(NewsNation) — Military personnel who were stationed at U.S. Marine Corps Base Camp Lejeune from the mid-1970s to mid-1980s had at least a 20% higher risk for several cancers than those stationed elsewhere, according to a new government study.

Federal health officials called the research one of the largest ever done in the U.S. to assess cancer risk by comparing a group who lived and worked in a polluted environment to a similar group that did not.

The landmark study, launched by the Centers for Disease Control and Prevention, analyzed the health of more than 200,000 military personnel who served at the North Carolina base from 1975 to 1985.

It found that personnel at the base faced a 20% higher risk for some types of leukemia and lymphoma and cancers of the lung, breast, throat, esophagus and thyroid. Civilians who worked at the base also were at a higher risk for a shorter list of cancers.

Camp Lejeune was built in a sandy pine forest along the North Carolina coast in the early 1940s. Its drinking water was contaminated with industrial solvents from the early 1950s to 1985. The contamination — detected in the early 1980s — was blamed on a poorly maintained fuel depot and indiscriminate dumping on the base, as well as from an off-base dry cleaner.

Before wells were shut down, contaminated water was piped to barracks, offices, housing for enlisted families, schools and the base’s hospital. Military personnel and families drank it, cooked with it and bathed in it.

The contamination has spawned a wave of litigation by law firms who have aggressively sought out clients with TV ads.

People who got sick after being at Camp Lejeune have accused the Marine Corps of failing to protect the health of its personnel and criticized the federal government for being slow to investigate. Marine Corps officials have repeatedly said that federal environmental regulations for these cancer-causing chemicals were not finalized until 1989 after the wells were shut down.

Peter Romano, a Marine veteran who served at Camp Lejeune, said what particularly bothers him is leaders at the base were aware of the contamination in the early 1980s and didn’t immediately initiate cleanup efforts.

“That’s the part that really gets to me. That’s where I feel it was really a dereliction of duty not getting it cleaned up the way they should have,” he said. “It’s a shame that it could’ve been taken care of but it wasn’t. We’re doing something now, and, hopefully, this will all come to a head sooner or later.”

Romano served from 1984 to 1988 and was stationed at Camp Lejeune for two years. He was diagnosed with testicular cancer in 1989 and underwent chemotherapy for four months before a 16-hour operation.

Jerry Ensminger, a Marine veteran, believes he experienced some of the tragic consequences when his 9-year-old daughter, who was raised at the base, died of leukemia.

For more than 20 years, he advocated for studies to be conducted.

“We knew there was a fuel problem, contamination problem on the base that they tried to hide. They hid it for a long time, and it’s starting to reveal itself now they can’t argue with these numbers,” Ensminger said.

A federal law signed by President Joe Biden in August 2022 included language to address concerns of people who developed certain health problems they believe were linked to Camp Lejeune water contamination. It gave them a two-year window to file claims.

The Associated Press contributed to this report.