The paper includes an analysis of cases about the interdicta de cloacis investigated by Roman jurists in I-III centuries AD, related to the right to conduct private sewers into public ones and to clean them, if obstructed, also in spite of neighbours’ opposition. The case system discussed by Roman jurists may also help solve a question at the top of interest among the scholars: did Romans think about an «environmental protection»? Can it be identified in a more modest and empirical, yet essential, protection of the hygienic, sanitary conditions in the Roman cities? Finally, some considerations of Severan jurists may help verify an interesting intersection among legal reasoning and medical theories on the onset of the epidemics, with particular reference to the miasma - theory of hippocratic origin, reassessed by Galen.
