The World Health Organization's cancer agency has classified talc (found in talcum powders) as "probably carcinogenic" to humans, sparking widespread concern. A working group of 29 scientists from 13 countries convened at the International Agency for Research on Cancer (IARC) in Lyon, France last month and based this classification on "limited evidence" talc could cause ovarian cancer in humans, "sufficient evidence" it was linked to cancer in rats and "strong mechanistic evidence" that it shows carcinogenic signs in human cells. They published their summary findings in a news article in the medical journal The Lancet Oncology on July 5.
Talc is a naturally occurring soft and lustrous mineral that is used extensively in various industries including plastics, ceramics, cosmetics, and pharmaceuticals (Shutterstock)
This announcement follows Johnson & Johnson’s recent $700 million settlement in the US over allegations of misleading customers about the safety of its talc-based products, although the company did not admit wrongdoing.
Talc is a naturally occurring soft and lustrous mineral that is used extensively in various industries including plastics, ceramics, cosmetics, and pharmaceuticals. In cosmetics, talc acts as an absorbent of sweat and moisture and a skin protectant in numerous products such as antiperspirants, powdered foundations, adult talcum powders, and baby care items. Talc particles can persist in the lungs and other organs even after exposure ends.
However, talc is often contaminated with asbestos which is a well-recognised cancer-causing agent. Asbestos often contaminates talc deposits and may make its way into consumer products. Industry standards often fail to detect asbestos in talc products adequately. Nonetheless, asbestos-contaminated talc is recognised as a cancer risk when inhaled, leading to diseases like lung cancer and mesothelioma.
What about talc that is free of asbestos? Human studies provide limited evidence that talc causes ovarian cancer, with most research focusing on talcum powder used in the genital area.
Recently, scientists from the National Institute of Environmental Health Sciences in the US published a study in the Journal of Clinical Oncology that finds using talcum powder as an intimate care product may be linked to an increased risk of ovarian cancer. The study involved over 50,000 women who were initially cancer-free. The researchers find a consistent link between intimate talc use and ovarian cancer, particularly among frequent and long-term users. The scientists emphasise the need for further research into the safety of intimate care products and encourage women to consider reducing their use or seeking alternatives.
In addition, animal studies demonstrated that talc exposure led to various cancers, particularly in female rats. Studies also showed that when rodents inhaled talc, it led to an abnormal increase in cell growth in their lungs.
The strongest evidence that talc might cause cancer mainly comes from experiments where asbestos contamination was unlikely, making it likely that the results were specific to talc itself. Talc can cause long-lasting inflammation and make cells grow uncontrollably, which is a key feature of cancer. These harmful effects were observed in many different experiments and means of exposure.
These findings suggest that talc might be harmful, especially with long-term use. There are two issues here. One is that talcum powders might be contaminated with asbestos, which is a known cancer-causing agent. The second is that talc itself might be harmful, though the evidence for this is still not definitive.
People should be aware of the potential risks but also understand that the evidence is still evolving. Clinical studies conducted on talc in people have been observational, meaning they can identify associations but cannot prove that talc causes cancer. This type of research can suggest a link, but it doesn't establish a direct cause-and-effect relationship. So, while there is evidence that points to the potential risks of talc, it isn't strong enough to be conclusive.
So, considering these current studies what should you do? In India, talc-based products, such as baby powders and cosmetics, are widely used. As always, you should discuss any specific concerns with your physician. If you are concerned about your own exposure, then heeding advice to limit or avoid use may be warranted.
Anirban Mahapatra is a scientist and author, most recently of the popular science book, When The Drugs Don’t Work: The Hidden Pandemic That Could End Medicine. The views expressed are personal.
E-Paper
