Last week a jury in St. Louis awarded US$4.69 billion in damages to 22 women who were claiming Johnson & Johnson's talcum powder products contained asbestos and induced ovarian cancer. While this isn't the first legal action brought against the company in recent years over these allegations, this is by far the largest payout it has ever faced despite many experts still suggesting the links between talcum powder and cancer are weak and inconclusive.

After six weeks of testimony, with multiple experts presented by both sides, the 12-person jury took only eight hours to return their verdict. The verdict orders Johnson & Johnson to pay $550 million in compensatory damages and an additional $4.14 billion in punitive damages.

"For over 40 years, Johnson & Johnson has covered up the evidence of asbestos in their products," says Mark Lanier, lead trial counsel for the plaintiffs. "We hope this verdict will get the attention of the J&J board and that it will lead them to better inform the medical community and the public about the connection between asbestos, talc, and ovarian cancer."

Johnson & Johnson has responded to the verdict with a statement expressing great disappointment at the verdict and suggesting their products, "do not contain asbestos and do not cause ovarian cancer." The company will appeal the result noting it was, "the product of a fundamentally unfair process."

From Johnson & Johnson's perspective this case highlights a serious problem with presenting a body of scientific evidence to a jury of laypeople. Over the years a number of studies have presented inconclusive evidence connecting talcum powder to cancer risks, and many cancer councils around the world now conclude that there is insufficient evidence to suggest talc causes cancer.

One of the primary allegations in this latest court case is the suggestion that talcum powder contains trace elements of asbestos. Back in the early 1970s it was revealed that there potentially were trace levels of asbestos contamination in commercially available cosmetic talcum powder products due to several talc mines also containing asbestos.

Since the mid-1970s Johnson & Johnson has claimed that all its consumer-grade talc products have been entirely asbestos-free. While public health concerns have persisted, several subsequent studies have found no trace of asbestos on talcum powder products, including an FDA study released in 2010.

The other argument is that talc, the mineral itself, can specifically increase risk factors for ovarian cancer. The suggestion is that perianal and genital use of talcum powder results in small particles entering a woman's reproductive organs. Prolonged use and accumulation is then hypothesized as increasing a woman's chance of developing ovarian cancer.

Numerous studies homing in on this connection have also resulted in inconclusive findings. Some research reports talc conveys no increased risk for ovarian cancer, while a few case-control studies have concluded there is a small increase in risk.

Katherine Taylor, CEO of Ovarian Cancer Action in the UK suggests that any link between ovarian cancer and talc is still unproven but also, not conclusively debunked.

"Given that the evidence is inconsistent," Taylor explains, "we do advocate a 'better safe than sorry' attitude and advise women using talc on their genitals to stop doing so – but it is important to remember that the suggested increased risk from using talcum powder is very small. We are talking about the difference between 2 percent and 2.5 percent."

Johnson & Johnson's plans to appeal this decision is no surprise, with several previous similar verdicts having been successfully appealed by the company. However, with an estimated 9,000 more plaintiffs waiting in line to take the company to court in cases involving talcum powders, this is not an issue that looks like going away any time soon.