The World Health Organization’s (WHO) cancer agency has classified talc as “probably carcinogenic” and acrylonitrile, a compound used in the production of polymers, as “carcinogenic.”
<p>Experts from the International Agency for Research on Cancer (IARC), meeting in Lyon (France), published their results on Friday, July 5, 2024 in the journal *The Lancet Oncology*.</p>Ovarian cancer
They classified talc, a natural mineral mined in many parts of the world, including the Luzenac quarry in Ariège, which supplies 10% of global production each year, as “probably carcinogenic” to humans. This classification is based on a combination of limited evidence of cancer in humans (ovarian cancer) and sufficient evidence in laboratory animals.
According to the experts, exposure to talc occurs mainly in occupational settings during the extraction, grinding, or processing of the mineral, or during the manufacture of products containing it.
In the general population, exposure primarily occurs through the use of cosmetics and body powders containing talc.
The risk of talc contamination by asbestos
However, the experts do not rule out some bias in studies that have shown an increase in cancer incidence. While the assessment focused on talc that did not contain asbestos, the possibility of asbestos contamination of talc might not be ruled out in most studies on exposed humans, they say.
In June, US pharmaceutical giant Johnson & Johnson (J&J) reached a final settlement with courts in 42 US states in a talc case accused of causing cancer.
A review of studies published in January 2020, which included 250,000 women in the United States, found no statistical link between the use of talcum powder on the genitals and the risk of ovarian cancer.
In the 1970s, concerns arose regarding the contamination of talc by asbestos, which is often found in nature near the minerals used to make talc. Later studies pointed to a higher risk of ovarian cancer in talc users.
The WHO agency has also classified acrylonitrile, a volatile organic compound mainly used in the production of polymers, as “carcinogenic” to humans.
Lung and bladder cancer
The decision is based on “sufficient evidence of lung cancer” and “limited” evidence of bladder cancer in men, according to the IARC.
These polymers are used in fibers for clothing, carpets, plastics for consumer products, or automotive parts.
Acrylonitrile is also present in cigarette smoke. Air pollution is another source of exposure.
Talc Classified as "Probably Carcinogenic" by WHO
The World Health Organization’s (WHO) International Agency for Research on Cancer (IARC) has classified talc as "probably carcinogenic" to humans. This classification, published in the journal The Lancet Oncology on July 5, 2024, is based on a combination of limited evidence of cancer in humans (specifically ovarian cancer) and sufficient evidence in laboratory animals.
Ovarian Cancer and Talc Exposure
The IARC experts highlight that exposure to talc primarily occurs in occupational settings during the extraction, grinding, or processing of talc or during the manufacture of products containing it. In the general population, exposure occurs through the use of cosmetics and body powders containing talc.
Asbestos Contamination and Talc-Related Cancer
While the assessment focused on talc that did not contain asbestos, the IARC experts acknowledge that asbestos contamination of talc might not be ruled out in most studies on exposed humans. This raises concerns regarding potential bias in previous studies showing an increased cancer incidence among talc users.
Talc and Ovarian Cancer: A Complex Relationship
In June 2024, Johnson & Johnson (J&J) reached a final settlement with courts in 42 US states in a talc case accused of causing cancer. However, a review of studies published in January 2020, involving 250,000 women in the United States, found no statistical link between the use of talcum powder on the genitals and the risk of ovarian cancer.
The complex relationship between talc and ovarian cancer has been a subject of debate for decades. Concerns regarding asbestos contamination in talc emerged in the 1970s, leading to investigations linking talc use to an increased risk of ovarian cancer.
Acrylonitrile Classified as "Carcinogenic"
In addition to the talc classification, the IARC has also classified acrylonitrile, a volatile organic compound mainly used in the production of polymers, as "carcinogenic" to humans. This classification is based on "sufficient evidence of lung cancer" and "limited" evidence of bladder cancer in men.
Sources of Acrylonitrile Exposure
Acrylonitrile is commonly found in:
- Fibers for clothing and carpets
- Plastics for consumer products and automotive parts
- Cigarette smoke
- Air pollution
The IARC’s classification of talc and acrylonitrile underscores the importance of ongoing research into the potential health risks associated with these substances and the need for continued monitoring of exposure levels in various settings.