First of all, being listed on California's Prop 65 list is not a valid method of ascribing toxicity. This proposition is one of the most idiotic things ever to come down the pike in my state. Every place you walk into here has a sign stating that something inside is carcinogenic. Since pretty much everything in existence is on this list, it's not too surprising. The signs everywhere are not surprising either, since the statute basically defines a carcinogenic or hazardous level as "any detectable amount."

Looking at your reference:

IARC Carcinogens 2B, Possible



U.S. NTP Carcinogens Reasonably Anticipated (??)

California Prop 65 Known Carcinogens Yes

U.S. EPA Carcinogens B2, Probable (Sufficient evidence of carcinogenicity from animal studies with inadequate or no data from epidemiologic studies in humans.)

TRI Carcinogen Not Listed



A little iffy, no?

While there might be some risk, telling someone you won't stop a malaria epidemic because they might get cancer someday probably won't make a very good impression.

As Mark says, balance is required. Work on alternatives is needed, but DDT should not be banned worldwide until these alternatives are available and affordable.