New York Public Advocate Bill de Blasio urged New York Mayor Michael Bloomberg’s administration to reconsider a decision not to undertake a thorough study of cancer rates among NY police officers who worked at Ground Zero after the 2001 terrorist attacks.

In a Feb. 1 letter, De Blasio, an ex-officio member of the New York City Council and participant in the legislative process, noted that a study by the Fire Department of New York found elevated cancer rates among firefighters and a similar study of the NYPD was essential to understand the full scope of the problem.

“This is far from academic—this research will significantly affect our ability to identify and better treat health problems incurred by first responders in the line of duty,” De Blasio said.

Many New York firefighters and rescue workers who inhaled dust, chemicals and asbestos debris at Ground Zero after the 9/11 terrorist attacks still have significantly abnormal lung function years afterward, according to a 2010 study published in The New England Journal of Medicine. Medical researchers found that 13 percent of firefighters and 22 percent of EMS workers who never smoked had abnormal lung function seven years after 9/11.

Pat Lynch, president of the N.Y. Patrolmen’s Benevolent Association, joined De Blasio in urging the Bloomberg Administration to conduct a thorough study of cancer among NYC police officers related to work at the World Trade Centers.

Lynch said the city was withholding information regarding cases of cancer linked to work at Ground Zero after the terrorist attacks.

“If the city releases the data it is now suppressing, it will confirm that over 56 young police officers have died from a variety of cancers—including lung, kidney and nasal cancers—and hundreds more are gravely ill with cancer as a direct result of their exposures at Ground Zero an other locations,” Lynch said in a statement issued by the Patrolmen’s Benevolent Association. “It is time to stop the obstruction and provide funs for treating cancers in those men and women who selflessly answered this city and nation’s call in its hour of greatest need.”

Some dust and airborne debris from the World Trade Center collapse contained asbestos and other contaminants, according to the U.S. Environmental Protection Agency. Breathing asbestos particles is linked with respiratory disease including lung cancer and mesothelioma, a cancer of the lining of the lung and abdominal cavity. The EPA said at the time that the majority of air samples at the site did not indicate levels of public concern. The symptoms of mesothelioma typically appear 20 years to 40 years after exposure to asbestos.

For more information about mesothelioma, click here.