Carbon monoxide and driving skills

An association between air pollution and daily most frequently visits of eighteen outpatient diseases in an industrial city

Toxic effects of air pollutants were individually identified in various organs of the body. However, the concurrent occurrences and the connection of diseases in multiple organs arise from air pollution has not been concurrently studied before. Here we hypothesize that there exist connected health effects arise from air pollution when diseases in various organs were considered together. We used medical data from hospital outpatient visits for various organs in the body with a disease-air pollution model that represents each of the diseases as a function of the environmental factors. Our results show that elevated air pollution risks (above 40%) concurrently occurred in diseases of spondylosis, cerebrovascular, pneumonia, accidents, chronic obstructive pulmonary disease (COPD), influenza, osteoarthritis (OA), asthma, peptic ulcer disease (PUD), cancer, heart, hypertensive, diabetes, kidney, and rheumatism. Air pollutants that were associated with elevated health risks are particular matters with diameters equal or less than 2.5 μm (PM_2.5), nitrogen dioxide (NO₂), ozone (O₃), particular matters with diameters equal or less than 10 μm (PM₁₀), carbon monoxide (CO), and nitrogen oxide (NO). Concurrent occurrences of diseases in various organs indicate that the immune system tries to connectively defend the body from persistent and rising air pollution.

Air quality in indoor go-kart facilities in Germany

Indoor go-kart driving and viewing is enjoyed by people of all ages. However, it may pose health hazards, especially for children, pregnant women, cardiovascular patients, and elderly individuals. Depending on the race length, for example, high concentrations of various contaminants may result in severe health problems. Therefore, this project investigated the Indoor Air Quality of eight indoor go-kart facilities. In general, karts that used regular fuel produced the highest concentrations of CO, benzene, TVOC, and BaP, with maximum levels up to 150 mg/m³ , 170 μg/m³ , 2690 μg/m³ , and 8.7 ng/m³ , respectively. As expected, the maximum CO concentrations at go-kart facilities that used liquid gas and electric karts (20 and <6 mg/m³ , respectively) were significantly lower than those at other facilities. The highest 95th percentile values for NO (2680 μg/m³ ) and NO₂ (280 μg/m³ ) were measured for karts with liquid gas. The alkane, alkene, and cycloalkane groups, as well as benzene and the alkyl benzenes, were the predominant components of the measured TVOCs. Overall, owners of indoor go-kart tracks should ensure that the ventilation with regard to combustion products is optimally adapted in any case to reduce the levels of critical air pollutants.

Carbon monoxide load in indoor carting

Personal experience and reports of colleagues made the authors aware of a possible problem of carbon monoxide exposure in indoor carting arenas. Symptoms such as nausea, headache and altered coordination are not uncommon. This prompted us to register carbon monoxide levels in 15 healthy volunteers in a recreational carting event in a random arena. After two sessions of 10 min and a finale of 20 min we measured a clear increase in carboxyhaemoglobin levels, up to a 16.5-fold increase. The mean rise in the carboxyhaemoglobin level (expressed as a percentage) was 2.06 (mean start carboxyhaemoglobin 0.49%, mean end carboxyhaemoglobin 2.55%). Nausea was noted in 53% of the drivers, headache and altered coordination in 33%, and 13% had a vague abdominal pain. The effects of carbon monoxide exposure during indoor carting should thus not be underestimated, and healthcare workers should be aware of the possible risks.

Importance of experimenter-blind procedure in neurotoxicology

The importance of having the investigator blind to the experimental condition of a human subject was demonstrated using meta analysis of 43 reports of the effects of carbon monoxide (CO) on behavior. It was shown that 75% of single-blind studies found significant CO effects as opposed to only 26% of double-blind studies (difference was significant, p < 0.005). It was also not possible to show that the difference could have been due to different CO exposure levels, different statistical practices, or different study group sizes. The failure to follow double-blind procedure has been partly responsible for disagreement about the effects of CO reported in the literature. Investigator blinding is also important in laboratory animal research.

