Carbon Monoxide Intake Research Articles

Assessment of the Impact of Motor Transport on the Ecological State of Atmospheric Air of Urbanized Areas

The article reflects the results of studies on assessing the impact of pollutants entering the atmospheric air from vehicles on the ecological state of the urban environment, analyzes the distribution of emissions of the main pollutants in the context of data for the North Caucasian Federal District and considers the dynamics of the qualitative composition of atmospheric air using the example of the city of Stavropol. As a result of analyzing the data for 2014-2019 in the district, a decrease in the intake of carbon monoxide, nitrogen oxide, sulfur oxide, volatile organic compounds into the atmospheric air from vehicles was found, an increase in carbon content was noted. The study of pollutants included in the daily monitoring program and the intensity of vehicles showed the maximum presence of oxides of sulfur, nitrogen, carbon at 14:00, an increase in gas content at 20:00 indicating the accumulation of harmful substances in the atmosphere during the day and negative impact on the ecological situation of the city.

Острые отравления токсическими газами на производстве (лекция)

В лекции представлены ведущие механизмы поражения организма, типичная клиническая картина и принципы оказания экстренной медицинской помощи (ЭМП) и интенсивной терапии пострадавшим с острыми отравлениями токсическими газами. В связи с тем, что риск одновременного появления большого количества пострадавших с указанными отравлениями всегда велик именно в условиях химического производства, вопросы оказания ЭМП этому контингенту больных всегда актуальны. В лекции рассматриваются особенности поражения организма человека аммиаком, хлором, сероводородом, арсином, окислами азота, формальдегидом, монооксидом углерода и парами бензина. Все эти химические соединения являются широко распространенными химическими реагентами и промежуточными продуктами химических реакций на производстве. Ингаляционный путь попадания летучих веществ в организм определяет ускоренное развитие клинической симптоматики вследствие быстрого поступления токсичных химических соединений в кровь пострадавших. Расстройства в функционировании системы внешнего дыхания являются одними из наиболее распространенных при вдыхании таких агрессивных химических соединений, как аммиак, хлор, окислы азота, формальдегид, пары бензина. Поступление в организм угарного газа, окислов азота и сероводорода обусловливает высокий риск образования гемической гипоксии и связанных с ней поражений центральной нервной и сердечно-сосудистой системы. Вдыхание таких соединений, как сероводород, арсин, формальдегид, окись углерода, определяет развитие нарушений функционирования тканевого дыхания. Практически все химические соединения, действие которых представлено в лекции, способны оказывать общий токсический эффект на организм пострадавших. При освещении аспектов предоставления ЭМП подчеркивается потребность в немедленном прекращении контакта пациентов с токсическим веществом, профилактике и интенсивной терапии синдрома острой дыхательной недостаточности, применении антидотов и препаратов с противогипоксическим эффектом, которые улучшают процессы тканевого дыхания и способствуют росту выработки энергии.

SmartCOdetect: An Automated Car Window Opening System on Detection of Carbon Monoxide

Motorized vehicles are the most important means of transport in which the vehicles with air conditioners play an important role. The number of unexpected death incidents as a result of enormous intake of carbon monoxide (CO) has currently increased. This paper focuses on the design and development of SmartCOdetect - an arduino based intelligent embedded device for a vehicle cabin that detects CO gas and displays it on the LCD screen. If the CO measure surpasses the specific threshold limit, an alarm automatically rings and, if necessary, the window for ventilation is activated immediately. A notification via GSM is sent to the owner’s number registered with the SmartCOdetect system and after receiving the response from the owner, the control unit sends the signal immediately to the control circuit of the vehicle's window to provide ventilation. It also provides the safety and assistance to an occupant in the car cabin. The advantage of this automated CO detection system compared to the manual method is that it provides fast response time and accurate detection of an emergency situation. The system is evaluated by different categories of users to gather the information about the level of satisfaction with SmartCOdetect.

High-dose transdermal nicotine and naltrexone: Effects on nicotine withdrawal, urges, smoking, and effects of smoking.

