NEXT PAGE -->
|
Updated Daily!
| * * * IN-HOUSE RESOURCES * * * |
|---|
August 26, 1999
CAUSE FOR PRECAUTIONARY ACTION
After four years of study, the National Research Council (NRC) of the National Academy of Sciences on August 4 published its report on hormone-disrupting chemicals in the environment.[1] The report represents a consensus statement by the NRC's Committee on Hormonally Active Agents in the Environment, a committee made up of 16 scientists,[2] including some who are closely aligned with the chemical industry. v The Committee had been asked by Congress and by U.S. Environmental Protection Agency (EPA) to evaluate the hazards posed by hormone-disrupting chemicals in the environment. Dozens, perhaps hundreds, of common industrial chemicals are known to interfere with hormones under some conditions, so the stakes are high.
Hormones are naturally-occurring chemicals that circulate at very low levels in the blood stream of all vertebrate animals including reptiles, amphibians, fish, birds and mammals. (Vertebrates are animals with a backbone.) In all vertebrate species, hormones act as chemical messengers and as switches, turning on and off bodily systems that control growth, development, learning and behavior. Hormones start affecting every animal shortly after it begins life as a fertilized egg. Hormones control growth and development prior to birth or hatching, and hormones continue to influence behavior throughout life. Hormones tell bears when to hibernate, tell salmon when to return to their spawning grounds, and cause women to menstruate every 28 days or so. Hormones profoundly affect the nervous system, the reproductive system, and the immune system. Naturally-occurring hormones are also implicated in some forms of cancer, such as female breast cancer which is widely believed to be linked to a woman's lifetime exposure to estradiol (estrogen), the main female sex hormone.[1,pg.197]
Because of the importance of hormones in the life of all vertebrates, industrial chemicals that can interfere with hormones are exceedingly important from a public health perspective. They also represent major embarrassments and liabilities for the corporations that put such chemicals into common use without adequate safety tests. The presence of synthetic [human-created] hormone-disrupting chemicals in air, water, sediments, soil and food also represents a major failure of the U.S. Public Health Service and the U.S. Environmental Protection Agency.
Furthermore, if hormone-disrupting chemicals in the environment are identified as an important problem, then someone may be held responsible (at least in the court of public opinion) and confidence in government and in the chemical industry may drop below their present subterranean levels. Therefore, there is powerful pressure from many parts of "the Establishment" to deny the existence of this problem. NEW YORK TIMES writer Gina Kolata has distinguished herself as the main spokesperson for the deniers.[3]
Despite the highly-charged nature of the subject, and despite the presence of chemical industry representatives on the committee, the NRC's consensus report is rather strong, as indicated by these verbatim quotations:
"Adverse reproductive and developmental effects have been observed in human populations, wildlife, and laboratory animals as a consequence of exposure to HAAs [hormonally active agents]."[1,pg.3]
"Most notable are the adverse reproductive and developmental effects that have been observed in birds such as cormorants, herrings gulls, Caspian terns, and bald eagles that feed on contaminated fish, which have led to drastically lowered reproductive success and population declines."[1,pg.9]
"Laboratory studies using male and female rats, mice, and guinea pigs, and female rhesus monkeys have shown that exposure of these animals during development to a variety of concentrations of certain HAAs (e.g., DDT, methoxychlor, PCBs, dioxin, bisphenol A, octylphenol, butyl benzyl phthalate (BBP), dibutyl phthalate (DBP), chlordecone, and vinclozolin) can produce structural and functional abnormalities of the reproductive tract."[1,pg.3]
"There is evidence of suppression of the immune system by exposure to organochlorines (predominantly PCBs) in birds in the Great Lakes region. There is also evidence of suppression of innate and acquired immune responses in seals fed fish from the PCB-contaminated Baltic Sea. Such immunosuppression is believed to be the reason for the increased incidences of bacterial and viral infections in seals in similarly contaminated waters."[1,pg.5]
"Environmental HAAs [hormonally active agents] probably have contributed to declines in some wildlife populations, including fish and birds of the Great Lakes and juvenile alligators of Lake Apopka [in Florida], and possibly to diseases and deformities in mink in the United States, river otters in Europe, and marine mammals in European waters."[1,pg.6]
"Synthetic HAAs [i.e., HAAs released by chemical corporations] have been detected in all environmental media [air, water, sediments, and soil], although concentrations of some compounds, such as PCBs and DDT, have declined in some regions, because their use has been discontinued in those countries. However, those HAAs and others can persist in some media, such as sediments, for years and can contaminate areas far removed from the original site of contamination (e.g., via atmospheric transport)."[1,pg.7]
