Posted by Bill Couzens, Founder Lesscancer.org
Open waste burning leads to cancer
By Donald L. Hassig, Cancer Action NY
POSTED: May 7, 2008
Open waste burninis one of the significant sources of cancer-causing air pollution. Carcinogens emitted by open burning of solid waste include dioxins, furans, polycyclic aromatic hydrocarbons (PAHs), benzene, cadmium, chromium, arsenic and lead. People are most exposed to dioxins, furans and PAHs due to food supply contamination. These chemicals deposit out of the air and settle upon forage crops and pasture. The pollutants are consumed by food animals and accumulate in their bodies. Human consumption of dairy products, meats and eggs results in intake of the dioxins, furans and PAHs that are stored in the fat tissue of the food animals.
There are no burning barrels or refuse heap fires in urban areas. Many city dwellers believe that open burning has no impact on them since they are not breathing the emissions of nearby fires. However, when one takes into account food supply contamination it becomes clear that an impact does indeed exist. Those who live far from where trash is burned are exposed to dioxins, furans and PAHs when they eat animal fat foods. People living in areas where frequent trash burning takes place are exposed to all the pollutant carcinogens listed above when they breathe the smoke and fumes. However, their respiratory exposure to dioxins, furans and PAHs is far less than the exposure they receive by way of food supply contamination.
Dioxins are a group of chemical compounds sharing the basic structure of two benzene molecules linked by two oxygen atoms. Dioxins are created in combustion processes. Poor combustion conditions increase dioxin production. The U S Environmental Protection Agency’s dioxin inventory lists open waste burning as the largest source of dioxin releases to the environment. Another significant source of dioxin creation is the high temperature processing of metals.
2,3,7,8-Tetrachlorodibenzo-p-dioxin is listed by the National Toxicology Program as “Known to Be a Human Carcinogen” (NTP, 2005). It is suspected that all dioxins and dioxin-like compounds, including furans and certain PCBs, are human carcinogens. People are exposed to a mixture of these chemicals. Total dioxin and dioxin-like compound exposure is expressed as a Toxicological Equivalent Quantity (TEQ) of dioxin, thus stating the exposure amount as a quantity of 2,3,7,8-Tetrachlorodibenzo-p-dioxin. This quantity is determined using Toxicological Equivalent Factors (TEF), which adjust for variations in toxicity between the various dioxin and dioxin-like compounds. Toxicity data for dioxins and dioxin-like compounds other than 2,3,7,8-Tetrachlorodibenzo-p-dioxin is relatively limited; therefore, some degree of uncertainty exists in using this method of dealing with exposure to a mixture of chemicals. Dioxins cause cancer by acting as promoters of the process whereby malignant tumors are formed. Promotion involves the accelerated development of cells that have lost the ability to control cell division.
The EPA has been working on a reassessment of dioxin exposure and adverse health effects since the early 1990s (EPA, 2003). Dietary surveys conducted by the United States Food and Drug Administration provide an estimate of American consumption of animal fat. Limited testing of animal fat foods has generated data for estimating dioxin levels in these foods. The dioxin reassessment reports an average dioxin intake rate of 1 pg dioxin TEQ per kg body weight per day. More than 95 percent of dioxin exposure is a result of consumption of animal fat.