Military pilots and the ground crews who fuel and maintain their aircraft have higher rates of certain types of cancer, a new study shows.

The Pentagon researched cancer cases in nearly 900,000 military members who served between 1992 and 2017, comparing them to the general U.S. population.

The study "proves that it's well past time for leaders and policy makers to move from skepticism to belief and active assistance," retired Air Force Col. Vince Alcazar, a member of the Red River Valley Fighter Pilots Association, told the Associated Press.

Congress required the study as part of the defense bill in 2021, the AP reported. Now, the new findings will necessitate an even bigger review.

Overall, the study found that air crews had a 24% higher rate of cancer of all types and ground crews had a 3% higher rate of all types of cancer.

Some specific types of cancer had even higher rates. Air crew members had an 87% higher rate of melanoma, and a 39% higher rate of thyroid cancer.

Male air crew members had a 16% higher rate of prostate cancer, while women had a 16% higher rate of breast cancer.

Ground crews faired more poorly in brain and nervous system cancers, with a 19% higher rate for those. They also had a 15% higher rate of thyroid cancer and 9% higher rate of kidney cancers. Female ground crew members had a 7% higher rate of breast cancer.

The actual number of cases may be even higher because of gaps in the data, the Pentagon said.

The Pentagon noted the study "does not imply that military service in air crew or ground crew occupations causes cancer, because there are multiple potential confounding factors that could not be controlled for in this analysis," such as family histories, smoking or alcohol use.

The study did also find that some cancer rates went down for these categories of service members, including lower rates of lung cancer for both ground and air crews and lower rates of bladder and colon cancer for air crews.