As Americans gather to remember those who died in the 9/11 terror attacks, media reports are surfacing on New York City’s air quality after the towers fell and sent plumes of dust and debris on first responders and bystanders.

More than 37,000 first responders and survivors registered with a federal program have been declared sick, and more than 1,100 have died while being treated under the World Trade Center Health Program (WTCHP) set up in 2011.

Most enrolled in WTCHP have respiratory illness, probably from the asbestos and other debris in the air that day, experts say. More than 5,000 first responders and survivors have cancer, and 12,500 have mental health issues.

But while thousands of 9/11 first responders and victims now have cancer, some follow-up studies have been less than conclusive about higher-than-normal cancer rates.

In 2011, when WTCHP considered adding cancer to its list of covered illnesses, it found the five peer-reviewed studies were ambivalent on the link between cancer and 9/11 first responders and survivors — WTCHP did add cancer to its coverage list in 2012.

For example, WTCHP reported two reviews of scientific literature done in 2006 and 2007 didn’t reveal “any epidemiologic evidence for a causal association between September 11, 2001, exposures and cancer.”

A 2012 study published in The Journal of the American Medical Association (JAMA) found “the intensity of World Trade Center exposure was not significantly associated with cancer of the lung, prostate, thyroid, non-Hodgkin lymphoma, or hematological cancer in” among first responders and survivors.

The JAMA study did find “an excess risk for prostate cancer, thyroid cancer, and myeloma in 2007-2008 compared with that for New York State residents,” but “these findings were based on a small number of events and multiple comparisons.”

“No significant associations were observed with intensity of World Trade Center exposures,” the study found, adding that “[l]onger follow-up for typically long-latency cancers and attention to specific cancer sites are needed.”

Similar findings were made for mortality rates from respiratory, heart and blood diseases for 9/11 victims and rescuers.

A 2010 study published by The Lancet found standardized mortality ratios (SMRs) “were significantly lower than that expected for rescue and recovery participants and non-rescue and non-recovery participants.”

“No significantly increased SMRs for diseases of the respiratory system or heart, or for haematological malignancies were found,” the study found.

“This is not unexpected,” the study found. “Rescue workers tend to be young and strong. To the rare extent poor outdoor air quality has killed in the past, it has generally killed old and/or sick people.”

For years, Democrats, including Democratic nominee Hillary Clinton, have criticized former President George W. Bush’s administration for declaring New York City’s air quality safe just a week after the attacks.

Newsweek recently reported cancer and other diseases linked to the 9/11 attacks are “surging” 15 years after that tragic day. WTCHP doctors have linked nearly 70 types of cancer to those at Ground Zero, according to Newsweek.

“The diseases stemming from the World Trade Center attacks include almost all lung diseases, almost all cancers—such as issues of the upper airways, gastroesophageal acid reflux disease, post-traumatic stress, anxiety, panic and adjustment disorders,” Dr. David Prezant, co-director for the New York fire department’s World Trade Center Medical Monitoring Program, told Newsweek.

“If you compare our cancer rates to the general U.S. population, our rates are about 10 percent higher than expected,” Prezan said of the 15,700 firefighters and emergency medical services workers whose health he tracks.

“If you compare it to our pre–September 11 data, the cancer rates range from 19 to 30 percent higher for our firefighters,” he said.

Other doctors tell reporters similar stories about 9/11 first responders and survivors.

“Here at Sinai, we see 10 to 15 new cancer patients in our population every week,” Dr. Michael Crane, who runs 9/11 Health Program Clinic at New York’s Mount Sinai Hospital, told CBS News Friday. “Each week. I’ve been in medicine for 40 odd years. It’s remarkable.”

New York Democratic Rep. Jerrold Nadler slammed former Environmental Protection Agency (EPA) Administrator Christine Todd Whitman for claiming air quality was safe so soon after 9/11.

“She knew or should have known” the air was dangerous, he told The Guardian.

Whitman did tell The Guardian she was “very sorry that people are dying,” but stopped short of admitting EPA was at fault.

“Every time it comes around to the anniversary I cringe,” she said, “because I know people will bring up my name, they blame me, they say that I lied and that people died because I lied, [they say] people have died because I made a mistake.”

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