bond energy and equilibrium geometry, and we used machine learning enabled via a feedforward neural network model to obtain the classical force field parameters. We used steered molecular dynamics simulations with a force field to characterize the mechanical strength of the hemoglobin-CO bond before rupture under different simulated O2-rich environments. The results show that as O2 approaches the Fe2+ of heme at a distance smaller than ∼2.8 Å, the coordination bond between CO and Fe2+ is reduced to 50% bond strength in terms of the peak force observed in the rupture process. This weakening effect is also shown by the free energy landscape measured by our metadynamics simulation. Our work suggests that the O2-rich environment around the hemoglobin-CO bond effectively weakens the bonding, so that designing of O2 delivery vector to the site is helpful for alleviating CO binding, which may shed light on de novo drug design for CO poisoning.

The Relationship between Fragmented QRS and Myocardial Injury in Patients with Acute Carbon Monoxide Poisoning

Background and Objectives: Carbon monoxide (CO) intoxication is one of the most common causes of poisoning-related deaths and complications. Myocardial injury is an important complication of CO poisoning. In our study, we aimed to evaluate the relationship between the presence and prevalence of fragmented QRS (fQRS) and myocardial injury in patients with CO intoxication. Materials and Methods: We retrospectively evaluated patients who presented to the emergency department of our tertiary care center with CO intoxication between January 2020 and December 2023. In our study, we performed subgroup analyses according to the presence of myocardial injury and fQRS. We evaluated the parameters and risk factors associated with myocardial injury. Results: Myocardial injury was detected in 44 patients, and fQRS was detected in 38 patients. In the myocardial injury (+) group, the fQRS rate was 38.6%, and the median number of leads with fQRS was 3 (2-6) and was significantly higher than in the myocardial injury (-) group (p < 0.001). We found that carboxyhemoglobin had a significant positive correlation with troponin (p = 0.001) and pro-B-type natriuretic peptide (proBNP) (p = 0.009). As a result of multivariate analysis, we determined that age, creatinine, proBNP, fQRS, and ≥3 leads with fQRS are independent risk factors for myocardial injury. Conclusions: Myocardial injury in CO intoxication patients is associated with proBNP, the presence of fQRS, and the number of leads with fQRS. Age, creatinine level, proBNP, the presence of fQRS, and ≥3 leads with fQRS are independent risk factors for myocardial injury in patients with CO intoxication.

Carbon monoxide as a cellular protective agent in a swine model of cardiac arrest protocol

Out-of-hospital cardiac arrest (OHCA) affects over 360,000 adults in the United States each year with a 50-80% mortality prior to reaching medical care. Despite aggressive supportive care and targeted temperature management (TTM), half of adults do not live to hospital discharge and nearly one-third of survivors have significant neurologic injury. The current treatment approach following cardiac arrest resuscitation consists primarily of supportive care and possible TTM. While these current treatments are commonly used, mortality remains high, and survivors often develop lasting neurologic and cardiac sequela well after resuscitation. Hence, there is a critical need for further therapeutic development of adjunctive therapies. While select therapeutics have been experimentally investigated, one promising agent that has shown benefit is CO. While CO has traditionally been thought of as a cellular poison, there is both experimental and clinical evidence that demonstrate benefit and safety in ischemia with lower doses related to improved cardiac/neurologic outcomes. While CO is well known for its poisonous effects, CO is a generated physiologically in cells through the breakdown of heme oxygenase (HO) enzymes and has potent antioxidant and anti-inflammatory activities. While CO has been studied in myocardial infarction itself, the role of CO in cardiac arrest and post-arrest care as a therapeutic is less defined. Currently, the standard of care for post-arrest patients consists primarily of supportive care and TTM. Despite current standard of care, the neurological prognosis following cardiac arrest and return of spontaneous circulation (ROSC) remains poor with patients often left with severe disability due to brain injury primarily affecting the cortex and hippocampus. Thus, investigations of novel therapies to mitigate post-arrest injury are clearly warranted. The primary objective of this proposed study is to combine our expertise in swine models of CO and cardiac arrest for future investigations on the cellular protective effects of low dose CO. We will combine our innovative multi-modal diagnostic platform to assess cerebral metabolism and changes in mitochondrial function in swine that undergo cardiac arrest with therapeutic application of CO.

Carbon Monoxide Poisoning: From Occupational Health to Emergency Medicine

Carbon monoxide poisoning remains a leading cause of accidental poisoning worldwide (both at home and at work), and it is also a cause of suicidal poisoning. Such poisoning can arise following prolonged exposure to low levels of CO or following brief exposure to high concentrations of the gas. In fact, despite exposure limits, high safety standards, and the availability of CO alarms, nearly 50,000 people in the United States visit the emergency department each year due to poisoning. Additionally, CO poisoning in the United States causes up to 500 deaths each year. Despite the widespread nature of this form of poisoning, known about for centuries and whose damage mechanisms have been recognized (or rather hypothesized about) since the 1800s, early recognition, especially of late complications, and treatment remain a medical challenge. A well-designed therapeutic diagnostic process is necessary so that indication for hyperbaric or normobaric therapy is correctly made and so that patients are followed up even after acute exposure to diagnose late complications early. Furthermore, it is necessary to consider that in the setting of emergency medicine, CO poisoning can be part of a differential diagnosis along with other more frequent conditions, making its recognition difficult. The last thirty years have been marked by a significant increase in knowledge regarding the toxicity of CO, as well as its functioning and its importance at physiological concentrations in mammalian systems. This review, taking into account the significant progress made in recent years, aims to reconsider the pathogenicity of CO, which is not trivially just poisonous to tissues. A revision of the paradigm, especially as regards treatment and sequelae, appears necessary, and new studies should focus on this new point of view.