Carbon monoxide in indoor ice skating rinks: evaluation of absorption by adult hockey players

We evaluated alveolar carbon monoxide (CO) levels of 122 male, adult hockey players active in recreational leagues of the Quebec City region (Canada), before and after 10 weekly 90-minute games in 10 different rinks. We also determined exposure by quantifying the average CO level in the rink during the games. Other variables documented included age, pulmonary function, aerobic capacity, and smoking status. Environmental concentrations varied from 1.6 to 131.5 parts per million (ppm). We examined the absorption/exposure relationship using a simple linear regression model. In low CO exposure levels, physical exercise lowered the alveolar CO concentration. However, we noted that for each 10 ppm of CO in the ambient air, the players had adsorbed enough CO to raise their carboxyhemoglobin (COHb) levels by 1 percent. This relationship was true both for smokers and non-smokers. We suggest that an average environmental concentration of 20 ppm of CO for the duration of a hockey game (90 minutes) should be reference limit not to be exceeded in indoor skating rinks.

Carbon monoxide exposure and human visual detection thresholds

In order to test for CO exposure effects on vision, a battery of visual tests was administered to male college students. All subjects completed the battery of tests both before and during an exposure period in a double-blind study. Experimental subjects received CO during the exposure period, whereas control subjects received only room air. The battery of visual tests was designed for the assessment of scotopic (dark adapted, rod mediated) detection, photopic (light adapted, cone mediated) detection, the pattern detection process and the motion detection process. Contrast thresholds for the detection of stimulus pattern and for the detection of stimulus motion were measured under both photopic and scotopic viewing conditions, and sensitivity was monitored throughout the course of dark adaptation by measuring luminance thresholds. The results indicated that visual function in healthy, young-adult males was not affected by a COHb level of about 17% which was maintained for over 2 hours.

The effects of carbon monoxide on dual-task performance

Thirty adult, nonsmokers were exposed for four hours to one of three concentrations of carbon monoxide (CO) 5 ppm, 35 ppm, and 70 ppm to produce blood levels of either 1%, 3%, or 5% carboxyhemoglobin (COHb) after the third hour of exposure. Performance in the double blind study was assessed by a tracking task paired with a peripheral monitoring task, each possessing two levels of difficulty. The results indicated that visual-manual tracking was significantly impaired by about 30%, during the fourth hour of exposure to 70 ppm of CO, when 5% COHb was reached, as compared to performance at 5 ppm and 35 ppm. The impairment occurred only during the high frequency tracking condition. Response times of subjects to the peripheral light-intensity-changes also increased during the third and fourth hours. The findings suggested that an assessment of the effects of low-level CO on human performance should include an analysis of the demand characteristics of the tasks as well as data on concentration and exposure duration.

Effects of low levels of carbon monoxide on visions of smokers and nonsmokers

The scotopic sensitivity, reaction time, eye movements, and visually evoked cortical potentials of 12 nonsmokers and 6 smokers were measured during the course of 3 hr of exposure both to air and to 200 ppm CO in air. No significant degradation in performance was observed for any of these measures in either group during the course of the exposure.

Physiological effects of acute passive exposure to cigarette smoke

Effects of passive inhalation of cigarette smoke at levels typically encountered in public buildings have been investigated. Twenty normal male and female nonsmokers (18 to 30 years) were each exposed for two hours on alternate days (in random order) to either room air or room air plus machine-produced cigarette smoke. Exposures were conducted in an unventilated chamber (14.6 m3). Subdivisions of lung volume, maximum expiratory flow-volume curves, single-breath nitrogen washout curves, blood carboxyhemoglobin levels, and heart rates were obtained before, during, and after exposure. A submaximal bicycle ergometer test and a symptom questionnaire were also administered after exposure. Statistical analysis revealed several significant differences between test and control days; the magnitude of the changes was small and of questionable biological significance, however, particularly when account was taken of the number of statistical comparisons made. Despite the relatively small physiological changes, subjective complaints were common-cough, and eye irritation, for example. It is concluded that in normal subjects the magnitude of physiological responses to acute exposures is minimal; thus arguments concerning effects rest on symptomatology and such other factors as the unknown risks of chronic exposure.

