Trends in Dioxin Levels in the Environment and in Humans

The facts:

1. There are many sources of dioxin in the environment. Dioxin is an unwanted byproduct of various industrial, societal and natural processes.
   
   
2. U.S. dioxin emissions from man-made sources have declined over 92 percent since 1987 due to a combination of effective government regulations and voluntary industry efforts. Industrial man-made sources have fallen so significantly that backyard trash burning is currently the largest man-made source of dioxin emissions to the environment.
   
   
3. The chlorine chemistry sector accelerated its progress in reducing dioxin in 2002 -- it achieved a 68 percent reduction in dioxin releases to the environment since 2000.
   
   
4. Current levels of dioxin in our bodies are so low that a 2003 study by the U.S. Centers for Disease Control and Prevention (CDC) reported dioxin levels in the blood of the average U.S. resident were below levels of detection.

1. There are many sources of dioxin in the environment. Dioxin is an unwanted byproduct of various industrial, societal and natural processes.

Strict government regulations and voluntary industry initiatives have drastically reduced industrial (e.g., manufacturing) dioxin emissions since 1987. As these sources have been curtailed, natural (e.g., forest fires) and societal sources (e.g., backyard trash burning) have overtaken industrial sources in significance. And according to EPA data, backyard trash burning - a societal activity -- is currently the largest man-made source of dioxin. A new EPA educational campaign discourages this pollution-generating practice, which, for some, has become a way of life in rural America. According to recent research, forest fires are a major natural source of dioxin(1) . As such, levels of naturally produced dioxins will remain even if all human-generated dioxins could be eliminated.

For more information on dioxins from forest fires:
http://www.dioxinfacts.org/sources_trends/forest_fires.html

For more information on backyard trash burning:
http://www.epa.gov/epaoswer/non-hw/muncpl/backyard/pubs/st_local1.pdf
http://www.dioxinfacts.org/sources_trends/trash_burning.html

(1) Gullett, B.K. and Touati, A. (2003). PCDD/F emissions from forest fire simulations, Atmospheric Environment 37, p. 803-13. "TEQ" denotes "toxic equivalent," a quantitative measure of the combined toxicity of a mixture of dioxin-like compounds.

2. U.S. dioxin emissions from man-made sources have declined over 92 percent since 1987 due to a combination of effective government regulations and voluntary industry efforts. Industrial man-made sources have fallen so significantly that backyard trash burning is currently the largest man-made source of dioxin emissions to the environment.

EPA credits industrial sources for making the greatest progress in reducing dioxin air emissions. Total dioxin emissions to air, water and land from 32 man-made sources have declined 92 percent since 1987, due to a combination of effective government regulation and voluntary industry efforts. Emissions from municipal solid waste incineration, historically, the largest industrial source of dioxin, declined more than 99 percent since 1987. One reason for these drastic reductions is technology improvements. Modern incinerators are engineered to burn wastes efficiently at high temperatures and to minimize the conditions known to promote the formation of dioxin and other unwanted byproducts.

For more information on dioxin, including dioxin sources:
http://www.cfsan.fda.gov/~lrd/dioxinqa.html
http://cfpub.epa.gov/ncea/cfm/recordisplay.cfm?deid=20797
http://www.dioxinfacts.org

3. The chlorine chemistry sector accelerated its progress in reducing dioxin in 2002 -- it achieved a 68 percent reduction in dioxin releases to the environment since 2000.

Since 1987, EPA has collected and tracked dioxin emission data for certain man-made sources(2). EPA began requiring facilities to report industrial dioxin releases to the environment as part of the year 2000 Toxics Release Inventory (TRI). In 2002, the most recent year of TRI reporting, the chlorine sector's dioxin releases fell to just 10.4 grams-TEQ, representing less than one percent of the total 2002/2004 EPA-projected dioxin emissions from quantified sources.

For more information on dioxin and TRI:
http://www.epa.gov/tri/
http://www.trifacts.org

(2 ) See the EPA database at http://cfpub.epa.gov/ncea/cfm/recordisplay.cfm?deid=20797

4. Current levels of dioxin in our bodies are so low that a 2003 study by the U.S. Centers for Disease Control and Prevention (CDC) reported dioxin levels in the blood of the average U.S. resident were below levels of detection.

"ppt" is parts per trillion
"LOD" means Level of Detection
"ND" means non detect

Studies confirm the fact that as environmental levels of dioxins fall-- and people are exposed to less dioxin--levels in the human body also fall. There have been significant declines in dioxin in human tissues since the 1970s(3). More importantly, CDC data confirm dioxin blood levels correspond to safe governmental intake guidelines established by three major health agencies. (4)

For more information on dioxin levels in humans:
http://www.cdc.gov/exposurereport/
http://www.dioxinfacts.org/dioxin_health/cdc/Dioxin_TEQcombined.pdf

(3) Although the CDC report is the first effort to obtain a statistically representative sampling of the U.S. population, previous studies of dioxin levels in general population groups have been conducted. These studies showed that the estimated mean dioxin-TEQ levels in 1970 were about 80 ppt-TEQ (Lorber, 2002). Lorber, M. (2002). A pharmacokinetic model for estimating exposure of Americans to dioxin- like compounds in the past, present, and future. Sci. Tot. Environ. 288, 81-95.

(4) The major health agencies that have considered and set risk levels for dioxin include US Agency for Toxic Substances and Disease Registry; the Joint United Nations Food and Agriculture Organization/World Health Organization Expert Committee on Food Additives and the European Commission Scientific Committee on Food.