Carbon monoxide exchanges between the human fetus and mother: a mathematical model

1977 ◽  
Vol 232 (3) ◽  
pp. H311-H323 ◽  
Author(s):  
E. P. Hill ◽  
J. R. Hill ◽  
G. G. Power ◽  
L. D. Longo
Keyword(s):  
Mathematical Model ◽  
Air Pollution ◽  
Carbon Monoxide ◽  
Cardiac Output ◽  
Human Fetus ◽  
Alveolar Ventilation ◽  
Co Concentration ◽  
Fetal Oxygenation ◽  
Ventilation Rates ◽  
Co Concentrations

A mathematical model was developed to calculate maternal and fetal carboxyhemoglobin concentrations, [HbCO], as functions of time during and after exposure of the mother to various inspired CO concentrations. Effects of variation in alveolar ventilation rates, pulmonary and placental fiffusing capacities, cardiac output, endogenous carbon monoxide production and other factors were studied. Following a change in the inspired CO concentration, fetal HbCO lags behind maternal HbCO by several hours. During CO uptake, fetal HbCO eventually overtakes maternal, and approaches an equilibrium value as much as 10% higher than the mother's. During CO washout the fetal levels again lag behind the mothers. Results indicate that treatment of pregnant women who have elevated HbCO levels with 100% oxygen reduces the time necessary to reduce the maternal HbCO level as expected, but that the rate of fetal CO elimination is not increased as much as that of the mother. Changes in maternal and fetal HbCO were also calculated for a representative exposure to changing inspired CO levels produced by fluctuating levels of air pollution. Finally, the effects of carboxyhemoglobin on fetal oxygenation were studied, including the effects of high altitude and exercise.

Competitive inhibition of carbon monoxide transport: evidence against a carrier

1981 ◽  
Vol 50 (5) ◽  
pp. 1061-1064 ◽  
Author(s):  
D. Z. Rubin ◽  
D. Fujino ◽  
C. Mittman ◽  
S. M. Lewis
Keyword(s):  
Carbon Monoxide ◽  
Competitive Inhibition ◽  
Normal Adult ◽  
Gas Mixture ◽  
Diffusing Capacity ◽  
Constant Amount ◽  
Pulmonary Diffusing Capacity ◽  
Co Concentration ◽  
Carrier Molecule ◽  
Co Concentrations

The existence of a saturable carbon monoxide (CO) carrier in the lung remains controversial. The carrier hypothesis was invoked to explain data that indicated that pulmonary diffusing capacity for CO (DLCO) decreases with increasing CO concentration. To test this hypothesis, we measured DLCO in 14 normal adult subjects at three alveolar CO concentrations (60, 660, and 2,060 ppm). Each mixture contained a constant amount of labeled C18O (60 ppm) and a balance of unlabeled C16O. If a saturable carrier exists at increasing CO concentrations, the unlabeled CO would compete for most of the sites on the carrier molecule, effectively inhibiting the uptake of the labeled C18O. C18O diffusing capacities (mean +/- SD) for the three levels of CO were 34.9 +/- 5.6, 33.0 +/- 6.0, and 34.7 +/- 7.8. There were no significant differences (P greater than 0.2) among the three levels. In another group of subjects we repeated the study using a gas mixture containing 130 ppm C18O. No significant differences were found. As a result, we find no evidence to support a CO carrier hypothesis.

scholarly journals Increased heme catabolism in critically ill patients: correlation among exhaled carbon monoxide, arterial carboxyhemoglobin, and serum bilirubin IXα concentrations

2006 ◽  
Vol 290 (1) ◽  
pp. L114-L119 ◽  
Author(s):  
Hiroshi Morimatsu ◽  
Toru Takahashi ◽  
Kyoichiro Maeshima ◽  
Kazuyoshi Inoue ◽  
Tomoko Kawakami ◽  
...  
Keyword(s):  
Carbon Monoxide ◽  
Critically Ill ◽  
Critically Ill Patients ◽  
Linear Regression Analysis ◽  
Multivariate Linear Regression Analysis ◽  
Arterial Blood ◽  
Exhaled Air ◽  
Co Concentration ◽  
Exhaled Carbon Monoxide ◽  
Co Concentrations

