One on the major complaints made by factory reformers concerned the state of the buildings that they children were forced to work in. Dr. Ward, who visited textile factories in Manchester in 1819 wrote: "I have had frequent opportunities of seeing people coming out from the factories and occasionally attending as patients. Last summer I visited three cotton factories with Dr. Clough of Preston and Mr. Barker of Manchester and we could not remain ten minutes in the factory without gasping for breath. How it is possible for those who are doomed to remain there twelve or fifteen hours to endure it? If we take into account the heated temperature of the air, and the contamination of the air, it is a matter of astonishment to my mind, how the work people can bear the confinement for so great a length of time."
William Dodd talked about the work in his book, A Narrative of the Experience and Sufferings of William Dodd a Factory Cripple: "One great cause of ill health to the operatives in factories is the dust and lime which is continually flying about. Animal skins are soaked in a strong solution of lime. The lime gets intermixed with the wool and hair. It is put through the teaser in order to shake out the lime and dust. The machine, and all around, are covered with the lime and dust. The result is difficulty of breathing, asthma, etc."
Most young workers complained of feeling sick during their first few weeks of working in a factory. Robert Blincoe said he felt that the dust and flue was suffocating him. This initial reaction to factory pollution became known as mill fever. Symptoms included sickness and headaches. Frank Forrest, a child worker in Dundee, reported: "About a week after I became a mill boy, I was seized with a strong, heavy sickness, that few escape on first becoming factory workers. The cause of the sickness, which is known by the name of "mill fever", is the contaminated atmosphere produced by so many breathing in a confined space, together with the heat and exhalations of grease and oil and the gas needed to light the establishment."
Sir Anthony Carlile, a doctor at Westminster Hospital visited some textile mills in 1832. He later gave evidence to the House of Commons on the dangers that factory pollution was causing for the young people working in factories: "labour is undergone in an atmosphere heated to a temperature of 70 to 80 and upwards". He pointed out that going from a "very hot room into damp cold air will inevitably produce inflammations of the lungs".
Doctors were also concerned about the "dust from flax and the flue from cotton" in the air that the young workers were breathing in. Dr. Charles Aston Key told Michael Sadler that this "impure air breathed for a great length of time must be productive of disease, or exceedingly weaken the body". Dr. Thomas Young who studied textile workers in Bolton reported that factory pollution was causing major health problems. A report published in July 1833 stated that most factories were "dirty; low-roofed; ill-ventilated; ill-drained; no conveniences for washing or dressing; no contrivance for carrying off dust and other effluvia". It was argued that the dust and floating cotton fibre in the atmosphere was a major factor in the high incidence of tuberculosis, bronchitis, asthma and byssinosis amongst cotton workers.
Edward Baines, argued in his book, The History of the Cotton Manufacture (1835): "The noise and whirl of the machinery, which are unpleasant and confusing to a spectator unaccustomed to the scene, produce not the slightest effect on the operatives habituated to it. The only thing that makes factory labour trying is that they are confined for long hours, and deprived of fresh air: this makes them pale, and reduces their vigour, but it rarely brings on disease. The minute fibres of cotton which float in the rooms are admitted, even by medical men, not to be injurious to young persons."
The factory owners were also defended by Andrew Ure. In his book The Philosophy of Manufactures (1835): "On my recent tour through the manufacturing districts, I have seen tens of thousands of old, young and middle-aged of both sexes earning abundant food, raiment, and domestic accommodation, without perspiring at a single pore, screened meanwhile from the summer's sun and the winter's frost, in apartments more airy and sulubrious than those of the metropolis in which our legislature and fashionable aristocracies assemble."