Edwin Chadwick
After a serious outbreak of typhus in 1838, he convinced the Poor Law Board that an enquiry was required.  The work was done by his friends who were doctors and he published it as Report on The Sanitary Condition of the Labouring Population of Great Britain  in 1842.   A lot of people bought it.  It said that  better water supplies and a drainage system to remove waste, would stop so many people dying. Evidence given by Dr Dyce Guthrie convinced Chadwick that every house should have a permanent water supply, rather than the intermittent supplies from standpipes that many poor people had to use. The report led to  the Public Health Act 1848, which was the first time the British government took responsibility for the health of its citizens.