For Submission to the Journal of Community Health: Carbon Monoxide Awareness and Detector Use in the State of Wisconsin

Carbon monoxide (CO) is a leading cause of poisoning. CO detectors are a known-effective prevention strategy, however, little is known about use of detectors or knowledge of risk. This study assessed awareness of CO poisoning risk, detector laws, and detector use among a statewide sample. Data collected from the Survey of the Health of Wisconsin (SHOW) included a CO Monitoring module added to the in-home interview for 466 participants representing unique households across Wisconsin in 2018-2019. Univariate and multivariable logistic regression models examined associations between demographic characteristics, awareness of CO laws and detector use. Less than half of households had a verified CO detector. Under 46% were aware of the detector law. Those aware had 2.82 greater odds of having a detector in the home compared to those unaware of the law. Lack of CO law awareness may lead to less frequent detector use and result in higher risk of CO poisoning. This highlights the need for CO risk and detector education to decrease poisonings.

Spatio-temporal analysis of deaths from carbon monoxide poisoning in Iran between 2011 and 2018: An ecological study

Background and Aims

Mortality caused by carbon monoxide every year threatens the lives of Iranian people, whose spatial and temporal distribution is not known for formulating prevention policies and interventions. This study was conducted to determine the trend of mortality rate changes due to carbon monoxide CO poisoning by Spatio-temporal analysis in Iran from 2011 to 2018.

Methods

An ecological study was conducted based on data from the reports at the National Center for Statistics of Iran for 8 years from 21 March 2011 to 21 March 2018. The number of deaths due to CO poisoning and the annual mortality rates of CO poisoning per 100,000 populations were calculated. To determine the geographical and temporal distribution of death caused by carbon monoxide, spatiotemporal statistical analysis was used.

Results

A total of 6078 deaths were reported due to CO poisoning 4497 deaths were male (74%) and 1596 were female (26%) from 2011 to 2018. Both sexes' mortality rate due to CO poisoning was 1.26 from 2011 to 0.91 in 2018. According to the results, the overall male-to-female ratio was 2.8. The mortality rate due to CO Poisoning had a decreasing trend. However, this trend did not have a linear trend (p = 0.37). The highest mortality due to CO poisoning was seen in the northern and western provinces of Iran.

Conclusion

Our results showed that the mortality rate due to CO poisoning had a decreasing trend during the understudied period. Also, most of the deaths due to CO poisoning occurred in the northern and western provinces of Iran. So, designing prevention programs as well as increasing people's awareness in these regions is recommended.

Global, regional, and national mortality due to unintentional carbon monoxide poisoning, 2000-2021: results from the Global Burden of Disease Study 2021

BACKGROUND

Unintentional carbon monoxide poisoning is a largely preventable cause of death that has received insufficient attention. We aimed to conduct a comprehensive global analysis of the demographic, temporal, and geographical patterns of fatal unintentional carbon monoxide poisoning from 2000 to 2021.

METHODS

As part of the latest Global Burden of Diseases, Injuries, and Risk Factors Study (GBD), unintentional carbon monoxide poisoning mortality was quantified using the GBD cause of death ensemble modelling strategy. Vital registration data and covariates with an epidemiological link to unintentional carbon monoxide poisoning informed the estimates of death counts and mortality rates for all locations, sexes, ages, and years included in the GBD. Years of life lost (YLLs) were estimated by multiplying deaths by remaining standard life expectancy at age of death. Population attributable fractions (PAFs) for unintentional carbon monoxide poisoning deaths due to occupational injuries and high alcohol use were estimated.

FINDINGS

In 2021, the global mortality rate due to unintentional carbon monoxide poisoning was 0·366 per 100 000 (95% uncertainty interval 0·276-0·415), with 28 900 deaths (21 700-32 800) and 1·18 million YLLs (0·886-1·35) across all ages. Nearly 70% of deaths occurred in males (20 100 [15 800-24 000]), and the 50-54-year age group had the largest number of deaths (2210 [1660-2590]). The highest mortality rate was in those aged 85 years or older with 1·96 deaths (1·38-2·32) per 100 000. Eastern Europe had the highest age-standardised mortality rate at 2·12 deaths (1·98-2·30) per 100 000. Globally, there was a 53·5% (46·2-63·7) decrease in the age-standardised mortality rate from 2000 to 2021, although this decline was not uniform across regions. The overall PAFs for occupational injuries and high alcohol use were 13·6% (11·9-16·0) and 3·5% (1·4-6·2), respectively.

INTERPRETATION

Improvements in unintentional carbon monoxide poisoning mortality rates have been inconsistent across regions and over time since 2000. Given that unintentional carbon monoxide poisoning is almost entirely preventable, policy-level interventions that lower the risk of carbon monoxide poisoning events should be prioritised, such as those that increase access to improved heating and cooking devices, reduce carbon monoxide emissions from generators, and mandate use of carbon monoxide alarms.

FUNDING

Bill & Melinda Gates Foundation.

Association of carbon monoxide poisonings and carboxyhemoglobin levels with COVID-19 and clinical severity

BACKGROUND

Coronavirus disease 2019 (COVID-19), which recently spread throughout the entire world, is still a significant health issue. Additionally, the most common cause of risky poisoning in emergency services is carbon monoxide (CO) poisoning. Both disorders seem to merit more research as they have an impact on all bodily systems via the lungs.

AIM

To determine how arterial blood gas and carboxyhemoglobin (COHb) levels affect the clinical and prognostic results of individuals requiring emergency treatment who have both COVID-19 and CO poisoning.

METHODS

Between January 2018 and December 2021, 479 CO-poisoning patients participated in this single-center, retrospective study. Patients were primarily divided into two groups for analysis: Pre-pandemic and pandemic periods. Additionally, the pandemic era was divided into categories based on the presence of COVID-19 and, if present, the clinical severity of the infection. The hospital information system was used to extract patient demographic, clinical, arterial blood gas, COVID-19 polymerase chain reaction, and other laboratory data.

