Saturday, May 31, 2014

BABY POWDER - TALCUM - LINKED TO CANCER

 

Who has not soothed their dear baby's bottom with Johnson's Baby Powder? Who has not enjoyed a generous dusting of Shower to Shower or some other beautifully perfumed powders?

It takes decades before someone tells us we have endangered our lives, the health of our babies, with the use of commonly marketed products.

Who is responsible?

Phyllis Carter

 

Talcum powder is made from talc, a mineral made up mainly of the elements magnesium, silicon, and oxygen. As a powder, it absorbs moisture well and helps cut down on friction, making it useful for keeping skin dry and helping to prevent rashes. It is widely used in cosmetic products such as baby powder and adult body and facial powders, as well as in a number of other consumer products.

In its natural form, some talc may contain asbestos, a substance known to cause cancers in and around the lungs when inhaled (see our document, Asbestos). All home-use talcum products in the United States have been asbestos-free since the 1970s.

Most concerns about a possible link between talcum powder and cancer have been focused on 2 main areas:

  • Whether people who have long-term exposure to natural talc fibers at work, such as talc miners, are at higher risk from lung cancer from breathing them in.
  • Whether women who apply talcum powder regularly in the genital area have an increased risk of ovarian cancer.

When talking about whether or not talcum powder is linked to cancer, it is important to distinguish between talc that contains asbestos and talc that is asbestos-free. Talc that has asbestos is generally accepted as being able to cause cancer if it is inhaled. This type of talc is not used in modern consumer products. The evidence about asbestos-free talc, which is still widely used, is less clear.

Researchers use 2 main types of studies to try to determine if a substance or exposure causes cancer.

One type of study looks at cancer rates in different groups of people. Such a study might compare the cancer rate in a group exposed to a substance versus the rate in a group not exposed to it, or compare it to what the expected cancer rate would be in the general population. But studies of people can sometimes be hard to interpret, because there may be other factors affecting the results that are hard to account for.

In studies in lab animals, other factors are easier to control for, but it's not always clear if the results in animals would be the same in humans.

In most cases neither type of study provides definitive evidence on its own, so researchers usually look at both human and lab-based studies.

Studies that exposed lab animals (rats, mice, and hamsters) to asbestos-free talc in various ways have had mixed results, with some showing tumor formation and others not finding any.

It has been suggested that talcum powder might cause cancer in the ovaries if the powder particles (applied to the genital area or on sanitary napkins, diaphragms, or condoms) were to travel through the vagina, uterus, and fallopian tubes to the ovary. Several studies in women have looked at the possible link between talcum powder and cancer of the ovary. Findings are mixed, with some studies reporting a slightly increased risk and some reporting no increase.

For any individual woman, the overall increase in risk, if it exists, is likely to be small. For example, one analysis combining data from 16 studies published before 2003 found about a 30% increase in ovarian risk among talc users. The average woman's lifetime risk of ovarian cancer is about 1.4%, so even with a 30% increase, her lifetime risk would be about 1.8%. Still, talc is widely used in many products, so it is important to determine if the increased risk is real. Research in this area continues.

Some studies of talc miners and millers have suggested an increased risk of lung cancer and other respiratory diseases, while others have found no increase in lung cancer risk. These studies have been complicated by the fact that talc in its natural form may contain varying amounts of asbestos and other minerals, unlike the purified talc in consumer products. When working underground, miners may also be exposed to other substances that might affect lung cancer risk, such as radon.

No increased risk of lung cancer has been reported with the use of cosmetic talcum powder.

Talc use has not been strongly linked to other cancers, although not all possible links with other cancers have been studied extensively. One recent study suggested genital talcum powder use may slightly increase the risk of endometrial (uterine) cancer in women who are past menopause, but further studies are needed to explore this possible link.

Several agencies (national and international) study different substances in the environment to determine if they can cause cancer. (A substance that causes cancer or helps cancer grow is called a carcinogen.) The American Cancer Society looks to these organizations to evaluate the risks based on evidence from laboratory, animal, and human research studies.

A few expert agencies have evaluated the cancer-causing nature of talc.

The International Agency for Research on Cancer (IARC) is part of the World Health Organization (WHO). Its major goal is to identify causes of cancer.

  • IARC classifies talc that contains asbestos as "carcinogenic to humans."
  • Based on the lack of data from human studies and on limited data in lab animal studies, IARC classifies inhaled talc not containing asbestos as "not classifiable as to carcinogenicity in humans."
  • Based on limited evidence from human studies, IARC classifies the perineal (genital) use of talc-based body powder as "possibly carcinogenic to humans."

The National Toxicology Program (NTP) is formed from parts of several different US government agencies, including the National Institutes of Health (NIH), the Centers for Disease Control and Prevention (CDC), and the Food and Drug Administration (FDA). The NTP has not fully reviewed talc (with or without asbestos) as a possible carcinogen.

(For more information on the classification systems used by these agencies, see our document, Known and Probable Human Carcinogens.)

It is not clear if consumer products containing talcum powder increase cancer risk. Studies of personal use of talcum powder have had mixed results, although there is some suggestion of a possible increase in ovarian cancer risk. There is very little evidence at this time that any other forms of cancer are linked with consumer use of talcum powder.

Until more information is available, people concerned about using talcum powder may want to avoid or limit their use of consumer products that contain it. For example, they may want to consider using cornstarch-based cosmetic products instead. There is no evidence at this time linking cornstarch powders with any form of cancer.

The following related information may also be helpful to you. These materials may be viewed on our website or ordered from our toll-free number, at 1-800-227-2345.

Asbestos

Known and Probable Human Carcinogens

No matter who you are, we can help. Contact us anytime, day or night, for information and support. Call us at 1-800-227-2345 or visit www.cancer.org.

© 2014 American Cancer Society, Inc. All rights reserved. The American Cancer Society is a qualified 501(c)(3) tax-exempt organization. Cancer.org is provided courtesy of the Leo and Gloria Rosen family.

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