. >> one of the new tools is actually go and look in the sugen system. and you can filter it and see if there's polio virus in there. in fact a virus was detected in the cairo sugen -- sewage and the genetics came out of pakistan. we want to make sure in cairo we don't have reinfection in egypt. that would be easy to clean up if it happened but it's a good example of the risk we run we have to just keep giving this vaccine to everyone until we get to zero. >> rose: what's interesting about what you have done, you started with tobacco. i remember the skepticism and cynicism when you started that. how do you decide. if it's right, you go ahead? what's the mechanism for saying okay i'll tackle this. >> we set out as a goal to go after things nobody else is going after. there's a lot of money for aids a lot of people are working with aids and lot of funding sources. no one was working on tobacco or traffic accidents. the next thing is obesity. obesity will kill more people in new york city this year. >> rose: because of related diseases from obesity, diabete