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July 29, 1999
PRECAUTION AND PVC IN MEDICINE, PT. 1
by Charlie Cray
The chlorine industry is desperate to avoid a ban on PVC plastic (also known as polyvinyl chloride, or simply "vinyl") but it's going to be an uphill battle.
Many chlorine-containing chemicals are toxic and long-lived and they tend to concentrate as they move up the food chain. Therefore, as the 20th century draws to a close, many high-volume chlorinated chemicals have already been phased out in countries around the world, and many more are under growing pressure:
** Chlorinated pesticides such as DDT, toxaphene, chlordane and heptachlor have been banned in many countries because they are toxic and long-lived and they kill creatures they were never intended to kill.
** CFCs [chlorofluorocarbons] are being phased out by international treaty because they have damaged the Earth's ozone shield;
** PCBs [polychlorinated biphenyls] were banned in many countries 20 years ago because they accumulate in food chains and interfere with the hormones of mammals, causing numerous kinds of subtle damage;
** Many industries are reducing their use of chlorinated solvents as they rediscover soap and water for de-greasing.
The chlorine industry has been able to absorb these phase-outs by creating new markets for chlorine, notably PVC plastic, or vinyl. Nearly one-third of the world's production of chlorine now goes into making PVC and the chlorine industry has big plans for increasing this proportion. PVC is supposed to remain the main "sink" for excess chlorine into the 21st century.
Saving PVC will not be easy. Just this year, many countries have imposed restrictions on soft PVC toys that contain "phthalates" (a class of chemical additives. During 1999, restrictions on PVC toys have been imposed by Austria, Canada, Denmark, Finland, Mexico, Norway, the Philippines, Germany, France, Greece and Sweden.[1]
Realizing that the stigma against PVC toys could spread to other PVC products, the Vinyl Institute initiated a $1 million ad campaign in 1999, highlighting the use of PVC in medicine.[2]
The pro-PVC ads ran on TV, in the WASHINGTON POST, and in ROLL CALL (a newspaper circulated mainly on Capitol Hill in Washington, D.C.). The ads depict a group of doctors and nurses in an operating room, along with PVC equipment such as intravenous (IV) bags, tubing and respiratory equipment. The ad explains that "medical professionals have placed their trust in one material time and time again: vinyl."[3]
Although PVC medical products comprise only 6% of the total North American PVC market, one quarter of all plastic medical products are made of PVC, including most IV bags and tubing.[4] Common PVC medical devices include IV and blood bags, tubing, gloves, catheters, ID bracelets, endotracheal tubes, feeding bags and other equipment.
The Vinyl Institute's ads did little to quiet public concerns about vinyl. Instead, they provoked action by a large and growing coalition of public health advocates -- the Health Care Without Harm campaign.[5]
Health Care Without Harm (HCWH) adapted its name from the Hippocratic Oath -- the ethical creed of the medical profession which obliges doctors and other practitioners to "first, do no harm."
HCWH had previously identified PVC as the major culprit in the generation of dioxin from medical waste incinerators, one of the largest sources of dioxin in the U.S.[6] In 1996, Physicians for Social Responsibility and other HCWH members convinced the American Public Health Association -- the country's largest association of public health professionals -- to call for a phase-out of PVC in medical devices because PVC generates dioxin when burned. Dioxin is a potent immune system poison, causes cancer in humans and other animals, and interferes with the hormone systems of mammals and other creatures.[7]
Similar resolutions seeking a ban on medical uses of PVC have been passed by the Chicago Medical Society, the Minnesota Medical Association, the California Medical Association and the American Nurses Association.[8]
PVC is unique in the polymer world because it requires large quantities of additives to achieve specific qualities. PVC is a relatively rigid and brittle polymer, so flexibility is achieved through the addition of chemical plasticizers. Other polymers can be made more or less flexible through the rearrangement of polymer chains or by mixing different polymers together, thus eliminating the need for plasticizers. Approximately 90% of the plasticizers produced globally end up in flexible PVC products. While there are numerous plasticizers on the market, the largest group, accounting for more than 69% of U.S. consumption, are the phthalate esters. The phthalate most commonly used in the production of PVC medical devices is Di-(2-ethylhexyl) phthalate, also known as DEHP.
