Excessive consumption of fat-soluble vitamins may be toxic because they are not easily eliminated (b) toxicity associated with fluorosis involves brittle teeth and bones (d) Removal of chemicals from the body excretion and biotransformation (metabolism) work in tandem to eliminate exogenous toxicants. Main routes: kidney urine (aqueous) Deals with molecular weight chemicals liver/bile fecal (lipids and aqueous) Deals with molecular weight chemicals characteristics favoring excretion: lipid solubility, free toxin = non-protein bound ionized and water soluble. Mechanisms of excretion filtration: renal urine active secretion, kidney urine and liver bile. Diffusion into glandular secretions: mammary, sweat, saliva these mechanisms can fail: lipid-soluble soluble bioaccumulation, reabsorbed. Active transport: binding storage bioaccumulation lead. High blood flow leaky podocytes spaces 40 angstroms: 1a = 1/100000000 cm. Hydrostatic filtration: hydrophilic chemicals are pushed through. Water, sugars, and peptides are reabsorbed transport mediated some transporters contribute to secretion. Bile ducts are arranged to collect fat-soluble waste: drain into the gall bladder.