Although treatment with transdermal nicotine replacement (TNR) has improved smoking abstinence rates, higher doses of TNR could improve effects on urge to smoke, nicotine withdrawal, and reinforcement from smoking, and naltrexone might further reduce reinforcement and urges. A laboratory investigation with 134 smokers using a 3 x 2 parallel-group design evaluated the effects of TNR (42-mg, 21-mg, or 0-mg patch) as crossed with a single dose of naltrexone (50 mg) versus placebo on urge to smoke, withdrawal, and responses to an opportunity to smoke (intake, subjective effects) after 10 hr of deprivation. Urge and withdrawal were assessed both prior to and after cigarette cue exposure. Only 42 mg TNR, not 21 mg, prevented urge to smoke, heart rate change, and cue-elicited increase in withdrawal. Both 21 and 42 mg TNR blocked cue-elicited drop in heart rate and arterial pressure. Naltrexone reduced cue-elicited withdrawal symptoms but not urges to smoke or deprivation-induced withdrawal prior to cue exposure. Neither medication significantly affected carbon monoxide intake or subjective effects of smoking except that 42 mg TNR resulted in lower subjective physiological activation. No interaction effects were found, and no results differed by gender. Results suggest that starting smokers with 42 mg TNR may increase comfort during initial abstinence, but limited support is seen for naltrexone during smoking abstinence.

Nicotine intake and dose response when smoking reduced–nicotine content cigarettes

The progressive reduction of the nicotine content of cigarettes has been suggested as a way to wean smokers from nicotine and tobacco. As a first step in evaluating this strategy, we studied smokers smoking cigarettes containing tobacco with differing nicotine content. Twelve healthy smokers participated in a semiblinded, within-subject, crossover study. Subjects were asked to smoke 1 of their usual brand of cigarette and then on 5 subsequent occasions to smoke a research cigarette, each with differing nicotine content. The research cigarettes contained 0.6 to 10.1 mg nicotine per cigarette. Plasma nicotine and blood carboxyhemoglobin levels, as well as subjective and cardiovascular responses, were measured after smoking. Systemic nicotine intake per cigarette was estimated by use of plasma nicotine concentrations over time and clearance data from the general population. Systemic nicotine intake (0.26-1.47 mg per cigarette) varied with nicotine content of the cigarette (r = 0.82, P < .001). Compensation when smoking single low-nicotine content cigarettes ranged from -1% (95% confidence interval, -23% to 21%) to 34% (95% confidence interval, -39% to 107%) for 1-mg to 8-mg research cigarettes. Carbon monoxide intake and estimated tar exposure were similar across cigarettes. Low-nicotine content cigarettes were rated as being of lower quality and less satisfying than the 12-mg research cigarette or the usual brand (P < .05 for both comparisons). Cigarette smoking increased heart rate and decreased skin temperature, but the nicotine dose-response curve flattened at higher doses, with a maximal response being observed in cigarettes at a nicotine content level of about 8 mg. Our study suggests that reduced-nicotine content cigarettes are reasonable candidates for trying to reduce the level of nicotine addiction in smokers. The flat nicotine dose-cardiovascular response curve is consistent with other studies demonstrating tolerance to the cardiovascular effects of nicotine.

Intake fraction of primary pollutants: motor vehicle emissions in the South Coast Air Basin

The intake fraction is defined for a specific species and emission source as the ratio of attributable population intake to total emissions. Focusing on California's South Coast Air Basin (SoCAB) as a case study, we combine ambient monitoring data with time-activity patterns to estimate the population intake of carbon monoxide and benzene emitted from motor vehicles during 1996–1999. In addition to exposures to ambient concentrations, three microenvironments are considered in which the exposure concentration of motor vehicle emissions is higher than in ambient air: in and near vehicles, inside a building that is near a freeway, and inside a residence with an attached garage. Incorporating data on motor vehicle emissions estimated by the EMFAC2000 model, we estimate that the 15 million people in the SoCAB inhale 0.003–0.009% (34–85 per million, with a best estimate of 47 per million) of primary, nonreactive compounds emitted into the basin by motor vehicles. This population intake of primary motor vehicle emissions is approximately 50% higher than the average ambient concentration times the average breathing rate, owing to higher concentrations in the three microenvironments and also to the temporal and spatial correlation among breathing rates, concentrations, and population densities. The approach demonstrated here can inform policy decisions requiring a metric of population exposure to airborne pollutants.

