Body burden. Think of it as "the pollution inside people".
Starting before birth, children are exposed to chemicals that impair normal growth and development.
Exposures continue throughout life.
Chemicals accumulate, interact within the body, and cause illness.
The sources for body burden are everywhere -- industry, foods, and many that are not obvious.
At least 75,000+ chemicals are in copious use and more than 23,000,000 are cataloged.
Approximately 1,000 new chemicals are introduced each year.
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Scant data exists regarding the chronic (long term, low level) health risks of most chemicals.
Scientists are generally trained to believe that "the dose makes the poison". Once a dose is low enough not to cause an effect, it is assumed that there is no need to test even lower doses.
Most chemical safety policies are based on this premise. The lowest level tested with no effect is used as a basis to establish safe standards for exposure to people.
But new research is demonstrating that harm can occur at much lower thresholds than previously considered possible. When smaller amounts cause greater effects than larger amounts the effect is called hormesis. Scientists are learning that many chemicals exhibit hormesis.
Furthermore, the timing of toxic exposure plays a much more significant role than previously recognized.
As a result, current safety standards based on high dose experiments don't guarantee shelter from toxic levels of exposure.
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Health data that does exist about a chemical is usually limited to effects when isolated from other variables.
But contaminants are known to occur in complex mixtures in the environment. A wide range of conditions are at play, and chemicals can behave very differently when combined with other chemicals.
Harm can be amplified when chemicals are combined. Synergistic toxicity is common. Even the body's own natural chemicals, such as hormones, can exhibit synergistic toxicity with other chemicals.
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Heavy metals, organophosphates, and other chemicals damage cells by excitotoxic activity.
Excitotoxins are deliberately added to a wide range of foods.
Excitotoxins increase synergistic toxicity.
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Some toxins that were banned decades ago persist in the soil, air and water. They can still pass through the skin, nostrils or mucus membranes and into the bloodstream and body tissue.
The Centers for Disease Control (CDC) is running the National Biomonitoring Program (NBP) started in 1998. Every two years the NBP attempts to assess exposure to environmental chemicals in the general U.S. population.
Data covering 2001-2002 found that the average adult American body carried 116 toxic synthetic compounds. In other studies, similar chemicals have been detected in the placenta, umbilical cord blood, bloodstream, and body fat of infants as well as in the human breast milk they drink.
In this Washington state study, ALL participants had detectable levels of PCBs, while 8 out of 10 had DDT in their blood.
This study in Maine found on average that each participant had measurable levels of 36 toxic chemicals in their bodies including phthalates from cosmetics and vinyl plastic, brominated flame retardants (PBDEs) from televisions and furniture, perfluorinated chemicals from stain-resistant and non-stick coatings, bisphenol-A from reusable water bottles and baby bottles, and toxic metals such as lead, mercury and arsenic.
In 2007, California launched the nation's first statewide biomonitoring program. The first report is due by January 1, 2010, with new reports to follow every two years.
Recognizing that "pre-polluted babies" are a reality, the Kid-Safe Chemicals Act (KSCA) has been introduced (S. 3040 and H.R. 6100) to overhaul the Toxic Substances Control Act (TSCA). Among other improvements, this legislation would require chemicals to be proven safe before entering the market or to remain in commerce.
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Genetic susceptibility plays a role in body burden.
For instance a large part of the population, possibly more than 20%, are unable to effectively excrete heavy metals. Their burden accumulates faster. Their illnesses are more obvious. They are the "canaries in a coal mine" in an environment that is increasingly toxic.
New evidence is showing that each person has an individualized genome — a unique pattern of whole DNA sections gained or lost.
Some chemicals change genes on-the-fly. Some of these genetic changes become permanent and are passed down in heredity.
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Viruses, bacteria, yeasts, parasites, and mold aggravate body burden at any stage of life.
Beyond the better understood mechanisms of infection, research is revealing that some microorganisms interact directly with chemicals to enhance susceptibility to infection.
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Each person's body burden is likely to fluctuate over the course of hours, months, and years depending on their particular exposures and metabolism. The science of body burden is complex and still in early stages.
Nonetheless it is becoming abundantly clear -- the spectrum of both 'rare' and 'common' illnesses is on the rise, and research is making a connection with the mechanisms of toxic body burden.
The NIH defines a rare disease as one affecting 200,000 or fewer Americans.
25 million Americans suffer from one of the nearly 6,000 identified rare diseases.
That rivals the 40 million Americans with one or more of the three "major" diseases: heart disease, cancer or diabetes.
Developing fetuses and infants are the most vulnerable.
The cost is colossal.
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Two comprehensive sites addressing body burden are by the Environmental Working Group (EWG) and Our Stolen Future.
Good journalistic coverage is given by Douglas Fischer in the San Francisco Bay area.
KQED has a body burden page. A recording of its October 19, 2006 public radio broadcast of Health Dialogues can be played here (061019KQED mp3 12 MB, duration 53 minutes). This program includes discussion about Prop 65, body burden, biomonitoring, and more.
Here is Environmental Defense's Canadian perspective.
Other sites that offer a starting point are shown on the links page. Or simply search phrases like "chemical body burden" and "human biomonitoring".
