In the United States, industry is the greatest source of pollution, accounting for more than half the volume of all water pollution and for the most deadly pollutants. Some 370,000 manufacturing facilities use huge quantities of freshwater to carry away wastes of many kinds. The waste-bearing water, or effluent, is discharged into streams, lakes, or oceans, which in turn disperse the polluting substances. In its National Water Quality Inventory, reported to Congress in 1996, the U.S. Environmental Protection Agency concluded that approximately 40% of the nation's surveyed lakes, rivers, and estuaries were too polluted for such basic uses as drinking supply, fishing, and swimming. The pollutants include grit, asbestos, phosphates and nitrates, mercury, lead, caustic soda and other sodium compounds, sulfur and sulfuric acid, oils, and petrochemicals.
In addition, numerous manufacturing plants pour off undiluted corrosives, poisons, and other noxious byproducts. The construction industry discharges slurries of gypsum, cement, abrasives, metals, and poisonous solvents. Another pervasive group of contaminants entering food chains is the polychlorinated biphenyl (PCB) compounds, components of lubricants, plastic wrappers, and adhesives. In yet another instance of pollution, hot water discharged by factories and power plants causes so-called thermal pollution by increasing water temperatures. Such increases change the level of oxygen dissolved in a body of water, thereby disrupting the water's ecological balance, killing off some plant and animal species while encouraging the overgrowth of others.
Other Sources of Water Pollution
Towns and municipalities are also major sources of water pollution. In many public water systems, pollution exceeds safe levels. One reason for this is that much groundwater has been contaminated by wastes pumped underground for disposal or by seepage from surface water. When contamination reaches underground water tables, it is difficult to correct and spreads over wide areas. In addition, many U.S. communities discharge untreated or only partially treated sewage into the waterways, threatening the health of their own and neighboring populations.
Along with domestic wastes, sewage carries industrial contaminants and a growing tonnage of paper and plastic refuse. Although thorough sewage treatment would destroy most disease-causing bacteria, the problem of the spread of viruses and viral illness remains. Additionally, most sewage treatment does not remove phosphorus compounds, contributed principally by detergents, which cause eutrophication of lakes and ponds. Excreted drugs and household chemicals also are not removed by present municipal treatment facilities, and can be recycled into the drinking water supply.
Rain drainage is another major polluting agent because it carries such substances as highway debris ( including oil and chemicals from automobile exhausts ), sediments from highway and building construction, and acids and radioactive wastes from mining operations into freshwater systems as well as into the ocean. Also transported by rain runoff and by irrigation return-flow are animal wastes from farms and feedlots, a widespread source of pollutants impairing rivers and streams, groundwater, and even some coastal waters. Antibiotics, hormones, and other chemicals used to raise livestock are components of such animal wastes. Pesticide and fertilizer residues from farms also contribute to water pollution via rain drainage.
Large and small craft significantly pollute both inland and coastal waters by dumping their untreated sewage. Oil spilled accidentally or flushed from tankers and offshore rigs ( 900,000 metric tons annually ) sullies beaches and smothers bird, fish, and plant life. In 1989 in one of the world's worst single instances of water pollution, the Exxon Valdez spilled 11 million gallons of oil in Prince William Sound, Alaska, causing great environmental destruction. In 1997, the 22 oil spills reported worldwide involved a total of 15 million gallons of oil. In addition to its direct damage to wildlife, oil takes up fat-soluble poisons like DDT, allowing them to be concentrated in organisms that ingest the oil-contaminated water; thus such poisons enter the food chains leading to sea mammals and people.
Both DDT, which has been banned in the United States since 1972, and PCBs are manufactured in many parts of the world and are now widespread in the Atlantic and Pacific oceans. In addition, tarry oil residues are encountered throughout the Atlantic, as are Styrofoam and other plastic rubbish. Plastic bits litter sections of the Pacific as far north as Amchitka Island near Alaska. Garbage, solid industrial wastes, and sludge formed in sewage treatment, all commonly dumped into oceans, are other marine pollutants found worldwide, especially along coastal areas.
Sewerage is the system for the removal and disposal of chiefly liquid wastes and of rainwater, which are collectively called sewage. The average person in the industrialized world produces between 60 and 140 gallons of sewage per day.
