WHO agency says talc ‘probably’ carcinogenic

The World Health Organization’s cancer agency on Friday classified talc as “probably carcinogenic” to humans. However, an outside expert warned that the announcement should not be misinterpreted as a “smoking gun.”

The decision was based on “limited evidence” that talc can cause ovarian cancer in humans, “sufficient evidence” that it was linked to cancer in rats and “strong mechanistic evidence” that it exhibits cancer-causing effects in human cells, the WHO’s International Agency for Research on Cancer (IARC) said.

Talc is a natural mineral mined in many parts of the world and often used to make talcum powder for babies.

According to the Lyon-based IARC, most people are exposed to talc through baby powder or cosmetics.

But the greatest exposure to talc occurs when talc is mined, processed or used to make products, the report said.

According to the agency, there are numerous studies consistently showing that ovarian cancer rates increase in women who use talcum powder on their genitals.

But it could not be ruled out that the talc in some studies was contaminated with carcinogenic asbestos.

“A causal relationship with talc could not be fully established,” the agency’s findings said in The Lancet Oncology.

Kevin McConway, a statistician at Britain’s Open University who was not involved in the research, warned that “the most obvious interpretation of the IARC assessment is in fact misleading”.

The agency only wants to “answer the question of whether the substance can cause cancer, under certain conditions that IARC does not specify,” he said.

Because the studies were observational and therefore no causal relationship could be established, “there is no convincing evidence that talc use carries an increased risk of cancer,” he added.

The announcement comes just weeks after US pharmaceutical and cosmetics giant Johnson & Johnson agreed to a $700 million settlement over allegations that the company misled customers about the safety of its talcum powder products.

Johnson & Johnson did not admit wrongdoing in the settlement, even though the company removed the product from the North American market in 2020.

A summary of studies published in 2020 among 250,000 women in the United States found no statistical association between using talcum powder on the genitals and the risk of ovarian cancer.

Also on Friday, the IARC classified acrylonitrile, a chemical compound used to make polymers, as “carcinogenic to humans,” its highest warning level.

Reference was made to ‘sufficient evidence’ of a link between acrylonitrile and lung cancer.

The polymers made with acrylonitrile are used in a variety of products, from fibers in clothing to carpets, plastics and other consumer products.

© 2024 AFP