It has been reported that exhaled carbon monoxide (CO) concentrations and arterial carboxyhemoglobin (CO-Hb) concentration in blood may be increased in critically ill patients. However, there was no study that examined correlation among amount of CO in exhaled air, CO-Hb concentrations in erythrocytes, and bilirubin IXα (BR) in serum, i.e., the three major indexes of heme catabolism, within the same subject. Here, we examined CO concentrations in exhaled air, CO-Hb concentrations in arterial blood, and BR levels in serum in 29 critically ill patients. Measurements of exhaled CO, arterial CO-Hb, and serum total BR have been done in the intensive care unit. As control, exhaled CO concentration was also measured in eight healthy volunteers. A median exhaled CO concentration was significantly higher in critically ill patients compared with control. There was significant correlation between CO and CO-Hb and CO and total BR level. We also found CO concentrations correlated with indirect BR but not direct BR. Multivariate linear regression analysis for amount of exhaled CO concentrations also showed significant correlation with CO-Hb and total BR, despite the fact that respiratory variables of study subjects were markedly heterogeneous. We found no correlation among exhaled CO, patients’ severity, and degree of inflammation, but we found a strong trend of a higher exhaled CO concentration in survivors than in nonsurvivors. These findings suggest there is an increased heme breakdown in critically ill patients and that exhaled CO concentration, arterial CO-Hb, and serum total BR concentrations may be useful markers in critically ill conditions.

scholarly journals Exposure to Carbon Monoxide while Commuting in Popular Modes of Transport in Karachi, Pakistan

2020 ◽  
Vol 63 (2) ◽  
pp. 123-129
Author(s):  
Zafar Iqbal Shams ◽  
Muhammad Saqib Khan ◽  
Syed Taha Ahmed ◽  
Rumaisa Ilyas ◽  
Zeeshan Akhtar
Keyword(s):  
Carbon Monoxide ◽  
Human Exposure ◽  
Motor Vehicle ◽  
Motor Vehicles ◽  
Co Concentration ◽  
Baseline Information ◽  
Control Devices ◽  
Low Sulfur ◽  
The City ◽  
Co Concentrations

Motor vehicles are the single largest source of toxic carbon monoxide in Karachi because advance emission control devices are not fitted in them mainly due to non-availability of low sulfur or sulfur-free fuel. On the contrary, commuters' exposure to carbon monoxide has not yet been investigated, while commuting in any motor vehicle of the city. Therefore, the present study investigated commuter's exposure to carbon monoxide, while travelling in nine different popular modes of transport. The exposure to CO concentrations was recorded inside the buses of seven standard routes of the city. Similarly, exposure to ambient carbon monoxide was also explored, while riding a motorbike on two different routes of the city. On an average, he came in contact with 6.82 ± 2.66 ppm CO during 7576 minutes travelling on nine routes of the metropolis. He was exposed to the highest CO concentration (15.20 ± 9.59 ppm), while riding a motorbike through Route 1 that passed through heavily populated neighborhood. Rider's exposure to carbon monoxide was found significantly (p < 0.05) correlated with wind velocity. As a whole, commuter's exposures to carbon monoxide during evening was significantly (p < 0.01) higher than those of the morning sessions. The present study will provide baseline information for reducing human exposure to the deadly carbon monoxide.    

scholarly journals Analysis of the influence of motor transport on the outdoor air pollution of the town of Yaworiw by Carbon monoxide

2012 ◽  
Vol 2 (40) ◽  
pp. 109-116
Author(s):  
M. Petrovska ◽  
L. Kaplun
Keyword(s):  
Air Pollution ◽  
Carbon Monoxide ◽  
Key Words ◽  
Traffic Density ◽  
Outdoor Air ◽  
Atmospheric Air ◽  
Motor Transport ◽  
Co Concentration ◽  
Harmful Substances ◽  
The Town

The dynamics of the harmful substances emissions from the motor transport in Yaworiv region has been determined as well as the traffic density on the streets of Yaworiv town. The coefficient of CO concentration on some highway strips has been calculated. The map of the intensity of the pollution from CO emissions in Yaworiv has been composed. Key words: atmospheric air, moving pollution sources, polluting sources, emissions, carbon monoxide.

METHOD OF ASSESSMENT LEVEL OF AIR POLLUTION EXHAUST GASES OF VEHICLES ON THE CO CONCENTRATION

2015 ◽  
Vol 2 (1) ◽  
pp. 170-173
Author(s):  
Тарасова ◽  
E. Tarasova ◽  
Волков ◽  
V. Volkov
Keyword(s):  
Air Pollution ◽  
Carbon Monoxide ◽  
Environmental Impact ◽  
Objective Analysis ◽  
Exhaust Gas ◽  
Exhaust Gases ◽  
Co Concentration ◽  
Method Of Assessment

The problem of air pollution by carbon monoxide road. The aim is to study the previously proposed methodology for the calculation of the level of concentration of carbon monoxide and make changes for a more objective analysis. This allows to evaluate the environmental impact of exhaust gas CO concentration

scholarly journals Indoor air pollution exposures and cardiometabolic health across four diverse settings in Peru: a cross-sectional study