Types of Sewage Disposal Systems
Domestic sewage, produced in urban residences, institutions, and businesses, is usually collected by pipes and conduits called sanitary sewers, which lead to a central discharge point. In rural residences domestic sewage is often collected in a septic tank on the property. Industrial wastes, which consist of liquids produced in manufacturing processes, are sometimes collected in sanitary sewers, but the nature of many industrial wastes may make it dangerous or difficult to do so. Often industries dispose of their own wastes. Storm sewage, which comes from rain and groundwater, is collected either in a storm sewer or, with domestic sewage and industrial wastes, in what is called a combined sewer.
Sewer pipe must be strong enough to withstand the structural stresses to which it is subjected by being buried in the ground. In addition, the pipe itself and the joints between sections of pipe must be capable of withstanding at least moderate water pressure without significant leakage of sewage into the environment. Materials used for sewer pipe include plastics, vitrified clay, cast iron and steel, corrugated iron, concrete, and asbestos cement. Although usually circular, pipes are also made egg-shaped or semi-elliptical so that suspended solids do not accumulate even at a relatively low rate of flow, about 2 ft (.6 m) per second. Sewer pipes are usually inclined downward toward the central collection point so that sewage will flow to it naturally, although pumping stations may be required.
Sewage is eventually discharged into underground or surface watercourses that naturally drain an area. In past centuries, the dilution produced by discharging sewage into large bodies of water was considered sufficient to render harmless any toxic substances contained in it. However, the volume of sewage is now so great that dilution is no longer considered an adequate safeguard.
The biochemical processes that take place in water bodies have also been relied on to neutralize sewage. Aerobic, or oxygen-requiring, bacteria feed on the organic material in sewage, decomposing it. However, this process uses the oxygen that is dissolved in water. Often the concentration of organic waste is so great that the biochemical oxygen demand (BOD) depletes the water's oxygen supply, killing fish and plants. In order to avoid these problems, it is now recognized that all sewage except unmixed storm sewage must be treated before it is discharged.
Sewage treatment is classified as primary, secondary, or tertiary, depending on the degree to which the effluent is purified. Primary treatment is removal of floating and suspended solids. Secondary treatment uses biological methods such as digestion. Complete, or tertiary, treatment removes all but a negligible portion of bacterial and organic matter. Industrial wastes are treated by a number of methods, depending on the specific nature of the waste. Increasingly, governments are forcing industries to process effluents either chemically or mechanically, or both ways, so that harmful substances are removed.
Domestic sewage must be treated to produce discharge water that is free of odors, suspended solids, and objectionable bacteria. ( Coliform bacteria, which inhabit the lower intestines of mammals, while not pathogenic of themselves, are taken as an index of contamination of watercourses. ) In rural areas, sewage can be stored in a holding tank, e.g., a septic tank; naturally occurring anaerobic bacteria can decompose the solids, which then settle to the bottom. While suitable for small systems, this method has several disadvantages. First, anaerobic decomposition produces noxious gaseous effluents, and it is fairly slow. Second, harmful bacteria may still be present in the liquid effluent.
In large urban systems, a combination of processes must be used. Decomposition can be speeded by forcing air through the mass so that aerobic bacteria can be used. This oxidation process is typically combined with filtration, either in sand or in granular activated carbon, and with several hours of aeration. The liquid can then be discharged, often after being disinfected with chlorine. Another method of removing solids is to allow the liquid to stand in large tanks until the solids fall out and form a sediment, but the process is slow and requires the accumulation of large volumes of liquid.
Once solids are removed, they are treated in one of several ways. Most often they are removed in a semi-liquid mass referred to as sludge. Sludge may be transferred to tanks where it is digested by aerobic or anaerobic bacteria. Gaseous byproducts of this digestion are collected for use as fuels. After digestion, solids may be dried and enriched with plant nutrients for use as fertilizer. In other cases, with or without digestion, they may be dried and incinerated at 1200 to 1400°F. In other cases solids are buried in landfills or dumped far at sea, although environmental objections to such dumping has led to its drastic curtailment.
Historical Sewage Systems
One of the earliest known sewers was the Cloaca Maxima in Rome, built ( circa 6th century B.C. ) to drain the site of the Forum. Although London's drainage system dates from the 13th cent., the discharge of offensive waste into it was illegal until 1815. The Parisian sewers were constructed before the 16th cent., but by 1893 fewer than 5% of the city's houses were connected to the system. As early as 1701, Boston had drains. Generally, however, systematic sewage disposal was not widely introduced until the mid-19th century.
