There is no scientific evidence linking exposure to 9/11 dust and diseases such as pulmonary fibrosis. That doesn’t stop the press and politicians from leaping to conclusions.

Take the case of New York Police Officer Cesar Borja, the police officer whose son was a guest of Senator Clinton at the State of the Union only hours after his father’s untimely and premature death from lung disease.

Officer Borja became a symbol of the second round of 9/11 victims. The press said that he rushed downtown to rescue office workers on September 11. Now it seems that Officer Borja was not sent to the site until the end of December and served fewer than 20 shifts. These details matter.

Even though high levels of exposure to the dust are not linked with the lung disease that killed him, the claim that such exposure killed Officer Borja becomes even less plausible given how much time went by before he was assigned to the World Trade Center area. The air there became significantly cleaner as the days, weeks, and months went by.

Politicians and many in the press, though, are rushing to judgment and making expensive, rash decisions based on misplaced sympathy rather than sound science.

Politicians have vowed to spend over $1 billion on people presumed to have mysterious lung disease caused by the World Trade Center collapse, inspired in part by public sympathy for figures like Officer Borja and World Trade Center site cleanup worker and nun Sister Cindy Mahoney, who died from another form of lung ailment.

Mayor Bloomberg is claiming that the health effects of September 11 are costing the city $393 million a year. The $1 billion in federal insurance money he wants to tap into is just a start. But shouldn’t any compensation tied to 9/11 be tied to good scientific evidence that September 11 is responsible for such health ailments?

Let me be clear: the growing evidence that there is no link between Officer Borja’s illness and 9/11 makes his death no less tragic. All police officers, firefighters, and other rescue workers deserve our utmost respect and appreciation for risking their lives to protect us — every day — throughout the city.

We should not, however, allow politicians to use our admiration for local heroes as a tool with which to manipulate our judgment about science and the facts. A good police officer would not want to assign blame to the wrong person in a murder investigation, and good public officials should not assign blame to the wrong cause in investigating diseases, no matter how desperately we all want explanations when decent people come in harm’s way.

Lung diseases and cancer are difficult facts of life that become slightly easier to deal with if we know their causes. But the reality is, we sometimes don’t know why people get these diseases. In fact, the New York medical examiner determined that Officer Borja’s death was due to “idiopathic pulmonary fibrosis.” The medical term “idiopathic” means that we do not know the cause.

If the medical community doesn’t know, how can New York’s congressional delegation and mayor claim to know?

We can ill afford amateur diagnoses with over $1 billion earmarked for purported victims of World Trade Center-induced lung disease when there are people with real medical conditions from heart disease to spinal injuries — on whom we should certainly be spending money. Misdirected resources are not a good way to show our compassion.

We are all lucky to have heroes in our community — but shouldn’t there still be a seat at the table for science?

Mr. Stier is an associate director of the American Council on Science and Health, ACSH.org, HealthFactsAnd-Fears.com.