Blocking cigarette filter vents with lips more than doubles carbon monoxide intake from ultra-low tar cigarettes.

Blocking cigarette filter vents with lips more than doubles carbon monoxide intake from ultra-low tar cigarettes.

Blocking cigarette filter vents with lips more than doubles carbon monoxide intake from ultra-low tar cigarettes.

Light and ultra-light cigarettes achieve their lower tar, nicotine, and carbon monoxide (CO) yields on smoking machines largely by means of air-dilution vents on the filters. Previous research showed that blocking 0%, 50%, and 100% of the filter vents on a 1 mg tar cigarette with tape directly increased expired air CO levels. The present experiment extended this research by replicating the 0% blocked and 100% blocked conditions with the addition of a condition in which participants (N = 12) were asked to block vents with their lips. Mean CO boosts for the unblocked, lip-blocked, and tape-blocked conditions were 2.7 ppm (SE = 0.52), 6.7 ppm (SE = 1.0), and 12.9 ppm (SE = 2.2), respectively. Analyses suggested that lip blockade effectively blocked approximately 50% of the filter vents. Subjective ratings of cigarette strength, harshness, and heat increased significantly as degree of vent blocking increased. Cigarette smokers need to be warned about the presence of vents and the consequences of vent blocking.

Glycerol particle cigarettes: a less harmful option for chronic smokers.

In 20 smokers who switched to a new type of virtually tar free cigarette for three days, average nicotine intake was reduced by 44%, carbon monoxide intake increased by 19%, while estimated tar intake was reduced by about 90%. Such cigarettes pose substantially less risk of cancer and chronic obstructive lung disease than conventional cigarettes, and their acceptability and safety could be improved by increasing nicotine yield, reducing carbon monoxide yield, and improving the flavour.

Evaluation of a low to middle tar/medium nicotine cigarette designed to maintain nicotine delivery to the smoker

A specific objective of this 6-week crossover study was to determine how 21 regular smokers of middle tar cigarettes changed their smoking behaviour and uptake of smoke constituents, when switching to either lower tar cigarettes capable of delivering amounts of nicotine similar to a conventional middle tar cigarette (maintained nicotine product), or to conventional low tar/low nicotine cigarettes. Subjects visited the laboratory every 2 weeks for detailed assessment of their smoking behaviour. Weekly per capita consumption was similar for all three cigarettes. They were smoked with variable intensities (low tar greater than maintained nicotine greater than middle tar), the tendency being for larger puff volumes, faster puffing and increased puff duration with the low tar cigarettes. The maintained nicotine cigarette was preferred to the middle tar cigarette, although acceptability ratings of the three cigarettes only differed marginally. The nicotine absorbed from the maintained nicotine and middle tar cigarettes was similar and significantly greater than the levels achieved from the low tar cigarettes. Intake of carbon monoxide into the mouth and absorption into the blood stream was lower for the maintained nicotine cigarette than for the middle tar cigarette, with the low tar cigarette occupying an intermediate position. Derived estimates of tar intake suggested reduced intake of tar into the respiratory tract (around 25%) from the maintained nicotine product relative to the middle tar product. The possible advantages of switching to maintained nicotine cigarettes is discussed.

Reduction of tar, nicotine and carbon monoxide intake in low tar smokers.

Blood nicotine, cotinine, and carboxyhaemoglobin (COHb) concentrations were measured in 392 smokers (255 women and 137 men) of "middle tar" (17-22 mg), "low to middle" (11-16 mg), and "low tar" (less than 11 mg) cigarettes. Since tar intake cannot yet be measured directly, we devised an index to estimate it based on the use of measured levels of an intake marker (eg, blood nicotine) and the ratio of the tar to marker yields of the cigarettes. This approach was validated by its ability to enhance the prediction of levels of one marker by use of another. In a practical test, using COHb and the CO/nicotine yield ratio of the cigarettes, the mean blood nicotine concentration of the low tar smokers was predicted to be 31.9 ng/ml compared with the measured mean of 31.8 ng/ml. Our main findings were that despite substantial compensatory increases in inhalation, the low tar smokers took in about 25% less tar, about 15% less nicotine, and about 10% less carbon monoxide than smokers of middle and low to middle tar cigarettes. These results indicate that low tar cigarettes of the type available in Britain since the late 1970s are likely to prove less harmful than other brands. Monitoring of smoke intakes could supplement epidemiological approaches and provide earlier evidence of whether changing cigarette designs lead to any significant dosage reduction that could affect the risk of disease.

