Myths vs. Facts about Cancer and Environmental Risks

by Devra Lee Davis, PhD, MPH, Director, Center for Environmental Oncology of UPCI, and Ronald B. Herberman, MD, Director, UPCI and UPMC Cancer Centers
Recently, the media heralded good news with banner headlines and televised lead-in stories: Cancer death rates are going down! This is certainly true for all types of cancer combined. But, this is not true for a number of specific types of the disease, nor do African Americans share in the same declines as do whites. This articles explores some of the many myths vs. facts about cancer, the environment, and sound public policy. It also features work from some leading voices, Teresa Heinz Kerry and David Steinman, who are educating the public about the links between environmental exposures and cancer. Further information can be found on the authors’ website:  

Myth: Rates of cancer deaths, of all types and in all populations, are going down.

Total deaths from cancers, indeed, are declining in the United States. This is largely because fewer people are smoking and more are getting screened for polyps and curable stages of colo-rectal cancer. However, incidence, or new cases of cancer, are increasing for a number of specific types of cancer, including non-Hodgkin’s lymphoma and childhood cancer. Childhood cancer is the second largest cause of death in children ages 0-15 in the United States (second only to accidents), and more than 8,000 new cases are diagnosed each year. While improvements in treatment have reduced deaths from childhood cancer, incidence rates increased nearly 21% between 1975 and 1998 — approximately 1% each year, and have continued to increase until at least 2003. [1] This is not due to improved detection (or smoking or an aging population) but to unexplained, environmental influences.
Race also plays an important role in cancer incidences. The American Cancer Society reports that African-American men and women have 40% and 20% higher death rates from all cancers combined when compared with whites. The use of hormone-containing personal care products is one possible explanation why young African American women get more breast cancer than do their white counterparts. Also, African Americans tend to live and work in more polluted areas than do other people. While one in eight Americans is African American, one in two African Americans works in a lower paying field and in jobs, such as sanitation, which puts them at increased exposure to toxins.

Myth: Most cancers are genetic in nature so there’s little we can do to protect ourselves.

In fact, the National Cancer Institute reports that only about one in ten cases of breast cancer occur in a woman born with a genetic risk of the disease. An expert panel convened by Mt. Sinai Hospital recently concluded that genetic predisposition accounts for no more than 20% of all childhood cancers and that the environmental-attributable fraction of childhood cancer could be between 5% and 90%, depending on the type of cancer. [1]
This means that a potentially large percentage of childhood cancers are preventable. One study of pesticide exposures testifies to the detrimental effects of toxic chemicals on children’s health, specifically in relation to cancers. In this study, children with leukemia were 4 to 7 times as likely to have been exposed to pesticides used in the yard or garden compared to children without the disease. Another study found that children with leukemia were 11 times as likely to have mothers who were exposed to pesticide sprays or foggers during pregnancy compared to healthy children. A report released by the Lowell Center for Sustainable Production concluded that instituting measures to reduce parental and childhood exposures to these and other substances suspected of causing cancer, including development of safer substitutes, should play an important role in a cancer prevention strategy. [1]

Myth: A small amount of a chemical carcinogen in a children’s product isn’t dangerous because the level is so low. Low doses of cancer-causing chemicals are safe because there is a threshold for cancer induction.

When experimental animals are tested at the lowest parts per billion level — over the animal’s lifetime — they develop cancer. The levels found in some children’s bathing products are one thousand times greater and measured in parts per million. The gold standard for cancer protection widely used by federal agencies is that an isolated chemical should not be estimated to cause more than one excess cancer per one million persons. This is called a one-in-one-million risk.
However, cancer risks from exposure to cancer-causing chemicals in several products substantially exceed this gold standard. Results from an independent chemical testing laboratory, released a month ago, found a probable human carcinogen, 1,4-dioxane, also known as para-dioxane, in some common children’s shampoos at levels higher than those recommended by the US Food and Drug Administration. The Environmental Working Group, (, a research and advocacy organization, estimates that more than a quarter of all personal-care-products sold in the United States may contain this cancer causing agent.
A recently published (February 15, 2007) “Newsweek” article stated, “The presence of a cancerous agent at levels above those suggested by the FDA is disturbing enough. The idea that such a compound exists at any amount in any products that can be in regular contact with babies’ skin is even more disconcerting. Scientists have long known that certain chemicals like paradioxane can cause cancer…Now we’re beginning to realize that the sum total of a person’s exposure to all the little amounts of cancerous agents in the environment may be just as harmful as big doses of a few well-known carcinogens.”[2]
The combined effects of our lifetime exposure to dioxane and other carcinogens can create synergistic effects, so what may look like low exposure levels for any one compound adds up and even multiplies.

