Cancer affects millions of American families and adds billions of dollars to our nation’s annual health care bill.

According to the National Cancer Institute, almost 45% of men and 38% of women in the United States will be diagnosed with cancer at some point in their lives.[1][2] Cancer is the second most common cause of death in the U.S., exceeded only by heart disease.[3] Nearly 1 out of every 4 deaths in the United States is caused by cancer.[4]

Over the past two decades, the rates of some cancers have risen significantly. These include:[5]

  • Kidney, liver, thyroid, esophageal, and testicular cancer, as well as melanoma in men;
  • Non-Hodgkin’s lymphoma, Hodgkin’s disease, melanoma, and cancers of the thyroid, liver, and kidney in women; and
  • Childhood cancers overall, especially childhood leukemia and brain cancer (see Figure 1).
Figure 1 – Cancer Incidence and Mortality for Children Under 20
Cancer incidence and mortality for children under 20
SOURCE: U.S. EPA. America’s Children and the Environment. www.epa.gov/envirohealth/children
DATA: National Cancer Institute, Surveillance, Epidemiology and End Results Program
Cancer is the second most common cause of death for Americans under the age of 20. The incidence of childhood cancer increased more than 20% between 1975 and 1990. Since 1990, the incidence has remained roughly at this elevated rate. Mortality declined substantially during this period, due largely to improvements in treatment.[6]

In 2010, the direct medical costs of cancer were $102.8 billion and the overall costs were $263.8 billion.[7] Medical costs for pediatric cancers in 2008 totaled an estimated $1.9 billion.[8]

The link to chemical exposure

Much of what we know about chemicals and cancer comes from experimental laboratory studies, long-term follow up of workers exposed to chemicals in their place of employment, and epidemiologic studies in communities where residents are exposed to hazardous substances. Laboratory animal studies are generally considered relevant for predicting toxic effects of chemicals in people, with certain exceptions.

The U.S. Department of Health and Human Services relies on these types of studies to develop and periodically update its Report on Carcinogens. The 12th edition of the report lists over 200 chemicals as known human carcinogens, such as formaldehyde, asbestos, hexavalent chromium, and vinyl chloride, or reasonably anticipated to be human carcinogens, such as trichloroethylene (TCE), methylene chloride (dichloromethane), styrene, and 1,4-dioxane.[9] Subsequent to the publication of the 12th edition, EPA officially concluded that trichloroethylene (TCE) is “carcinogenic in humans for all routes of exposure,” noting that there is substantial potential for human exposure as TCE is widespread in ambient air, indoor air, soil, and groundwater.[10] The classifications of these and the other chemicals listed in Table 1 are largely based on studies of similarly exposed and diagnosed workers.

Despite being classified as known or probable carcinogens, many of these chemicals remain nearly ubiquitous in the environment where people are easily exposed. For example, formaldehyde is a common indoor air contaminant because of its use in furniture, cabinets, countertops, insulation, wallpaper, paints, and paneling. It is present in a wide variety of other consumer products, such as antiseptics, medicines, cosmetics, dishwashing liquids, fabrics and fabric softeners, shoe-care agents, carpet cleaners, glues and adhesives, lacquers, paper, coatings, and plastics.[11] In a 2009 California study, nearly all new single-family homes had indoor formaldehyde concentrations that exceeded guidelines for cancer and chronic lung irritation.[12]

Trichloroethylene is present in some paint removers, adhesives, rug cleaners, metal cleaners, pepper sprays, and spot removers.[13] TCE has been detected in ambient air, surface water, and groundwater and is one of the most common contaminants found at toxic waste sites.[14] According to the Agency for Toxic Substances and Disease Registry (ATSDR), between 9% and 34% of drinking water supply sources tested in the U.S. contain some TCE.[15]

Early exposure, cancer later in life

Recent research shows that early life exposures can increase the risk of cancer many decades later. Laboratory animal studies, for example, show that early exposures increase the susceptibility of the breast and prostate gland to cancer in adulthood.[16][17] In humans, in utero exposure to diethylstilbestrol, a synthetic estrogen, increased the risk of reproductive tract and breast cancer in women decades after birth.[18]

A 2007 report documented a strong association between higher early-life exposure to a pesticide called dichlorodiphenyltrichloroethane (DDT) and later development of breast cancer.[19] While previous studies that had looked at the relationship between breast cancer and the levels of DDT in women at the time of breast cancer diagnosis did not find a strong connection,[20] the more recent study used stored blood samples to determine the DDT levels the women were exposed to when they were younger. Women who were exposed to higher levels of DDT before age 14 had a markedly increased risk of breast cancer later in life, compared to women whose DDT levels were lower. But higher exposures after the age of 14 were not associated with an increased risk. These and many other studies demonstrate that exposures to hazardous chemicals during vulnerable periods of development can have profound effects that may not manifest until later in life.[21][22]

