How can I analyse the claims made in the quotation below?
It was the Industrial Revolution, accompanied by a huge shift in population from rural to urban areas, which created a public health problem. As with so many other social problems, it was the very concentration of people which caused the difficulty. It was only urbanisation that necessitated that essential combination of preventive medicine, civil engineering and community administrative and legal resources known collectively as ‘public’.
The main claim of the passage is that many of the problems of epidemic diseases found in the wake of the Industrial Revolution were due to increasing urbanization, a factor that increased transmission of disease and allowed epidemics to propagate.
Of course, the Black Death (bubonic plague) that was the scourge of the late medieval and early modern period existed before the industrial revolution, as was the plague that decimated Athens during the Peloponnesian wars. Thus we cannot attribute epidemics solely to the Industrial Revolution. Nonetheless, the correlation with urbanization well attested.
To analyse the text's discussion of remedies for this, you might want to look at the changes to the water distribution systems in the wake of cholera epidemics in London.
Another major change in public health not mentioned in the passage is the developments in medicine, and the germ theory of disease, which enabled accurate assessment of the causes of epidemics.