I have several cotton and woollen millworkers from the age of 9 upwards in my family, but I think the worst of their jobs was to be a woolsorter, grading the raw wool as it arrived at the mill. There was a possibility that you could catch the deadly woolsorter's disease, which was connected with anthrax.
Woolsorter's pneumonia - a form of anthrax infection acquired by inhalation of dust containing Bacillus anthracis; initial symptoms (chill and cough and dyspnea and rapid pulse) are followed by extreme cardiovascular collapse.
Luckily for both my gt-grandfather and his father, neither of them was infected.