The drug warfarin is an anticoagulant that is used after heart surgery to inhibit blood coagulation and diminish the risk of forming dangerous clots. This drug has a very narrow

therapeutic index (i.e. concentration in plasma at which drugs is inhibits major clot formation, but does not prevent basal levels of clotting in response to injury). In plasma, the drug is highly protein bound with 99% found bound to various serum proteins. Individuals on this drug who are exposed to high levels of Polychlorinated Benzene (PCB) pesticides, such as DDT, can suffer severe and life threatening bleeding episodes, where their blood is unable to clot in response to minor injuries. Provide a likely explanation of how PCB exposure could increase the activity of this drug, resulting in an enhanced risk of excessive bleeding episodes (limit 5-6 sentences).