Breast cancer is a leading cause of death in women.[23] Breast cancer rates in the U.S. increased by more than 40% between 1973 and 1998.[24] Today, a woman’s lifetime risk of breast cancer is one in eight, up from 1 in 10 in 1973.[25] The study of DDT exposure in young women, described above, has been modeled in laboratory animals, where early life exposures to low doses of chemicals have been shown to increase the risk for breast cancer by affecting mammary development and lifetime susceptibility to cancer. For example, in laboratory animals, bisphenol A, dioxin, and perfluorooctanoic acid (PFOA) have been shown to alter gene expression and/or modify mammary gland development, increasing the later risk of cancer.[26][27][28]

A 2007 literature review identified 216 chemicals associated with increases in mammary gland tumors in at least one well-conducted animal study.[29] Of these, 73 have been present in consumer products or as contaminants of food, 35 are air pollutants, 29 are produced at more than 1 million pounds per year in the United States, and 25 have involved occupational exposures to more than 5000 women. Yet, despite the near certainty of widespread human exposure to many of these chemicals, the findings have triggered virtually no regulatory or other policy response.

President’s Cancer Panel calls for increased regulation of chemicals

In its 2008-2009 Annual Report, the President’s Cancer Panel—appointed by President George W. Bush—summarized its investigation on evidence linking chemicals to various kinds of cancer, and concluded that, despite remaining uncertainties, we know enough to act. According to the Panel, “the true burden of environmentally induced cancer is grossly underestimated.”[30]

Singling out TSCA as an “egregious example of ineffective regulation of environmental contaminants,” the Panel called on President Obama to use the power of his office “to remove the carcinogens and other toxins from our food, water, and air that needlessly increase health care costs, cripple our Nation’s productivity, and devastate American lives.”[31]

The asbestos example

asbestosEffective TSCA reform will give EPA the power to restrict cancer-causing chemicals like asbestos, a material that has been banned in 55 other countries.[32] In 1989, EPA banned asbestos in almost all products, but a federal appellate court overturned the ban on the grounds that the agency failed to meet its burden of proving that asbestos presented an unreasonable risk. The chilling effect of this court decision is clear: EPA hasn’t tried to use TSCA to ban or restrict the production or use of a chemical since.[33]

To protect public health, EPA needs the proper authority to restrict human carcinogens to which people are exposed. TSCA should require EPA to assess chemicals and hold chemical manufacturers responsible for demonstrating the safety of their products.

