Effects of Temperature and Humidity of Inhaled Air on the Concentration of Ethanol in a Man's Exhaled Breath

1. Ten healthy men each drank a moderate dose of ethanol in experiments to test if the temperature and moisture content of inhaled air could alter the concentration of ethanol in exhaled breath. 2. They breathed air at various temperatures and relative humidities (RH) for about 1 min before the concentration of ethanol and the temperature of end-expired breath were determined. Control breaths were analysed after the same men breathed ordinary room air (23°C, 55% RH). All tests were made during the postabsorptive phase of ethanol metabolism and the breath samples were analysed by gas-liquid chromatography. 3. When the men breathed cold dry air (5°C, 0% RH), the expired ethanol concentration decreased by 9·6 ± 0·69% (mean ± se) and breath temperature dropped by 1·40 ± 0·08°C. Cold moist air (5°C, 100% RH) decreased breath ethanol concentration by 6·4 ± 1·02% and breath temperature dropped by 1·1 ± 0·07°C. With hot dry air (80°C, 0% RH) as the breathing medium the concentration of ethanol was lowered by 4·3 ± 1·27% but expired breath temperatures were unchanged from the control tests. On breathing hot moist air (50°C, 100% RH), breath ethanol concentrations decreased by 10·3 ± 0·59%, even though breath temperatures rose by 1·8 ± 0·14°C above that of the controls. 4. Ethanol dissolves in the watery mucous membrane of the upper respiratory tract and can equilibrate with inhaled and exhaled air. It seems likely that during exchanges of heat and water vapour between respired air and the mucus, which largely depends on the temperature and humidity of inhaled air, the equilibrium of ethanol at the breath/mucus interface becomes disrupted. This leads to changes in the concentration of ethanol in expired air.

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Breath Alcohol Analysis and the Blood: Breath Ratio

Medicine Science and the Law ◽

10.1177/002580247501500309 ◽

1975 ◽

Vol 15 (3) ◽

pp. 205-210 ◽

Cited By ~ 28

Author(s):

B. M. Wright ◽

T. P. Jones ◽

A. W. Jones

Keyword(s):

Liquid Chromatography ◽

Blood Analysis ◽

Gas Liquid Chromatography ◽

Upper Respiratory Tract ◽

Breath Sampling ◽

Breath Alcohol ◽

History Of ◽

Upper Respiratory ◽

Sampling Procedures

The history of breath alcohol analysis and of the concept of a blood: breath ratio is briefly reviewed and it is suggested that the ratio is always lower and more variable than predicted by accepted theory. Using gas liquid chromatography for both breath and blood it has been shown that the blood: breath ratio falls during expiration and only reaches its presently accepted value of 2100: 1, predicted from in vitro studies, after prolonged rebreathing. It is suggested that this is due to alcohol being absorbed from the breath during expiration by the mucosa of the upper respiratory tract, to replace that lost during inspiration. Proposals are made for further studies and for modifications in present breath sampling procedures which could make breath analysis an acceptable substitute for blood analysis in all except marginal cases.

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Effects of Temperature and Humidity on the Metabolism of the Fasting Bed-Bug (Cimex lectularius), Hemiptera

Parasitology ◽

10.1017/s0031182000020813 ◽

1932 ◽

Vol 24 (3) ◽

pp. 419-428 ◽

Cited By ~ 30

Author(s):

Kenneth Mellanby

Keyword(s):

Dry Matter ◽

Moist Air ◽

Bed Bugs ◽

Bed Bug ◽

Dry Air ◽

Loss Of Weight ◽

Cent Relative Humidity ◽

Effects Of Temperature ◽

Rate Of Evaporation ◽

Food Reserves

A method is described by which individual bed-bugs, weighing only 5 mg., can be accurately weighed, and their rate of loss of weight measured during starvation.Fasting bed-bugs were kept for various periods at five temperatures, ranging from 8° C. to 37° C., and at four humidities—0, 30, 60 and 90 per cent. relative humidity—at each temperature. Analysis after the experiments showed that the same amounts of food reserves were used up at each humidity for one temperature, and, as more water was evaporated from those kept in dry air than from those in moist, the proportion of dry matter rose most rapidly in dry air. Protein was the main food reserve used.Although the rate of loss of water was greatest in dry air, the rate of loss was relatively greater in moist air when the saturation deficiencies are compared. It appears that the insects conserve their water in dry air, but their surface area being so great in comparison with their volume, they cannot prevent all evaporation. This evaporation is at a rate nearly proportional to the saturation deficiency of the air.In moist air water appears to be evaporated freely. It is suggested that the spiracles are kept closed more in dry air and less in moist, which accounts for the fact that the rate of evaporation is proportionately greatest in moist air.A comparison is made between the results obtained with Cimex and Rhodnius.