2020 ◽  
Author(s):  
Josiah L Kephart ◽  
Magdalena Fandiño-Del-Rio ◽  
Kirsten Koehler ◽  
Antonio Bernabe-Ortiz ◽  
J Jaime Miranda ◽  
...  
Keyword(s):  
Air Pollution ◽  
Carbon Monoxide ◽  
Standard Deviation ◽  
Indoor Air ◽  
Indoor Air Pollution ◽  
Geometric Mean ◽  
Geometric Standard Deviation ◽  
Pm 2.5 ◽  
Daily Average ◽  
Co Concentrations

Abstract Background Indoor air pollution is an important risk factor for health in low- and middle-income countries. Methods We measured indoor fine particulate matter (PM 2.5 ) and carbon monoxide (CO) concentrations in 617 houses across four settings with varying urbanisation, altitude, and biomass cookstove use in Peru, between 2010 and 2016. We assessed the associations between indoor pollutant concentrations and blood pressure (BP), exhaled carbon monoxide (eCO), C-reactive protein (CRP), and haemoglobin A1c (HbA1c) using multivariable linear regression. Results We found high concentrations of indoor PM 2.5 across all four settings (geometric mean ± geometric standard deviation of PM 2.5 daily average in µg/m 3 ): Lima 41.1 ± 1.3, Tumbes 35.8 ± 1.4, urban Puno 14.1 ± 1.7, and rural Puno 58.8 ± 3.1. High indoor CO concentrations were common in rural households (geometric mean ± geometric standard deviation of CO daily average in ppm): rural Puno 4.9 ± 4.3. Higher indoor PM 2.5 was associated with having a higher systolic BP (1.51 mmHg per interquartile range (IQR) increase, 95% CI 0.16 to 2.86), a higher diastolic BP (1.39 mmHg higher DBP per IQR increase, 95% CI 0.52 to 2.25), and a higher eCO (2.05 ppm higher per IQR increase, 95% CI 0.52 to 3.57). There was no evidence of associations between indoor air exposures and CRP or HbA1c outcomes. Conclusions Excessive indoor concentrations of PM 2.5 are widespread across varying levels of urbanisation, altitude, and biomass cookstove use in Peru and are associated with worse BP and higher eCO.

scholarly journals Feasibility of Using Oscillatory Catalytic Oxidation Phenomenon for Selective Carbon Monoxide Sensing

1987 ◽  
Vol 12 (4) ◽  
pp. 291-301 ◽  
Author(s):  
Heikki Torvela
Keyword(s):  
Carbon Monoxide ◽  
Tin Dioxide ◽  
Ambient Air ◽  
Major Influence ◽  
Processing Conditions ◽  
Response Characteristics ◽  
Co Concentration ◽  
Different Temperatures ◽  
Oscillatory Response ◽  
Co Concentrations

Tin dioxide based sensors with different additives were constructed and tested in air environment containing carbon monoxide. Conductance oscillations were observed in samples containing palladium but not in those without. Oscillations occurred at temperatures ranging from 150℃ to 320℃. Within this temperature region the range of CO concentrations at which oscillations appeared became higher as the test temperature increased. The lowest CO concentration at which oscillations were observed was 200 ppm and the highest 10000 ppm.By comparing sensor responses obtained in synthetic and ambient air it was concluded that water vapour has a major influence on oscillations and increases the frequency. The ranges of CO concentrations in which oscillations occurred at different temperatures, however, remained roughly the same in both environments. It was also noticed that processing conditions had an influence on the oscillatory response characteristics of the sensors.

scholarly journals Indoor air pollution concentrations and cardiometabolic health across four diverse settings in Peru: a cross-sectional study

2020 ◽  
Author(s):  
Josiah L Kephart ◽  
Magdalena Fandiño-Del-Rio ◽  
Kirsten Koehler ◽  
Antonio Bernabe-Ortiz ◽  
J Jaime Miranda ◽  
...  
Keyword(s):  
Air Pollution ◽  
Carbon Monoxide ◽  
Standard Deviation ◽  
Indoor Air ◽  
Indoor Air Pollution ◽  
Geometric Mean ◽  
Geometric Standard Deviation ◽  
Pm 2.5 ◽  
Daily Average ◽  
Co Concentrations