"Human dietary intake of synthetic HAAs remains substantial, even intake of HAAs that have not been used commercially for many years. For example, a recent survey of the U.S. diet found detectable residues of DDT in 16% of the food samples. Human exposure is further demonstrated by concentrations of DDT in the adipose (fatty) tissue. Over 95% of adipose tissue samples taken from the U.S. population contained detectable concentrations of some HAA. Although the concentrations were found to be greatest in older individuals, even children were not immune from exposure."[1,pg.76]
"Concentrations of HAAs and other xenobiotics [chemicals foreign to the body] have been measured in milk from humans around the globe."[1,pg.82]
"In the Michigan/Maternal Infant Cohort Study, Fein et al. (1984) evaluated the birth size and gestational age of 242 infants and found that maternal consumption of fish and concentrations of PCBs in cord serum [in blood in the umbilical cord] were correlated with lowered birth weight, shortened gestation [time in the womb], and smaller head circumference. Lower weight was also observed in children from this cohort at 4 yr [years] in a dose-dependent fashion (Jacobson et al. 1990). Children with cord serum PCB levels of 5.0 ng/mL [nanograms per milliliter] or more weighed 1.8 kg [4 pounds] less on average than the lowest exposed children. Prenatal exposure was also associated with deficits in neurologic development in followup studies of these children at up to 11 yr [years]."[1,pg.125]
"Elevated levels of the herbicide atrazine found in municipal water supplies in Iowa were associated with excess rates of cardiovascular, urogenital, and limb-reduction deficits [birth defects]."[1,pg.130]
"Studies with laboratory animals have shown that prenatal exposure to some HAAs, such as methoxychlor, TCDD [dioxin], and octylphenol and bisphenol A can reduce sperm production."[1,pg.131] v "A neurologic assessment of an aging population of Great Lakes fisheaters is currently being conducted by Schantz et al. (1996). In all, 104 fisheaters and 84 nonfisheaters, age 50 or older, were enrolled in the study.... the fisheaters performed more poorly on tests requiring cognitive flexibility, word naming, auditory recall, and more complex motor task [sic] compared with individuals who do not eat fish."[1,pg.173]
"Long-term epidemiologic studies of cognitive and neurobehavioral development have been conducted in Michigan, New York, North Carolina, and the Netherlands on children exposed pre- and postnatally to PCBs from maternal consumption of contaminated fish or other food products. Studies of cognitive development (i.e., short-term memory, visual discrimination, and IQ scores) in Michigan show consistent correlations between prenatal exposure to PCBs and deficits at up to 11 yr [years]. Similarly, in the Netherlands, lower cognitive scores were associated with prenatal exposure when tested in 3.5-yr-old children."[1,pg.174]
"Taken together, the results of animal and human studies indicate that prenatal exposure to PCBs can affect neurologic development."[1,pg.175]
"It has been well documented that HAHs [halogenated aromatic hydrocarbons] such as TCDD [dioxin], polychlorinated dibenzofurans (PCDFs), and PCBs, affect immune response, and they appear to affect all functional arms of the immune system (innate immunity and host resistance, cell-mediated immunity, and humoral immunity)."[1,pg.178]
"There have only been a few studies of the effects of HAAs [hormonally active agents] in humans, but the results of laboratory and wildlife studies suggest that HAAs have the potential to affect human immune functions."[1,pg.194]
The NRC report concludes that, at present, the 70,000 industrial chemicals already in use cannot be tested to see if they are hormone-disrupters or not, because the necessary tests do not exist.[1,pg.414] Meanwhile between 1000 and 2000 new chemicals are being put into commercial use each year, inadequately tested.
Therefore, adequate knowledge of hormone-disrupting chemicals lies many decades in the future, a kind of scientific holy grail. What is not known about hormone-disrupting chemicals is considerably larger than what is known and will remain so for a long time to come.
Yet the NRC report has amply documented, from studies of wildlife, laboratory animals, and humans, that many industrial chemicals, at levels already present in the environment, are currently interfering with hormones, causing problems in reproduction and development, the nervous system (including diminished IQ and learning ability), and the immune system (which protects us all from bacteria, viruses and cancers). Harm is happening now.
Thus hormone-disrupting chemicals meet the two tests established by the precautionary principle: scientific uncertainty, and a reasonable suspicion of harm. (See REHW #657.)
Therefore, while scientific study continues, decision-makers have a duty to take precautionary action to prevent further harm even though scientific certainty has not been established. As a signatory to the Rio Declaration of 1992, the U.S. is legally obligated to take precautionary action. But of course our government will not act spontaneously merely to comply with the law or do the right thing. To put it bluntly, our government will only respond if popular pressure is sufficient to offset inertia, the forces of denial, and election-time bribery from the chemical industry. Building that pressure is up to us.
