One showed where the major malaria-infested lands of Palestine were as of 1920, according to a British report.
I found a similar map from 1925:
The other showed where Jews had bought land in Palestine as of 1944 (blue=JNF, green=privately owned):
The two maps are remarkably similar.
The conclusion is that Jews bought the worst swamp lands, drained them and made them into usable, arable areas, to the benefits of everyone.
It took until 1968, but Israel was the first nation in Asia to eradicate malaria completely.
If you hate Israel, though, this can be considered an evil colonialist plot.
The book "Healing the Land and the Nation: Malaria and the Zionist Project in Palestine, 1920-1947"
by Sandra M. Sufian (2007) says that the swamps that were infested with malaria-spreading mosquitoes were in fact considered sacred, therapeutic pools to rural Palestinian Arabs:
Just two competing narratives. Who is to say that the Jewish conception of swamps as spreading disease is the correct one? Maybe they were really holy, healing swamps as the Arabs say. Draining them was just another example of oppression.
This review of the book, published in academic journal H-Levant, lays out the thesis that the entire malaria-clearing project was nothing more than a Zionist colonialist plot:
According to Sufian, the Zionist leadership, like the Mandate government, tried to manage the health of the Palestinian Arabs as though they were part of the natural environment. Diseases from the “natives” might be transmitted to the colonial authorities or the Zionist settlers and so should be managed through official public health policies. The Zionists imported European and U.S. medical technologies and foreign capital to restore the land to what was in their eyes its original state, with little concern for those who had long made their living from it. The Zionist settlers had no sense of the national rights of the Palestinian Arabs, who they believed had no real attachment to the land. Like European settlers elsewhere, the Zionists considered the indigenous population primitive and backward. The land was a swampy wasteland inhabited by an unproductive people. In this, the Zionists were merely drawing upon racial views of non-European, indigenous populations then prevalent among colonialists. As Sufian points out, Zionists, like other Europeans, saw malaria not as an environmental problem, but one caused by the neglectful, indifferent, and lazy lifestyles of the natives, whose watering holes and leaky irrigation ditches were ideal places for mosquitoes to breed. The Zionists' goal was to drain the swamps and pools of water to eradicate the disease, thereby expanding the land available for settlement and agricultural production. As the author notes, in many parts of world European settlers made this connection between disease eradication, immigration, and settlement. When the Zionists drained the swamps they also reduced the pasture land long used by Bedouins and other Arab agriculturalists for grazing their livestock. Despite stiff resistance, land formerly held collectively by Palestinian Arabs became private land owned by Zionist settlers.Evil Zionists eradicating malaria were really oppressing the Arabs whose lives they were saving.
That is a hell of a take.