Earlier this year, Health Care Without Harm (HCWH) issued a health alert about the leaching of phthalates from IV bags.[9] HCWH also asked the Center for Sustainable Production at the University of Massachusetts Lowell to evaluate the health risks associated with human exposure to DEHP, as well as alternatives to its use.[10]
The toy industry stopped using DEHP in 1986, shortly after the U.S. EPA [Environmental Protection Agency] listed it as a probable human carcinogen.[11]
Independent laboratory tests conducted for Greenpeace in early 1999 found that medical devices contain up to 81% (by weight) DEHP.[12] By law, toys such as teething rings have been limited to less than 3% DEHP, and U.S. FDA [Food and Drug Administration] limits plasticizers in food containers to 30%.[13] However there are no FDA restrictions on DEHP content or releases into the body from PVC medical devices.
DEHP has been found to leach from IV bags, blood bags, tubing (endotracheal and transfusion) and catheters into solutions, blood products, and eventually into the human body.[14] Of greatest concern is exposure to premature infants, hemophiliacs, and dialysis patients, who suffer from compromised immune and metabolic systems, have long term exposure to DEHP, or are exposed at critical junctures in development.
Some drugs -- especially those with fatty components -- accelerate the DEHP leaching process. Taxol (used to treat breast cancer, ovarian cancer, and AIDS-related Kaposi's sarcoma) is one of the drugs with these characteristics.
Taxol's instructions for intravenous administration include this paragraph: "Contact of the undiluted concentrate with plasticized polyvinyl chloride (PVC) equipment or devices used to prepare solutions for infusion is not recommended. In order to minimize patient exposure to the plasticizer DEHP, which may be leached from PVC infusion bags or sets, diluted Taxol solutions should preferably be stored in bottles (glass, polypropylene) or plastic bags (polypropylene, polyolefin) and administered through polyethylene-lined administration sets."[15]
The two IV manufacturers with about 80% of the U.S. market, Abbott Laboratories and Baxter Healthcare, print warnings about the leaching of DEHP into a variety of solutions. The literature that accompanies Baxter's Viaflex container, for instance, advises that "solutions in contact with the plastic container can leach out certain of its chemical components in very small amounts within the expiration period, e.g., di-2-ethylhexyl phthalate (DEHP) up to 5 parts per million."[16] As a 1994 article in the JOURNAL OF INTRAVENOUS NURSING warns, printed instructions are not enough: hospital staff may not be aware that DEHP leaches from PVC IV products, and may not routinely read package literature that directs the use of non-vinyl products.[17]
The Lowell Center's review examined the published literature on animal laboratory studies, in-vitro studies in human and animal cell lines, and available human exposure studies. It found evidence that DEHP or its metabolite MEHP can affect the testes, ovaries, kidneys, liver, circulatory system, pulmonary system and heart.
There is consensus that DEHP causes a wide range of adverse impacts in experimental animals, including cancer, testicular atrophy, and cardiac toxicity. However, the relevance of these results to humans is disputed. No long-term human studies have been conducted. Nevertheless, many animal studies demonstrate health effects from DEHP at exposure levels documented in people who receive many blood transfusions, kidney dialysis patients and high risk newborn babies:
** Hemodialysis patients may be exposed to 10 to 20 times more DEHP than the levels that caused liver damage in rhesus monkeys.[18]
** A hemorrhaging patient may receive more DEHP from PVC blood bags and tubing than the equivalent amount that significantly reduced the heart rate of rats.[19]
** An infant receiving Extracorporeal Membrane Oxygenation (ECMO) therapy with PVC tubing may be exposed to more DEHP than the level that damaged the testes of immature rats.[20]
Given the evidence of adverse effects of DEHP in laboratory animals, evidence of human exposure, limited evidence of health effects in humans, and uncertainty regarding the mechanism by which these effects occur, it is clearly prudent to take a precautionary approach to the health risks posed by DEHP in medical devices.