RESULTS

The mean age of the 479 patients was 54.93 ± 11.51 years, and 187 (39%) were female. 226 (47%) patients were in the pandemic group and 143 (30%) of them had a history of COVID-19. While the mean potential of hydrogen (pH) in arterial blood gas of all patients was 7.28 ± 0.15, it was 7.35 ± 0.10 in the pre-pandemic group and 7.05 ± 0.16 in the severe group during the pandemic period (P < 0.001). COHb was 23.98 ± 4.19% in the outpatients and 45.26% ± 3.19% in the mortality group (P < 0.001). Partial arterial oxygen pressure (PaO2) was 89.63 ± 7.62 mmHg in the pre-pandemic group, and 79.50 ± 7.18 mmHg in the severe group during the pandemic period (P < 0.001). Despite the fact that mortality occurred in 35 (7%) of all cases, pandemic cases accounted for 30 of these deaths (85.7%) (P <0.001). The association between COHb, troponin, lactate, partial arterial pressure of carbon dioxide, HCO3, calcium, glucose, age, pH, PaO2, potassium, sodium, and base excess levels in the pre-pandemic and pandemic groups was statistically significant in univariate linear analysis.

CONCLUSION

Air exchange barrier disruption caused by COVID-19 may have pulmonary consequences. In patients with a history of pandemic COVID-19, clinical results and survival are considerably unfavorable in cases of CO poisoning.

Thoracic cavity fluid as an alternative specimen for carboxyhaemoglobin measurement in post-mortem toxicology

Post-mortem blood is most frequently used for the measurement of carboxyhaemoglobin (COHb) in post-mortem forensic cases, when investigating suspected inhalation of carbon monoxide (CO). However, in many post-mortem cases (especially severe burns and charring deaths), adequate blood specimens are not always available for toxicological analyses. Here, the availability of an alternative specimen for COHb analysis is required. This study investigated the suitability of thoracic cavity fluid (TCF) as an alternative specimen for the measurement of COHb. TCF and comparative blood samples from fifteen potential CO toxicity cases were collected into green-top tubes (containing lithium heparin) and analysed immediately after collection using a validated method on the ABL825 FLEX Radiometer CO-oximeter. Pearson's correlation coefficient indicated a strong positive relationship between the two specimens (r = 0.975, n = 10, p < 0.001). A statistical agreement between COHb concentrations from blood and TCF was demonstrated using the Bland-Altman plot, with a slight bias of 1.54 % when blood was taken as the standard. This study found that TCF would be a suitable alternative to blood for the measurement of COHb using the ABL825 FLEX blood gas analyser.

In situ infrared CO detection using silver loaded EMT zeolite films

Ag cluster catalyst-based oxidation of CO to CO2 is an important way to remove CO at low temperatures. However, the instability of silver clusters seriously limits the catalytic application. Herein, sub-nanosized EMT zeolite nanoparticles served as Ag cluster carriers with high selectivity, low coordination, and unsaturated atom active sites. The silver clusters with sub-nanometer size can be controlled with different charge states and loading rates. A detection film with 500 nm was further prepared by assembling the Ag-EMT composites with a small amount of Nalco as an adhesive. For CO detection, a completely enclosed gas sensing device based on in situ infrared spectroscopy was employed without air interference. CO was accurately introduced into the detection chamber and catalysed into CO2 by silver loaded EMT zeolite films, and the whole process was accurately recorded by infrared spectroscopy. CO with a detection range of 2-50 ppm was realized, showing great application potential in gas monitoring.

Pd2 and CoPd dimers/N-doped graphene sensors with enhanced sensitivity for CO detection: A first-principles study

CONTEXT

The detection and monitoring of CO gas are essential to avoid human health problems. Therefore, the CO adsorption on Pd2 and PdCo dimers deposited on pyridinic Nx-doped graphene (PNxG; x = 1 - 3) was investigated employing the auxiliary density functional theory. In the most stable arrangements for the Pd2 dimer supported on PNxG, a Pd atom is in the PNxG vacancy, and the other Pd atom is placed on C atoms. For the PdCo dimer deposited on PNxG, the most stable interaction is like Pd2 dimer supported on PNxG, but with the Co atom centered over the vacancy site. Concerning the stability of the Pd2 and PdCo dimers supported on PNxG, the interaction energies (Eint) of the PdCo dimer deposited on PNxG are higher than those obtained with the Pd2 dimer. Also, the Eint of Pd2 and PdCo dimers deposited on PNxG are higher than those supported on pristine graphene. The CO adsorption energies on Pd2/PNxG and PdCo/PNxG composites are higher than those reported in the literature for pristine graphene, showing that the Pd2/PNxG and PdCo/PNxG composites have a good sensitivity toward the CO molecule.

METHODS

All electronic structure calculations were performed using the auxiliary density functional theory implemented in the deMon2k program. For exchange and correlation functional, the revised PBE was used. The Pd atoms were treated with an 18-electron QECP|SD basis set, while the remaining atoms were subjected to a DZVP-GGA basis set. The GEN-A2* auxiliary-function-set was used for all computations.

Acute Cardiomyopathy and Delayed Neuropsychiatric Sequelae of Carbon Monoxide Poisoning: A Case Report

Carbon monoxide (CO) is an odorless and colorless gas that is formed by the combustion of hydrocarbon. CO poisoning is not an uncommon phenomenon that can have serious consequences for morbidity and mortality. The most frequent causes of accidental poisoning include smoke inhalation from fires, malfunctioning heating devices, smoke from motor vehicles in a poorly ventilated or enclosed space, and electrical cable fires. CO has a higher affinity to hemoglobin than oxygen leading to the formation of carboxyhemoglobin. It impairs the oxygen transport and cytochrome chain which, therefore, leads to further cellular and immunological changes. Here, we present a case of CO poisoning resulting in combined cardiac and neuropsychiatric complications.

