The four phases of the disposition of a toxic compound to assess its toxicity are absorption through membranes in a system, the distribution throughout the system, the excretion and elimination from the system and lastly, the metabolic fate of the chemical. Using these four phases assess the toxicity on DDT. I would also like to know how DDT is transported through the cell membranes. Is it passive diffusion, facilitated diffusion, filtration, active transport, etc. I know it is lipid soluble.