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The Temperature And Humidity Relations Of The Cockroach

Journal of Experimental Biology ◽

10.1242/jeb.15.4.555 ◽

1938 ◽

Vol 15 (4) ◽

pp. 555-563 ◽

Cited By ~ 1

Author(s):

D. L. GUNN ◽

C. A. COSWAY

Keyword(s):

Temperature Gradient ◽

Temperature Reaction ◽

Air Humidity ◽

Moist Air ◽

Uniform Temperature ◽

Preferred Temperature ◽

Dry Air ◽

Blatta Orientalis ◽

Temperature And Humidity ◽

Humidity Reaction

1. In a diffusion gradient of humidity at uniform temperature, some cockroaches (Blatta orientalis, L.) show a tendency to spend more time in the drier region. Other individuals appear to be indifferent to the stimulus of air humidity. 2. On desiccation, there is a tendency for cockroaches to become hygro-positive. 3. In a temperature gradient, those individuals which react to humidity have a slightly but significantly higher preferred temperature in somewhat moist air than they have in dry air. 4. It seems, then, that the observed preferred temperature represents a kind of balance between a pure temperature reaction and a humidity reaction. The change in humidity reaction resulting from desiccation is qualitatively satisfactory to explain the fall in preferred temperature which occurs at the same time.

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The Temperature and Humidity Relations of the cockroach

Journal of Experimental Biology ◽

10.1242/jeb.13.1.28 ◽

1936 ◽

Vol 13 (1) ◽

pp. 28-34

Author(s):

DONALD L. GUNN ◽

F. B. NOTLEY

Keyword(s):

Body Temperature ◽

The Body ◽

Moist Air ◽

Dry Air ◽

Thermal Death ◽

Temperature And Humidity ◽

Ecological Importance

1. The thermal death-points of three species of cockroaches in dry and in moist air have been determined for 1-day and 1-hour exposures. 2. Moist air is more favourable than dry in the longer exposures, because in dry air death occurs from desiccation when the temperature itself is not fatal. 3. Dry air is more favourable than moist in the shorter exposures, owing to the fact that the evaporation of water lowers the body temperature. 4. Bearing in mind the thermotactic behaviour of these animals, these observations would seem to have little ecological importance.

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How Breathing Technique Can Influence the Results of Breath-Alcohol Analysis

Medicine Science and the Law ◽

10.1177/002580248202200409 ◽

1982 ◽

Vol 22 (4) ◽

pp. 275-280 ◽

Cited By ~ 34

Author(s):

A. W. Jones

Keyword(s):

Contact Time ◽

Ethanol Concentration ◽

Breath Holding ◽

Upper Respiratory Tract ◽

Moderate Dose ◽

Breath Sample ◽

Healthy Men ◽

Mucous Membranes ◽

Shallow Breathing ◽

Upper Respiratory

This paper reports experiments to test how a person's breathing technique can influence the concentration of ethanol and the temperature of end-expired breath samples. The experiments were performed with healthy men after they drank a moderate dose of ethanol and the concentration of ethanol in breath was determined by gas chromatography. The results were compared with control breaths, which were deep inspirations and forced expirations of room air, analysed within 2–3 minutes of the test-breath sample. With breath-holding (30 seconds) before expiration, the concentration of ethanol increased by 15.7 ± 2.24 per cent (mean ± SE) and the temperature of breath rose by 0.6 ± 0.09°C. Hyperventilating for 20 seconds, immediately before the analysis of breath, decreased the concentrations of ethanol by 10.6 ± 1.37 per cent and the breath temperature dropped by 1.0 ± 0.22°C. Keeping the mouth closed for 5 minutes (shallow breathing) increased expired ethanol concentration by 7.3 ± 1.2 per cent and the breath temperature rose by 0.7 ± 0.14°C. After a slow (20 second) exhalation expired ethanol increased by 2.0 ± 0.71 per cent but breath temperatures remained unchanged from control tests. My results suggest that the changes in expired-ethanol concentrations are partly caused by the rise or fall in the temperature of breath. But an equally important factor is the amount of time the breath spends in contact with the mucous membranes of the upper respiratory tract. A long contact time increases the concentration of ethanol and rapid ventilation lowers it. Regardless of the breathing technique tested, the results recovered to control values immediately the subjects began breathing normally again.

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Temperature and Humidity of Expired Air of Sheep

Australian Journal of Biological Sciences ◽

10.1071/bi9880309 ◽

1988 ◽

Vol 41 (3) ◽

pp. 309 ◽

Cited By ~ 4

Author(s):

KG Johnson ◽

SM Callahan ◽

R Strack

Keyword(s):

Air Temperature ◽

Upper Respiratory Tract ◽

Deep Body Temperature ◽

Thermally Induced ◽

Air Temperatures ◽

Temperature And Humidity ◽

Before And After ◽

Upper Respiratory ◽

Deep Body ◽

Expired Air

The temperature and humidity of expired air from three adult Merino sheep were measured at air temperatures of 20, 30 and 40�C before and after the animals were shorn. Expired air was apparently always saturated with water vapour. At the higher air temperatures the temperature of expired air was close to deep body temperature; at lower air temperatures, expired air had been significantly cooled, e.g. to 32� 3�C in shorn sheep at 20�C air temperature. Expired air was cooler from shorn than from unshorn animals at 20 and 30�C air temperature, possibly due to thermally induced vasomotor changes in the upper respiratory tract. Cooling of expired air would be expected to lead to recovery of some of the water evaporated during inspiration; at 20�C air temperature, this fraction was estimated to be 25% in unshorn sheep and 36% in shorn sheep.

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