translation.en: They found in the late '30s -- 10 years after they'd made these dams -- that the people in Northern Alabama were infected with malaria, about a third to half of them were infected with malaria.
translation.zh: 他们发现在最近30年代后期--在建造了这些大坝后的十年内-- 北阿拉巴马的人们感染了疟疾。 大约三分之一到一半的人感染了疟疾。