The precautionary approach is receiving critical attention from the public health community, which is why the PVC-in-medicine issue has galvanized a huge industry backlash. More next week.
PESTICIDES IN THE NEWS
Pesticides continue to produce unpleasant surprises around the world.
** In April, researchers in Switzerland announced that much of the rain falling on Europe contains such high levels of pesticides that rainwater would be illegal if it were supplied as drinking water.[1] Rain over Europe is laced with atrazine, alochlor and other common agricultural poisons sprayed onto crops.
The European Union has set a drinking water standard of 100 nanograms per liter for any individual pesticide. Stephan Muller at the Swiss federal Institute for Environmental Science and Technology in Dubendorf reported finding one sample of rain containing 4000 nanograms per liter of 2,4-dinitrophenol, a common pesticide (not to be confused with the weed killer 2,4-D).
Muller had previously studied samples of rain from 41 storms over Europe and found Atrazine at levels exceeding 100 nanograms per liter in 9 of them. A 1999 study of rainfall in Greece found one or more pesticides in 90% of 205 samples taken. Atrazine was measurable in 30% of the 205 samples.[2]
Atrazine is a weed killer used on 96% of the U.S. corn crop each year. Introduced in 1958, some 68 to 73 million pounds were used in the U.S. in 1995, making it the best-selling pesticide in the nation. Atrazine interferes with the hormone systems of mammals. In female rats, it causes tumors of the mammary glands, uterus, and ovaries. Two studies have suggested that it causes ovarian cancer in humans. EPA [U.S. Environmental Protection Agency] categorizes it as a "possible human carcinogen." Atrazine is found in much of the drinking water in the midwestern U.S., and it is measurable in corn, milk, beef and other foods.
** Last March, well-known Swedish scientists Lennart Hardell and Mikael Eriksson published a case-control study (404 cases and 741 controls) showing once again that non-Hodgkin's lymphoma (NHL) is linked to pesticide exposures. Hardell and Eriksson published their first study linking phenoxy herbicides to non-Hodgkin's lymphoma (NHL) in 1981.[3]
Non-Hodgkin's lymphoma (NHL) is a group of cancers that arise in the white blood cells. NHL is increasing rapidly in the U.S. and elsewhere in the industrialized world.
Between 1973 and 1991, the incidence of non-Hodgkin's lymphoma increased at the rate of 3.3% per year in the U.S., making it the third fastest-growing cancer (after prostate cancer, growing at 3.9% per year, and melanoma of the skin, also growing at 3.9% per year).[4] In Sweden, the incidence of NHL has increased at the rate of 3.6% per year in men and 2.9% per year in women since 1958.
In recent years, AIDS patients have contributed to the increase in NHL, but a steady rise in the incidence of this disease was apparent long before the AIDS epidemic. Together the known "risk factors" for NHL --including immune-suppressing drugs, rare immune-system diseases, and AIDS, explain only a small proportion of NHL cases.
One of the herbicides linked to NHL by the most recent Hardell study is glyphosate, sold by Monsanto under the trade name Roundup. A previous study of human subjects in 1998 had implicated Roundup in hairy cell leukemia (cancer of the blood-forming organs), a rare kind of NHL.[5] Several animal studies have shown that Roundup can cause gene mutations and chromosomal aberrations.[3]
The use of Roundup is expected to increase substantially in the next few years because several of Monsanto's genetically engineered crops (such as potatoes and corn) are "Roundup Ready" which means they have been specifically designed to withstand a thorough dousing by Roundup. The goal is to create crops that are not affected by Roundup so that unusually large quantities of Roundup can be applied to eradicate weeds without harming the crop. Roundup is Monsanto's most profitable product.
