INDUSTRIAL PROBLEMS OF HEALTH 381 



some chemical works, the body should be provided with warmer 

 clothing and the humidity of the atmosphere may be higher. 

 In mines, bakeries, tunnels, foundries, rolling mills, or other 

 places where the temperature has to be high, workers should 

 wear light clothing or even be stripped to the waist. In such 

 cases humidity must be kept low and the air must be in con- 

 stant circulation, so as to increase the evaporation from the skin. 

 Another source of injury to the welfare of workers is noise. 

 Most people endure a great deal of noise day after day without 

 being aware that they are disturbed by it ; but it is bound to 

 have an irritating effect and "get on the nerves" sooner or 

 later. Excessive noise is the cause of a large proportion of 

 difficulty in hearing. 



285. Gases and fumesf In many industries poisonous gases 

 and fumes are produced. These either "eat away" the delicate 

 linings of the lungs or are absorbed and injure the whole sys- 

 tem. ^Most acid fumes act in the former way. Alcohols used in 

 varnishes, phosphorus fumes, lead fumes, benzene, and other 

 fumes poison the body. It is for these reasons that the man- 

 ufacture of white-phosphorus matches has been entirely pro- 

 hibited by law in this country, and that the use of wood alcohol 

 in varnishes and shellacs has been prohibited in some states 

 and cities. 



Where the work produces fumes or gases, these must be re- 

 moved by flues connected with exhaust fans. No person should 

 work regularly in any establishment that permits irritating or 

 dangerous fumes to enter the air breathed in the shop. In laun- 

 dries and garages, as well as in other places, men and women 

 have been poisoned by carbon monoxid (see section 141). 



286. Dust. In many occupations the worker is constantly 

 exposed to dust which may be injurious in several ways. 



I. It may form a crust over part of the lung lining, thus 

 reducing the actual breathing surface and at the same time 

 weakening the resistance of the cells to disease microbes. Ex- 

 amples are coal dust and the fluff from the fibers used in 

 spinning and weaving. 