Abstract Background: Indoor air pollution is an important risk factor for health in low- and middle-income countries. Methods: We measured indoor fine particulate matter (PM 2.5 ) and carbon monoxide (CO) concentrations in 617 houses across four settings with varying urbanisation, altitude, and biomass cookstove use in Peru, between 2010 and 2016. We assessed the associations between indoor pollutant concentrations and blood pressure (BP), exhaled carbon monoxide (eCO), C-reactive protein (CRP), and haemoglobin A1c (HbA1c) using multivariable linear regression among all participants and stratifying by use of biomass cookstoves. Results: We found high concentrations of indoor PM 2.5 across all four settings (geometric mean ± geometric standard deviation of PM 2.5 daily average in µg/m 3 ): Lima 41.1 ± 1.3, Tumbes 35.8 ± 1.4, urban Puno 14.1 ± 1.7, and rural Puno 58.8 ± 3.1. High indoor CO concentrations were common in rural households (geometric mean ± geometric standard deviation of CO daily average in ppm): rural Puno 4.9 ± 4.3. Higher indoor PM 2.5 was associated with having a higher systolic BP (1.51 mmHg per interquartile range (IQR) increase, 95% CI 0.16 to 2.86), a higher diastolic BP (1.39 mmHg higher DBP per IQR increase, 95% CI 0.52 to 2.25), and a higher eCO (2.05 ppm higher per IQR increase, 95% CI 0.52 to 3.57). When stratifying by biomass cookstove use, our results were consistent with effect measure modification in the association between PM 2.5 and eCO: among biomass users eCO was 0.20 ppm higher per IQR increase in PM 2.5 (95% CI -2.05 to 2.46), and among non-biomass users eCO was 5.00 ppm higher per IQR increase in PM 2.5 (95% CI 1.58 to 8.41). We did not find associations between indoor air concentrations and CRP or HbA1c outcomes. Conclusions: Excessive indoor concentrations of PM 2.5 are widespread in homes across varying levels of urbanisation, altitude, and biomass cookstove use in Peru and are associated with worse BP and higher eCO.

scholarly journals Modeling of CO Accumulation in the Headspace of the Bioreactor during Organic Waste Composting

Energies ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1367
Author(s):  
Karolina Sobieraj ◽  
Sylwia Stegenta-Dąbrowska ◽  
Jacek A. Koziel ◽  
Andrzej Białowiec
Keyword(s):  
Carbon Monoxide ◽  
Organic Waste ◽  
Short Term ◽  
Surrounding Environment ◽  
Advanced Technologies ◽  
Maximum Value ◽  
Initial Stage ◽  
Co Concentration ◽  
The Impact ◽  
Co Concentrations

Advanced technologies call for composting indoors for minimized impact on the surrounding environment. However, enclosing compost piles inside halls may cause the accumulation of toxic pollutants, including carbon monoxide (CO). Thus, there is a need to assess the occupational risk to workers that can be exposed to CO concentrations > 300 ppm at the initial stage of the process. The objectives were to (1) develop a model of CO accumulation in the headspace of the bioreactor during organic waste composting and (2) assess the impact of headspace ventilation of enclosed compost. The maximum allowable CO level inside the bioreactor headspace for potential short-term occupational exposure up to 10 min was 100 ppm. The composting was modeled in the horizontal static reactor over 14 days in seven scenarios, differing in the ratio of headspace-to-waste volumes (H:W) (4:1, 3:1, 2:1, 1:1, 1:2, 1:3, 1:4). Headspace CO concentration exceeded 100 ppm in each variant with the maximum value of 36.1% without ventilation and 3.2% with the daily release of accumulated CO. The airflow necessary to maintain CO < 100 ppmv should be at least 7.15 m3·(h·Mg w.m.)−1. The H:W > 4:1 and the height of compost pile < 1 m were less susceptible to CO accumulation.

Carbon monoxide fixation by plants

1974 ◽  
Vol 52 (8) ◽  
pp. 1841-1847 ◽  
Author(s):  
R. G. S. Bidwell ◽  
Gail P. Bebee
Keyword(s):  
Carbon Monoxide ◽  
Uptake Rate ◽  
Average Rate ◽  
Fresh Weight ◽  
Tropical Plants ◽  
Gas System ◽  
Co Concentration ◽  
Co Concentrations ◽  
Bean Leaves

Leaves of 35 species of temperate and tropical plants absorbed CO in light from air containing 6 ppm CO at an average rate of 0.19 μl/h g fresh weight. CO absorption was measured by the uptake of 14CO from a closed flowing gas system. CO uptake by bean leaves varied considerably with age. Uptake by nine species having widely different rates of absorption was exactly proportional to CO concentration in the range 0 to 100 ppm CO. Absorbed CO was metabolized either by oxidation to CO2 and fixation as such or by reduction and incorporation into serine. Corn, a C4 plant, emphasized the former pathway and bean, a C3 plant, emphasized the latter pathway. CO had various effects on the photosynthesis of leaves of different species; ranging from being inhibitory at concentrations as low as 65 ppm to exerting no influence, or even permitting an increase in net CO2 fixation at 99% CO because of the absence of O2.Plants do not contribute significantly to the global CO balance because their uptake rate is low at the CO concentration normally encountered in interurban areas. However, their contribution may become very important in or near urban and polluted areas, where elevated CO concentrations are frequently found.

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