Tom Murphy (@viewfromthecave) has an interesting post on new research into the relationship between irrigation and malaria. Obviously farmers benefit greatly from improved irrigation in arid regions. It’s well known that increasing irrigation, however, also brings about more mosquitos and more malaria. This new paper finds that the malarial effect lasts a lot longer than expected.
It’s true that areas that have long had irrigation have lower malaria rates, but those numbers don’t start falling until a decade or longer after the improvements. Regions that are newly transitioning to irrigation, on the other hand, are at much greater risk of malaria. This is true even when the government enacts proactive policies to combat the problem.