Here's an interesting article about the environmental impact of human drugs
flushed into the environment after use (i.e. down the toilet). (from
"RACHEL'S ENVIRONMENT & HEALTH WEEKLY #702 "):
Last December two scientists -- Christian G. Daughton and Thomas
A. Ternes -- writing in ENVIRONMENTAL HEALTH PERSPECTIVES, a
respected, peer-reviewed journal, pointed out the relationship
between the human genome project and new drugs: "The enormous
array of pharmaceuticals will continue to diversify and grow as
the human genome is mapped. Today there are about 500 distinct
biochemical receptors at which drugs are targeted.... The number
of targets is expected to increase 20-fold (yielding 3000 to
10,000 drug targets) in the near future...."[6] Daughton and
Ternes go on to say, "Escalating introduction to the marketplace
of new pharmaceuticals is adding exponentially to the already
large array of chemical classes, each with distinct modes of
biochemical action, many of which are poorly understood."
Daughton and Ternes say that the quantity of pharmaceuticals and
personal care products entering the environment each year is
roughly comparable to the amounts of pesticides used each year.
Huge quantities of prescription drugs and biologics, diagnostic
agents, "neutraceuticals," fragrances, sun-screen agents and
numerous other classes of compounds enter the environment each
year, without any government agencies taking notice. As daughton
and Ternes point out, these chemicals tend to have several
worrisome characteristics:
** Many are very long-lived, many break down into other
long-lived compounds with their own peculiar chemical
characteristics, and almost nothing is known about their movement
in the environment;
** Pesticides tend to enter the environment in seasonal pulses.
In contrast, pharmaceuticals and personal care products (PPCPs)
enter the environment continuously via domestic and industrial
sewage systems and via wet-weather runoff (for example, from
confined animal feeding operations such as hog factories).
** Unlike many pesticides, most drugs and personal care products
have not been examined for adverse environmental effects.
Daughton and Ternes comment, "This is surprising especially since
certain pharmaceuticals are designed to modulate [change]
endocrine and immune systems and cellular signal transduction and
as such... have obvious potential as endocrine disruptors in the
environment."[6,pg.908]
** Many of these chemicals are designed to have profound
physiologic effects, so it would not be surprising if they were
found to affect fish, shellfish, birds, worms, frogs, insects,
and other forms of life.[6,pg.925]
** With pharmaceuticals, unpredicted and unknown side effects are
often the norm: "The possible actions and biochemical
ramifications on nontarget aquatic biota are even less
understood; many are totally unknown," Daughton and Ternes say.
** "It is important to recognize that for many drugs, their
specific modes of action even in the target species are also
unknown. For these drugs, it is impossible to predict what
effects they might have on non-target organisms." [6,pg.923]
** Most drugs don't cure illnesses, they control symptoms -- they
lower cholesterol levels or blood pressure, or they alleviate
pain or depression, or they revive limp libidoes. However, to
achieve these results, they must be taken continuously, often for
many years. Therefore, even relatively short-lived PPCPs can
cause chronic exposures because they are continuously infused
into the environment;
** Aquatic organisms are captives of their aquatic environment so
must endure perpetual exposure;
** The bioaccumulation/bioconcentration potential for at least
some PPCPs matches that of organochlorine compounds;[6,pg.910]
** Some PPCPs show "very high acute aquatic toxicity" while
others "can elicit constellations of significant but subtle
effects across numerous species."[6,pg.910]
** It must also be recognized that even though individual
concentrations of any drug might be low, the combined
concentrations from drugs sharing a common mechanism of action
could be substantial."[6,pg.925]
** Most chemical researchers don't have the tools needed to look
for these chemicals in the environment. Researchers use gas
chromatography (GC) and mass spectrometry (MS). The signals
produced by such analytic equipment are compared to "spectral
libraries," allowing unknown chemicals to be identified. But the
standard spectral libraries available from U.S. Environmental
Protection Agency (EPA), the National Institute of Standards and
Technology (NIST), and the National Institutes of Health (NIH) do
not include most pharmaceuticals. Therefore typical researchers
are not prepared to identify pharmaceuticals in the environment.
** Daughton and Ternes list 66 classes of pharmaceuticals,
including antidepressants; cancer chemotherapy drugs;
tranquilizers and psychiatric drugs; pain killers of many kinds;
anti-inflammatory drugs; many kinds of antihypertensives (blood
pressure reducers); antiseptics; fungicides; anti-epileptics;
bronchodilators (such as albuterol); many lipid regulators or
anti-cholesterol agents; chemicals to increase the contrast in
x-rays; muscle relaxants; anti-psychotic drugs; oral
contraceptives; anorectics (diet pills); antibiotics; and
synthetic hormones (estrogen and thyroid). Details about the 200
most popular prescription drugs in the U.S. in 1999 can be found
at www.rxlist.com/top200.htm. These 200 reportedly account for
two thirds of all the prescriptions filled each year in the U.S.
