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Humans have created pollutants that do not break down naturally, that are stored in the body fat of animals and human and that threaten the existence, let alone health, of future generations.
|By Carol Dansereau|
|Persistent Bioaccumulative Pollutants (PBTs) are long-lasting
pollutants that lodge in the tissues of living creatures, including people, and which
do not break down naturally. They can be passed on to succeeding generations both
in utero through the umbilical chord and afterward through breast milk. PBTs include
banned substances such as DDT (which, though banned for use in the United States,
is still manufactured and used in various parts of the world), metals like mercury,
some persticides, and substances like dioxins that are produced by incinerators,
pulp mills, and other sources.
For decades, governments have authorized the release into the environment of pollutants, including PBTs. As a result, there is now literally no place on earth that is not contaminated with industrial chemicals, pesticides, and other pollutants. From the farthest reaches of the Arctic to the depths of the ocean, our pollutants can be found. They are in salmon, birds, whales, other wildlife, and people.
One of the key lessons from wildlife is that offspring are at much greater risk than adults are. Another lesson from wildlife is that a lot of pollutants (e.g. dioxins, lead, mercury, and various pesticides) mimic or block hormones the chemical messengers in wildlife and humans that are central to proper development, reproduction, and survival. A third lesson from wildflife is the many implications of PBTs for humans. Every person now has hundreds of synthetic chemicals in her or his body fat, even if living far from point sources of pollution.
Dioxin is one PBT to which we are all exposed. This extraordinarily potent pollutant can cause severe injury in minute concentrations. A single extremely small dose of dioxin given to a pregnant rat on day fifteen of gestation causes lower sperm counts, genital abnormalities, and other problems in her male offspring, for example. The average American adult has levels of this pollutant in her or his body fat that create cancer risks which greatly exceed so-called "acceptable cancer risks," according to the Environmental Protection Agency (EPA). These average body burdens of dioxin are comparable to or even higher than levels in laboratory animals, in which they have been linked to a wide array of problems such as birth defects, inability to resist disease, and reproductive problems.
|Signals from Wildlife
In recent years we have begun to recognise the price of our pollution, as scientists have linked disturbing problems in wildlife to their pollution exposures. Here are just a few examples:
- Scientists studying alligators in Florida lakes have linked low-hatching survival, severe deformities of penises and ovaries, and skewed hormone ratios to prehatching exposures to pesticides.
- Young male otters on the Columbia River have higher levels of pollutants in their bodies than do otters from less polluted areas. The more pollutants they carry, the smaller the penises.
- 40 to 50 percent of juvenile sole in the Hylebos Waterway in Tacoma mature sexually too early, and this early maturation correlates to PCB levels in the fish. Early maturation is associated with less viable eggs.
- Scientists suspect pollution as the cause of hermaphroditism (having both male and female sex organs) in Arctic polar bears.
|One of the groups identified by EPA as being "highly exposed" to dioxins
is infants. Already exposed to dioxins in the womb, they also receive concentrated
dioxins in breast milk and continue to be exposed to dioxins after infancy. Consumer
Reports found that an average jar of meat-based baby food contains more than
one hundred times the EPA's so-called daily limit for dioxins. (That limit is based
on cancer risks and does not take into account brain damage or other dioxin-linked
Dioxins are only one example of the persistent bioaccumulative pollutants we have spread throughout the world. Breast milk contains other poisons such as DDT, lead, mercury, hexachlorobenzene, and polycyclic aromatic hydrocarbons.
Scientists from around the planet have begun to issue unprecedented consensus statements warning about the implications of hormone-disrupting pollutants. Focusing on the importance of hormones to brain development, for example, doctors and scientists signed a joint statement in Erice, Sicily, in 1995. The statement warns that every pregnant woman on earth is passing hormone disrupters on to her unborn child, and that hormone disrupters can undermine neurological and behavioral development. It is imperative to reduce production and release of these contaminants, the statement notes. A variety of human studies backed up by animal laboratory studies link prenatal toxic exposures to learning impairment. A long-term study in Great Lakes region, for instance, has found that lower IQ and decreased ability to pay attention correlate to amounts of pollutants measured in children's umbilical chords.
And, finally, pollution may also be involved in the cancer epidemic around us. Men now have a one-in-two lifetime risk of developing cancer; women have a one-in-three risk. These rates are far greater than rates experienced decades ago, even after adjustments are made for aging of the population and lung cancer increases. Discrepancies between industrialized and developing countries, studies linking tumors in wildlife to toxic exposures, and a variety of human and laboratory studies strongly indicate that environmental factors may be involved. The National Cancer Advisory Board states that the "elimination or reduction of exposure to carcinogenic agents is a top priority in the prevention of cancer."
Note: Washington State is the first state in the US to plan the banning of PBTs. The initial proposal is to stop releases from new sources by 2005, from existing sources by 2020, and from toxic sites by 2025).
|Carol Dansereau is Director of the Washington Toxics Coalition.
Taken from Earth Letter, March 1999, a newsletter of Earth Ministry, 1305 NE 47th St., Seattle, WA 98105, USA.