Contaminant Summary Contaminant Summary
Over 45 million Americans drink water from treatment plants that have found the cyst Cryptosporidium, the protozoan found in tap water that infected over 400,000 people and killed over 100 in Milwaukee. Giardia, a cyst that has been recognized since the 1960's, has been estimated to cause 5 to 10 waterborne outbreaks annually, an average of 4000 hospital admissions per year, and an average of 6 million dollars in hospital treatment costs annually. Natural Resources Defense Council (NRDC) attorney Erik Olson cited a report by the Centers for Disease Control (CDC) estimating that 900,000 people a year are made sick by such microbial contamination of tap water. More and more people are wondering what to do about cryptosporidium and other cysts in their water supplies.
The Surface Water Treatment Rule states that all surface water that may potentially be used for drinking water must be filtered. Unfortunately, problems with Cryptosporidium, Giardia, and newer protozoans (like Cyclospora, which is larger in size than Crypto, thus more easily filtered) are still occurring, predominantly in ground water sources (which do not fall under the Surface Water Treatment Rule). Also, because Cryptosporidium is pliable, it can fold down to one micron in size, thus slipping through most public utilities filtration systems. The only water treatment devices that can effectively filter Crypto are those certified for submicron filtration (less than one micron).
Healthy individuals infected by these parasites experience a cholera-like illness: watery diarrhea, headache, abdominal cramps, nausea, vomiting, and low-grade fever. For the immunocompromised, however, the results of infection are much more dire: the parasites can severely damage the liver and respiratory tract, as well as the gall-bladder and pancreas. Even worse, there is a 40 -50% mortality rate for the immunocompromised who are infected with Cryptosporidium. Those at risk include cancer patients undergoing chemotherapy, infants, the elderly, kidney dialysis patients, recent transplant recipients, AIDS patients, and others with suppressed immune systems.
To the over 5 million Americans at risk, the CDC and the Environmental Protection Agency have issued a guidance to either boil all of their tap water, invest in certain bottled water, or purchase a filter that is certified by NSF International to remove cysts. As many can attest, boiling all of the tap water can be unduly burdensome. The bottled water alternative also presents problems. Carol Browner, head of the EPA, warned that bottled water is not tested for microbial contaminants like Cryptosporidium, so consumers really don't know what they're getting with bottled water. It just may be the case that point-of-use filtration is the only viable alternative to rid the nation's tap water of these dangerous organisms. Only those filters that are certified under NSF Standard 53 for cyst removal are recommended by the CDC and the EPA.
The second most frequently detected volatile organic chemical in groundwater, MTBE, has been found from coast-to-coast. In 1991, EPA approved MTBE as an air-cleaning gas additive against high smog and carbon monoxide in dense urban areas. Today, MTBE is a suspected chemical carcinogen, which the U.S. Geological Survey has found in more than a quarter of the nation's shallow urban wells and in streams, lakes, rain and snow, and even in remote rural areas.
The Association of California Water Agencies reports that California and about a third of the rest of the country now use gasoline with high levels of MTBE; the rest use gas with low levels of the chemical. Even if MTBE were banned today, years would be required to remove it from the nation's water, and the cost could run into billions of dollars.
Although the EPA classifies MTBE as a possible human carcinogen because laboratory rats and mice that breathe or drink it have developed lymphoma, leukemia, testicular tumors, thyroid tumors, and kidney tumors, so far, the EPA has resisted calls to ban MTBE. One of the subtleties of the MTBE scare in tap water across America is that MTBE is considered a fast-leaching compound. The U.S. Geological Survey reported that MTBE doesn't biodegrade; it can affect water supplies for years.
Asbestos is an inorganic compound, found both naturally in the environment and in building materials. Asbestos is a proven carcinogen, and it has been suggested that there may be an elevation in colorectal cancer risk associated with asbestos in drinking water where the naturally occurring levels are high.
Contaminants that are causing widespread concern as of late are Disinfection By-Products (DBP's). Many believe that DBP's are the single greatest health threat in water supplies. DBP's are contaminants, some of them cancer-causing, that are left behind by the very chemical (chlorine) that utilities use to make their water potable. About 15 years ago scientific testing identified chlorine as a potential health hazard, but it is not the chlorine in itself that is dangerous. Scientists discovered that chlorine reacted with organic material in water, such as decaying leaves, to produce hundreds of chemical by-products, several of which have been proven to be carcinogenic (Trihalomethanes make up the bulk of the cancer-causing DBP's).