Table 1: Commonly Found Chemicals Known or Reasonably Anticipated to Be Human
Carcinogens[34]
Arsenic
Asbestos
Benzene
Benzidine
Butadiene
Cadmium
Carbon Tetrachloride
Chromium (hexavalent)
Coal Tars
1,4-dioxane
Ethylene oxide
Formaldehyde
Lead
Methylene Chloride
Nickel
Silica
Styrene
Sulfuric Acid
Toluene Diisocyanate
Trichlorethylene (TCE)
Vinyl Chloride
Citations:
  1. SEER Cancer Statistics Review, 1975-2008 [Internet]. Bethesda: National Cancer Institute; [2012 March 25]. Available from: http://seer.cancer.gov/csr/1975_2008/browse_csr.php?section=1&page=sect_01_table.15.html.
  2. SEER Cancer Statistics Review, 1975-2008 [Internet]. Bethesda: National Cancer Institute; [2012 March 25]. Available from: http://seer.cancer.gov/csr/1975_2008/browse_csr.php?section=1&page=sect_01_table.16.html.
  3. Deaths and Mortality [Internet]. Atlanta: U.S. Centers for Disease Control and Prevention; [updated 2012 January 27]. Available from: http://www.cdc.gov/nchs/fastats/deaths.htm.
  4. Cancer Facts & Figures 2012 [Internet]. Atlanta: American Cancer Society; [2012]. Available from: http://www.cancer.org/acs/groups/content/@epidemiologysurveilance/documents/document/acspc-031941.pdf.
  5. Clapp RW, et al. Environmental and occupational causes of cancer: new evidence 2005-2007. Environmental Health 2008;23(1):1-37.
  6. America’s Children and the Environment: Measures of contaminants, body burdens, and illnesses [Internet]. Washington, DC: Environmental Protection Agency; [update 2011 March 8; cited 2003]. Available from: www.epa.gov/ace/publications/index.html.
  7. Economic Impact of Cancer [Internet]. Atlanta: American Cancer Society; [2011 August 15]. Available from: www.cancer.org/Cancer/CancerBasics/economic-impact-of-cancer.
  8. Trasande L, et al. Reducing the staggering costs of environmental disease in children, estimated at $76.6 billion in 2008. Health Affairs 2011;30(5):863-870.
  9. Report on Carcinogens, Twelfth Edition [Internet] Research Triangle Park: National Toxicology Program, U.S. Department of Health and Human Services; [2011 June]. Available from: http://ntp.niehs.nih.gov/?objectid=03C9AF75-E1BF-FF40-DBA9EC0928DF8B15.
  10. Toxicological Review of Trichloroethylene: In support of summary information on the Integrated Risk Information System (IRIS) [Internet]. Washington, DC: U.S. Environmental Protection Agency; [2011 September]. Available from: http://epa.gov/iris/toxreviews/0199tr/0199tr.pdf.
  11. Toxicological Profile for Formaldehyde [Internet] Washington, DC: Agency for Toxic Substances and Disease Registry, Department of Health and Human Services; [updated 2011 March 3; cited 1999]. Available from: www.atsdr.cdc.gov/toxprofiles/tp.asp?id=220&tid=39.
  12. Offermann FJ. Ventilation and indoor air quality in new homes. California air resources board and California energy commission, PIER energy-related environmental research program [Internet]. 2009. [cited 2009 November];CEC-500-2009-085. Available from: www.arb.ca.gov/research/apr/past/04-310.pdf.
  13. Trichloroethylene (TCE): Toxicity and exposure assessment for children’s health, chemical summary [Internet]. Washington, DC: Environmental Protection Agency; [updated 2007 September 20]. Available from: www.epa.gov/teach/chem_summ/TCE_summary.pdf.
  14. Trichloroethylene (TCE): Toxicity and exposure assessment for children’s health, chemical summary [Internet]. Washington, DC: Environmental Protection Agency; [updated 2007 September 20]. Available from: www.epa.gov/teach/chem_summ/TCE_summary.pdf.
  15. Toxicological Profile for Trichloroethylene (TCE) [Internet]. Washington, DC: Agency for Toxic Substances and Disease Registry, Department of Health and Human Services; [updated 2011 March 3] Available from: http://www.atsdr.cdc.gov/toxprofiles/tp.asp?id=173&tid=30.
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  17. Prins G. Endocrine disruptors and prostate cancer risk. Endocrine-Related Cancer 2008;15(3):649-656.
  18. Hoover R, et al. Adverse health outcomes in women exposed in utero to diethylstilbestrol. New England Journal of Medicine 2011; 365(14):1304-1314.
  19. Cohn B, et al. DDT and breast cancer in young women: New data on the significance of age at exposure. Environmental Health Perspectives 2007;115(10):1406-1414.
  20. Brody J, et al. Environmental pollutants and breast cancer: Epidemiologic Studies. Cancer 2007;109(12):2667-2711.
  21. Cohn B, et al. DDT and breast cancer in young women: New data on the significance of age at exposure. Environmental Health Perspectives 2007;115(10):1406-1414.
  22. Diamanti-Kandarakis E, et al. Endocrine-disrupting chemicals: an Endocrine Society scientific statement. Endocr Reviews 2009; 30(4):293-342.
  23. Cancer Facts & Figures 2012 [Internet]. Atlanta: American Cancer Society; [2012]. Available from: http://www.cancer.org/acs/groups/content/@epidemiologysurveilance/documents/document/acspc-031941.pdf.
  24. Howe H, et al. Annual report to the nation on the status of cancer (1973 through 1998), Featuring cancers with recent increasing trends. Journal of the National Cancer Institute 2001;93(11):824-842.
  25. State of the Evidence: The connection between breast cancer and the environment [Internet]. San Francisco: Breast Cancer Fund; [2010 October 1]. Available from: www.breastcancerfund.org/media/publications/state-of-the-evidence/.
  26. Dairkee S, et al. Bisphenol A induces a profile of tumor aggressiveness in high-risk cells from breast cancer patients. Cancer Research 2008;68(7):2076-80.
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  28. Fenton SE. The mammary gland: a tissue sensitive to environmental exposures. Reviews on Environmental Health 2009:24(4):319-325.
  29. Rudel R, et al. Chemicals causing mammary gland tumors in animals signal new directions for epidemiology, chemicals testing, and risk assessment for breast cancer prevention. Cancer 2007; 109(12 suppl):2635-2666.
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  32. Current Asbestos Ban Restrictions [Internet]. International Ban Asbestos Secretariat; [updated 2011 January 6]. Available from: http://ibasecretariat.org/alpha_ban_list.php.
  33. The Promise and Limits of the United States Toxic Substances Control Act [Internet]. Lowell: Lowell Center for Sustainable Production; [2003 October 10]. Available from: http://www.chemicalspolicy.org/downloads/10-03_Chemicals_Policy_TSCA.pdf.
  34. Report on Carcinogens, Twelfth Edition [Internet]. Research Triangle Park: National Toxicology Program, U.S. Department of Health and Human Services; [2011 June]. Available from: http://ntp.niehs.nih.gov/?objectid=03C9AF75-E1BF-FF40-DBA9EC0928DF8B15.