A Turn-On Quinazolinone-Based Fluorescence Probe for Selective Detection of Carbon Monoxide

Carbon monoxide (CO) is a toxic, hazardous gas that has a colorless and odorless nature. On the other hand, CO possesses some physiological roles as a signaling molecule that regulates neurotransmitters in addition to its hazardous effects. Because of the dual nature of CO, there is a need to develop a sensitive, selective, and rapid method for its detection. Herein, we designed and synthesized a turn-on fluorescence probe, 2-(2'-nitrophenyl)-4(3H)-quinazolinone (NPQ), for the detection of CO. NPQ provided a turn-on fluorescence response to CO and the fluorescence intensity at 500 nm was increased with increasing the concentration of CO. This fluorescence enhancement could be attributed to the conversion of the nitro group of NPQ to an amino group by the reducing ability of CO. The fluorescence assay for CO using NPQ as a reagent was confirmed to have a good linear relationship in the range of 1.0 to 50 µM with an excellent correlation coefficient (r) of 0.997 and good sensitivity down to a limit of detection at 0.73 µM (20 ppb) defined as mean blank+3SD. Finally, we successfully applied NPQ to the preparation of a test paper that can detect CO generated from charcoal combustion.

Analyses of physical factors that contribute to the blood carboxyhemoglobin saturation in autopsy cases of house fire fatalities

The authors analyzed data from forensic autopsies of 75 patients who died as a result of house fires to clarify the physical factors that affect blood carboxyhemoglobin (COHb) saturation. Blood COHb saturation levels were significantly lower in patients who survived in the hospital. No significant differences were found in the blood COHb saturation levels between patients who died immediately at the scene and those who were pronounced dead at the receiving hospital without heartbeat being restored. The COHb saturation levels were significantly different among the groups of patients classified by the amount of soot. Although age, coronary artery stenosis, and blood alcohol concentration did not significantly affect blood COHb saturation, on comparing patients who died in the same fire, lower COHb saturation was observed in two patients, one with severe coronary artery stenosis and other with severe alcohol intoxication. To accurately interpret blood COHb saturation during forensic autopsy, the heartbeat status (present or absent) at the time of the rescue and the amount of soot in the trachea must be determined. Low levels of COHb saturation may be observed in fatalities with severe coronary atherosclerosis or severe alcohol intoxication.

Significant shifts in preclinical and clinical neurotoxicology: a review and commentary

The ever-expanding prevalence of adverse neurotoxic reactions of the brain in response to therapeutic and recreational drugs, dietary supplements, environmental hazards, cosmetic ingredients, a spectrum of herbals, health status, and environmental stressors continues to prompt the development of novel cell-based assays to better determine neurotoxic hazard. Neurotoxicants may cause direct and epigenetic damage to the nervous tissue and alter the chemistry, structure, or normal activity of the nervous system. In severe neurotoxicity due to exposure to physical or psychosocial toxicants, neurons are disrupted or killed, and a consistent pattern of clinical neural dysfunction appears. In utero exposure to neurotoxicants can lead to altered development of the nervous system [developmental neurotoxicity (DNT)]. Patients with certain disorders and certain genomic makeup may be particularly susceptible to neurotoxicants. Traditional cytotoxicity measurements, like cell death, are easy to measure, but insufficient at identifying current routine biomarkers of toxicity including functional impairment in cell communication, which often occurs before or even in the absence of cell death. The present paper examines some of the limitations of existing neurotoxicology in light of the increasing need to develop tools to meet the challenges of achieving greater sensitivity in detection and developing and standardizing methods for exploring the toxicologic risk of such neurotoxic entities as engineered nanomaterials and even variables associated with poverty.

Carbon monoxide combined with artificial blood cells acts as an antioxidant for tissues thermally-damaged by dye laser irradiation

Artificial red blood cells [i.e., hemoglobin vesicles (HbVs)] can be used as photosensitizers in pulsed-dye laser (PDL) treatment for port wine stains in animal models. Small HbVs are distributed in the vicinity of the endothelial cells of the blood vessels. In our previous in vivo experiments, both HbVs and red blood cells absorbed photons of the laser and generated heat, contributing to removal of very small blood vessels and large deeper subcutaneous blood vessels with PDL irradiation. Herein, we tested carbon monoxide-bound HbVs (CO-HbVs) that would produce heat energy while releasing CO in vessels after dye laser irradiation in a rabbit auricle model. We conducted this experiment to confirm secondary progression of thermal injury being reduced with the antioxidative property of CO. We histopathologically evaluated the damages to the large vessels and surrounding dermal tissue following PDL irradiation alone or subsequent to the intravenous injection of the qualified HbVs. The soft tissue damages were graded on a five-point scale and compared statistically. Intravenous CO-HbVs significantly reduced damage to the surrounding tissue after subsequent PDL irradiation; however, the degree of damage to the larger vessel wall resulted in a variety of changes, including a slight increase in our histopathological grades. This beneficial effect in dye laser treatment for port wine stains may be the result of the antioxidative property of CO against free radicals in the zone of stasis that may still be theoretically viable in burns. This effect of CO protecting tissues from thermal damage is consistent with previous reports of CO as a reducing agent. If the reducing agent can be delivered directly to the affected area immediately after the burn injury, even in a small amount, the complex inflammatory cascade may be reduced and unnecessary inflammation after laser treatment that lowers the patient's quality of life can be avoided.

Imaging of glutamate in acute carbon monoxide poisoning using chemical exchange saturation transfer

Aims

This study adopted the Glutamate Chemical Exchange Saturation Transfer (GluCEST) imaging technique to quantitatively analyze cranial glutamate and discussed the effectiveness of GluCEST values in identifying the pathogenesis of encephalopathy after CO poisoning.

Methods

The routine MRI and functional MRI scans of two cohorts of subjects (CO group, n = 29; Control group, n = 21) were performed. Between-group comparisons were conducted for GluCEST% in regions of interest (ROI), including the basal ganglia, the thalamus, the frontal lobe, the occipital lobe, the genu of corpus callosum, the cingulate gyrus, and the cuneus. Moreover, an age-stratified subgroup analysis was devised, and a correlational analysis was performed for GluCEST% in each ROI, including the time in coma, Simple Mini-Mental State Examination Scale (MMSE) score, Hamilton Anxiety Scale score, and blood COHb%.

