THE MICROBIOLOGY OF THE ATMOSPHERE 



(1948) for a Birmingham hospital, where they found from 210 bacteria and 

 moulds per cubic metre under quiet conditions, to 2,800 per cubic metre 

 with bed-making in progress (one very high count of 22,000 per cubic 

 metre, including many moulds, was obtained with the ward windows 

 closed). 



Recommendations for the maximum tolerable number of particles 

 carrying bacteria in operating theatres are 700 per cubic metre for minor 

 operations, and down to 70 or even 15 per cubic metre for dressing burns 

 and for operations on the central nervous system (Bourdillon et al., 

 1948/'; and see Bourdillon & Colebrook, 1946). 



FACTORIES AND WORKSHOPS, SCHOOLS, PUBLIC BUILDINGS 



Anthrax is one of the few bacterial diseases which is clearly spread by 

 airborne dust to workers who handle wool and hair contaminated by 

 infected animals. Inhalation of airborne spores of Bacillus anthracis 

 sometimes produces fatal infection of the lung. 



Bacterial counts in a variety of English factories and offices were 

 reported on by Bourdillon et al. [i^^^a). 



SUBWAYS, MINES, AND CAVES 



London's underground railways have been investigated by Andrewes 

 (1902) and by Forbes (1924), and the New York Subway by Soper (1908). 



Studies in caves are few, but include those by Lurie & Way (1957) 

 and by Mason-Williams & Benson-Evans (1958). 



SEWERS 



Miquel (1880), in Paris, gave special attention to the sewer in the Rue 

 de Rivoli near its junction with the large collector of the Boulevard 

 Sebastopol. He found a steady load of from 800 to 900 bacteria per cubic 

 metre. Pollens were absent, and cryptogamic spores were only | to j 

 as numerous as in outdoor air at the same time. The contamination of the 

 air in the near-by Rue de Rivoli was lower in winter but higher in summer 

 than it was in the sewer. 



Comparable results were reported from London in sewers under the 

 Palace of Westminster (Carnelley & Haldane, 1887). 



AIR-SPORA OF FARM BUILDINGS 



High microbial concentrations often occur in farm buildings, such as 

 cowsheds, where hay is being fed to animals, or in barns where thrashing 

 or cleaning is in progress. Inhalation may produce symptoms of the still- 

 little-understood farmer's lung and thrasher's lung, as well as various 

 diseases of farm animals. Milk also needs protection from contamination 

 by barn air {see Ruehle, 191 5; Ruehle & Kulp, 191 5). 



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