"The No. 1 cause of death in Maryland is heart disease; the No. 2 cause is cancer," he said. "Why do firefighters enjoy a benefit for the presumption when the entire population is susceptible to those same diseases? … They have a good lobby and good politicians."

The case for presumptions

Michael Rund, president of the Professional Fire Fighters of Maryland union, said cancer presumptions reflect the real dangers faced by those in the fire service. Because "firefighters are willing to risk their lives to save the lives of others, if, God forbid, they come down with one of these deadly cancers, they should be covered for workers' comp."

Rund, a 51-year-old Howard County firefighter, speaks from experience: He won a workers' compensation claim related to his own prostate cancer.

The county paid his medical bills and covered his lost wages when he underwent radiation treatment in 2011. He says he also won a permanent-damages award worth more than $30,000, paid in weekly installments.

To Rund, it's justified. "You hear a lot about prostate cancer in men, but it's typically later in life, certainly not in your 40s. I'm convinced it's the job that caused mine."

Fellow Howard County firefighter John Orth received a rectal cancer diagnosis in May 2012 at the age of 44.

After two surgeries, he returned to light duty but has been sidelined at home for months because of the effects of his treatment. Last year the state commission found his disease was job-related. He has not sought compensation from the county but says he will consider that option.

"I can't tell you how many car fires I went on where the wind was blowing toward the firetruck," said Orth, a 16-year department veteran. "I'm breathing this crap in." The same happened at structure fires, he said, where construction materials and furniture often contain harmful chemicals.

Orth says no one else in his family has rectal cancer, so it's not hereditary, and his diet and lifestyle didn't increase his risk. Asked whether he simply had bad luck, he said, "Maybe, but prove it."

Some former firefighters have filed cancer-related claims more than a decade after leaving the job. Joseph B. Morris retired as a Baltimore firefighter in 1999. In 2011, he learned he had prostate cancer and successfully pursued a claim.

Morris, 68, estimates he responded to "thousands" of fires in Northwest Baltimore over his 29-year career. He said better protective equipment emerged only in the 1990s, leaving him "exposed to the elements back in the '70s and '80s."

His disease is in remission, he said, and he has been told the city will pay for any future medical care related to the cancer. Before his workers' compensation award, he says he relied on Medicare and insurance, paying out of pocket for prescription medications.

The advantages of a statutory presumption are prized by public safety workers for good reason, said claimants' lawyer P. Matthew Darby, who represents McElroy and sits on the General Assembly's oversight committee on workers' compensation. Without them, he said, firefighters would win as rarely as governments currently do.

"On an individual basis it is difficult to prove Joe Smith's lung cancer is caused by the firefighting," he said. "Why? Because we have no idea what Joe Smith was involved in, what things he sucked in over the course of his career."

Darby said lawmakers have made a policy decision to allow some firefighters to get awards they might not be entitled to as a way of ensuring that no entitled firefighters are shut out — as long as they meet minimum service requirements and can show they missed work because of the disease.

In McElroy's case, the city argues that the expanded law should not apply because her breast cancer was diagnosed in 2009 and lawmakers did not intend to cover older cases. The city has also questioned her eligibility because she spent most of her career as a paramedic.

"We shouldn't be on the hook for that," said Kerr, Baltimore's risk manager. McElroy, now retired, and her lawyer maintain that she's eligible; they declined to comment on her case.

Under state law, the presumptions apply to cancer cases that were "caused by contact with a toxic substance that the individual has encountered in the line of duty."

Presumption cases confer an added benefit on recipients after they retire. While permanent damage awards are typically offset dollar for dollar by pension payments, employees in presumption cases can "stack" their pension and workers' compensation benefits up to 100 percent of their preretirement salary.