Results

As compared to the healthy control, the CO group led to significantly increasing GluCEST% in the basal ganglia, the occipital lobe, the genu of the corpus callosum, the cingulate gyrus, and the cuneus (p < 0.05). In the subgroup analysis for age, adult patients had higher GluCEST% in the basal ganglia, the thalamus, the occipital lobe, the cingulate gyrus, and the cuneus compared to healthy adults (p < 0.05). In addition, the correlational analysis of CO-poisoned patients revealed a statistical association between the GluCEST% and the MMSE in the thalamus and the genu of the corpus callosum.

Conclusion

The GluCEST technique is superior to routine MRI in that it can identify the cerebral biochemical changes sooner after acute CO poisoning, which is significant for our understanding of the role of neurotransmitters in the pathological basis of this disease. Brain injury caused by CO poisoning may be different in adults and children.

Quantifying the effects of cold waves on carbon monoxide poisoning: A time-stratified case-crossover study in Jinan, China

Background

Previous studies have shown that carbon monoxide (CO) poisoning occurs mostly in winter and is associated with severe cold weather (e.g., ice storms, temperature drops). However, according to previous studies, the impact of low temperature on health has a delayed effect, and the existing research cannot fully reveal the delayed effect of cold waves on CO poisoning.

Objectives

The purpose of this study is to analyze the temporal distribution of CO poisoning in Jinan and to explore the acute effect of cold waves on CO poisoning.

Methods

We collected emergency call data for CO poisoning in Jinan from 2013 to 2020 and used a time-stratified case-crossover design combined with a conditional logistic regression model to evaluate the impact of the cold wave day and lag 0-8 days on CO poisoning. In addition, 10 definitions of a cold wave were considered to evaluate the impact of different temperature thresholds and durations.

Results

During the study period, a total of 1,387 cases of CO poisoning in Jinan used the emergency call system, and more than 85% occurred in cold months. Our findings suggest that cold waves are associated with an increased risk of CO poisoning in Jinan. When P01, P05, and P10 (P01, P05, and P10 refer to the 1st, 5th, and 10th percentiles of the lowest temperature, respectively) were used as temperature thresholds for cold waves, the most significant effects (the maximum OR value, which refers to the risk of CO poisoning on cold wave days compared to other days) were 2.53 (95% CI:1.54, 4.16), 2.06 (95% CI:1.57, 2.7), and 1.49 (95% CI:1.27, 1.74), respectively.

Conclusion

Cold waves are associated with an increased risk of CO poisoning, and the risk increases with lower temperature thresholds and longer cold wave durations. Cold wave warnings should be issued and corresponding protective policies should be formulated to reduce the potential risk of CO poisoning.

Carbon Dioxide Monitoring inside an Australian Brewery Using an Internet-of-Things Sensor Network

Maintaining a high standard of indoor air quality (IAQ) is vital to ensuring good human health. The concentration of CO₂ in air is a good proxy for IAQ, while high levels of CO₂ have been shown to cause cognitive or physiological impairment. Work environments that generate CO₂ as an inherent part of their business present a unique and significant risk in terms of poor IAQ. Craft breweries generate CO₂ and, unlike larger breweries, often lack the technology to capture and re-use the fermentation CO₂ for beer carbonation. The purpose of this study is to demonstrate that the venting of fermentation CO₂ and the unintentional venting of CO₂ during the filling of CO₂ storage tanks can cause the indoor CO₂ levels to rise significantly. This is shown by monitoring CO₂ levels inside an Australian craft brewery using a newly developed system containing three Internet of Things (IoT) sensor nodes positioned strategically in different sections of the brewery. The maximum CO₂ level recorded was in excess of 18,000 ppm, with the maximum time period levels exceeding 1000 and 10,000 ppm being equivalent to 425 and 26 min, respectively. The identification of differences in measured CO₂ at different times and locations throughout the brewery reveals that a single hard-wired CO₂ sensor may be inadequate to support IAQ monitoring. For this purpose, a network of portable or wearable CO₂ sensor nodes may be most suitable. The battery life of the sensors is a key consideration, and the current sensor battery life is too short. Low-power sensors and communication protocols are recommended for this task.

Photocatalytic Oxidation of Carbon Monoxide Using Synergy of Redox-Separated Photocatalyst and Ozone

Separating the redox centers of photocatalysts is the most promising strategy to enhance photocatalytic oxidation efficiency. Herein, I investigate a site-selective loading of Pt on facet-engineered TiO₂ to achieve carbon monoxide (CO) oxidation at room temperature. Spatially loaded Pt on {101} facets of TiO₂ attracts photoinduced electrons efficiently. Thereby, oxygen dissociation is facilitated on the Pt surface, which is confirmed by enhanced oxidation of CO by 2.4 times compared to the benchmark of Pt/TiO₂. The remaining holes on TiO₂ can be utilized for the oxidation of various gaseous pollutants. Specifically, gaseous ozone, which is present in indoor and ambient air, is converted to a hydroxyl radical by reacting with the hole; thus, the poisoned Pt surface is continuously cleaned during the CO oxidation, as confirmed by in situ diffuse reflectance infrared transform spectroscopy. While randomly loaded Pt can act as recombination center, reducing photocatalytic activity, redox-separated photocatalyst enhances charge separation, boosting CO oxidation and catalyst regeneration via simultaneous ozone decomposition.

Mathematical modeling in the health risk assessment of air pollution-related disease burden in China: A review

This review paper covers an overview of air pollution-related disease burden in China and a literature review on the previous studies which have recently adopted a mathematical modeling approach to demonstrate the relative risk (RR) of air pollution-related disease burden. The associations between air pollution and disease burden have been explored in the previous studies. Therefore, it is necessary to quantify the impact of long-term exposure to ambient air pollution by using a suitable mathematical model. The most common way of estimating the health risk attributable to air pollution exposure in a population is by employing a concentration-response function, which is often based on the estimation of a RR model. As most of the regions in China are experiencing rapid urbanization and industrialization, the resulting high ambient air pollution is influencing more residents, which also increases the disease burden in the population. The existing RR models, including the integrated exposure-response (IER) model and the global exposure mortality model (GEMM), are critically reviewed to provide an understanding of the current status of mathematical modeling in the air pollution-related health risk assessment. The performances of different RR models in the mortality estimation of disease are also studied and compared in this paper. Furthermore, the limitations of the existing RR models are pointed out and discussed. Consequently, there is a need to develop a more suitable RR model to accurately estimate the disease burden attributable to air pollution in China, which contributes to one of the key steps in the health risk assessment. By using an updated RR model in the health risk assessment, the estimated mortality risk due to the impacts of environment such as air pollution and seasonal temperature variation could provide a more realistic and reliable information regarding the mortality data of the region, which would help the regional and national policymakers for intensifying their efforts on the improvement of air quality and the management of air pollution-related disease burden.