Intravenous nicotine simulation of passive smoking to estimate dosage to exposed non-smokers.

SummaryTo estimate nicotine intake from passive smoking, six subjects received slow intravenous infusions of known doses of nicotine at a steady rate over one hour. The plasma and urinary nicotine concentrations produced by the infusions were compared with those found in previous studies of non‐smokers exposed to tobacco smoke, in non‐smokers in the general population, and in smokers during and after smoking their first cigarette of the day. It was estimated that the average rate of nicotine absorption was 0.23 mg/hr in a group of non‐smokers exposed in a poorly ventilated public house, 0.36 mg/hr in non‐smokers exposed to more extreme conditions in a smoke‐filled unventilated room, and that the average daily‐life exposure of a sample of 188 urban non‐smokers was 0.014 mg nicotine per hour. In contrast, the dose absorbed by three smokers from their first cigarette of the day averaged 1.4 mg nicotine. The results indicate that when passive exposure of non‐smokers results in carbon monoxide intake equivalent to the active smoking of one cigarette, the amount of nicotine absorbed is much less ‐ equivalent to about one third of a cigarette dose. In view of the small samples and various assumptions in deriving these estimates, they can only be viewed as approximate.

Nicotine and carbon monoxide intake from high- and low-yield cigarettes.

We measured daily nicotine intake in 11 habitual smokers who smoked their usual brand or commercial high-yield (Federal Trade Commission [FTC] yield 1.2 mg nicotine, 16 mg tar) or low-yield (0.4 mg nicotine, 5 mg tar) cigarettes. Daily nicotine intake was measured from metabolic clearance data in conjunction with blood and urinary concentrations of nicotine during 24-hr smoking periods. On the average, subjects consumed 35 mg nicotine while smoking their usual cigarettes and 26 mg while smoking either high- or low-yield commercial cigarettes different from their usual brand. This level of nicotine consumption from low-yield cigarettes was because smokers obtained 60% more nicotine per cigarette than predicted by FTC yield and they smoked 25% more cigarettes a day. Although there was considerable variability in nicotine intake between subjects, there was a correlation within subjects between intake while smoking their usual brand and experimental cigarettes. Nicotine intake between the two commercial high- or low-yield cigarettes also correlated (r = 0.86). These findings are consistent with a minimal level of acceptable daily intake of nicotine for individuals that is related to usual intake. We suggest that our protocol provides a better quantitative estimate of the yield of different cigarette brands and potential health hazards than those currently provided by the FTC.

Relative intakes of tar, nicotine, and carbon monoxide from cigarettes of different yields.

The relative intakes of tar, nicotine, and carbon monoxide were estimated in 2455 cigarette smokers, who freely smoked their usual brands of cigarette. The estimates were derived by using an objective index of inhaling based on the measurement of carboxyhaemoglobin divided by the carbon monoxide yield of the cigarettes smoked, after background and carry over carboxyhaemoglobin effects had been allowed for. Separate analyses were performed according to the yield and type (plain, filter, etc) of cigarette smoked. The analyses based on yield indicated that the extent of inhaling was adjusted sufficiently to achieve similar intakes of nicotine/carbon monoxide regardless of the nicotine/carbon monoxide yield. It was not, however, sufficiently increased to achieve a similar intake of tar as the tar yield of the cigarette decreased. The analyses based on type of cigarette indicated that the extent of inhaling was adjusted to achieve similar intakes of tar and nicotine regardless of the type of cigarette smoked, but that this led to a greater intake of carbon monoxide among filter cigarette smokers than that among smokers of plain cigarettes--more so than would have been expected from their relative carbon monoxide yields. Two conclusions arise from these results. Firstly, any harmful effects of nicotine/carbon monoxide are unlikely to be materially reduced by smoking cigarettes with lower yields of nicotine/carbon monoxide, but the harmful effects of tar are likely to be reduced by smoking cigarettes with lower tar yields. These predictions appear to be borne out by epidemiological observations. Secondly, any harmful effects of carbon monoxide on the cardiovascular system will be greater in smokers of modern filter cigarettes than in smokers of modern plain cigarettes, provided that these two groups of smokers are otherwise similar with respect to risk of cardiovascular disease.

