Organochlorine pesticides such as DDT have comparatively lower direct human toxicity; it is their impact on the food chain that leads to acute human toxicity. Which of their properties cause them to be impactful on the food chain?

Organochlorines like DDT act on the food chain through their persistence and their solubility in fats.

Statement 1 holds, as persistence lets the compound survive for years without breaking down.

Statement 3 holds, since fat solubility lets it store in the fatty tissues of organisms.

Together these traits drive biomagnification up successive trophic levels.

Statement 2 fails, as insolubility in water alone would not cause build-up in tissue.

Statement 4 fails, since these compounds are non-polar rather than polar.

This is why DDT concentrations rise sharply toward the top of the food chain.