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Date: Thu, Nov 21, 1996, 11:33 AM
Subject: EndoDisruptors: Where are they?
WHERE DO WE FIND ENDOCRINE DISRUPTORS,
CHEMICALS THAT CAN DISRUPT LIVING SYSTEMS?
A wide range of chemicals, including some in common, often unregulated,
undisclosed use are now associated with affecting the health, reproduction,
and behavior of animals. George Lucier, director of the Environmental
Toxicology Program of the National Institute of Environmental Health Sciences,
describes the problem: "Although trends in hormonally related diseases have
not been clearly linked to environmental chemicals, it is probable that
endocrine disruptors are contributing to human diseases and dysfunction. The
question then becomes how much they are contributing." <<PD NOTE: I think the
case for the connection between hormone disruptors and health problems can be
stated more strongly than that - see the book "Our Stolen Future".>>
Fortunately, alternatives to suspect chemicals exist and there are many
ways to reduce exposures until industry and government research can provide
more certainty as to what is safe. Industry must share with the public
information it claims confidential about additives in plastics and detergents
and inert ingredients in pesticides. EPA, through the 1996 reauthorization of
the Safe Drinking Water Act, was directed to address possible endocrine
disruptors in drinking water. The White House has convened an interagency
task force of national experts to improve the national response to the issue.
While consumer exposures are of concern, we must also consider workplace
exposures to even larger amounts of these chemicals, and facility releases of
chemicals that do not biodegrade easily, such as residues in sewage entering a
river or sewage sludge applied to food crops.
These "endocrine disruptors" include both natural compounds and
synthetic chemicals. Some, called phytoestrogens, occur naturally in a
variety of plants. Living things evolved with them; they are metabolized or
degraded so that they do not bioaccumulate. Of current concern are the
synthetic estrogens produced either through industrial manufacture or as
byproducts of such processes or burning. Those we know about have been
identified by lab tests such as those that measure a chemical's ability to
speed the growth of cultures of breast cancer cells. They can cause effects
at parts per trillion levels, levels at which most chemicals have never been
PESTICIDES: Many pesticides have been found to be estrogenic. They range
from 2,4-D and 2,4,-T to tributyl tin, carbaryl, chlordane, DDT, lindane,
malathion, parathion, aldicarb, DBCP to synthetic pyrethroids. Exposure can
occur during application, through consumption of contaminated produce and
other foods, through contaminated drinking water, or even from house dust in
agricultural areas. Production of DDT for use in the U. S. was banned in
1972. However, other countries, especially tropical countries like Mexico,
still use it for mosquito control to combat malaria. DDT and its metabolites
bioaccumulate in wildlife and humans can be exposed through the food chain.
LIQUID SOAPS, SHAMPOOS, CONDITIONERS, AND HAIR COLORS: Many industrial and
consumer products contain alkylphenol ethoxylates (APEs) which break down into
alkylphenols such as nonylphenol which has been found in sewage and rivers
near outfalls. One of their main uses is in liquid detergents. In Europe these
products have been replaced by the more expensive, but much safer, alcohol
ethoxylates. Denmark based its phaseout of alkyphenol exthoxylate on research
done in the United Kingdom which found that its breakdown products,
alkylphenols, caused male fish to take on female characteristics. Alkylphenols
do not biodegrade easily and they bioaccumulate, which is why they may cause
problems when sewage sludge is applied to the land.
PLASTICS: Plastics contain additives, such as phthalates, bisphenol-A, and
nonylphenols, usually present as plasticizers to make them flexible and
durable. They can leach out into liquids and foods. Heating speeds this,
which is why microwaving foods in plastic is discouraged. Estrogenic butyl
benzyl phthalate is found in vinyl floor tiles, adhesives, and synthetic
leathers. Its cousin, di-butyl phthalate is present in some food-contact
papers. Bisphenol-A is a breakdown product of polycarbonate plastics, used in
water bottles, baby bottles, and the linings of some food cans.
PCBS: PCBs are a family of toxic industrial chemicals commercialized in 1929
by Monsanto. Although their production in the U. S stopped in 1977, world
production continued. PCBs are still present in the U. S. in electrical
equipment and frequently found at toxic waste sites and in contaminated
sediments. A recent [study] confirmed that children exposed to low levels of
PCBs in the womb because of their mother's fish consumption grow up with low
IQs, poor reading comprehension, difficulty paying attention, and memory
DIOXINS: Chlorinated dioxins and dibenzofurans are byproducts of chlorine
bleaching of paper, the burning of chlorinated hydrocarbons such as
pentachlorophenol, PCBs, and polyvinyl chloride, the incineration of municipal
and medical wastes, and natural events such as forest fires and volcanic
eruptions. They often contaminate toxic wastes sites, especially where there
have been fires. They bioaccumulate in fish and other wildlife and the most
common human route of exposure is through the food chain.
SPERMICIDES: Many spermicides contain nonoxynol-9, a nonylphenol that kills
PRESERVATIVES: BHA, butylated hydroxyanisole, is added to foods like
breakfast cereal, or its packaging, to prevent it from becoming rancid.
METALS: Lead, methyl mercury, and cadmium. These metals can disrupt the
endocrine system by causing problems in steroid production.
The Sierra Club is addressing the problem of chemical disruptors through an
electronic mail forum for networking and discussion of these matters. Contact
Doris Cellarius, chair, Sierra Club Community Health Committee, 360-943-6875
or (firstname.lastname@example.org) for more information or documentation of
the information in this article.