Toxic waste is waste material, often in chemical form, that can cause death or injury to living creatures. It usually is the product of industry or commerce, but comes also from residential use, agriculture, the military, medical facilities, radioactive sources, and light industry, such as dry cleaning establishments. The term is often used interchangeably with "hazardous waste, " or discarded material that can pose a long-term risk to health or environment. Toxins can be released into air, water, or land.
In 1976 the Toxic Substances Control Act required the Environmental Protection Agency to regulate potentially hazardous industrial chemicals, including halogenated fluorocarbons, dioxin, asbestos, polychlorinated biphenyls (PCBs), and vinyl chloride. Other federal legislation pertaining to hazardous wastes includes the Atomic Energy Act (1954), the Resource Conservation and Recovery Act (1976), and the Comprehensive Environmental Response, Compensation, and Liability Act, or Superfund Act (1986).
Toxic waste treatment and control has proved to be expensive and time-consuming with more resources spent on court battles than on actual cleanup. The disposal of toxic wastes is also a topic of international concern. In 1989, some 50 countries signed a treaty aimed at regulating the international shipment of toxic wastes. In some cases such wastes are shipped to developing countries for cheap disposal without the informed consent of their governments. The often substandard shipping, storage, and treatment methods endanger human health and the health of the environment.
Polychlorinated biphenyl, or PCB, is the name for any of a group of organic compounds originally widely used in industrial processes but later found to be dangerous environmental pollutants. Polychlorinated biphenyl is a fat-soluble, water-insoluble hydrocarbon containing chlorine. It is extremely stable, withstanding temperatures of up to 1,600°F, is fire-resistant, and has been used as a heat-transfer and insulating fluid in cooling systems and electrical equipment; it has also been used in sealants, rubber, paints, plastics, printing ink, and insecticides.
Exposure to mixtures of these compounds can cause health problems, such as skin rashes and severe acne. Also harmful effects to the nervous, immune, and reproductive systems have been reported, along with hepatotoxicity, endocrine and developmental effects, and even a probable source of carcinogens to the human body.
PCBs have entered the environment largely as a pollutant from equipment leaks, the weathering of many materials that contain PCB, and through interaction with food products. PCBs are not readily biodegradable. Production has been banned in several industrialized countries; the United States stopped producing PCBs in 1977.
PCB Contamination in the New York Bight
According to the EPA, between 1947 and 1977 General Electric discharged an estimated 1.3 million pounds of polychlorinated biphenyls (PCBs) into the Hudson River from electric transformer manufacturing plants at Hudson Falls and Fort Edward. Approximately 200,000 pounds of PCBs still remain concentrated in the 40-mile stretch of the upper Hudson, and continue to migrate downriver, distributing throughout the basin, down to the tidal estuary at the mouth of the river.
Study finds little risk from PCBs
By John H. Cushman, Jr.
Copyright 1999 New York Times
March 10, 1999
WASHINGTON -- the largest ever study of occupational exposure to toxic PCB chemicals has found no significant increase in cancer deaths among workers who were exposed on the job. The study was financed by the General Electric Co., which faces potential liabilities of hundreds of millions of dollars for cleaning up waters that are contaminated by PCBs. It is being published on Wednesday in the Journal of Occupational and Environmental Medicine, a peer-reviewed journal.
The chemicals are complex mixtures that were widely used by industry as insulation in electrical capacitors and transformers from the 1930s to 1977, when their production was banned because of a suspected link to cancer. PCBs persist for decades in the environment, and can be taken up by fish and other organisms. They are also suspected of causing other health problems. Even though the exposed workers in this study had high levels of the chemicals in their blood, their rate of cancer deaths was not high. Previous studies had found extra cancer deaths after PCB exposure. ( the study did not address non-cancer problems associated with PCBs. ) "This is the largest cohort of male and female workers exposed to PCBs, " the study says. "The lack of any significant elevations in the site-specific cancer mortality of the production workers adds important information about human health effects of PCBs."