Measuring the Air Quality Using Low-Cost Air Sensors in a Parking Garage at University of Minnesota, USA

The concentration of air pollutants in underground parking garages has been found to be higher compared to ambient air. Vehicle emissions from cold starts are the main sources of air pollution in underground parking garages. Eight days of measurements, using low-cost air sensors, were conducted at one underground parking garage at the University of Minnesota, Minneapolis. The CO, NO, NO₂, and PM2.5 daily average concentrations in the parking garage were measured to be higher, by up to more than an order of magnitude, compared to the ambient concentration. There is positive correlation between exit traffic flow and the air concentrations in the parking garage for lung deposited surface area (LDSA), CO₂, NO, and CO. Fuel specific emission factors were calculated for CO, NO, and NOx. Ranging from 25 to 28 g/kg_fuel for CO, from 1.3 to 1.7 g/kg_fuel for NO, and from 2.1 to 2.7 g/kg_fuel for NOx. Regulated emissions were also calculated for CO and NOx with values of 2.4 to 2.9 and 0.19 to 0.25 g/mile, respectively. These emissions are about 50% higher than the 2017 U.S. emission standards for CO and nearly an order magnitude higher for NOx.

Early processes in heme-based CO-sensing proteins

Carbon monoxide has been recognized relatively recently as signaling molecule, and only very few dedicated natural CO sensor proteins have been identified so far. These include in particular heme-based transcription factors: the bacterial sensor proteins CooA and RcoM. In these 6-coordinated systems, exchange between an internal protein residue and CO as a heme ligand in the sensor domain affects the properties of the DNA-binding domain. Using light to dissociate heme-ligand bonds can in principle initiate this switching process. We review the efforts to use this method to investigate early processes in ligand switching and signaling, with an emphasis on the CO-“trappingˮ properties of the heme cavity. These features are unusual for most heme proteins, but common for heme-based CO sensors.

Examination of central nervous system by functional observation battery after massive intravenous infusion of carbon monoxide-bound and oxygen-bound hemoglobin vesicles in rats

Carbon monoxide (CO) is known as a toxic gas inducing "CO poisoning", which acutely affects the central nervous system (CNS) and which persistently affects brain functions depending on the exposure time and CO concentration. By contrast, in pathological rodent models, intravenous infusion of CO-bound hemoglobin vesicles (CO-HbV) has shown various beneficial effects such as anti-oxidative and anti-inflammatory reactions. This study assessed effects of CO-HbV infusion on CNS using a functional observation battery, sensory reflexes, grip strength, and landing foot splay measurements. The test fluids were CO-HbV and O₂-bound HbV (O₂-HbV) suspended in saline ([Hb] ​= ​10 ​g/dL), and saline alone for comparison. The rats received either 16 or 32 ​mL/kg of fluid intravenously at 1.5 ​mL/min/kg. Observations were made before infusion, and at 5 ​min, 4, 8, 24, 48 and 72 ​h after infusion. Massive doses of 16 and 32 ​mL/kg respectively corresponded to about 29 and 57% of the whole circulating blood volume (56 ​mL/kg). No toxicological effect was observed in any measurement item for any group in comparison to the control saline infusion group. Histopathological examination of hippocampal tissue at 14 days after infusion showed the number of necrotic cells to be minimal. Results obtained from rats in this experiment suggest that the massive intravenous infusion of CO-HbV yields beneficial anti-oxidative and anti-inflammatory effects without showing CO-poisoning-related symptoms of CNS damage.

The Effects of Pandemic Restrictions on Public Health-Improvements in Urban Air Quality

The present study aims to provide evidence on the effects of pandemic curtailment measures on public health, targeting the changes in breathable air quality, within urban areas. The analyzed period covers the full impact of lockdowns in Europe in 2020. We used everyday data for each analyzed pollutant, NO₂, SO_2, CO, PM_2.5 and PM₁₀, from urban monitoring stations that provided real-time concentrations (provided by Copernicus Atmosphere Monitoring Service, Environmental Protection Agency repository and European Environment Agency map services) and satellite data (provided by NASA Orbiting Carbon Observatory 2). In the present study, the urban air quality was computed using a composite index that was further analyzed in comparison with pandemic restrictions. Descriptive statistics, charts and maps were used to visualize the data that covered the analyzed countries. Our results show that air pollution was reduced by 12% after lockdowns in European urban areas, with a 0.76 correlation between air pollution and pandemic restrictions. All air pollutants registered significant drops.

Role of Dopamine Transporter in the Relationship Between Plasma Cortisol and Cognition

OBJECTIVE

Cortisol is associated with cognition in both healthy individuals and patients with neuropsychiatric disorders. Regarding the effects of cortisol on the dopamine system and the association between dopamine transporter (DAT) and cognition, DAT might be a central target linking cortisol and cognition. This study explored the role of striatal DAT in the cortisol-cognition relationship.

METHODS

We recruited 33 patients with carbon monoxide poisoning and 33 age- and sex-matched healthy controls. All participants underwent cognitive assessments of attention, memory, and executive function. Single-photon emission computed tomography with 99mTc-TRODAT was used to determine striatal DAT availability. Plasma cortisol, tumor necrosis factor α, and interleukin-10 levels were measured using enzyme-linked immunosorbent assays.

