A Sioux Falls woman is accusing Johnson and Johnson and two mining companies of failing for decades to warn consumers about a link between ovarian cancer and talcum powder.

Deane Berg, 52, applied talc-based body powder to her perineum each day after showering from 1975 to 2007, she says in a federal lawsuit filed last week. She contracted ovarian cancer in 2006.

Berg maintains that talc caused her cancer and that the companies selling the mineral knew there was a risk but failed to warn the public.

“I feel like women have been kept in the dark about a known hazard,” said R. Allen Smith, Berg’s lawyer. “It’s the classic definition of why we need product liability lawsuits.”

Some studies have associated the regular use of talc in the genital area to an increased risk of ovarian cancer. The most recent came in 2008, when a study from Harvard University epidemiologist Margaret Gates suggested women who used the product once a week might increase their risk of contracting the disease by 36 percent. For daily users, the risk jumped by 41 percent.

However, some studies have suggested no association between talc use and ovarian cancer. The American Cancer Society calls the study results inconsistent but advises those with concerns to switch to cornstarch-based powders.

“While the findings aren’t considered fact just yet by the American Cancer Society, studies do cause some concern,” said Charlotte Hofer, South Dakota’s American Cancer Society representative.

Berg and her lawyers are convinced there is a link. The lawsuit, filed in U.S. District Court in South Dakota, cites studies about a possible link from as long ago as 1982. While government health agencies in countries such as Great Britain have noted the possible risk, the topic has flown under the radar in the U.S., Smith said.