The science of assessing the risks of PCBs and other toxic chemicals is among the trickiest tasks for regulators. This was not the first time that the cancer risks of PCBs, the focus of intense regulatory review over the years, have been played down by scientific studies. The Environmental Protection Agency has previously reduced the factors it uses to estimate PCB cancer risks. The study focused on more than 7,000 men and women who worked from 1946 to 1976 in two General Electric factories in upstate New York, following their medical histories for an average of 31 years and comparing the causes of death of the 1,195 who have died to national and regional averages. The study found that 353 workers died of cancer, while 400 people would be expected to die of cancer in a statistically similar sample.
The study's lead author was Dr. Renate Kimbrough, of the Institute for Evaluating Health Risks, a Washington-based nonprofit research organization. "The findings of this study are consistent with a belief that cancer risks from exposure to PCBs have been overstated, " said Dr. John A. Moore, president of the institute. He is a former official of the EPA and the National Institutes of Health. General Electric has fought a vigorous campaign to prevent the federal government from requiring it to dredge sediments in waters contaminated by PCBs. It has frequently cited scientific studies that it says show no link between exposure to the chemicals and cancer in humans.
Dioxins & Furans
Dioxin is one of the most toxic and environmentally stable tricyclic aromatic compounds of its structural class. Due to its very low water solubility, most of the dioxin occurring in water will adhere to sediments and suspended silts. Similarly, it tends to adhere to soil if released to land, and is not likely to leach to ground water. Two processes which may be able to remove dioxin from water and soil are evaporation and breakdown by sunlight. Dioxin is generally resistant to microbial breakdown.
Dioxin is released to the environment in emissions from the incineration of municipal refuse and certain chemical wastes, in exhaust from automobiles powered by leaded gasoline, in emissions from wood burning in the presence of chlorine, in accidental fires involving transformers containing PCBs and chlorinated benzenes, and from the improper disposal of certain chlorinated chemical wastes. It has been released to the environment as a low level impurity in various pesticides.
Dioxin has a very great tendency to accumulate in aquatic life, from algae to fish. Dioxin is formed as a by-product of the manufacture, molding, or burning of organic chemicals and plastics that contain chlorine. It made headlines several years ago at places such as Love Canal, where hundreds of families needed to abandon their homes due to dioxin contamination, and Times Beach, Missouri, a town that was abandoned as a result of dioxin.
Furan is a viscous, colorless liquid that has a pleasant aromatic odor; upon exposure to air it turns dark brown or black. It boils at about 160°C. It is commonly used as a solvent; it is soluble in ethanol and ether and somewhat soluble in water. It is prepared commercially by dehydration of pentose sugars obtained from cornstalks and corncobs, husks of oat and peanut, and other waste products. It is used in the manufacture of pesticides, phenolfurfural resins, and tetrahydrofuran. Tetrahydrofuran is used as a commercial solvent and is converted in starting materials for the preparation of nylon.
EPA's Never-Ending Dioxin Scare
Thursday, July 13, 2006
By Steven Milloy
If ever there was an example of what's wrong with the intersection of government and science, the Environmental Protection Agency's 20-year campaign to scare the public about dioxin is certainly a leading candidate.
The EPA slammed into a bureaucratic wall this week when a National Academy of Sciences panel told the agency to take its dioxin report back to the drawing board. But the NAs' rejection of the EPA report was handled with kid gloves -- permitting the agency to save face by allowing the dioxin scare to continue indefinitely. "EPA assessment of dioxin understates uncertainty about health risks and may overstate human cancer risk, " was the headline of the NAs' media release announcing (and summarizing) its review of the EPA's latest dioxin scaremongering.
The NAS said the evidence that dioxin caused cancer in humans was "not strong" and that risk estimates had to be imagined through use of mathematical models. Despite the acknowledged absence of evidence linking dioxin with cancer in humans, the NAS panel bizarrely agreed that dioxin was "likely to be carcinogenic to humans." It's the sort of 2-plus-2-equals-five conclusion that only connoisseurs of regulatory bureaucracy can fully appreciate.
The EPA issued in 2003 a draft report on dioxin alleging that the substance was 10 times more carcinogenic than the agency previously claimed -- and some dioxin hysterics had already been calling it the "most toxic manmade chemical" for which there was "no safe exposure." these claims were obviously not true since we are all unavoidably exposed to dioxin everyday -- it's in our air, food, and water -- from natural and manmade sources without any health effects having been credibly detected despite decades and billions of dollars of scientific research. The only known health effect from dioxin -- a severe acne-like skin condition called chloracne -- is caused by unusually high exposures, such as from an industrial accident or intentional poisoning.