RESULTS

Compared with healthy controls, patients with carbon monoxide poisoning had lower cognitive performance, bilateral striatal DAT availability, and plasma tumor necrosis factor-α levels and higher cortisol and interleukin-10 levels. In all participants, plasma cortisol level and bilateral striatal DAT availability were negatively and positively related to cognition, respectively, including memory and executive function with β from -0.361 (95% confidence interval [CI] = -0.633 to -0.090) to 0.588 (95% CI = 0.319 to 0.858). Moreover, bilateral striatal DAT mediated the cortisol-cognition relationship with indirect effects from -0.067 (95% CI = -0.179 to -0.001) to -0.135 (95% CI = -0.295 to -0.024). The cytokine levels did not influence the mediation effects.

CONCLUSIONS

This is the first study to demonstrate that striatal DAT mediates the cortisol-cognition relationship. Future studies are needed to comprehensively evaluate the role of the dopamine system in cortisol-cognition associations and treatment implications.

SnO2 Nanoparticles-CeO2 Nanorods Enriched with Oxygen Vacancies for Bifunctional Sensing Performances toward Toxic CO Gas and Arsenate Ions

In this paper, we present a novel, one-step synthesis of SnO₂ nanoparticle-CeO₂ nanorod sensing material using a surfactant-mediated hydrothermal method. The bifunctional utility of the synthesized sensing material toward room-temperature sensing of CO gas and low-concentration optosensing of arsenic has been thoroughly investigated. The CeO₂-SnO₂ nanohybrid was characterized using sophisticated analytical techniques such as transmission electron microscopy, X-ray diffraction analysis, energy-dispersive X-ray analysis, X-ray photoelectron spectroscopy, and so forth. The CeO₂-SnO₂ nanohybrid-based sensor exhibited a strong response toward CO gas at room temperature. Under a low concentration (3 ppm) of CO gas, the CeO₂-SnO₂ sensing material showed an excellent response time of 21.1 s for 90% of the response was achieved with a higher recovery time of 59.6 s. The nanohybrid sensor showed excellent low-concentration (1 ppm) sensing behavior which is ∼6.7 times higher than that of the pristine SnO₂ sensors. The synergistically enhanced sensing properties of CeO₂-SnO₂ nanohybrid-based sensors were discussed from the viewpoint of the CeO₂-SnO₂ n-n heterojunction and the effect of oxygen vacancies. Furthermore, the SnO₂-CeO₂ nanoheterojunction showed luminescence centers and prolonged electron-hole recombination, thereby resulting in quenching of luminescence in the presence of arsenate ions. The photoluminescence of CeO₂-SnO₂ is sensitive to the arsenate ion concentration in water and can be used for sensing arsenate with a limit of detection of 4.5 ppb in a wide linear range of 0 to 100 ppb.

Fatal Unintentional Non-Fire Related Carbon Monoxide Poisoning: Data from Narrative Verdicts in England and Wales, 1998-2019

Unintentional non-fire related (UNFR) carbon monoxide (CO) poisoning continues to cause fatalities. The narrative verdicts from coroners concerning fatal UNFR CO poisoning in England and Wales, 1998–2019, were collated by the Office for National Statistics. Search terms related to CO exposure were used to obtain information regarding the circumstances of death. Findings were grouped by the location of death, the source of CO, and the reason or behaviour underlying the exposure. There were 750 deaths (77% male). The annual number of deaths decreased over the period studied. Two thirds (68%) of the deaths occurred in the autumn or winter. From the records with information, 59% of deaths occurred within a dwelling (67% male). Males also predominated deaths within vehicles (91%) and garages or outbuildings (95%). From the deaths with information, domestic piped gas was the most common source of CO (36%) and the most frequent underlying factor was inadequate ventilation of exhaust gases (39%, 91% male). Despite the decrease in the annual number of deaths over the study period, there remains a clear need for measures that raise awareness of the dangers of CO poisoning, especially amongst men working alone in garages or outbuildings. Education campaigns and fitting and maintaining CO alarms in high-risk areas should be encouraged.

Pediatric Carbon Monoxide Poisoning: Effects of Hyperbaric Oxygen Therapy on Thiol/Disulfide Balance

OBJECTIVES

Carbon monoxide (CO) poisoning remains the foremost cause of poisoning worldwide. This study aimed to investigate the effects of hyperbaric oxygen therapy (HBOT) and normobaric oxygen therapy (NBOT) on thiol/disulfide homeostasis in children with CO intoxication.

METHODS

Eighty-one children aged 0 to 18 years with CO intoxication were included in this cross-sectional study. No changes were made in the routine clinical evaluation and treatment practices of the patients. Thirty-two children who received HBOT and 49 children who received NBOT were compared for serum native thiol, disulfide, and total thiol levels, as well as for the changes in disulfide/native thiol, disulfide/total thiol, and native thiol/total thiol ratios before and after treatment.

RESULTS

Antioxidant levels, such as native thiol and total thiol, were significantly decreased in patients who received HBOT and increased in those who received NBOT (P = 0.02 and P = 0.01, respectively). There was no statistically significant difference between the 2 groups concerning the change of native thiol/total thiol ratios (P = 0.07). In addition, there was no significant difference regarding changes in disulfide, disulfide/native thiol, and disulfide/total thiol levels before and after treatment (P = 0.39, P = 0.07, and P = 0.07, respectively).

CONCLUSIONS

Although thiol-disulfide balance is maintained in patients treated with HBOT, antioxidant levels decrease significantly compared with NBOT. Despite efficiency of HBOT in CO intoxication, oxidative stress and reperfusion injury due to hyperoxygenation should be considered in the treatment of HBOT.