** Last month, researchers in the U.S. and Canada announced that they had measured pesticides in the amniotic fluid of 30% of a sample of 9 pregnant women in Los Angeles, California.[4] A baby growing in the womb floats in amniotic fluid for 9 months before birth.
The particular pesticide found in amniotic fluid -- p,p'-DDE -- is a breakdown byproduct of DDT and is known to interfere with male sexual development by de-activating the male sex hormone, testosterone. Until now, pesticides had not been measured in amniotic fluid.
The unpublished study of pesticides in amniotic fluid was reported at the 81st annual meeting of the Endocrine Society in San Diego, California, in June.[6] The researchers released a statement in San Diego saying, "The concentrations of p,p'-DDE found (range of 0.01 to 0.63 nanograms per milliliter [parts per billion]) are sufficient to cause concern, since the levels measured are in the same range as some steroids [hormones] which occur naturally in the fetus at the same time of development." The statement also said, "Of the various health problems associated with these chemicals, developmental abnormalities of the male reproductive tract, suppression of immune function, development of the brain and neurobehavioral problems in children are of major concern because they are potentially avoidable and irreversible."
One of the authors of the study, Siu Chan of the University of Calgary in Canada, told NEW SCIENTIST magazine that researchers cannot be sure that DDE would have any affect on babies exposed continuously in the womb.[7] But Chan pointed out that alligators were harmed by exposure to a similar chemical in Florida after a chemical spill. "In males, the penis was much smaller than normal," Chan said. (See REHW #372.) Several studies of laboratory animals have confirmed that DDE can interfere with normal sexual development of males and can cause enlarged prostate glands.[8,9]
** A study published in May in ENVIRONMENTAL HEALTH PERSPECTIVES, a U.S. government science journal, makes the case that insecticides sprayed on forests in eastern Canada in the mid-1970s led to a dramatic decline in the population of Atlantic Salmon (45% reduction in small salmon, 77% reduction in large salmon).[10] Salmon are born in fresh water but after 2 or 3 years they undergo physical changes called "smoltification," after which they move downstream into salt water. Smoltification is controlled by hormones. Researchers believe the pesticide interfered with the hormones of the salmon, somehow disrupting smoltification, leading to the loss of large numbers of fish.
The pesticide in question was called Matacil 1.8D. The "active ingredient" in Matacil 1.8D is aminocarb, which makes up about 25% of the insecticide by weight. The other 75% of Matacil 1.8D is an "inert ingredient" called 4-nonylphenol (4-NP for short). In laboratory tests, 4-NP is anything but inert. It is a powerful hormone disrupter.
The authors of the study point out that many U.S. streams contain levels of hormone-disrupting chemicals comparable to the levels that they believe wiped out so many Atlantic salmon.
** Consumer's Union, publisher of CONSUMER REPORTS magazine announced last February that many U.S. fruits and vegetables carry pesticide residues that exceed the limits that EPA considers safe for children. "Using U.S. Department of Agriculture statistics based on 27,000 food samples from 1994 to 1997, the magazine looked at foods children are most likely to eat," the NEW YORK TIMES reported.[11] "Almost all the foods tested for pesticide residues were within legal limits, but were frequently well above the levels the Environmental Protection Agency says are safe for young children. According to the Consumer's Union Report, even one serving of some fruits and vegetables can exceed safe daily limits for young children," the TIMES reported.
"Methyl parathion accounts for most of the total toxicity on the foods that were analyzed, particularly peaches, frozen and canned green beans, pears and apples. Late last year [EPA] said that methyl parathion posed an 'unacceptable risk' but that it had not taken any action to ban it or reduce its use. Organophosphates [such as methyl parathion] are neurological poisons and work the same on humans as they do on insects," the TIMES said.
