environment of the area. >> reporter: dr. faisal kahn is the director of public health in st. louis county. >> some disasters unfold slowly over time and their true nature and extent and severity only becomes clear in terms of human cost once you start counting people around you. >> reporter: to keep count these neighbors keep a list. >> the landises, the dubells, shirley shank died of breast cancer. >> there's 21 people on this list. >> and they were all on the same street? >> right. on palm drive. >> reporter: all of the residents in north st. louis with health issues told us they believe they had long-term exposure to the low-level contamination. this type of prolonged exposure has rarely been studied. scott, we are going to continue to follow this story. >> vinita, thank you very much. >>> something that surprised us today, in west virginia president obama said drug overdoses kill more americans each day than car wrecks. 120 overdose deaths every day. in a decade heroin use by...