Cancer made up about 71 percent of the conditions the World Trade Center Health Program logged last year

The program's totals count conditions documented in people who enrolled for screening and covered care. An incidence rate is a different quantity. Screening finds disease, and it finds more of it than in a population nobody is examining. A growing count in a monitored group is partly a measure of how closely that group is being watched. The 71 percent describes one year of the program's records. Assigning those cancers to the dust would need rates from a comparable unexposed population, and this material does not report any.

The ranking has the same problem. Nonmelanoma skin cancer leads among cohort members living with cancer, then prostate, then breast. Without baseline rates for similar people who were not there, that ordering does not identify which cancers exposure raised. The rarer diagnoses on the same list are brain cancer, testicular cancer and leukemia. An unusual exposure would be easier to separate from ordinary background there. The source gives no counts for them.

More than 139,000 conditions across more than 150,000 members works out at roughly 0.93 conditions per person. That is not a statement that most members have one condition: documented conditions stack in individuals, so some carry several and others none. Enrollment of 150,000 against the CDC's estimate of 400,000 exposed is about 38 percent. Roughly 250,000 exposed people sit outside these figures entirely. Scientific American writes that the true health impact of the attacks is impossible to measure.

The clinics describe what they are seeing now. "We still see new patients, and a lot of our patients that are coming in now are coming in with a diagnosis of cancer or other latent conditions like interstitial lung disease," said Denise Harrison, clinical director at New York University Grossman School of Medicine's World Trade Center program.

On money, the material is thin. Treatment for dozens of conditions associated with the attacks is covered for survivors and first responders under the James Zadroga 9/11 Health and Compensation Act, signed into law in 2011 after years of lobbying by 9/11 health advocates. Many survivors and their families contend that this still does not account for the risks they faced. The source carries no appropriation figure and no projection of the cohort's future care costs. There is no enrollment forecast either. The case for sustained surveillance in this source rests on one clinical observation: new diagnoses are still arriving.

Matthew McCauley, a former police officer, was working as a law clerk blocks from the towers. He went on to help sift the rubble at Ground Zero, where fires burned for more than a month. The plume that rose over the financial district contained concrete, asbestos and glass, and reached more than a kilometer above it. He now has a persistent cough and sinus problems. "I wake up every morning, and you'd think that I smoked. I don't smoke," he told Scientific American. McCauley, now a lawyer for the advocacy organization 9/11 Health Watch, says he has known hundreds of people who died in the aftermath of the attacks.