Brake reaction time--effects of age, sex, and carbon monoxide

Simulated braking responses have been tested in relation to blood carboxyhemoglobin (HbCO) levels. The main determinants of percentage of HbCO in 352 subjects attending a fall fair were daily cigarette consumption and minutes since the last cigarette. In women the brake response time deteriorated from age 16 yr, but in the men there was an improvement from age 16 to the early 20s. Times at all ages were better for men than for women. Average response times and the rate of aging of the braking response were very similar in smokers and in nonsmokers. In the nonsmokers, however, response time with step function CO increments of as much as 7% HbCO. There was a suggestion of a small increase of reaction time, with an opposing decrease of leg movement time, during the first few minutes after CO exposure; nevertheless, these trends were statistically insignificant.

Cigarette smoke in enclosed public facilities

A portable carbon monoxide detector (catalytic electrode) was used to record carbon monoxide concentrations in enclosed public facilities, including night clubs, bars, restaurants, stores, hospitals, and public transit vehicles. The highest concentrations of carbon monoxide were found in night clubs, where evening indoor readings averaged 13.4 ppm, which was 4.1 +/- 1.5 ppm higher than outdoor readings. In one poorly ventilated establishment, values ranged from 20 to 40 ppm, with substantial gradients around the room. Adequate ventilation and screening of restaurant employees for ischemic heart disease should prevent problems from cigarette-induced build-up of carbon monoxide. Unfortunately, much lower concentrations of other constituents of smoke cause symptoms and changes of pulmonary function in the nonsmoker. If carbon monoxide is used as an indicator of cigarette smoke accumulation, concentrations should not exceed ambient readings by more than 5 ppm.

Carbon monoxide in school buses

Following an incident in which eight children became ill from carbon monoxide in a school bus, an investigation was made of CO levels in school buses in the Seattle area. The procedure selected for the evaluation was to test a large number of buses at a nearby ski resort. On the day selected for the sampling, over 200 buses arrived, bringing school children from a number of school districts in the Seattle are for skiing lessons. As they arrived, 33 buses were checked immediately to determine in-transit levels of CO. Four of the 33 buses had CO levels in excess of Environmental Protection Agency maximum allowable concentrations for an 8-hr exposure. As the buses sat idling in the parking lot, 65 of them were tested--during the lunch hour when the students returned to the buses to have their lunch and to rest. Two buses had nearly 3 times the concentration of CO permitted by the EPA for a 1-hr exposure. A total of seven buses (10 per cent) had concentrations of CO not permitted by the EPA for more than a 1-hr period. Altogether there were 24 buses (36 per cent) that had levels of CO in excess of EPA standards for an 8-hr exposure. As a result of these determinations and other observations a number of recommendations were made to reduce the hazard of exposure to carbon monoxide in school buses.

Carbon monoxide in the urban atmosphere: hazards to the pedestrian and the street-worker

The carbon monoxide (CO) concentrations encountered by pedestrians and workers in the streets of a large metropolis were monitored by a reliable and sensitive portable detector (the Ecolyzer). Up to 1,000 observations per day were collected for several months during the summer and fall of 1973. The CO levels ranged from 10 to 50 ppm (varying with wind speed and direction, atmospheric stability, traffic density, and the height of nearby buildings). Much higher average concentrations were found in such adverse sites as poorly ventilated underpasses and underground garages. Street closures for a pedestrian mall reduced levels on the mall to around the general urban background withoug large increases in readings on adjoining streets. Many street-workers have little medical supervision, and for this reason the urban eight-hour CO ceilings may be a more appropriate air quality target than the usual industrial figure of 50 ppm. However, even the latter is sometimes exceeded on busy city streets.