To debunk the dioxin scare, JunkScience.com had a sample of Ben & Jerry's ice cream tested in 1999 for dioxin -- Ben & Jerry's had claimed in one of its "green" marketing campaigns that there was no safe exposure to dioxin. We found that a single serving of the Ben & Jerry's "World's Best Vanilla" contained 200 times the level of dioxin that the EPA said was safe. Our findings -- published in the proceedings of the 20th International Symposium on Halogenated Environmental Organic Pollutants -- jumped up to 2,000 times the EPA's "safe" level using the agency's risk estimates advocated in its 2003 dioxin report.
Despite the commonsense nature of the evidence indicating that dioxin doesn't constitute a public health threat, the EPA has opted to press ahead with the dioxin scare. It's not a surprising choice for the agency given what's at stake. Dioxin has been a high-profile EPA regulatory program for years. The EPA has contributed a great deal to efforts to scare the public about dioxin -- most infamously in the 1980s fiasco at Times Beach, Mo., where the EPA evacuated the entire town and "cleaned up" non-toxic levels of dioxin -- concentrations of dioxin in soil about half the level detected in the Ben & Jerry's ice cream -- for $200 million.
The EPA has also used dioxin hysteria to impose regulations limiting dioxin emissions and to force Superfund clean-ups of dioxin - all costing untold billions of dollars. After so much time and money has gone into promoting and enforcing the dioxin scare, the EPA can't simply give up on bad-mouthing dioxin - much less pronounce the substance safe - lest the agency risk losing even more of its credibility with the public and invite legal challenges to ongoing dioxin regulatory programs.
Not only is it likely that EPA will continue its dioxin persecution, but regulated industries are losing interest in contesting the science of dioxin. Since the late 1980s, industry emissions of dioxin have been reduced by almost 90 percent. As dioxin becomes less of a regulatory cost and concern for industries, they'll lose interest in contesting the science - that, of course, will leave the EPA unchallenged in its campaign against dioxin. And don't count on the National Academy of Sciences to pressure the EPA to stick to sound science on dioxin.
The NAS is a highly politicized organization - opposite sides of an issue, for example, have input concerning the composition of committees reviewing various issues. Including advocates from both sides may sound like a good idea - it ensures that both sides of an issue are heard - but it also often guarantees that NAS reports frequently represent compromises negotiated by committee members rather conclusions based on the best available science.
The NAS dioxin report reflects this sort of compromise - it threads the dioxin needle without angering either regulated industries or the EPA. For industry, the NAS blocked the EPA from declaring that dioxin is a highly dangerous human health risk, which would help give the agency increased regulatory authority. For the EPA, the NAS endorsed continued agency efforts on dioxin and upheld the agency's public image. This is "political science" at its best. Given the EPA's persistent - and regulated industry's steadily declining - interest in dioxin, there's little doubt that the EPA will win in the end. But I wish the agency luck in regulating the remaining major sources of dioxin in the environment, such as volcanic eruptions and forest fires.
Steven Milloy publishes JunkScience.com and CSRWatch.com. He is a junk science expert, an advocate of free enterprise and an adjunct scholar at the Competitive Enterprise Institute.
Mercury & Heavy Metals
Mercury is a potent neurotoxin that is especially harmful to developing fetuses. It can cause sensory loss, tremors, loss of muscular coordination, speech, hearing, and visual problems, as well as increased risk of heart attack. Mercury occurs naturally in the environment, and can also be released into the air through industrial pollution. Mercury falls from the air and can get into surface water, accumulating in streams and seas. Bacteria in the water cause chemical changes that transform mercury into methylmercury that can be toxic. Fish absorb methylmercury from water as they feed on aquatic organisms.
Nearly all fish contain trace amounts of methylmercury, which are not harmful to humans. However, long-lived, larger fish that feed on other fish accumulate higher levels of methylmercury and pose a greater risk to people who eat them regularly. While it is true that the primary danger from methylmercury in fish is to the developing nervous system of the unborn child, it is prudent for nursing mothers and young children not to eat these fish as well. You can protect your unborn child by not eating these large fish that can contain high levels of methylmercury:
- King Mackerel
Eat More Fish !
