and that getetic changnge can be passed down from generation to generation based onn a chemical exposure. >> your grandmother could have been exposed to something that you didn't know about, she didn't know about, that is affecting your health today. >> the evidence that we d dhave from laboratory experiments in animals certainly gives us cause for concern. >> some people are more exposed to chemicals because of the job they do or where they live. low income and minority commumunities often live nenear points of f pollution like chemical plants and waste dudump sites, , or in ageded and substandard housing. and these communities share a disproportionate burden of disease. >> higher rates of asthma, higher rates of obesity, higher rates of lead poisoning. >> so the aststhma rate in whae calll central l and east h harlm is at one in 4 children. um, and w when you gogo basicallly 0 blocksks south to o the upperr eastside, you find that t the asthma rate for c children is le half of that. >> we house over one third of the new york city's diesel bus fleleet. and d when you fige that we've got