Whakaotihia te rerenga e whai ake nei: He mea nui te mahi a John Snow mō te āwhina ki te hanga i te hononga i waenganui i te mate pukupuku me te mate pukupuku me nga puna wai poke, i whai wāhi ki te matenga o te ariā miasma. I roto i te
Ko te mate pukupuku o te mate pukupuku o te tau 1854, i kitea e Snow te nui o te mate i waenga i nga taangata o Soho ki te papu wai i Broad Street. I whakaponohia e Snow te kāwanatanga ā-rohe ki te tango i te ringa o te papu, nā reira i tino heke iho ai ngā take o te mate korera i te rohe. I te tau 1857, i tukuna e Snow he pepa ki te British Medical Journal e kii ana he maha nga keehi o te mate pukupuku ki nga puna wai kua poke i te paru tangata. I whakamahia e Snow ngā raraunga tatauranga hei whakaatu he iti ake te tūponotanga o te mate korora ki ngā tāngata i whiwhi wai mai i ngā puna i runga ake i te awa, i te hunga i whiwhi wai mai i ngā puna i raro iho. Ahakoa i tautokona e tana rangahau tana whakaaro ko te wai poke, ehara i te hau poke te pūtake o te korera