The influence of the atmosphere on our health and comfort in confined and crowded places / by Leonard Hill [and others].

Date:
[1913]
Catalogue details

Licence: In copyright

Credit: The influence of the atmosphere on our health and comfort in confined and crowded places / by Leonard Hill [and others]. Source: Wellcome Collection.

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    minutes. We can confirm these findings. High percentages of CO2, for example, 30 to 50 per cent cause spasm of the glottis and cannot be inhaled by the normal individual. At each hreath we rebreathe intO' our lungs the air in the nose and large air-tubes (the dead-space air), and about one-third of the air which is breathed in is dead-space air when we are resting. Thus, no man breathes in pure outside air into his lungs, but air con- taminated perhaps by one-third or (on deep breathing dining muscu- lar work) by one-tenth with his own expired air. When a child goes to sleep with its head partly buried under the bed clothes, and in a cradle confined by curtains, it rebreathes the expired air to a still greater extent; and so with all animals that snuggle together for warmth’s sake. Not only the new-born babe sleeping against its mother’s breast, but pigs in a sty, young rabbits, rats and mice clustered together in their nests, and young chicks under the brood- ing hen, all alike breathe a far higher percentage than that allowed by the Factory Acts. Cattle in ill-ventilated stalls may breathe 10 times the normal percentage ^ of COo. When the air of a room is still, the expired air may not be blown away and hangs round a person recumbent therein. Thus B. Hey- maniH found 0.44 per cent in the inspired air, against 0.0318 in the air of the room. On putting an electric fan to blow across his face at a rate of 3.3 meters per second the COo in the inspired air fell to 0.0307 per cent. To rebreathe one’s own breath is a natural and inevitable per- formance, and to breathe some of the air exhaled by another is the common lot of men who, like animals, have to crowd together and husband their heat in fighting the inclemency of the weather. Lehmann found in a brewery 1.5 to 2.5 per cent CO2 in the air of the fermentation rooms. This was breathed by 5 to 8 workers for hours long with no ill effects. All were strong, healthy young men, some having done the work for years. Weak men with affections of the lungs are not allowed to do this form of work. With 11.6 to 14.7 per cent most were constrained to leave the room in two minutes, but two strong young men endured it for 5 minutes and were all right afterwards. An experiment was made of breathing for three-fourths of an hour 1.8 to 3.5 per cent COo, rising finally to 10 per cent, when the ^ .Schultze u. Maercker. Neben den CO2 Gehalt der Stallfult. Gottingen, i86q. Cited after B. Heymann. ^Ztschr. f. Hygiene, Vol. 49, 1905, p. 403.