(CNN) A cancer cluster is suspected at a Cincinnati police headquarters building, according to the Police Department's union president. Sergeant Dan Hils, who spoke on the steps of the headquarters Tuesday morning, called on the city's mayor and council members to relocate police officers working at the District 5 headquarters building before Christmas with a deadline of October 30 to put a plan into place.

"A number of officers started to talk to me about an unusual number of cancer deaths here in District 5," said Hils, who became union president in 2015 and has been with the Cincinnati Police Department since 1987.

"In two years, from 2015 to 2016, six officers died and they were all under the age of 60, most of them right around the age of 50, and all of them had worked in District 5," Hils told CNN before he addressed reporters at his news conference . All six officers had worked in jobs requiring a lot of time in the office and "many had spent large portions of their careers here," he said.

"Those six people all lived very clean lives and were still young," said Hils. He added there are a number of "living cancer cases" among others who spent significant time in the District 5 building, but he would not release the names for "privacy reasons."

Hils said the police department has five districts yet none of the other four districts has a comparable number of cancer cases.

"The Police Department and other City Departments are in the process of assessing temporary locations on a leased basis and are working toward a long-term solution as well," said Steve Saunders, a spokesman with Cincinnati Police Department, on behalf of Police Chief Eliot Isaac.

Cincinnati Councilman Charlie Winburn, who also spoke at the news conference, has requested a transfer of police personnel within 30 days.

"This has been going on and on and on," said Winburn. "Close this place down -- close this place down now."

Pesticides and possible contamination

Anyone who visits the building at 1012 Ludlow Avenue, which is nicknamed "the three bedroom ranch," can see the problems for themselves, said Hils.

"The first problem is it just isn't big enough to house the folks and the records and all the things that we have there, which then makes it impossible to clean," said Hils. Because of this crowding, he said, the building has had "half a dozen, at least" bed bug infestations over the past year or so.

"They're constantly throwing pesticides in here," he said. High power lines run over the building, which sits next to an expressway that is itself beside Mill creek "which has been known as a toxic place for many, many years," said Hils.

Though named "the most endangered urban river in North America" in 1997, Mill creek has shown improved water quality in recent years, according to American Rivers , a national river conservation organization.

Add to that, there is asbestos on the boiler and there was a target range in the basement of the building up until the 1970s, "so lead contaminants are a possibility there," Hils said. Specifying that he does not have a Ph.D., he said "common sense" indicates something is wrong at the District 5 building.

"It's like a cocktail," said Hils, who raised this issue within the police department beginning in November last year.

Spokesman Saunders confirmed that testing of the building had been done and "the results did not show anything significant that would contribute to cancer or any other serious health issues."

"Even though they can't point to one thing that's making people sick," said Hils, an "inordinate amount of officers" have become sick with cancer and at this point he just wants people out of the building.

City government, though, has been slow to act, likely because there's no "one thing."

Building is 'not ideal'

In a January 25, 2017 memo to the mayor and city council, Harry Black, city manager, acknowledged that the administration was continuing to examine the building and investigate concerns.

"Thus far, a series of internal and external inspections and tests have indicated the building is in good condition from an environmental perspective," wrote Black. "However it is not ideal in the long term primarily due to the lack of space." Black noted that the District 5 building was erected in 1957 and "was never intended as a permanent facility."

"It was built as a temporary headquarters required as a result of the Mill Creek Expressway construction," Black wrote of the building.

Hils said 122 police department employees are assigned to the building, though the majority are street officers who spend very little time there. "Somewhere in the range of 30" people, investigators and administrative officers, sit at their desks most of the day "making phone calls, doing computer searches things like that," said Hils.

"It's the investigative unit where you will find a lot of those cancers," said Hils.

In an email to the mayor and city council in February, Black referenced their discussion of a temporary relocation of "all or a portion" of District 5 headquarters staff. "Please do whatever you think makes the most sense," said Black at that time and offered his assistance with this matter.

Winburn said "this issue has been going on forever" and the administration was "stonewalling this situation." Mentioning the fact that his wife suffered from cancer, the city councilman said the administration was "callus to this, they are not sensitive to what is going on here."

"This is a disgrace," he said.

Cancer cluster defined

To be considered a cancer cluster , a group of cancer cases must meet various criteria, according to the US Centers for Disease Control and Prevention.

First, the number of cases must be higher than typically observed in a similar setting -- in a group with similar population, age, race, or gender.

"All of the cases must involve the same type of cancer, or types of cancer scientifically proven to have the same cause," the CDC website reads.

Additionally, the time period and geographic area must be carefully defined when calculating both the number of cases in a suspected cluster and the number of expected cases in a comparison group. "It is possible to "create" or "obscure" a cluster by selection of a specific area," reads the website.

The National Cancer Institute maintains that most suspected cancer clusters turn out, on detailed investigation, not to be "true cancer clusters... no cause can be identified, and the clustering of cases turns out to be a random occurrence."

'Sworn to uphold their duty'

Though many of District 5 staff have been diagnosed with cancer, Hils said, to get his point across he prefers to discuss just the six officers who died between 2015 and 2016.

"Stephanie Bradford was an investigator here for 18 years," said Hils, noting the 50-year-old died of appendix cancer.

"Darrell Chapman was in the neighborhood unit, had a lot of desk duty time and everything," said Hils. This 59-year-old died of some sort of gastrointestinal cancer, said Hils, just like Jana Cruise, who performed a good deal of desk duty, and passed in her early 50s.

Robert McGuire, 50, "loved working the desk" and died of colon cancer, said Hils, while Anthony Wagers, 53, died of a rare stomach cancer following years of administrative duty in District 5. Ingrid Weber, 51, died of lymphoma following her stint in the investigative unit.

"Almost all of them had [gastrointestinal] types of cancer," said Hils, who said he reported this cluster to the Cincinnati Department of Health. "I've talked to everyone who would listen," said Hils, who is clearly disappointed in the lack of response. The department of health did not return a request to comment from CNN.

"I wanted to press the button and get them out of here," said Hils. A recent diagnosis of cancer in another officer "made me regret that I backed off," he said. "I want that to be their Christmas present -- to have another place to go."

Asked whether police officers might strike if his demands are not met, Hils said "the men and women are sworn to uphold their duty. They're not allowed to take those actions."

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With a mayoral election in November, the timing may appear political, said Hils, but it's more a matter of family members reaching out to him and asking him to resolve this situation.

"Do politics really matter right now?" said Hils. "There's elections -- and then there's life and death."