By WILLIE SOON and ROBERT FERGUSON
August 15, 2005
Perhaps the most repeated refrain driving the mercury alarmism campaign is that "630,000 American babies are born each year" with elevated concentrations of mercury in their blood, with the potential for "permanent brain damage and learning disabilities." these infants are said to be "poisoned" at birth because their mothers consumed fish containing microtraces of mercury. As a result, pregnant women are being terrified away from fish consumption, and thus denied a source of nutrition shown to enhance both fetal brain development and maternal health.
The genesis of this myth was the 2003 Centers for Disease Control release of its results from the 1999-2000 nutrition and health survey. It was reported that 8% of women of childbearing age (16-49 years old) had blood mercury concentrations above the so-called "safe" mercury reference dose established by the Environmental Protection Agency (EPA). Since there are over four million births in the U.S. annually, mercury opponents and several government scientists extrapolated that at least 320,000 babies born are "at risk" in the U.S. each year due to "unsafe" mercury levels in their mother's blood.
In January 2004, an EPA employee revised the number of babies born at risk upward to 630,000, based on "new" information that mercury in maternal cord blood (shared with the fetus) is more concentrated than in body blood. But the information was not "new, " it was a double-counting, since the EPA had already accounted for the blood-concentration difference in 2001, helping make its "safe" mercury dose the most stringent in the world.
It must be recognized that the EPA's safe mercury dose is based on inappropriate studies of people who consume whale meat and blubber (a unique diet very different from typical U.S. consumption) containing multiple chemicals -- PCBs, cadmium, pesticides, persistent organic pollutants, DDT, etc. -- of which mercury is only one.
There are other reasons why mercury alarmists' emotive claims are neither justified nor credible. For example, a recent survey in Japan reported that 87% of the population, including 74% of Japanese women of child-bearing age, had mercury concentrations above EPA's "safe" level. Logically, one must either conclude that generations of Japanese are "brain-damaged" (and suffering from severe and permanent learning deficits), or that EPA's "safe" mercury dose is simply arbitrary and extreme.
Similarly, children in grades four and eight from traditionally high-fish-consumption cultures in Japan, Korea, Singapore and Hong Kong consistently outperformed U.S. students on international standardized math and science tests. This despite the fact that Hong Kong children have mean blood mercury levels some 10 times higher than U.S. children. Even the mummified remains of four Aleutian infants dated to 1445 A.D. contained higher mean mercury levels than young children reported in the CDC surveys.
None of these findings are surprising, considering numerous studies report no adverse affects on children from maternal fish consumption -- as high as 12-14 meals per week -- of the kinds of fish widely available in U.S. markets and restaurants. Only benefits have been reported, such as superior eyesight, higher child mental development scores, less hyperactivity, good heart and brain function, and improved intelligence at four years of age.
Finally, an examination of the actual CDC data shows that the 1999-2000 survey documented seven out of 705 children (or 1%) with blood mercury above the EPA's "safe" mercury dose, while the 2001-2002 survey found only four out of 872 children (or 0.5%) exceeding it. More importantly, even the highest mercury level measured in this four-year survey has a safety cushion of more than 500% of the lowest exposure level of concern.
Yet hardly anyone is rushing to report these important updates, let alone downward revisions in the numbers of children "at risk." Instead, one observes repetition of the near-religious dogma that "600,000-plus American children are born each year" at risk of "birth defects, including mental retardation and problems with motor skills." Basing enormously consequential energy and health policies -- both nationally and internationally -- on myth is both irresponsible and harmful.
Mr. Soon is chief science researcher, and Mr. Ferguson executive director, of the Center for Science and Public Policy.
Plastics are so durable that they will not rot or decay as do natural products such as those made of wood. As a result great amounts of discarded plastic products accumulate in the environment as waste. Plastics are harmful to marine life when ingested, as when a sea turtle mistakes a drifting sandwich bag for a jellyfish, and subsequently chokes on it. They are also entanglement hazards, from plastic six-pack bands that can kill birds and other small creatures to drifting ropes and nets which can strangle whales. It has been suggested that plastics could be made to decompose slowly when exposed to sunlight by adding certain chemicals to them.
