BRADENTON, Fla. (WFLA) — A years-long study into whether or not the buildings and grounds of a Bradenton school led to hundreds of alumni being diagnosed with cancer or rare diseases did not find any evidence of a “cancer cluster,” according to Manatee County health officials.

A “cancer cluster” is defined by the CDC as a “greater than expected number of cancer cases that occurs within a group of people in the same place during the same period of time.”

For years the alumni of Bradenton’s old Bayshore High School have been convinced that something at the school created a cancer cluster. Hundreds of former students and staff have reported cancer or birth defects in their children over the years.

Cheryl Jozca, whose older sister died of leukemia in 1999, remains convinced despite the county’s findings that something at the school made her sister sick.

More than 20 years later, Jozca is still searching for closure.

“My sister was such a beautiful soul, anybody that knows her could tell you,” Jozca said.

Both sisters graduated from the old Bayshore High School, a campus torn down the same year Terri died. As the years went by, Jozca noticed many of their classmates also developed cancer and died.

To date, she says more than 500 staff and alumni families have suffered cancer and birth defects.

In 2017, pressure from the community forced Manatee County to launch an investigation. When no environmental link to the cancer could reportedly be found, the Department of Health compared Bayshore’s zip code to those around the state.

They determined cancer rates in that part of Bradenton were no higher than what would be expected, concluding this week there was no evidence of a cancer cluster.

Jozca, who has carried out her own concurrent research, disagrees.

“We have had experts look at it and they absolutely concur that we are a cancer cluster,” she said.

Jozca remains convinced the county didn’t find anything because it didn’t want to find anything.

“The DOH wasn’t even interested in the numbers I had,” she explained.

Suspicions pointed to possibly contaminated water at the old high school from a nearby factory that once handled hazardous chemicals. The county says no soil studies found contaminants.

However, Department of Environmental Protection documents, including a memo from 1996, warn the nearby property contained known carcinogens. Another letter states there is sufficient data showing the old factory’s land poses a “health and environmental threat.”

It may be case closed for the county, but not for Cheryl Jozca. She’s determined to solve this cancer mystery for her sister.

“She’s the reason that I do this,” she said. “Her and all the others we’ve lost.”

Jozca and a group of survivors and victims’ families are preparing a formal response to the county’s conclusion. She says she is also preparing to release more evidence she’s obtained that will refute the county’s conclusion.

“Communities who bring forward contamination and health concerns need a meaningful investigation with criteria that includes blood and environmental testing. Waiting to establish a cancer cluster creates new victims of toxic exposures. It’s time to acknowledge that 31 students in the same graduating class coming down with cancer like it’s a virus isn’t normal,” Jozsa said.