Other disinfection by-products may cause adverse effects on the liver, and nervous and reproductive systems. The use of chlorine for water treatment to reduce the risk of infectious disease may account for a substantial portion of the cancer risk associated with drinking water. Trihalomethanes are associated with increased risk of bladder and rectal cancer, possibly accounting for 5,000 new cases of bladder cancer and 8,000 new cases of rectal cancer per year in U.S. According to a study done by the American Water Works Association, more than 230 million people (approximately 90% of America's population) receive disinfected drinking water containing hundreds of disinfection by-products. Given the large number of people who consume chlorinated drinking water, the number of cases of cancer potentially attributable to this exposure is substantial. Since a large percentage of the DBP's are developed after leaving the treatment plan our only viable course of action is point-of-use filtration using an activated carbon filter. Currently carbon filtration is the only known way to get cancer-causing Trihalomethanes and other dangerous disinfection by-products out of our nation's drinking water.
Turbidity can be caused by suspended colloidal material (gelatinous or mucinous substance), coliform contamination, and surface water treatment. Although not health threatening in itself, turbidity interferes with disinfection and is related to disinfection by-products (see summary of trihalomethanes above).
Recent headlines have warned of the newly-discovered dangers caused by certain Volatile Organic Chemicals (VOCs) known as Endocrine Disrupters. Many industrial chemicals we have been dumping into the ecosystem in huge quantities for years are now thought to interfere with hormones. Since the publishing of Rachel Carson's book, Silent Spring, public attention has been focused on the carcinogenic effects of VOCs. Now there is even more cause for concern regarding VOCs. Certain VOCs, known as Endocrine Disrupters (also known as "Hormone Mimickers," "Estrogen Mimickers," and "Xeno-Estrogens"), can wreak havoc in the Endocrine System, Reproductive System, and Immune System. The effects of exposure to Endocrine Disrupters early in life are permanent and irreversible.
To understand how these Endocrine Disrupters function, let us first take a look at the Endocrine System itself. The endocrine system is a complex set of bodily organs and tissues whose actions are coordinated by chemical messengers called hormones, which control sexual reproduction, growth, development, and behavior. If these chemical "messages" are disrupted by hormone mimicking chemicals, then the systems receiving the messages are going to be damaged. According to Dr. Peter Montague of the Environmental Research Foundation, the range of problems that may be caused by hormone disruption is large: cancer, birth defects, stunted growth, reproductive failure, diminished sperm count, smaller penises, endometriosis ( a painful disease of menstrual tissues), ectopic (tubal) pregnancies, damage to the immune system, loss of muscle tone, weakened reflexes, impaired short-term memory, decreased ability to pay attention, lower IQs, and violent behavior.
Endocrine Disrupters can get into water supplies in various ways. Since many Endocrine Disrupters are herbicides and pesticides, agricultural run-off can carry these chemicals to water supplies. Some Endocrine Disrupters are products of industrialization and may get into water supplies through various means, such as leakage of storage tanks, accidental spills, or illegal dumping of toxic wastes. With no visible characteristics, smell, or taste, Endocrine Disrupters are virtually undetectable in drinking water. The Environmental Working Group (in their report "Weed Killers by the Glass") has noted that people are "routinely exposed to many different pesticides in a single glass of water."
According to the Environmental Working Group, the only reliable technology that can effectively remove Volatile Organic Chemicals, including certain Endocrine Disrupters, from tap water is Activated Carbon. Public utilities, in most cases, are using only conventional water treatment (chlorination and sand filtration) which does nothing to reduce Endocrine Disrupter levels in consumers' tap water . Other types of water treatment can not as effectively reduce Endocrine Disrupters in tap water.
Lead, a heavy metal, has no known functions or health benefits for humans. Lead, by its nature, is toxic to humans and other forms of life. It is considered a metabolic poison (meaning it inhibits some of the basic enzyme functions) and untold ills: damage to the kidneys and liver, and to the nervous, reproductive, cardiovascular, immune, and gastrointestinal systems. In children, as scientists have recognized, lead has a particularly damaging effect.