** Most exposure to drugs and personal care products occurs in
the aquatic environment, but it also occurs on land: "...the
primary source for terrestrial exposure is probably from disposal
of biosolids [sludge] from [sewage treatment plants] and from
animal wastes both applied to land and stored in open-air pits
(waste lagoons)..." [6,pg.925]
** Daughton and Ternes say, "Theoretically, [pharmaceuticals and
personal care products] in sewage sludge applied to crop lands
could be taken up by plants."[6,pg.921] Surely everyone can agree
that this problem should be examined carefully BEFORE allowing
sewage sludge to be mixed with soil.
Is this a new problem? Daughton and Ternes show that, "It
therefore was clearly recognized over 20 years ago that the
continual, daily introduction of kilogram quantities of drugs
from a given [sewage treatment plant] into receiving waters could
result in sustained concentrations with the potential to lead to
exposures in aquatic organisms." [6,pg.925]
But for 20 years regulatory officials and drug corporations have
pretended that the problem does not exist, perhaps because they
have no idea what to do about it. Now the problem seems about to
get worse for three reasons: (1) The genome-induced gold rush to
produce new drugs, mentioned above; (2) the Internet, which is
allowing people to purchase drugs that they previously could not
get their hands on; and (3) recent public hearings by the U.S.
Food and Drug Administration (FDA) to consider allowing many
prescription drugs to be sold without a prescription. The last
time FDA held such hearings, in 1972, 600 drugs switched from
prescription to non-prescription status.[7]
Christian Daughton, a scientist with U.S. Environmental
Protection Agency, is aggressively urging environmental
scientists to pay more attention to this problem. However
Daughton acknowledges that the problem may already be too large
for detailed scientific analysis: "In the final analysis, given
the vast array of mechanisms of drug action and side effects, the
total number of different toxicity tests possibly required to
screen the effluent from a typical [sewage treatment plant] could
be impractically large." [6,pg.923]
In June of this year, Daughton and others organized a scientific
conference in Minnesota.[8] There, Glen R. Boyd, a civil engineer
from Tulane University in New Orleans reported finding drugs in
the Mississippi River, in Louisiana's Lake Ponchetrain, and in
Tulane's tap water. In all the waters tested, Boyd and his team
found low levels of the anti-cholesterol drug clofibric acid
along with the pain killer naproxen and the hormone estrone. In
Tulane's tap water, estrone averaged 35 parts per trillion with a
high of 80 parts per trillion.
Naturally, the water-dwelling creatures will bear the brunt of
all this because they cannot escape civilized peoples' habit of
urinating and defecating in all the available fresh water. At the
Minnesota meeting in June a team of scientists reporting finding
male carp and walleyes producing "sky high" quantities of
vitellogenin, an egg-yolk protein normally made only by females.
In 1998, Environment Canada, Canada's federal environmental
agency, reported high levels of estrogens and birth control
compounds in the effluent of sewage treatment plants nationwide.
Chris D. Metcalfe of Trent University in Peterborough, Ontario
created laboratory conditions similar to those found by
Environment Canada and he reported in June that those conditions
cause some fish to become intersex -- having the characteristics
of both males and females. Metcalfe has found intersex white
perch in the Great Lakes.
** Daughton and Ternes say, "A major unaddressed issue regarding
human health is the long-term effects of ingesting via potable
waters very low subtherapeutic doses of numerous pharmaceuticals
multiple times a day for many decades." [6,pg.923] What will it
mean to raise our babies on water contaminated with low levels of
birth control drugs and athlete's foot remedies plus Viagra,
Prozac, Valium, Claritin, Amoxicillin, Prevachol, Codeine,
Flonase, Ibuprofen, Dilantin, Cozaar, Pepcid, Albuterol,
Naproxen, Warfarin, Ranitidine, Diazepam, Bactroban, Lotrel,
Lorazepam, Tamoxifen, Mevacor, and dozens of other potent drugs,
along with hair removers, mosquito repellants, sunburn creams,
musks and other fragrances? No one knows, but evidently we're
going to find out, learning by doing.
--Peter Montague
============
[1] Nicholas Wade, "Genetic Code of Human Life is Cracked by
Scientists," NEW YORK TIMES June 27, 2000, pg. 1.
[2] Nicholas Wade, "Now the Hard Part: Putting the Genome to
Work," NEW YORK TIMES June 27, 2000, pg. D1.
[3] Kenneth Chang, "Incomplete, Project Is Already Paying off,"
NEW YORK TIMES June 27, 2000, pg. D1.
[4] Andrew Pollack, "Is Everything for Sale?" NEW YORK TIMES June
28, 2000, pg. C1.
[5] Andrew Pollack, "Finding Gold in Scientific Pay Dirt," NEW
YORK TIMES June 28, 2000, pg. C1, C12.
[6] Christian G. Daughton and Thomas A. Ternes, "Pharmaceuticals
and Personal Care Products in the Environment: Agents of Subtle
Change," ENVIRONMENTAL HEALTH PERSPECTIVES Vol. 107 Supplement 6
(December 1999), pgs. 907-938.
[7] Sheryl Gay Stolberg, "U.S. May Ease Sale of Drugs Over the
Counter," NEW YORK TIMES June 28, 2000, pg. A1.
[8] Janet Raloff, "Excreted Drugs: Something Looks Fishy,"
SCIENCE NEWS June 17, 2000, pg. 388.
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