--Peter Montague
August 19, 1999
THE CARBON PUSHERS
Four years ago the Intergovernmental Panel on Climate Change (IPCC) concluded that humans are at least partly responsible for global warming: "The balance of evidence suggests a discernible human influence on global climate," IPCC said.[1] IPCC is an international group of 2500 meteorologists gathered under the auspices of the United Nations, trying to figure out why the Earth is warming up and what it might mean for human civilization.
The mechanism of warming is called the "greenhouse effect." Sunlight streams in from outer space, strikes the surface of the planet, turns to heat and then is radiated back out toward outer space. But some of the heat cannot escape because it is reflected back to Earth by "greenhouse gases" in the atmosphere. These "greenhouse gases" (water vapor, carbon dioxide and methane) allow sunlight to pass through but they block heat, thus acting like the glass roof on a greenhouse, producing warmth within.
The greenhouse effect is natural -- without it the Earth would be a frozen rock spinning through space. But over the past few hundred years, humans have contributed substantially to an increase in greenhouse gases. Burning coal, oil and natural gas (so-called fossil fuels), plus deforestation, have increased the atmospheric content of carbon dioxide by 31% (from 275 parts per million [ppm] to 360 ppm) during the past few hundred years, a trend that continues today. Fossil fuel combustion and deforestation now add about 7.7 billion tons (7 billion metric tonnes) of carbon dioxide to the atmosphere each year. Other human activities have increased the methane content of the atmosphere -- growing cattle, growing rice, and landfilling garbage.
Since 1995, much new evidence has come to light indicating that the Earth is indeed warming and that human activities are at least partly responsible. A recent summary article by Bette Hileman in CHEMICAL & ENGINEERING NEWS, voice of the American Chemical Society, describes some of the new evidence indicating that the planet is warming at an accelerating pace:
** The Earth's average temperature has been rising for at least 100 years, but in recent decades the rate of increase has speeded up. Eleven of the past 16 years have been the hottest of the century. The average global temperature in 1998 was higher than it had been at any other time during the previous 1000 years.
** The polar regions of the planet are heating up much more rapidly than the average. Alaska is now as much as 10 degrees Fahrenheit (F.) (6 degrees Celsius [C.]) warmer than it was 35 years ago. As the frozen north warms and thaws, peat buried in the tundra decays, releasing carbon dioxide. This is a positive feedback mechanism that could speed up the rate of increase of greenhouse gases in the atmosphere -- the warmer the tundra becomes, the more carbon dioxide it releases, in turn warming the tundra further. According to Walter C. Oechel, director of the Global Change Research Group at San Diego State University (California), the arctic tundra has been a sink (or storage place) for carbon for the last 9000 years, but since 1982 its role has reversed and now it has become a source of carbon to the atmosphere.
Some far-northern (boreal) forests also seem to be shifting their role from that of a carbon sink to a carbon source for the atmosphere as warmer temperatures thaw frozen soils.[2] Whether the entire boreal forest belt, which encircles the Earth, has become a net source of carbon remains unknown.
Bette Hileman does not say so, but the warming arctic tundra will likely also release methane gas which, pound for pound, is about 20 times as powerful as carbon dioxide at creating a greenhouse effect.[3] The quantity of carbon locked in arctic soils is huge and the positive feedback loop that has begun to release it to the atmosphere is ominous.
** Average summertime temperatures in Antarctica have risen 4.5 degrees F. (2.5 degrees C.) since the 1940s. According to members of the British Antarctic Survey, ice shelves along the coast of the Antarctic Peninsula have been breaking up for 50 years, having lost 7000 square kilometers (2703 square miles) during that time. The loss of 3000 square kilometers (1158 square miles) within just the last year indicates that the breakup of ice shelves has accelerated.
The Greenland Ice Sheet, the world's second largest glacier, is growing thinner at the rate of a meter (39 inches) per year. However, snowfall may be increasing in polar regions, so no one is yet sure whether the overall amount of ice at the poles is changing.
** The bleaching and loss of corals in the world's warm oceans (Indo-Pacific, western Atlantic, and Caribbean) provide further evidence of accelerated global warming. Corals are showing signs of stress in areas of human habitation and in uninhabited regions. In uninhabited regions, the main causes are likely to be increased ultraviolet light penetrating through the Earth's damaged ozone shield, and global warming. Coral bleaching occurs when water temperatures rise, and coral bleaching has been increasing worldwide since the 1970s as Earth's temperature has risen most steeply.