One of the main aims of the CONSUMER REPORTS study was to compare pesticide levels on U.S.-grown foods vs. imported foods. In almost every case imported foods had lower levels of pesticides and/or less toxic pesticides than U.S.-grown foods.
In sum, many of us are being exposed -- without our informed consent -- to industrial poisons starting in the womb, then in our food and water more or less continuously throughout childhood and into adulthood. Wildlife are being continuously exposed as well. Many of these substances interfere with mental and sexual development and can cause learning disorders and violent behavior. (See REHW #529, #551, and #648.) Science has no way of assessing what effects combinations of these poisons will have.
Yet risk assessors working for the poisoners, and their apologists in government, make a good living manipulating mathematical models to "prove" that all of this is acceptably safe. They are the conductors keeping the trains running on time to Auschwitz, just doing their jobs.
But of course the owners of the trains are the industrial poisoners and the political representatives they own.
It boils down to this: we must get private money out of our elections so that we can choose political representatives who are not in the pockets of the poisoners. Until that happens, the poisoning will continue.
WRECKING THE OCEANS
Until recently, the oceans seemed so vast that no one could imagine humans damaging them. Now, however, a decade of scientific research has shown that this view is mistaken. Human activities are degrading the oceans in numerous ways.
** The dominant view among experts is that burning coal and oil, including gasoline, is contributing to a warming trend in the atmosphere and the surface of the planet, including the oceans.
** As a result of global warming, according to the International Council of Scientific Unions and the World Health Organization, we should expect the sea level to rise because melting glaciers and ice caps will increase the amount of water in the oceans and because water expands as it grows warmer.[1] In fact, the average temperature of the oceans has risen about 1.8 degrees Fahrenheit this century and sea level has been rising, though not in a steady progression, since 1920.
** Recent studies reported in SCIENCE magazine indicate that the Pacific Ocean off the California coast is considerably warmer and consequently much less productive than it used to be. For example, the size and number of kelp have declined, in step with rising water temperature.[2] More ominously, during the past 40 years, the production of zooplankton (tiny floating animals) in the California Current has declined 70% as sea surface temperatures have steadily risen.[3]
** The species of animals inhabiting the tidal areas of the central California coast have changed during the past 60 years because of a northward shift in animal life in response to rising water temperatures.[4]
** As species have moved northward and zooplankton production has declined dramatically, the number of pelagic (ocean-dwelling) birds off the California coast has declined 40% since 1987, largely as a result of a 90% decline in the numerically dominant bird species, the sooty shearwater.[5]
** As populations of kelp, zooplankton and birds have declined off the California coast in recent decades, researchers have been documenting a loss of nutrients on the deep ocean floor. Here, in the cold darkness 2 miles or more below the surface, we find fish, snails, worms, slugs, barnacles, corals, crabs, prawns, sponges, sea anemones, brittle stars, sea cucumbers, sea urchins, feather stars and sea lilies in addition to untold numbers of zooplankton, bacteria and other creatures whose existence has never been recorded.
Because people experience the ocean floor at low tide when barren-looking mud flats emerge, we have the idea that the ocean bottom is bare. This is not the case. Tidal mud flats do not support much visible life because waves beat on them constantly, tending to break anything that grows large. But the floors of the ocean -- particularly along the continental shelves -- support abundant life. An estimated 10 million species inhabit the ocean floors, compared to 1.4 million known land dwellers.
Most of the food supply for these deep dwellers is produced in the upper ocean where sunlight is available to drive the basic process of photosynthesis whereby carbon, hydrogen and oxygen are made into carbohydrates, forming the first level of the oceanic food chain. Leftovers from the surface-level food chain, including dead plants and animals and fecal matter, rain down on the ocean floor, providing food for those below.
