so did amit friedlander. he was a student at stuyvesant high school, which is just three blocks from ground zero. at age 22, he successfully battled hodgkin's lymphoma. >> in hindsight i think my cancer was probably 9/11 related, and now that i know that, if i could go back in time, maybe i wouldn't have gone back to school. >> reporter: more than 70 cancers are on the list of 9/11- related illnesses identified by the federal government, ranging from asthma to skin cancer. less than 100,000 people, just a quarter of civilians and first responders exposed, have enrolled in the c.d.c.'s world health program, which provides screenings and treatment. of those, over 52,000 have 9/11- related illnesses and more than 2,000 have died. >> we're unfortunately seeing a rise in cancers. >> reporter: dr. michael crane runs the world trade center health program at mount sinai e'spital. >> we're watching for increasing numbers of cancers, particularly ulose which might be related to longer-acting and longer- ikration toxins