Myth: We are protected, thanks to the FDA, which has established a recommended level of no more than 10 parts per million in consumer products.

David Steinman’s research, discussed in his book Safe Trip to Eden and additional studies after the book was published, shows that at least 15 percent of cosmetic products with 1,4-dioxane exceed the FDA recommended upper limit. But since these so-called limits are only voluntary, companies not meeting them face no consequences from the federal government.
Within a day of the “Newsweek” article appearing, ATSDR, an agency charged with evaluating toxic hazards, withdrew from its website the toxicological profile of 1, 4-dioxane. The revised posting as of April, 2007 says, “In February, 2007, ATSDR was informed by the Director of the Food and Drug Administration’s (FDA) Office of Cosmetics and Colors, that an error was present in the Public Health Statement of the toxicological profile. The FDA pointed out to ATSDR that the FDA had not recommended a limit for 1, 4-dioxane in cosmetic products.” In fact, the only FDA recommendation about 1, 4-dioxane pertains to levels in adhesives and food additives. [3]
The ATSDR revised notice advises consumers to read labels:
“1, 4-dioxane may be a contaminant in cosmetics, detergents, and shampoos that contain the following ingredients (which may be listed on the product label): “PEG,” “polyethylene,” “polyethylene glycol,” “polyoxyethylene,” “-eth-“ or “-oxynol-.” *Most manufacturers remove 1, 4-dioxane from these ingredients to concentrations recommended by the FDA as safe. Thus, most products on the market today contain 1,4-dioxane in very small amounts or not at all. However, some cosmetics, detergents, and shampoos may contain 1, 4-dioxane at levels higher than recommended by the FDA. Because products contaminated at concentrations higher than the FDA-recommended levels are not possible to determine without testing, families should avoid using products containing the ingredients listed above unless the manufacturer can guarantee that 1, 4-dioxane is below the FDA-recommended level. [4] 
In 1992, 1, 4-dioxane was listed as a banned ingredient in cosmetics. [5] But, in 2001, FDA scientists reported finding increased levels in a number of consumer products. [6] Within the past few years, the European Union has banned the use of para-dioxane in all personal care products and recently initiated a recall of any contaminated products, including a number of children’s bath products. [7]

Reprinted with permission from Healthy Choices, Healthy Lives, the University of Pittsburgh Cancer Institute Newsletter, Spring 2007.



[1]      Gouveia-Vigeant, T. & Tickner, J. “Toxic chemicals and childhood cancer: A review of the evidence.” Lowell Center for Sustainable Production, University of Massachusetts Lowell, One University Avenue, Lowell, Massachusetts 01854.

[2]      Devra Davis. “Cancer: How Dangerous Are Our Cosmetics?” Newsweek February 15, 2007 3.

[3]      FDA website.

[4]      Ibid.

[5]      Ibid.

[6]      Black, R.E., Hurley, F.J., Havery, D.C., Journal of AOAC International, Vol.84, No. 3, 2001.

[7]      European Union Council Directive. “ The Rules Governing Cosmetic Products in the European Union”, Approximation of the laws of the Member States relating to cosmetic products (76/768/EEC). 27 July 1976, p. 27. Viewed at : Annex II List of Substances Which Cosmetic Products Must Not Contain: #342, Dioxane.