Asbestos as pipe insulation - once common everywhere, now a health hazard if breathed.
Asbestos is the common name for any of a variety of silicate minerals within the amphibole and serpentine groups that are fibrous in structure and more or less resistant to acid and fire. It is a naturally occurring mineral that is still mined in Australia, Canada, South Africa, and the former Soviet Union. Asbestos-bearing minerals are categorized into two groups. The first are called "serpentines" and have a layered sheet-like structure. The second are called "amphilboles" and are chain-like.
Because asbestos fibers are resistant to heat and most chemicals, they have been mined for use in a variety of products ( over 3,000 different products in the United States. ) In 1988, asbestos was consumed in roofing products, 28%; friction products, 26%; asbestos cement pipe, 14%; packing and gaskets, 13%; paper, 6%; and other 13%. Pipe products find use in water supply, sewage disposal, & irrigation systems. Asbestos cement sheets are used in a wide variety of construction applications. Other uses of asbestos include fire resistant textiles, friction materials ( ie, brake linings ), underlayment & roofing papers, & floor tiles. Crocidolite can be spun & woven using modified cotton industry machinery; the asbestos cloth is used for fireproof clothing & curtains.
Since the 1960s, asbestos has been recognized as a potent carcinogen and serious health hazard. This mineral is unhealthy when the microscopic fibers are inhaled, and is only dangerous when it becomes airborne. Substantial exposure can cause scarring of the lung tissue called Asbestosis. Asbestos can also lead to a cancer of the pleural lining called Mesothelioma, or malignant tumors of the bronchi covering.
In 1972, the Occupational Safety and Health Administration began regulating asbestos and strengthening work safety standards. Large class action lawsuits were filed and won against asbestos companies, which had probable prior knowledge of the dangers involved. In 1989, the Environmental Protection Agency imposed a ban on 94% of U.S. asbestos production and imports, to be phased in over a seven year period. Most current asbestos exposure comes from asbestos in older buildings and products such as automobile brakes.
Asbestos is not a concern as a marine pollutant to scientists and marine ecologists. Low levels of asbestos occur naturally in all waters, even in drinking water. Water-borne asbestos at these concentrations is considered harmless. It is only included here because of the furor created over it by
Clean Ocean Action in their attempt to block the sinking of the
Redbird subway cars.
Green Slime is Choking the Life
Out of the State's Bays
Sunday, September 05, 2004
By Alexander Lane
Runoff of Nutrients Fuels Growth of Algae
A wet-suit-clad researcher leapt off a motorboat into Little Egg Harbor one morning last month and set about scouring the bottom for elegant blades of sea grass. He emerged with handfuls of slimy green algae. "The stuff is growing like wildfire, " said Rutgers professor Michael Kennish, supervising the research from onboard the boat. "In a balanced system it doesn't grow like that." Something is amiss off the Jersey coast.
Eutrophication, a pollution problem that causes runaway algae growth and throws entire ecosystems out of whack, is tightening its grip on New Jersey's long, shallow coastal bays, scientists say. Evidence has been piling up for years. Some 7,500 acres of beneficial underwater plants such as eel grass disappeared from Barnegat Bay between the mid-1970s and the late 1990s, choked off by algae, according to one study. Another study showed the hard clam population in Little Egg Harbor dropping by 67 percent between 1986 and 2001.
Recently, with pollution ending up in the bay in ever-increasing quantities, scientists have intensified efforts to understand the problem. In April, at a two-day workshop on conditions in Barnegat Bay and Little Egg Harbor, researchers found the system "highly eutrophic, " the worst rating on a scale developed by the National Oceanic and Atmospheric Administration. At least two studies aimed at pinpointing eutrophication's effects are under way: Kennish's federally funded sea-grass inventory, and research on brown tides by visiting Rutgers professor Sybil Seitzinger.
Similar concern is mounting around the world. Among the many bodies of water looking more and more like neglected fish tanks are San Francisco Bay, the Chesapeake Bay and the Black Sea. The Gulf of Mexico has gotten so bad there's a vast dead zone every year, which left sharks scrambling for food near the Texas coast this summer, according to Nancy Rabalais, a professor at the Louisiana Universities Marine Consortium. Three bathers were bitten.