Now however, these deep-dwelling species are in for trouble, according to a report published in SCIENCE magazine in May.[6] A seven-year study of nutrients raining down from the surface layers has documented a 50% decline in food reaching the deep floor. The culprit seems to be declining productivity in the upper ocean, caused by rising sea temperature. "If the food deficit continues, it is going to change the configuration of the deep-sea communities," says Kenneth L. Smith, Jr., of the Scripps Institution of Oceanography in San Diego, and an author of the recent report in SCIENCE. "Some species will die out while those that can survive on a very low food supply will still be able to maintain themselves," he told the NEW YORK TIMES.[7]
** But there is still more bad news. About 10% of the corals in the world's oceans have already died because their watery home has grown too warm. Many more have become bleached, which is a step toward death for corals. If current conditions and trends persist, an additional 20% to 30% of the world's coral could be lost during the next century, according to James W. Porter, an ocean studies specialist at the University of Georgia.[8] Dr. Porter says "Corals are like the canary in the mine. They are telling us that the water where they live is becoming suboptimal for their existence."
In some parts of the world, the death of corals has reached alarming proportions. In the Seychelles (in the Indian Ocean off the east coast of Africa), 80% of corals have been lost.[9] Along the coast of Indonesia, 90% of corals are reported dead.
Fish do not eat corals, but many fish feed on crabs, clams, and worms that live among the coral, and coral provides protection for much of the swimming life in tropical oceans. So the loss of coral is a serious blow to oceanic ecosystems. "If there are no healthy coral, the fish won't be there," says Thomas F. Goreau, president of the Global Coral Reef Alliance in Chappaqua, New York.[9,10]
Corals are degraded not only by ocean warming, but also by bacteria and viruses released by humans. Since 1996 James W. Porter has observed a four-fold increase in disease at 160 coral sites along the coast of Florida. Almost none of the responsible pathogens (bacteria and viruses) have been seen before. They are "new to science," Dr. Porter says.[8]
** Humans are being affected too. One study found that nearly 25% of those who visit Florida beaches for swimming, windsurfing or boating become sick as a result. Huge colonies of viruses are being released into Florida's coastal waters by 1.6 million septic tanks, according to Joan B. Rose, a University of South Florida researcher. An estimated 20% to 24% of humans who encounter such viruses at the beach develop ear infections, sore eyes and throats, and respiratory or gastrointestinal disease. Some of the viruses detected in coastal water are associated with serious ailments, such as heart disease, meningitis and hepatitis. Viral infections cannot be cured by antibiotics. Most people recover from infections they get while swimming or boating in coastal Florida, but an estimated 1% of those infected remain chronically ill.[8]
Viruses with human origins are also found in shellfish, and not just in Florida. Studies in New York coastal waters have found up to 40% of the shellfish infected. Many of the viruses that can infect humans directly, or through contaminated shellfish, cannot be detected by routine monitoring, Professor Rose says.
** Humans degrade coral reefs in other ways. On May 16 this year the NEW YORK TIMES reported that a shrimp boat ran aground on a coral reef in the Caribbean Sea off the coast of Mexico, destroying 1300 square yards of reef. Mexican officials are reportedly seeking a $1 million fine from the owner of the boat. A cruise liner in 1997 reportedly destroyed 550 square yards of coral reef in the same area.[11] It doesn't take much to break a branch off a coral reef -- an anchor carelessly deployed from a pleasure boat can do it, or even a kick by a human diving or snorkeling.
Then of course there is modern fishing. The world's fishing fleet has doubled since 1970. New fishing gear (global positioning system [GPS] receivers, fish finders, and new kinds of trawls and nets) have made it possible to sweep the oceans like a vacuum cleaner, sucking up nearly everything that lives. A recent report from the Marine Conservation Biology Institute in Redmond, Washington, says modern fishing is comparable to forest clearcutting -- except that the wreckage caused by modern "factory trawlers" is hidden from view.[12] As a result of new fishing technologies, 13 of the world's 17 major fisheries are depleted or in steep decline. For fish and for fishing, the future looks grim.
In sum, until governments take "sustainability" seriously and assert control over private corporations, the oceans seem likely to continue to deteriorate.
--Peter Montague
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