Interaction of ozone and cigarette smoke exposure

Possible interactions of ozone and cigarette smoke exposure have been tested in 2-hr chamber exposures of 26 male and 6 female subjects, all of whom were habitual smokers. Treatment conditions were air alone, air + cigarette smoking, ozone alone, and ozone + cigarette smoking. Ozone levels were increased progressively over four trials (0.37 ppm, 0.75 ppm, 0.50 ppm + intermittent exercise, and 0.75 ppm + intermittent exercise); exercise (50 W for 15 min alternating with 15-min rest) was intended to increase ventilation by a factor of 2.5. Ozone exposure reduced the carbon monoxide intake normally seen with smoking, as judged from smaller increments of blood carboxyhemoglobin readings. Ozone exposure alone gave rise to a decrease of lung function (forced vital capacity (VC), 1-sec forced expiratory volume, and maximum flow rates at 25 and 50% of VC), but the onset was slower and the response less dramatic than previously seen in nonsmokers, suggesting that the chronic effect of smoking may be to delay bronchial irritation by ozone. Smoking increased heart rate both at rest and during exercise, but this response was not materially influenced by simultaneous ozone exposure. It is concluded that over an acute 2-hr exposure, there is no appreciable interaction between cigarette smoking and responses to ozone.

Would a medium-nicotine, low-tar cigarette be less hazardous to health?

Smoking behaviour and exposure to carbon monoxide, nicotine, and tar were studied in 19 middle-tar smokers. All smoked their own brands for three weeks and then switched to either a conventional low-nicotine, low-tar brand (control) or a medium-nicotine, low-tar cigarette for a further three weeks, the order then being reversed. The medium-nicotine, low-tar brand also had a low delivery of carbon monoxide. With the medium-nicotine, low-tar cigarette mouth-level delivery and intake of nicotine was similar to that with the smokers' usual brands, and significantly greater than with the control low-tar cigarette. Intake of carbon monoxide from the medium-nicotine, low-tar cigarette was significantly less than with either own or control brands. With both low-tar brands mouth-level exposure to tar was reduced relative to smokers' usual cigarettes. There was no evidence, however, that the reduction in tar exposure was greater with the medium-nicotine brand than with the control low-tar cigarette. Both low tar brands were "'oversmoked" relative to subjects' usual middle-tar cigarettes. The medium-nicotine, low-tar cigarette was marginally more acceptable than the control brand, and the particular design used in the study resulted in a lower intake of carbon monoxide. In terms of reducing mouth-level exposure to tar, however, the medium-nicotine, low-tar cigarette had no advantage over the control low-tar product. In part this was because of the ratio of tar to nicotine delivery obtained by human smokers was not the same as that obtained by smoking machine.

Should intake of carbon monoxide be used as a guide to intake of other smoke constituents?

The relation between blood carboxyhaemoglobin (COHb) and plasma nicotine concentrations was studied in a group of 12 smokers smoking cigarettes of three levels of standard delivery. While the intake of carbon monoxide from a single cigarette was unrelated to the intake of nicotine, presmoking "trough" concentrations of the two substances (reflecting longer-term exposure) were highly correlated. Various other measures of nicotine exposure were at best only moderately correlated with blood nicotine concentrations. Thus trough COHb concentrations might be used to provide a reliable indication of the exposure to nicotine of individual smokers smoking the same type of cigarette, and of the relative exposure to nicotine of populations smoking cigarettes of different standard deliveries.