Cancer and Toxic Chemicals

Cancer is the second leading cause of death in the United States; it accounts for 1 in 4 deaths in the US and claims more than 1,500 lives a day. There are over 100 different types of cancer and there are many different factors that affect the susceptibility to cancer such as family history, occupation, living conditions, and socioeconomic status.

Cancer is a broad term that refers to a range of complex diseases affecting various organs in the human body. Some of the most frequently diagnosed cancers include lung, breast, prostate, and brain cancer.

• Lung cancer leads to the most number of deaths in both men and women, accounting for about 30% of all cancer deaths.
• Breast cancer is the second leading cause of cancer death in women, after lung cancer; it is also the second most frequently diagnosed cancer in women, after skin cancers. In the US, breast cancer results in the highest mortality rates of any cancer in women between the ages of 20 and 59.
• Prostate cancer is the most frequently diagnosed cancer in men, killing 40,000 each year.
• Brain cancer is the leading cause of cancer death in children under the age of 20 and the third leading cause of death in young adults ages 20-39.

In addition to the pain and suffering caused by the disease, cancer places an enormous economic burden on our society. In 2010, cancer was estimated by the National Institutes of Health to cost $102.8 billion in medical costs, $20.9 billion in loss of productivity due to illness, and $140.1 billion in loss of productivity due to premature death, for a grand total of $263.8 billion.

Yet much of these costs could be avoided, because many cancers are preventable. In May of 2010, the President’s Cancer Panel reported to President Obama that “the true burden of environmentally induced cancers has been grossly underestimated.” Exposure to environmental carcinogens (chemicals or substances that can lead to the development of cancer) can occur in the workplace and in the home, as well as through consumer products, medical treatments, and lifestyle choices. It has long been known that exposure to high levels of certain chemicals, such as those in some occupational settings, can cause cancer. There is now growing scientific evidence that exposure to lower levels of chemicals in the general environment is contributing to society’s cancer burden.

Environmental factors including tobacco smoke, nutrition, physical activity, and exposure to environmental carcinogens are estimated to be responsible for 75-80% of cancer diagnosis and death in the US. About 6%of cancer deaths per year -- 34,000 deaths annually -- are directly linked to occupational and environmental exposures to known, specific carcinogens. The potential of environmental carcinogens to interact with genetic and lifestyle factors, as well as each other, in the development of cancer, is not well-understood. Nor are chemicals in the environment exhaustively tested as to their carcinogenicity. Therefore the cancer burden caused by exposures to environmental carcinogens may be even larger.

Human biomonitoring studies show that many environmental contaminants, including known and potential carcinogens, are finding their way into people’s bodies. The sources of these contaminants are wide-ranging:

• Pesticides: conventional pesticides used in agriculture, industry, home, and garden, as well as chlorine and other disinfectants, and wood preservatives.
• Industrial chemicals, wastes, and waste byproducts from mining facilities, smelting operations, chemical manufacturing and processing plants, petrochemical plants, and medical and municipal waste facilities. Such facilities release billions of pounds of chemicals into the environment every year.
• Chemicals in consumer products, including building materials, furniture, and food packaging materials, and cosmetics.
• Pollution from coal-fired power plants, automobile exhaust, and other sources.

The following are examples of common environmental chemicals linked to cancer. Some are listed as known carcinogens by the International Agency for Research on Cancer (IARC), part of the World Health Organization, or by the Environmental Protection Agency. Others are probable or possible carcinogens. Because something has been classified as a carcinogen does not mean that every instance of exposure to that substance will result in the development of cancer. By the same token, a listing of “probable” or “possible” carcinogenicity does not mean we have exhausted study on that substance. It means the substance is not yet sufficiently studied. Such substances may, with further study, turn out to be definitively carcinogenic.

There are hundreds of other substances definitively linked to cancer in people.

Arsenic

Asbestos

Benzene

Bisphenol A (BPA)

Chromium Hexavalent compounds

Dioxins

Formaldehyde

Polybrominated diphenylethers (PBDEs)

Polycyclicaromatic hydrocarbons (PAHs)

Vinyl Chloride

Resources

11^th Report on Carcinogens. The National Toxicology Program, US Department of Health and Human Services.   

Cancer Causes and Risk Factors. National Cancer Institute at the National Institutes of Health.

Cancer Facts and Figures 2010. American Cancer Society

Cancer Working Group. The Collaborative on Health and the Environment.

Cancer. Safer Chemicals Healthy Families.

IARC Monographs on the Evaluation of Carcinogenic Risk to Humans. International Agency for Research on Cancer, World Health Organization.

Reducing Environmental Cancer Risk: What we can do now. Annual report 2008-2009. President’s Cancer Panel, 2010.

State of the Evidence: The connection between breast cancer and the environment. Janet Gray, PhD, 2010. The Breast Cancer Fund.