Exploring Health Impacts of Occupational Exposure to Carbon Monoxide in the Labour Community of Hattar Industrial Estate

This study was designed to assess the health impacts related to noninvasive carbon monoxide saturation (SPCO %) in the blood of respondents. For this purpose, 150 respondents from the labour community of Hattar Industrial Estate (testing site) and 100 respondents from Sultan Pur (control site) were selected. To achieve this objective, a Rad-57 Pulse CO-Oximeter was used for noninvasive carboxyhemoglobin measurement. Carbon monoxide saturation (SPCO%) in the blood of respondents from Hattar Industrial Estate, Haripur, Pakistan has been compared with the WHO’s standard concentration of SPCO% (5%). High saturation of carbon monoxide (carboxyhemoglobin SPCO) in the blood of respondents and disease association have been interpreted in graphs formed on the basis of statistical analysis in terms of frequencies, using statistical software (SPSS), based on demographic entries as well as exposure time of the employees in the processing, food and steel industries. The highest SPCO% measured was 17% in the steel industry and the lowest measured level was 4.2%. Frequencies and percentages of respiratory inflammation, dermatosis, asthma, breathing issues and eye inflammation among respondents were 29%, 35%, 16.7%, 23.5% and 9%, respectively. Prevalence of disease in three different groups of respondents (from three testing sites) was also analyzed on the basis of exposure time (hrs.) to carbon monoxide emissions. Prevalence of disease among the exposed and non-exposed groups was analyzed and showed comparatively lower disease prevalence in the group of respondents who were not exposed to high carbon monoxide emissions. The data of the current study was also subjected to statistical modelling to find the health risk of air pollutants (carbon monoxide) on population health by calculating attributable risk (AR) or attributable proportion (AP). Results indicated that attributable risk of carbon monoxide exposure for respiratory diseases, dermatosis and eye inflammation were 61.12%, 65.77% and 24.95% respectively. Findings of statistical modelling indicated that dermatosis and respiratory diseases were more prevalent in laborers of industrial units than those at control site.

A Review of Air Pollution Mitigation Approach Using Air Pollution Tolerance Index (APTI) and Anticipated Performance Index (API)

Air pollution is a global environmental issue, and there is an urgent need for sustainable remediation techniques. Thus, phytoremediation has become a popular approach to air pollution remediation. This paper reviewed 28 eco-friendly indigenous plants based on both the air pollution tolerance index (APTI) and anticipated performance index (API), using tolerance level and performance indices to evaluate the potential of most indigenous plant species for air pollution control. The estimated APTI ranged from 4.79 (Syzygium malaccense) to 31.75 (Psidium guajava) among the studied indigenous plants. One of the selected plants is tolerant, and seven (7) are intermediate to air pollution with their APTI in the following order: Psidium guajava (31.75) > Swietenia mahogany (28.08) > Mangifera indica L. (27.97) > Ficus infectoria L. (23.93) > Ficus religiosa L. (21.62) > Zizyphus Oenoplia Mill (20.06) > Azadirachta indica A. Juss. (19.01) > Ficus benghalensis L. (18.65). Additionally, the API value indicated that Mangifera indica L. ranges from best to good performer; Ficus religiosa L. and Azadirachta indica A. Juss. from excellent to moderate performers; and Cassia fistula L. from poor to very poor performer for air pollution remediation. The Pearson correlation shows that there is a positive correlation between API and APTI (R2 = 0.63), and this implies that an increase in APTI increases the API and vice versa. This paper shows that Mangifera indica L., Ficus religiosa L., and Azadirachta indica A. Juss. have good potential for sustainable reduction in air pollution for long-term management and green ecomanagement development.

County-Wide Mortality Assessments Attributable to PM2.5 Emissions from Coal Consumption in Taiwan

Over one-third of energy is generated from coal consumption in Taiwan. In order to estimate the health impact assessment attributable to PM2.5 concentrations emitted from coal consumption in Taiwan. We applied a Gaussian trajectory transfer-coefficient model to obtain county-wide PM2.5 exposures from coal consumption, which includes coal-fired power plants and combined heat and power plants. Next, we calculated the mortality burden attributable to PM2.5 emitted by coal consumption using the comparative risk assessment framework developed by the Global Burden of Disease study. Based on county-level data, the average PM2.5 emissions from coal-fired plants in Taiwan was estimated at 2.03 ± 1.29 (range: 0.32-5.64) μg/m3. With PM2.5 increments greater than 0.1 μg/m3, there were as many as 16 counties and 66 air quality monitoring stations affected by coal-fired plants and 6 counties and 18 monitoring stations affected by combined heat and power plants. The maximum distances affected by coal-fired and combined heat and power plants were 272 km and 157 km, respectively. Our findings show that more counties were affected by coal-fired plants than by combined heat and power plants with significant increments of PM2.5 emissions. We estimated that 359.6 (95% CI: 334.8-384.9) annual adult deaths and 124.4 (95% CI: 116.4-132.3) annual premature deaths were attributable to PM2.5 emitted by coal-fired plants in Taiwan. Even in six counties without power plants, there were 75.8 (95% CI: 60.1-91.5) deaths and 25.8 (95%CI: 20.7-30.9) premature deaths annually attributable to PM2.5 emitted from neighboring coal-fired plants. This study presents a precise and effective integrated approach for assessing air pollution and the health impacts of coal-fired and combined heat and power plants.

Energy Poverty among Tertiary Students in Aotearoa New Zealand

Energy poverty in Aotearoa New Zealand is well-documented, and tertiary students have been identified as an at-risk group. However, there has been very little research on tertiary students’ experiences of energy poverty in New Zealand. This paper used a nationwide online survey to investigate the extent and impact of energy poverty among tertiary students. Furthermore, it aimed to identify disparities between different demographic groups, understand the effects of COVID-19 and evaluate the effectiveness of the support policies available to students. Responses from 522 students were analysed; 85% were under 30 years old, 72% were female, 14% identified as Māori, and 14% reported having long-term disabilities or health concerns. The findings of this study are concerning. Tertiary students in New Zealand are largely living in dwelling conditions that do not meet recommended health standards and exacerbate energy poverty. Energy poverty has adverse effects on their physical and mental health; however, available support is limited or inaccessible. Most significantly, the impact of energy poverty is disproportionally affecting students with long-term disabilities or health concerns as well as students identifying as Māori. Moreover, the impact of COVID-19 further strained students experiencing energy poverty and again, disproportionally affected more vulnerable students.