Cancer and Environmental Influences

Despite overall decreases in incidence and mortality, cancer continues to shatter and steal the lives of Americans.  Approximately 41% of Americans will be diagnosed with cancer at some point in their lives, and about 21% will die from cancer.  The incidence of some cancers, including some most common among children, is increasing for unexplained reasons…

A growing body of research documents myriad established and suspected environmental factors linked to genetic, immune, and endocrine dysfunction that can lead to cancer and other diseases…

Key Issues for Reducing Environmental Cancer Risk

• Environmental Cancer Research.  Research on environmental causes of cancer has been limited by low priority and inadequate funding.  As a result, the cadre of environmental oncologists is relatively small, and both the consequences of cumulative lifetime exposure to known carcinogens and the interaction of specific environmental contaminants remain largely unstudied.  There is a lack of emphasis on environmental research as a route to primary cancer prevention, particularly compared with research emphases on genetic and molecular mechanisms in cancer.
• Environmental Exposure Measurement, Methodologic, Assessment, and Classification Issues.  …Some scientists maintain that current toxicity testing and exposure limit-setting methods fail to accurately represent the nature of human exposure to potentially harmful chemicals.  Current toxicity testing relies heavily on animal studies that utilize doses substantially higher than those likely to be encountered by humans.  These data — and the exposure limits extrapolated from them — fail to take into account harmful effects that may occur only at very low doses.  Further, chemicals typically are administered when laboratory animals are in their adolescence, a methodology that fails to assess the impact of in utero, childhood, and lifelong exposures.  In addition, agents are tested singly rather than in combination.
• Regulation of Environmental Contaminants.  The prevailing regulatory approach in the United States is reactionary rather than precautionary.  That is, instead of taking preventive action when uncertainty exists about the potential harm a chemical or other environmental contaminant may cause, a hazard must be incontrovertibly demonstrated before action to ameliorate it is initiated.  Moreover, instead of requiring industry or other proponents of specific chemicals, devices, or activities to prove their safety, the public bears the burden of proving that a given environmental exposure is harmful.  Only a few hundred of the more than 80,000 chemicals in use in the United States have been tested for safety.

– In the Executive Summary of the 2008 – 2009 Annual Report to the U.S. President titled Reducing Environmental Cancer Risk: What We Can Do Now, created by the President’s Cancer Panel