Furthermore, recent work shows that, as the carbon dioxide content of the atmosphere increases, so does the carbon dioxide content of ocean water. This in turn lowers the concentration of carbonate ion, reducing the ability of corals to build their skeletons.[4] The future for coral reefs looks grim.
Coral reefs are economically important -- they provide food, coastal protection, and new medications for drug-resistant diseases. And they attract tourists by the millions: Caribbean countries derive half their income from coral reefs. The coral reefs of southeast Asia provide homes for one-quarter of the world's fish species.
** Annual precipitation over the continental U.S. has increased about 10% during this century, much of it during the winter, and much of it in heavy events. For example, the number of days with rainfall exceeding 2 inches has increased about 10% during the past century. Similar trends are observable in Canada, Japan, Russia, China, and Australia.
Other consequences of global warming include:
** Moisture in the lower atmosphere has increased about 10% during the past 20 years.
** The annual number of intense storms over the North Atlantic and the North Pacific has doubled since 1900.
** There have been more, and longer-lasting, El Nino events since the 1970s. El Nino is a huge but localized warming in the eastern Pacific Ocean that gives rise to violent storms along the U.S. Pacific coast, devastating droughts in Africa and Australia, and often a failure of the monsoon rains in Asia.
** New computer models have been able to mimic past climate changes, and they predict future warming of the atmosphere. Skeptics used to say that computer models had done such a poor job of mimicking past events that their predictive ability must also be flawed. That argument has been put to rest by better models that track past events properly and which now predict an average global temperature rise somewhere between 1.2 degrees C. (2.2 degrees F.) and 4 degrees C. (7.2 degrees F.) in the next century. Even a 1 degree C. (1.8 deg. F.) average temperature rise could have important consequences because of exaggerated effects already evident at the poles, though not all scientists agree with this assessment.
** Rather than diminish production of carbon dioxide, the U.S. government favors a technical fix: U.S. global warming policy relies on the ability of forests and agricultural soils to sop up excess carbon dioxide from the atmosphere. A 1998 paper by U.S. government scientists seemed to show that North American forests and soils were absorbing all of the carbon dioxide being emitted by the burning of fossil fuels in North America.[5] Based on that study, the U.S. demanded that forests-as-carbon -sinks be written into the Kyoto Treaty, an international agreement intended to slow the production of greenhouse gases. (See REHW #577.) At the meeting in Kyoto (Japan), the European Union remained skeptical of the U.S. approach, but the U.S. threatened to walk out if its approach was rejected. Now, according to Bette Hileman, two additional studies -- one from France and the other from Australia -- have challenged the findings of the original U.S. study, but these new studies remain unpublished and therefore outside the debate.
This issue of forests as "sinks" for excess carbon has paralyzed Kyoto Treaty negotiations since the Kyoto meeting because the issue is not fully resolvable with present-day science and the U.S. continues to insist that its viewpoint is defensible. Paralysis suits many U.S. leaders just fine -- key members of Congress have indicated that the Kyoto Treaty will be ratified over their dead bodies because they say the Kyoto Treaty will harm the U.S. economy. But what if global warming will harm the economy for our children in the future? Let the unborn speak now or forever hold their peace.
Independent U.S. scientists who have examined the ability of forests to absorb carbon dioxide are not optimistic that the U.S. "sinks" plan has much merit. Under ideal conditions, forests may be able to absorb as much as 50% of excess carbon dioxide from the atmosphere, but to achieve that level of absorption would require all trees to be young and all trees to be as responsive to carbon dioxide as the most responsive, the loblolly pine. And of course when the trees die, they will release the excess carbon back into the ecosystem. To prevent global warming, trees would have to keep excess carbon out of the atmosphere forever.
Cleaner sources of energy are already available and affordable. Adopting them in the U.S. alone would create 770,000 jobs, save $530 per household per year, and significantly reduce the threat of global warming.[6] Why can't we make the shift? A recent report from the Natural Resources Defense Council (NRDC), U.S. Public Interest Research Group, and the Union of Concerned Scientists points out that 80% of greenhouse gases are produced by only 122 corporations,[7] which act as "carbon pushers" comparable to drug pushers. The authors of the report do not express it quite this way, but the conclusion is obvious: these 122 corporations are jeopardizing the integrity of the entire global ecosystem, endangering the future for all children, and holding the world's people and their governments hostage by a combination of bribery and brute force. A simple question: Why do we allow such antisocial -- even sociopathic -- behavior to go unrewarded by prison sentences for culpable executives and boards of directors? Please give it some thought.
--Peter Montague
NEXT PAGE -->
|
| * * * IN-HOUSE RESOURCES * * * |
|---|