New York, NY —

Legislators are writing laws, litigants are suing, scientists are researching -- all over what happened to the health of workers and others in the aftermath of the World Trade Center attacks. Thousands of people have been getting sick, and some are dying. But if injury, illness and death are the effects, what exactly is the cause? As WNYC's Fred Mogul reports, finding the answer – and proving it -- is difficult.

REPORTER: It sounds straightforward. If working at the World Trade Center site caused health problems that eventually kill people, their survivors should get full pension benefits. Many public leaders seem to agree.

PATAKI: If they died…if it can be conclusively proved…

CLINTON: … they should be compensated for that…

KELLY: …but you have to be able to show causality...

REPORTER: Governor Pataki, Senator Clinton, and NYPD Commissioner Kelly all support “line of duty” benefits. That’s when someone dies and his survivors get 100-percent of his final pay, because he died in the line of duty. But does getting sick and dying 5 or 25 years after working at Ground Zero count as “in the line of duty”? All three say, “Sure.” But notice how the governor says, “…if it can be conclusively proved…” How tough is it to prove? Someone was healthy. He worked at the World Trade Center site. He got ill. He got worse. He died. Isn’t that what Kelly calls, “causality,” and most of us simply call ‘cause-and-effect’? Well…maybe…Sure, he had a hacking cough from clearing rubble for 10 weeks, but is that what caused his heart attack in the year 2027? Albany Attorney Douglas Goldman helped draft a proposed state law with bipartisan support in both chambers. It basically says the 9-11 connection trumps all other factors. All you have to do is prove your loved one worked at the Trade Center site for at least 40 hours between September 11th, 2001, and September 12th, 2002.

GOLDMAN: It allows the survivor to apply for this death benefit, and in many cases, it’s going to be 100% of what they were earning as their final average salary.

REPORTER: The bill covers death from many different kinds of respiratory and skin problems, cancer, cardiovascular disease – even some mental illnesses. And under this "presumption," as the pension system calls it, it wouldn’t matter if someone smoked or had a family history of health problems? Her survivors could still apply for and receive 100-percent of her wages automatically?

GOLDMAN: Without using the word “automatic,” yes: they would be entitled to the presumption under those circumstances.

REPORTER: Presumptions occur in many forms for many pension applicants. But, no, they’re not quite automatic. Medical and administrative boards scrutinize and challenge every case. Applicants still need to prove cause-and-effect – that exposure to adverse work conditions caused the death, not a different exposure or accident, and not a pre-existing condition. That goes for the 9-11 presumption, too. So how do you prove it? Take the case of the late NYPD Detective James Zadroga…

PALADINO: Multiple sections of the lungs are examined…

REPORTER: Zadroga died in December at age 34, after working at Ground Zero and the Staten Island landfill for more than 500 hours. His family qualifies for pension benefits, but not the full “line of duty” benefits – although many lawmakers are trying to change that. Earlier this spring Detectives Endowment Association President Michael Paladino read an autopsy report at a news conference. The coroner who wrote it was the first to directly say ….

PALADINO: It is felt with a reasonable degree of medical certainty that the cause of death was directly related to the 9-11 incident.

REPORTER: Is that proof? Not everyone agrees. Mayor Bloomberg suggested there could be “lots of other contributing factors.'' And he and his health commissioner have said they would need to see more tests – suggesting some of the problems pension applicants could face, even if a new “9-11 presumption” gives them the benefit of the doubt and lowers the burden of proof. But Dr. Robin Herbert, co-director of the World Trade Center Medical Monitoring program at Mount Sinai Hospital, read the autopsy and says the case does meet a basic standard of “plausibility.”

HERBERT: That is exactly the kind of condition we’re worried about. So Detective Zadroga’s situation is certainly biologically believable. It should be a red flag.

REPORTER: But it’s not just about pensions, public employees and their survivors. That’s about compensating people for work-related death. There’s a much broader issue of pain and suffering – who’s suffering it, and who’s responsible for it. This isn’t just firefighters, police officers and other responders. It’s also volunteers, residents and workers for private employers, like ConEd and Verizon and cleanup contractors. Many of them say the government and their employers are liable for failing to protect them, both by declaring the area safe prematurely and by not supplying the right gear or enforcing safety regulations. Lawyer David Worby represents more than 8-thousand plaintiffs.

WORBY: We have everything from dermatologic problems to breathing problems to deaths to leukemias to white blood cell cancers.

REPORTER: It’s one thing to say Ground Zero dust-and-debris causes breathing problems. That is pretty obvious, and there is a lot of research on that. But what about, say, cancer? Not a lot of data. Not yet. Dr. Herbert says most of the known environmental cancers – like the one caused by asbestos – take years to develop. But she’s concerned how this might play out with all the constant coughing.

HERBERT: Ongoing inflammation is known to hasten some cancers. Our WTC patients had marked inflammatory responses. So is there any chance that we may see cancers earlier than we would expect?

REPORTER: If the speculation proves true, it is bad news for people who were exposed. But it might help them get damages in the courtroom. Then again, the wheels of justice turn slowly, but the wheels of science can be even slower. Can those suffering or their survivors ever get enough ‘lab-coat’ proof to win damages? Worby says the answer is in the odds.

WORBY: We have close to 40 white blood cell, leukemic-type cancers in a population of 50k people who were exposed. That means considering it’s usually 1 in 150k from that age bracket, that the chances of having this many people from anything else are zero.

REPORTER: Well, zero percent is a little extreme. Sort of like its opposite, 100 percent. You might have a hard time getting a scientist to sign onto either one of those. But the interesting thing is the growing use of probability and statistics as courtroom evidence, according to Edward Cheng. He’s a professor who teaches at Brooklyn Law School. So, of course, he has an analogy:

CHENG: If you have a bag of quarters, and you throw it up in the air, and you have them disperse throughout the room. Most of the quarters will be distributed uniformly across the room in scattershot fashion, and most will be apart from each other. But there’s a good chance there are a couple of areas in the room, where 4 or 5 quarters have congregated. And that doesn’t mean the room is warped.

REPORTER: In other words, a “cluster” of illness does not cause-and-effect make. Some of the World Trade Center workers would have developed leukemia anyway. Maybe even a whole bunch of them. There have been many “cancer clusters” that seemed to be caused by power lines or environmental pollution. The effects were indisputable, and the cause seemed to be, too -- but scientific research and even the long odds couldn’t prove it. Those were statistical anomalies, Worby says, but the 9-11 cases are not.

WORBY: The clusters that haven’t been proven, normally they don’t know what caused them – they just say, here’s 6 people who have leukemia who live in the same New Jersey town, or here’s 7 people who have brain tumors who live near wires, but where they never proved anything that caused the brain tumors or the leukemia, or the breast cancer in Long Island. We know the toxins. We know the huge amounts of dioxin, cadmium, lead, benzene, toluene, asbestos, and we know what these toxins cause.

REPORTER: Worby will need to persuade a judge and jury that he has science on his side, and can prove the deadliest illnesses were caused by these substances. The city, the largest of the dozens of defendants, has filed a motion to dismiss. Hearings begin today.