INDUSTRIAL PROBLEMS OF HEALTH 



391 



Fatigue and strain increase the accident rate. This is shown 

 by the variation in the number of accidents from hour to 

 hour during the day (see Fig. 172). Undernourishment, poor 

 ventilation, defective illumination, and alcoholism also contrib- 

 ute their share to the high accident rate. Reckless workers ex- 

 pose themselves to dangers. On the other hand, some workers 



16 

 14 



Cotton mills - 

 Metal trades- 



Hours of work 



Fig. 172. Variation in the percentages of accidents hour by hour 



In industry in general the number of accidents per hour increases steadily from the 

 time work starts in the morning until past the middle of the forenoon; then the num- 

 ber declines to a minimum between twelve and one. In the afternoon again, each hour 

 sees an increase in the number of accidents until about four oclock, when there is a 

 decline to the end of the day's work. This is shown by the shape of the solid line in 

 the figure. The same general facts are found to hold for such different industries as 

 cotton manufacture (the solid columns) and metal trades (the columns with dotted 

 lines). A very important factor in bringing about this condition is the fatigue of 

 the worker. By introducing a short rest period in the middle of the forenoon and 

 another in the middle of the afternoon many industries have succeeded in greatly 

 reducing accidents, errors, and the spoiling of material 



fail to consider the possible results to others of careless work- 

 manship or habits, as in setting up scaffolding, tightening sup- 

 ports, turning off electric current or power, leaving tools or 

 other objects out of place, and so on. It is the workers who 

 cause accidents, and it is the workers who suffer, but it is not 

 always the same workers. 



