 Nyorai kupfuurira kweiyi ndima - Broad Street yakanga ine mukurumbira wakashata senzvimbo yekuputika kwa 1854yekorera. Dr. John Snow vakatevera kupararira kwechirwere ichi kusvika papombi yemvura yomunharaunda iri mumugwagwa, uye vakaidzima. Nguva iyi isati yasvika, chirwere chacho chaifungidzirwa zvikuru kuti chinokonzerwa nemiasma inofambiswa nemhepo; zvakawanikwa naSnow zvakaratidza kuti chinoparadzirwa nemvura. 