At low levels, it reduces a person's intelligence, makes it difficult to concentrate or pay attention, and harms hearing. According to a recent study in the Journal of the American Medical Association, lead may be even more dangerous than previously thought, causing high blood pressure and kidney impairment at unexpectedly low levels. The lead level proved more closely linked to hypertension than several other factors that have been implicated in other studies, including smoking, alcohol, and salt in the diet. These effects are permanent. At higher levels, lead has many additional severe effects including kidney disease, blindness, seizures, and death.
In young or unborn children, at very low levels, lead reduces height, weight, circumference of chest and head; damages hearing; reduces the body's ability to manufacture an essential component of red blood cells (called heme); causes hyperactivity; interferes with an important blood enzyme; and interferes with the body's use of vitamin D. Lead consumption in childhood can lead to a lower IQ and impairment in reading, writing, math, visual and motor skills, language, abstract thinking, and concentration. Children may also suffer irritability, insomnia, colic, and anemia. Damage to the child's nervous system is permanent. Children are particularly susceptible to lead's toxic effects because they absorb lead more readily than adults do. Lead can also cross the placental barrier, passing from a pregnant woman's blood to the blood of the fetus; red blood cells of fetuses attract and hold lead more readily than do red cells of adults.
What is even more frightening is recent discoveries about the dangers of lead poisoning for children. Exposure to the toxic metal may contribute to crime and anti-social behavior in children. Boys with high levels of lead in their bones were more likely to engage in bullying, vandalism, setting fires, and shoplifting than those with low lead levels. According to Dr. Herbert Needleman, a psychiatrist at the University of Pittsburgh Medical Center, "Lead is a brain poison that interferes with the ability to restrain impulses." Lead is known to interfere with development of the central nervous system, and previous studies have linked exposure in children with learning disabilities, restlessness, and the tendency to be distracted. As a result of this new study, the researchers concluded that limiting children's exposure to lead could help prevent them from becoming criminals as adults.
According to Dr. Peter Montague of the Environmental Research Foundation, studies have found that lead in water is possibly the largest source of lead in the human blood stream. But how does lead get into our water? Older homes may have lead pipes that leach lead into the water. Newer homes may have copper pipes, but those copper pipes may also be joined with lead solder which may also leach lead into the water. If you suspect that lead is in your drinking water, you should have your water tested. Data obtained from your local public water utility may not be of help, since most lead is picked up after the water has left the public water facilities. Public utilities are advising households that have high levels of lead in their tap water to invest in a water filter that can effectively reduce lead.
Like lead, mercury is a heavy metal that can have serious health effects. It is an inorganic contaminant that may get into water supplies via natural deposits or through crop run-off or may seep into water supplies near spills and toxic waste sites that are contaminated with mercury. Once mercury has entered the body, it may be months before all of it leaves. At lower levels, Mercury can cause kidney and nervous system disorders. Long-term exposure can permanently damage the brain, kidneys, and developing fetuses. According to the Hall Water Report, "Pressure is building for EPA to release an overdue report on mercury that suggests the metal is more potent and widespread as a public health threat than previously believed, estimating that 85,000 American women are being exposed to mercury at levels high enough to affect the brain development of unborn children."
Chloramine is used instead of chlorine to protect against microbes so as to reduce the level of disinfection by-products in compliance with EPA rules. Americans are concerned about the use of chloramines because there are so may unknowns about this disinfectant and the possible Chloramine by-products. Water disinfected with Chloramine is not suitable for home dialysis machines or fish aquariums.
Volatile Organic Chemicals (VOC's) are contaminants that may be found in drinking water supplies across the nation. VOC's are those organic chemicals (pesticides, herbicides, and other chemicals) that are "readily vaporizable at a relatively low temperature" (Webster's Collegiate Dictionary). With no visible characteristics, smell, or taste, VOC's are virtually undetectable in drinking water by the consumer. The only way to know if your water has VOC's is to have it tested or to obtain test results from local public water supplier. VOC's are often toxic and pose intimidating health risks.
Almost every region in the U.S. has VOC's in the water supplies. Urban areas may get VOC's from industrialization, and rural areas may get VOC's from agriculture. Also, 90% of U.S. drinking water is chlorinated (and most likely contains disinfection by-products); thus, VOC's are practically everywhere. In a recent study by the Environmental Working Group, 28 of 29 cities tested were found to have herbicides or pesticides in their tap water.