In New Jersey, as elsewhere, it's getting worse. "It's continuing to escalate, and I don't see it stopping, " said Kent Mountford, a longtime Environmental Protection Agency scientist who wrote a book on Barnegat Bay. "People are not connected to the water around them."
Barnegat Bay, Little Egg Harbor and Manahawkin Bay form one long estuary, the term for an area where freshwater mixes with saltwater. It stretches 44 miles down the Ocean County coast, washing onto broad beaches and expansive marshes. Narrow spits of sand, Long Beach Island and a similar barrier island just to the north of it, shelter the estuary from the Atlantic, save for three inlets.
The estuary is one to four miles wide and just a few feet deep in places. But such bodies of water are among the most productive environments on earth, and this one is no exception. More than 100 species of young fish flit among the sea grasses, finding shelter and food as they grow large enough to brave the open ocean. More than 200 other animal species dwell on the bottom, along with 100 plant species. People are also drawn here, to boat, fish and swim. Tourists spend close to $2 billion a year in Ocean County, supporting some 50,000 jobs, many in and around the estuary.
But the estuary is not what it was. "At one time these systems were teeming with oysters, scallops and hard clams, " Kennish said, as he cruised across Little Egg Harbor last week. "The oysters are gone, the scallops are basically gone, and the hard clams are declining dramatically."
The major problem is eutrophication -- an overload of nutrients, notably nitrogen, that are crucial in small quantities and deadly in large ones, Kennish said. Nitrogen washes into the estuary off fertilized lawns and farms, pours out of sewage discharge pipes and falls in rain that is laced with power-plant emissions. Then it fuels runaway growth of certain plants.
Massive algae blooms cloud the water, and sometimes coat the surface with a thick, smelly slime. They blot out the sun, stressing sea grass beds and the creatures that depend on them. Other large algae grows on the bottom, choking the sea grass from below. When the algae dies, it sucks oxygen out of the water.
The vigorous water movement that flushes open water bodies, like Delaware and Raritan bays, is absent from this sheltered, shallow water. "It's like a bathtub, " said Suzanne Bricker, a eutrophication expert with the National Oceanic and Atmospheric Administration. "You put nutrients in and because it doesn't flush well you have ample time for these different kinds of problems to develop."
Some scientists also suspect eutrophication is the culprit behind brown tides, a type of phytoplankton bloom that is harmful to sea life and has become commonplace in the estuary in the past 20 years. Eutrophication may also have caused the rapid rise of the sea nettle, a stinging jellyfish that lives off phytoplankton and has appeared in increasingly large numbers in Barnegat Bay in recent years.
Barnegat Bay has the highest production rate of phytoplankton of 11 similar coastal lagoons around the world. At times as many as 2 million cells of phytoplankton have been found in one milliliter -- which is just a few drops -- of bay water.
The Population Factor
What to do about the problem is far from clear. The state Department of Environmental Protection passed rules in February requiring better management of storm-water runoff by towns and developers. Beyond that, the problem gets trickier, due to a worldwide dependence on nitrogen.
Reactive nitrogen, first produced for gunpowder in the early 1900s, turned out to be a fertilizer so remarkable that people have come to rely on it. Half the quantity ever produced came in the past 15 years, according to an article last year in the journal BioScience. As the environment struggles to find a place for it, it is causing not just coastal eutrophication, but also global warming, ground-level ozone and smog.
In the Barnegat Bay-Little Egg Harbor Estuary, fertilized lawns are as much a problem as agriculture. Half the nitrogen in the estuary washes in from streams and rivers, 39 percent falls down in rain from the atmosphere -- much of it from power plants in the Midwest -- and 11 percent comes from groundwater, Kennish said.
Some scientists have suggested strategies for minimizing eutrophication, such as bringing back clams and other water-cleaning filter feeders through cultivation, preserving more open space and restoring stream banks and wetlands. But as long as the population keeps growing, the bay will likely struggle, experts said.
The story is the same around the world. More than half the U.S. and world population resides within 62 miles of the coast, and that number is growing steadily, according to the Institute of Marine Sciences at the University of North Carolina. "The reason we have such a problem with eutrophication in so many of our coastal waters is we have so many people, " Seitzinger said.
Alexander Lane covers the environment. He can be reached at firstname.lastname@example.org or (973) 392-1790.
compiled from various sources
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