1. Measuring Carcinogens in People: Exposures come from a variety of sources
Thousands of natural and man-made chemicals are present in the environment – indoors and out, in air, food, water and consumer products. Most commercially used chemicals have never been adequately assessed for safety and most have not been biomonitored for their presence in people. Under the broken and outdated federal Toxic Substances Control Act only about 7 percent of the approximately 3,000 high volume chemicals (used in excess of a million pounds a year) have been tested for safety. The gold standard for assessing exposure to chemical carcinogens is biomonitoring – the measurement of chemicals or their metabolites in blood, urine, breast milk, hair or other human samples.Biomonitoring is vital for accurate determination and tracking of exposures. An inventory of carcinogens measured in people would provide a knowledge base for researchers and a tool for policy-makers and regulators to assess and reduce exposures. This is especially important in light of the conclusions of the 2008-2009 report of the President’s Cancer Panel: The Panel was particularly concerned to find that the true burden of environmentally induced cancer has been grossly underestimated. With nearly 80,000 chemicals on the market in the United States, many of which are used by millions of Americans in their daily lives and are un- or understudied and largely unregulated, exposure to potential environmental carcinogens is widespread. . . . [T]he public remains unaware of many common environmental carcinogens. . . . Most also are unaware that children are far more vulnerable to environmental toxins and radiation than adults.4 A comprehensive review by EWG of the scientific literature revealed a stunning number of carcinogens—up to 420* – that have been detected in people through biomonitoring studies. The carcinogens detected include both natural and man-made chemicals that come from a wide range of sources, including: industrial processes, commercial products, pesticides and naturally occurring materials. Table 1 provides examples of the types of carcinogens detected and their sources (the full list of carcinogens detected in people can be found in Appendices A & B). Biomonitoring studies are a window into the amount of exposure, but do not address the source or route of exposure. Grouping the carcinogens detected in the human body into categories based on primary use can help us better understand these factors. Table 1: Selected carcinogens measured and detected in the human body Chemical Detections in NHANESa Associated Cancer(s) Source and Exposure Agency & Classification Industrial chemicals Asbestos (all forms) not tested Strong evidence: lung (including mesothelioma), larynx, ovary; Some evidence: pharynx, stomach, colon & rectum Source/Use insulating material, flooring, brake pads and shoes, roofing, gaskets, cement pipes and sheets, textiles, and natural occurance. Exposure environmental: inhalation and ingestion of particles (breakdown of materials); occupational: inhalation during mining, manufacturing and repair operations. IARC (Known); NTP (Known); EPA (Human carcinogen); CA Prop 65 Benzene 51.40% Strong evidence: leukaemia and/or lymphoma Source/Use component of inks, solvents, gasoline additive, and intermediate chemical (rubber, lubricants, dyes, detergents, pesticides). Exposure environmental: inhalation and some dermal absorption from industrial emissions, fuel, exhaust; occupational: inhalation/dermal exposure to solvents, paint, oil refining and working in manufacturing IARC (Known); NTP (Known); EPA (Known/likely); CA Prop 65 1,3-Butadiene range: >99% ;